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A new provocative test for the diagnosis of the carcinoid syndrome
A New Provocative Test for the Diagnosis of the Carcinoid Syndrome
Edwin L. Kaplan, MD, Chicago,
Illinois
Bernard M. Jaffe, MD, St. Louis, Missouri Gerald W. Peskin, MD,* San Diego, California
Because of the unavailability and delicacy of blood serotonin determinations and the frequent errant results noted in 5hydroxyindoleacetic acid levels in patients suspected of having a carcinoid tumor, a need has arisen for a simple screening test to aid the clinician in the diagnosis of the carcinoid syndrome. Flushing and hyperventilation have been induced in patients with carcinoid tumors by alcohol ingestion and injection of catecholamines. However, the results have been inconsistent and the correlation with chemical values in the blood often lacking. The purpose of this study is to report a new provocative test, the calcium infusion test, which may be useful in the diagnosis of carcinoid and other serotoninelaborating tumors. Methods Calcium gluconate (10 to 15 mg/kg Ca+ + /4 hr) was administered intravenously to a group of controls and to patients known to have carcinoid tumors or other endocrinopathies associated with carcinoid symptoms, such as medullary carcinoma of the thyroid gland. Serum calcium was determined on basal and hourly specimens by atomic absorption spectrophotometry. Blood serotonin (5-hydroxytryptamine) and urinary 5-hydroxyindoleacetic acid (5HIAA) were evaluated by the methods of Udenfriend and associates [1,2].
From the Departments of Surgery, Michael Reese Hospital, University of Chicago, Pritzker School of Medicine, Chicago, Illinois, and the Washington University School of Medicine, St. Louis, Missouri. This work was supported in part by the USPHS Grants AM 14499-01, HE 11909-04, and Trainina Grant NIGMS 371. Reprint requests should be addressed to Dr Kaplan, Department of Surgery, University of Chicago Hospitals, 950 E. 59th Street, Chicago, Illinois 60837. Presented at the Twelfth Annual Meeting of the Society for Surgery of me Alimentary Tract, Atlantic City, New Jersey, June 19 and 20, 1971. ‘Department of SUrgery. University of California at San Diego, San Diego, California 92103.
Volume 123, Fobwary
1972
Results Corresponding to an elevation of serum calcium concentration of 2 to 4 mg/lOO ml during calcium infusion, control patients experienced occasional minimal nausea and dizziness but no other symptoms or circulatory effects. (Table I.) Of eleven patients studied, seven are of special interest and will be described in some detail. Four patients with known or previously resected carcinoid tumors were evaluated; two had full-blown carcinoid syndrome. Case I. The patient (JG), a fifty-four year old housewife, had flushing over the upper half of the body in 1962 after alcohol ingestion. These episodes were associated with “puffiness,” tachycardia, and a feeling that “blood was having trouble getting through my legs.” In recent years the attacks increased in frequency and seemed to be precipitated by nervousness. Diarrhea occurred infrequently but followed abdominal palpation by her physician on several occasions. She had peptic ulcer symptoms which were relieved by antacids but had no demonstrable ulcer on barium studies. Preoperatively, a calcium infusion test was performed as part of an evaluation of the gastric secretory state. Severe flushing, wheezing, hypotension, and weakness developed soon after the calcium infusion was begun and the infusion was discontinued. In February 1970, a 1.8 cm ileal carcinoid with lymph node involvement and multiple metastases of both lobes of the liver was found at operation. Resection of the terminal ileum and ascending colon and excision of multiple liver nodules (50 gm) were performed. Postoperatively, the symptoms were markedly relieved. Six months after surgery, a repeated calcium infusion test was performed. (Figure 1.) After two and a half hours, the infusion had to be discontinued because of the development of a bright flush, facial swelling, weakness, difficulty in breathing, hypotension, and the passage of flatus. Blood serotonin rose from 1.65 to 4.16 pg/ml during the attack. The symptoms subsided after one hour. She de-
173
Kaplan, Jaffe, and Peskin
TABLE I
Results of Calcium Infusion in Eleven Patients Studied Calcium
Carcinoid Syndrome
Urinary 5-HIAA* (mg/24 hr)
lleal carcinoid, hepatic metastases
+
73-126
RT, 66, W,F
Ovarian carcinoid, metastases
+
32,49
WC, 54, W,M
Rectal carcinoid; hepatic metastases Carcinoid appendix with metastases to nodes; post appendectomy
0
3.0
0
8.7-14
Patient, Age (yr),
Race, and Sex JG, 54, W,F
DW, 40, N,F
JH. 19, W,F
Diagnosis
Medullary carcinoma with cervical metastases
6.4, 9.6
Serum Calcium (mg/lOO ml) B 9.2 1 .. 2 10.6 2’12 12.2 B 9.6 1 10.7 2 10.6 2% 11.7 B 8.6 1 10.0 2 10.0 3 10.6 B 8.5 1 10.6 2 ‘11.5 3 12.6 4 12.7 Pre-op B 9.3 1 10.6 2 10.8 3 11.8 3% 12.3 Post-op B 7.8 1 8.9 2 9.9 3 12.0
Infusion Blood Serotonint (pg/mt) 1.85
Symptoms with Infusions
Tissue Serotonin
+
51.3
+
8.4
(rglgm)
. 2.48 4.16$ 0.09 0.14 0.14 0.55s 0.09 0.11 0.07 0.07 0.11 0.12 0.13 0.21 0.20 0.15
o:&$ 0.25
0
0:&i
*Normal 5-hydroxyindoleacetic acid <17 mg/24 hours TNormal blood serotonin concentration 0.1-0.3 pg/ml SInfusion discontinued because of severe symptoms
scribed both attacks associated with calcium infusion as the worst she had ever experienced. Tissue from a liver metastasis contained a serotonin concentration of 51.3 pg/ gm wet weight. Case II. The patient (RT), a sixty-six year old woman, had a malignant tumor of the ovary removed in 1958. At surgery, peritoneal implants were present. Microscopically, the tissue was described as a “homogeneous population of malignant cells.” In 1968 she noted increasing symptoms of asthma, cyanosis, flushing, and three or four watery stools per day. Carcinoid syndrome with hepatic metastases, presumably from the ovarian tumor, was diagnosed in 1970. A four hour calcium infusion was begun, but had to be terminated after two and a half hours because of severe symptoms of flushing, wheezing, and diarrhea. (Figure 2.) She described this as her worst attack. Blood serotonin, normal under basal conditions, increased sixfold to 0.55 wg/ml and correlated well with the symptoms. Case III. The patient (WC), a fifty-four year old man, had a rectal carcinoid removed by anterior resection in 1958. In 1967 he was noted to have a local recurrence with
174
massive liver metastases. Liver biopsy confirmed the diagnosis of metastatic rectal carcinoid. He never experienced symptoms of the carcinoid syndrome and urinary 5-HIAA was within normal limits. Calcium infusion resulted in no symptoms and no change in normal blood serotonin values. Case IV. The patient (DW), a forty year old woman, was operated on for acute appendicitis in March 1969. Pelvic inflammatory disease was found. Appendectomy was performed and an infiltrating carcinoid of the appendix was noted. Four months later at re-exploration, no abnormalities were noted. The mesentery at the base of the appendix was removed and proved, on permanent sections, to contain four lymph nodes, two of which contained microscopic carcinoid tumor. In 1971 she was again admitted because of symptoms of pelvic inflammatory disease. Urinary 5-HIAA determinations gave repeatedly normal results as did the liver scan, bone survey, and barium studies of the stomach, small intestines, and colon. During calcium infusion, neither symptoms nor elevation of blood serotonin concentrations occurred. At exploration on January 22, 1971, no abnormalities of the liver or intestines were noted. Mesenteric and periaortic lymph nodes were biopsied and
The American Journal of Surgery
Test for Diagnosing
Calcitim
Carcinoid Syndrome
Urinary 5-HIAA* (mg/24 hr)
Pheochromocytoma excised; medullary carcinoma with cervical, skin, and bone metastases Neurofibromatosis, retroperitoneal malignant neurogenic tumor
0
3.0
Diarrhea, malabsorption syndrome
0
VS, 22, W,F
Flushing after cheese ingestion
0
KG, 43, N,F
Duodenal ulcer
0
Patient, Age (yr), Race, and Sex LC, 24, W,M
PH, 17, N,F
HB, 51, W,F
EK, 35. W,M
contained formed.
Diagnosis
Control
no tumor.
A gynecologic
Two patients with medullary thyroid gland and another with genie tumor and neurofibromatosis
0
0
procedure
22.8
7.0
4.3
12.7
was per-
carcinoma of the a malignant neurowere studied.
Case V. The patient (JH), a nineteen year old girl, had noted enlarged lumps in the left side of the neck for several years. They did not respond to antibiotic therapy. One node was biopsied and a diagnosis of metastatic medullary carcinoma of the thyroid was made. For several years she had had loud borborygmi, which could be heard by others several rooms away. She had occasional watery stools, not more than three or four per day. Her father had neurofibromatosis and she had mild scoliosis of the dorsal spine, a cafe au lait spot on the chest, and a hard mass of the left thyroid lobe with multiple lymph node metastases of the left cervical chain. Serum thyroxine, T3 resin, urinary catecholamines, blood corticoids, and urinary total hydroxy- and 17-ketosteroids were within normal limits as were serum calcium, phosphorous, and roentgenograms of the hands. Urinary 5-HIAA determinations were likewise within normal limits on two occasions. Preoperatively, a
Volume 123, February 1972
Serum Calcium (mg/lOO ml)
the Carcinoid
Syndrome
Infusion Blood Serotonint (Ccg/mt)
Symptoms with Infusions
Tissue Serotonin (rglgm)
B 1 2 3 4
10.9 12.0 12.2 12.1 12.3
0.11 0.08 0.07
B 1 2 3 4 B 1 2 3 B 1 2 3 4 B 1 2 3 4 B 1 2 3
9.7
0.15
0
0.2
11.1 12.4 12.3 8.1 11.5 13.4 14.8 9.8 10.3 11.1 12.4 13.2 8.5 10.7 13.3 14.5 13.2 10.0 11.2 12.6 13.5
0.23 0.41 0.41 0.10
0
.
0
0.13
.. . 0.17 0.11 0.11 0.11 0.16 0.22 0.16
0
0
.
. . 0.18 0.12 0.12 0.21 0.20
0
.
calcium infusion test was performed. (Figure 3.) After three and a half hours this had to be discontinued because of flushing of the face and upper trunk, vomiting, and explosive diarrhea. Blood serotonin increased sixfold from normal to 0.89 pg/ml in association with these symptoms. Postoperatively, after total thyroidectomy and left radical neck dissection, a repeated calcium infusion was performed. This time she had no symptoms and blood serotonin was within normal limits and did not change. The thyroid tumor contained serotonin in a concentration of 8.4 pg/gm wet weight. Case VI. The patient (LC), a twenty-four year old man, had a right adrenal pheochromocytoma removed in 1966. In 1969 he noted a mass in the left lobe of the thyroid. Six months later this had grown to the size of a grapefruit, and multiple lymph node and bone metastases and extensive subcutaneous deposits of tumor were present. A left thyroid lobectomy for palliation established the diagnosis of medullary carcinoma of the thyroid. Tissue contained calcitonin and prostaglandins on assay. The patient had no symptoms related to the carcinoid syndrome and urinary 5-HIAA was within normal limits. During a calcium infusion, no unusual symptoms occurred and blood serotonin remained within normal limits.
175
Kaplan, Jaffe, and Peskin
5.0
J.G.
,
I LEAL
CARCI NOID
, 13.0
r
z
l
3
4.0-
Four other patients, one with diarrhea from a malabsorption syndrome, another with duodenal ulcer, a third with flushing after cheese ingestion, and lastly, an asymptomatic volunteer, experienced no untoward effects from calcium infusion and blood serotonin values remained normal.
Comments
Time (Hours)
Figure 1. Case I. JG, a patient with carcinoid syndrome from an ileal carcinoid tumor with metastases, was infused with calcium gluconate. Blood serotonin concentration increased and severe flushing and other symptoms ensued (*) necessitating discontinuation of the infusion. Normal blood serotonin is 0.1 to 0.3 pglml.
Case VII. The patient (PH), a seventeen year old girl, had multiple neurofibromatosis, cafk au lait spots, scoliosis, and an abdominal mass which was present for seven years but recently became tender. She had never experienced flushing, diarrhea, or any other carcinoid symptoms. Urinary 5-HIAA, however, was minimally elevated (22.8 mg/ 24 hr). A preoperative calcium infusion was accomplished with no abnormal symptoms; however, blood serotonin concentration rose from 0.15 to 0.41 pg/ml during the procedure. (Figure 4.) At operation, a vascular retroperitoneal tumor weighing 1,040 gm was removed. Microscopically it was classified as a ganglioneuroma with focal areas of malignant schwannoma. The tissue contained 0.2 pg/gm of serotonin.
0.6
R.T.
(
OVARIAN
CARCINOID .
,
120
Time (Hours)
Figure 2. Case Il. RT, a patient with carcinoid syndrome of ovarian origin, received calcium gluconate intravenously. Severe flushing and other symptoms occurred after two and a half hours (*). Blood serotonin became markedly elevated at this time.
176
Carcinoid tumors occur in the appendix, jejunoileum, rectum, duodenum, stomach, colon, ovary, biliary tract, and pancreas in decreasing order of frequency. Bronchial adenomas are microscopically of the carcinoid type in 85 per cent of cases, and one case of carcinoid of the larynx has been described. Of 3,718 cases of abdominal carcinoid tumors collected by Wilson et al [3], only 136 patients (3.7 per cent) had symptomatic endocrinologic activity and were classified as having the carcinoid syndrome. The tumors giving carcinoid symptoms are mostly from the jejunoileum followed in frequency by the ovary, stomach, appendix, colon, and duodenum. Unfortunately, in gastrointestinal carcinoids, endocrinologic manifestations almost always signify widespread metastatic disease to the liver. The liver contains large amounts of monamine oxidase, an enzyme needed in the first step of degradation of serotonin. On the other hand, the venous drainage of ovarian and bronchial carcinoids is systemic and bypasses the liver; hence, early disease without metastases may produce symptoms despite the fact that only 6 per cent had metastatic disease. Thus, ovarian teratomas offer a unique opportunity for surgical cure [3]. It is highly likely that not all carcinoids are endocrinologically active. There is only one recorded carcinoid syndrome associated with a rectal carcinoid [4]. However, many patients have symptoms which go undetected until far advanced disease is present. This results from two basic factors: (1) a lack of general appreciation of the multiplicity of variant symptoms produced by carcinoid tumors and (2) the lack of an entirely suitable screening procedure for diagnosis of the disease. Most patients with the “classical” carcinoid syndrome present with episodic watery diarrhea, abdominal cramps, and borborygmi. Intestinal obstruction, peptic ulcer, hepatomegaly, asthmatic symptoms, cutaneous flushing, or the murmurs of tricuspid insufficiency and/or pulmonary stenosis may also be present. The biochemical hallmark of the carcinoid syndrome has been a demonstration of excessive urinary excretion of 5-hydroxyindoleacetic acid. However, in some patients with full-blown carcinoid syndrome 5-HIAA may be normal [5]. Williams and associates [S], for example, recently studied eleven pa-
The American Journal of Surgery
Test for Diagnosing
tients with carcinoid syndrome. In three, large amounts of indolic acids (indoleacetic, indolelactic, indolepyruvic, and indoleacrylic) were present without elevation of the hydroxylated indolic derivatives. Thus, if the diagnosis is based exclusively on the urinary 5-HIAA levels, many carcinoids may be missed. Serotonin has been extracted from carcinoid tumors [7] and has been found to be elevated in the blood of many persons with the carcinoid syndrome [I]. The diarrhea has been attributed to action of this hormone or 5-hydroxytryptophan; however, episodes of flushing have not correlated well with elevations of these amines [5,8]. Several groups have demonstrated a rise of serum bradykinin concentration associated with induced flushing [9]; however, this has not been a consistent finding [IO]. Kallikrein, a bradykininreleasing enzyme, has been extracted from some carcinoid tumors [11]. Variant syndromes include metastatic gastric carcinoids which secrete large amounts of histamine and 5-hydroxytryptophan rather than serotonin [12]. Vivid, red patchy flushing may occur after meals and diarrhea may not be prominent. The urine in these instances contains serotonin and 5-hydroxytryptophan as well as 5-HIAA. Bronchial carcinoids may be endocrinologically asymptomatic but may present with very severe attacks of flushing which are prolonged and often associated with facial edema [13]. Heart lesions are predominantly left-sided in these patients. Bronchial tumors seem to be associated more frequently with acromegaly, pluriglandular adenomatosis, and Cushing’s disease than are other carcinoid tumors
[141. In several patients with carcinoid tumors, elevations of catecholamines and their metabolites have been found, but this is unusual [5]. An ectopic ACTHlike hormone and prostaglandins may also be present in some carcinoid tumors. Increased serotonin or its metabolites and hyperinsulinism, hyperglycemia, and the Zollinger-Ellison syndrome also have been reported in some patients [15]. Thus, a whole spectrum of syndromes may be associated with carcinoid tumors. Flushing and diarrhea often occur spontaneously in these patients, but they may also be precipitated by emotional stress, food, enemas, exercise, or abdominal palpation, as in one of our patients. Oral or intravenous alcohol and injections of epinephrine, norepinephrine, dopamine, and histamine have all been used as bedside provocative tests to induce flushing with some success [16]. In recent years it has been recognized that medullary carcinoma of the thyroid gland and carcinoid
Volume 123, February 1972
the Carcinoid
of the THYROID Postop
Syndrome
13.0
r
I_ 12.0 $ 11.0 10.0 6 9.0 ;
a0 y 10 p g 3
Ttme (Hours)
Figure 3. Case V. JH, a patient with medullary carcinoma of the thyroid with cervical node metastases, developed Nushing for the first time during calcium infusion (*) at which time blood serotonin was markedly increased (left). After extirpation of all known tumor, a repeated calcium infusion resulted in no untoward symptoms and blood serotonin values remained normal (right).
tumors have many features in common [17]. C cells, the cells of origin of medullary carcinomas, take up 5-hydroxytryptophan and convert it to serotonin. Argentaffin-staining cells have been demonstrated in these thyroid tumors. Moertel et al [18] described a syndrome of flushing and severe diarrhea associated with medullary carcinoma. Since that time, it has been recognized that about one third of patients with this type of thyroid cancer present with or subsequently have diarrhea which is often severe [19]. Like that of the carcinoid syndrome, the diarrhea appears to be related to hypermotility of the intestinal tract. At times, flushing is also associated with this symptom complex. Elevated blood and tissue levels of serotonin and prostaglandins have been found in
0.5
!
t?H
,
NEUROGENIC
TUMOR
,130
w m
0.4_
< 9 0.3c s ‘0 0.2&
_
JO.l-
I _ _
z 0.0
:I = _ _ _ _ E = = -
B
1
2
c’ =
=
_ _ i s = = _ = = _ _ =
_ e _ _ = _ = = _ _ _ E _ _ =
3
= = _ -i-
4
120
3
6 ir 11.0 5’ 7 10.0 fQ . B 90 3
a.0 f
Time (Hours)
Figure 4. Case VII. PH, a patient with neurofibromatosis and a retroperitoneal malignant neurogenic tumor, had no untoward effects from the calcium infusion. However, blood serotonin concentration became elevated. Serotonin was found to be present in the tumor.
177
Kaplan, Jaffe, and Peskin
patients with medullary carcinoma with diarrhea and the tumor has been demonstrated occasionally to contain kallikrein as well as an ectopic ACTH-like hormone. Recent studies also suggest that calcitonin, the hallmark of medullary thyroid cancers, may also be present in some carcinoid tumors [20]. These findings are in keeping with the hypotheses that both of these tumors are of neuroectodermal origin and are derived from the same primitive cell. This may also explain the presence and release of serotonin from the malignant retroperitoneal neurogenic tumor just described herein. Calcium infusion may offer .the prerequisites of specificity, safety, and ease of performance which qualify it as a new provocative test for endocrinologically active carcinoid tumors and other related neoplasms which contain and secrete serotonin. Using this method, each of two patients with the carcinoid syndrome (from tumors of ileal and ovarian origin) developed severe flushing and other manifestations of their symptom complex. One patient with medullary carcinoma of the thyroid who had borborygmi and occasional diarrhea had flushing for the first time in her life during induced hypercalcemia. Kinins were not measured but elevations of blood serotonin correlated well with the symptoms. Another patient with a retroperitoneal neurogenic tumor had no symptoms; however, blood serotonin concentrations also became elevated during the infusion. Finally, normal serotonin concentrations in basal and postinfusion states were found in a patient with a rectal carcinoid, in another in whom a recurrence of carcinoid from the appendix was suspected, and in several other patients who had flushing or diarrhea of other causes. Calcium infusion induces the release of calcitonin from medullary thyroid lesions and an associated decrease in cellular granularity [19]. It is, therefore, not completely unexpected that serotonin is released as well by increased concentrations of this divalent cation. Control of calcitonin secretion from C cells of normal thyroid tissue is closely related to serum calcium concentration. It remains to be determined if this stimulus is active in secretory regulation of normal Kultschitzky cells as well. Rasmussen [21] has recently hypothesized that intracellular calcium ion concentration as well as cyclic-AMP may be important factors in the control of many different hormonal secretions. The present observations support this concept.
Summary A new provocative test for the carcinoid syndrome is described and its use in a series of patients with various endocrinopathies detailed. Although the series of patients is small, it is hoped that additional
178
trials will confirm these results and allow the utilization of calcium infusion as an early and specific diagnostic aid for carcinoid and related tumors. Acknowledgment: We would like to thank Barbara J. Hill, Susan Locke, and David N. Toth for their expert technical assistance and Drs Cyril Costello, Bud Loeb, and David Wagner for permitting us to study their patients.
References 1. Udenfriend S, Weissbach H, Clark CT: The estimation of 5hydroxytryptamine (serotonin) in biological tissues. J Biol Chem 215: 337,1953. 2. Udenfriend S, Titus E, Weissbach H: The identification of 5hydroxy-3-indoleacetic acid in normal urine and a method for its assay. J Biol Chem 216: 449, 1955. 3. Wilson H, Cheek RC, Sherman RT, Storer EH: Carcinoid tumors. Curr Probl Surg Chicago, Yearbook Medical Publishers, 1970. 4. Saegesser F, Gross M: Carcinoid syndrome and carcinoid tumors of the rectum. AmerJ Procfol20: 27, 1969. 5. Levine RJ, Sjoerdsma A: Pressor amines and the carcinoid flush. Ann Int Med 58: 818, 1963. 6. Williams HE, Wilson KM, Trager W, Melmon KL: Tryptophanjnduced indoleaceticaciduria: a new variant of the carcinoid syndrome. C/ii, Res 19: 406, 1971. 7. Lembeck F: 5-Hydroxytryptamine in carcinoid tumors. Nature (London) 172: 910,1953. a. Robertson JIS, Peart WS, Andrews TM: The mechanism of facial flushes in the carcinoid syndrome. Quart J Med 31.1 103,1962. 9. Oates JA, Melmon K, Sjoerdsma A, Gillespie L, Mason DT: Release of a kinin peptide in the carcinoid syndrome. Lancet 1: 514,1964. 10. Dollinger MR, Gardner B: Newer aspects of carcinoid spectrum. Surg Gynec Obstet 122: 1335, 1966. 11. Melmon, K, Lovenberg W, Sjoerdsma A: Identification of lysyl-bradykinin as the peptide formed’in vitro by carcinoid tumor kallikrein. C/in Chim Acta 12: 292, 1965. 12. Oates JA, Sjoerdsma A: A unique syndrome associated with secretion of 5-hydroxytryptophan by metastatic gastric carcinoids. Amer J Med 32: 333, 1962. 13. Schneckloth RE, Mclsaac WM, Page IH: Serotonin metabolism in carcinoid syndrome with metastatic bronchial adenoma. JAMA 170: 1143,1959. 14. Williams ED, Celestin LR: The association of bronchial carcinoid and pluriglandular adenomatosis. Thorax 17: 120,1962. 15. Weichert RF I II, Roth LM, Harkin JC: Carcinoid-islet cell tumor of the duodenum and associated multiple carcinoid tumors of the ileum. Cancer 27: 910, 1971. 16. Adamson AR, Grahame-Smith DG, Peart WS, Starr M: Pharmacological blockade of carcinoid flushing provoked by catecholamines and alcohol. Lancef 1: 293, 1969. 17. Williams ED, Karim SMM, Sandler M: Prostaglandin secretion by medullary carcinoma of the thyroid-a possible cause of the associated diarrhea. Lancet 1: 22, 1966. 16. Moertel CG, Beahrs OH, Woolner LB, Tyce GM: “Malignant carcinoid syndrome” associated with noncarcinoid tumors. New Eng J Med 273: 244.1965. 19. Kaplan EL, Peskin GW: Physiologic implications of medullary carcinomaof the thyroid. Surg C/in N Amer 51: 125, 1971. 20. Beceiro J, Ouais S, Hill CS, Samaan NA: Serum calcitonin levels in medullary carcinoma of thyroid, hypercalcemia associated with malignancy and carcinoid tumors. C/in Res 19: 367,1971. 21. Rasmussen H: Cell communication, calcium ion and cyclic adenosine monophosphate. Science 170: 404,197O.
The American Journal of Surgery
Test for Diagnosing
Discussion Robert C. Hickey (Houston, Texas): 1 would like to ask the authors if the levels of calcitonin were measured in all of the patients studied. With medullary cancer and calcium intravenous infusion there may occur the syndrome described as well as a concomitant elevation of calcitonin. The cells of origin, for both tumors, are thought to be the same. Doctor Moore: Several years ago Dr Ben Eiseman and I observed that serotonin can release histamine. Did the authors find any alterations in histamine concentration that might account for some of the symptoms? Jack W. Cole (New Haven, Conn): Years ago it was very difficult to measure the level of serotonin in the blood and it was a fairly erratic determination. I wonder if Dr Kaplan would comment on this. Edwin L.Kaplan (closing): Doctor Hickey, we have tissue from several tumors and serum samples from all patients. Calcitonin was easily demonstrated by bioassay from the tumors of both patients with medullary carcinoma of the thyroid. Analyses of other tumors are in progress. Since the quantity of serum is limited, we plan to analyze the calcitonin content by radioimmunoassay. There are at least
Volume 123, February 1972
the Carcinoid
Syndrome
four groups of investigators in this country that have developed very sensitive immunoassays for measuring this polypeptide in man. Doctor Moore, the only humoral substance measured at this time was serotonin. Several groups have developed radioimmunoassays for bradykinin, and it would be helpful to know if blood kinin concentrations changed with calcium infusion as well. Similarly, histamine was not analyzed. Doctor Bernard ,Jaffe has done some preliminary work on prostaglandins utilizing a very sensitive radioimmunoassay for measuring these compounds which he developed. In several of our patients, serum prostaglandin concentrations did not change with calcium infusion. These findings are of interest since prostaglandins may be one of the factors responsible for diarrhea in endocrine syndromes. Finally, Dr Cole, the measurement of serotonin in blood is relatively complex. The upper limit of normal is 0.3 pg/ ml. Most of our normal patients fall within a range of 0.1 to 0.2 pg/ml. Therefore, we are able to measure normal subjects without great difficulty. Most people with advanced carcinoid syndrome have blood concentrations of 0.5 pg/ml. or greater. When values are borderline, the calcium infusion test should prove useful by further separating abnormal from normal values of blood serotonin.
179
Edwin L. Kaplan, MD, Chicago,
Illinois
Bernard M. Jaffe, MD, St. Louis, Missouri Gerald W. Peskin, MD,* San Diego, California
Because of the unavailability and delicacy of blood serotonin determinations and the frequent errant results noted in 5hydroxyindoleacetic acid levels in patients suspected of having a carcinoid tumor, a need has arisen for a simple screening test to aid the clinician in the diagnosis of the carcinoid syndrome. Flushing and hyperventilation have been induced in patients with carcinoid tumors by alcohol ingestion and injection of catecholamines. However, the results have been inconsistent and the correlation with chemical values in the blood often lacking. The purpose of this study is to report a new provocative test, the calcium infusion test, which may be useful in the diagnosis of carcinoid and other serotoninelaborating tumors. Methods Calcium gluconate (10 to 15 mg/kg Ca+ + /4 hr) was administered intravenously to a group of controls and to patients known to have carcinoid tumors or other endocrinopathies associated with carcinoid symptoms, such as medullary carcinoma of the thyroid gland. Serum calcium was determined on basal and hourly specimens by atomic absorption spectrophotometry. Blood serotonin (5-hydroxytryptamine) and urinary 5-hydroxyindoleacetic acid (5HIAA) were evaluated by the methods of Udenfriend and associates [1,2].
From the Departments of Surgery, Michael Reese Hospital, University of Chicago, Pritzker School of Medicine, Chicago, Illinois, and the Washington University School of Medicine, St. Louis, Missouri. This work was supported in part by the USPHS Grants AM 14499-01, HE 11909-04, and Trainina Grant NIGMS 371. Reprint requests should be addressed to Dr Kaplan, Department of Surgery, University of Chicago Hospitals, 950 E. 59th Street, Chicago, Illinois 60837. Presented at the Twelfth Annual Meeting of the Society for Surgery of me Alimentary Tract, Atlantic City, New Jersey, June 19 and 20, 1971. ‘Department of SUrgery. University of California at San Diego, San Diego, California 92103.
Volume 123, Fobwary
1972
Results Corresponding to an elevation of serum calcium concentration of 2 to 4 mg/lOO ml during calcium infusion, control patients experienced occasional minimal nausea and dizziness but no other symptoms or circulatory effects. (Table I.) Of eleven patients studied, seven are of special interest and will be described in some detail. Four patients with known or previously resected carcinoid tumors were evaluated; two had full-blown carcinoid syndrome. Case I. The patient (JG), a fifty-four year old housewife, had flushing over the upper half of the body in 1962 after alcohol ingestion. These episodes were associated with “puffiness,” tachycardia, and a feeling that “blood was having trouble getting through my legs.” In recent years the attacks increased in frequency and seemed to be precipitated by nervousness. Diarrhea occurred infrequently but followed abdominal palpation by her physician on several occasions. She had peptic ulcer symptoms which were relieved by antacids but had no demonstrable ulcer on barium studies. Preoperatively, a calcium infusion test was performed as part of an evaluation of the gastric secretory state. Severe flushing, wheezing, hypotension, and weakness developed soon after the calcium infusion was begun and the infusion was discontinued. In February 1970, a 1.8 cm ileal carcinoid with lymph node involvement and multiple metastases of both lobes of the liver was found at operation. Resection of the terminal ileum and ascending colon and excision of multiple liver nodules (50 gm) were performed. Postoperatively, the symptoms were markedly relieved. Six months after surgery, a repeated calcium infusion test was performed. (Figure 1.) After two and a half hours, the infusion had to be discontinued because of the development of a bright flush, facial swelling, weakness, difficulty in breathing, hypotension, and the passage of flatus. Blood serotonin rose from 1.65 to 4.16 pg/ml during the attack. The symptoms subsided after one hour. She de-
173
Kaplan, Jaffe, and Peskin
TABLE I
Results of Calcium Infusion in Eleven Patients Studied Calcium
Carcinoid Syndrome
Urinary 5-HIAA* (mg/24 hr)
lleal carcinoid, hepatic metastases
+
73-126
RT, 66, W,F
Ovarian carcinoid, metastases
+
32,49
WC, 54, W,M
Rectal carcinoid; hepatic metastases Carcinoid appendix with metastases to nodes; post appendectomy
0
3.0
0
8.7-14
Patient, Age (yr),
Race, and Sex JG, 54, W,F
DW, 40, N,F
JH. 19, W,F
Diagnosis
Medullary carcinoma with cervical metastases
6.4, 9.6
Serum Calcium (mg/lOO ml) B 9.2 1 .. 2 10.6 2’12 12.2 B 9.6 1 10.7 2 10.6 2% 11.7 B 8.6 1 10.0 2 10.0 3 10.6 B 8.5 1 10.6 2 ‘11.5 3 12.6 4 12.7 Pre-op B 9.3 1 10.6 2 10.8 3 11.8 3% 12.3 Post-op B 7.8 1 8.9 2 9.9 3 12.0
Infusion Blood Serotonint (pg/mt) 1.85
Symptoms with Infusions
Tissue Serotonin
+
51.3
+
8.4
(rglgm)
. 2.48 4.16$ 0.09 0.14 0.14 0.55s 0.09 0.11 0.07 0.07 0.11 0.12 0.13 0.21 0.20 0.15
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*Normal 5-hydroxyindoleacetic acid <17 mg/24 hours TNormal blood serotonin concentration 0.1-0.3 pg/ml SInfusion discontinued because of severe symptoms
scribed both attacks associated with calcium infusion as the worst she had ever experienced. Tissue from a liver metastasis contained a serotonin concentration of 51.3 pg/ gm wet weight. Case II. The patient (RT), a sixty-six year old woman, had a malignant tumor of the ovary removed in 1958. At surgery, peritoneal implants were present. Microscopically, the tissue was described as a “homogeneous population of malignant cells.” In 1968 she noted increasing symptoms of asthma, cyanosis, flushing, and three or four watery stools per day. Carcinoid syndrome with hepatic metastases, presumably from the ovarian tumor, was diagnosed in 1970. A four hour calcium infusion was begun, but had to be terminated after two and a half hours because of severe symptoms of flushing, wheezing, and diarrhea. (Figure 2.) She described this as her worst attack. Blood serotonin, normal under basal conditions, increased sixfold to 0.55 wg/ml and correlated well with the symptoms. Case III. The patient (WC), a fifty-four year old man, had a rectal carcinoid removed by anterior resection in 1958. In 1967 he was noted to have a local recurrence with
174
massive liver metastases. Liver biopsy confirmed the diagnosis of metastatic rectal carcinoid. He never experienced symptoms of the carcinoid syndrome and urinary 5-HIAA was within normal limits. Calcium infusion resulted in no symptoms and no change in normal blood serotonin values. Case IV. The patient (DW), a forty year old woman, was operated on for acute appendicitis in March 1969. Pelvic inflammatory disease was found. Appendectomy was performed and an infiltrating carcinoid of the appendix was noted. Four months later at re-exploration, no abnormalities were noted. The mesentery at the base of the appendix was removed and proved, on permanent sections, to contain four lymph nodes, two of which contained microscopic carcinoid tumor. In 1971 she was again admitted because of symptoms of pelvic inflammatory disease. Urinary 5-HIAA determinations gave repeatedly normal results as did the liver scan, bone survey, and barium studies of the stomach, small intestines, and colon. During calcium infusion, neither symptoms nor elevation of blood serotonin concentrations occurred. At exploration on January 22, 1971, no abnormalities of the liver or intestines were noted. Mesenteric and periaortic lymph nodes were biopsied and
The American Journal of Surgery
Test for Diagnosing
Calcitim
Carcinoid Syndrome
Urinary 5-HIAA* (mg/24 hr)
Pheochromocytoma excised; medullary carcinoma with cervical, skin, and bone metastases Neurofibromatosis, retroperitoneal malignant neurogenic tumor
0
3.0
Diarrhea, malabsorption syndrome
0
VS, 22, W,F
Flushing after cheese ingestion
0
KG, 43, N,F
Duodenal ulcer
0
Patient, Age (yr), Race, and Sex LC, 24, W,M
PH, 17, N,F
HB, 51, W,F
EK, 35. W,M
contained formed.
Diagnosis
Control
no tumor.
A gynecologic
Two patients with medullary thyroid gland and another with genie tumor and neurofibromatosis
0
0
procedure
22.8
7.0
4.3
12.7
was per-
carcinoma of the a malignant neurowere studied.
Case V. The patient (JH), a nineteen year old girl, had noted enlarged lumps in the left side of the neck for several years. They did not respond to antibiotic therapy. One node was biopsied and a diagnosis of metastatic medullary carcinoma of the thyroid was made. For several years she had had loud borborygmi, which could be heard by others several rooms away. She had occasional watery stools, not more than three or four per day. Her father had neurofibromatosis and she had mild scoliosis of the dorsal spine, a cafe au lait spot on the chest, and a hard mass of the left thyroid lobe with multiple lymph node metastases of the left cervical chain. Serum thyroxine, T3 resin, urinary catecholamines, blood corticoids, and urinary total hydroxy- and 17-ketosteroids were within normal limits as were serum calcium, phosphorous, and roentgenograms of the hands. Urinary 5-HIAA determinations were likewise within normal limits on two occasions. Preoperatively, a
Volume 123, February 1972
Serum Calcium (mg/lOO ml)
the Carcinoid
Syndrome
Infusion Blood Serotonint (Ccg/mt)
Symptoms with Infusions
Tissue Serotonin (rglgm)
B 1 2 3 4
10.9 12.0 12.2 12.1 12.3
0.11 0.08 0.07
B 1 2 3 4 B 1 2 3 B 1 2 3 4 B 1 2 3 4 B 1 2 3
9.7
0.15
0
0.2
11.1 12.4 12.3 8.1 11.5 13.4 14.8 9.8 10.3 11.1 12.4 13.2 8.5 10.7 13.3 14.5 13.2 10.0 11.2 12.6 13.5
0.23 0.41 0.41 0.10
0
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0
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.
calcium infusion test was performed. (Figure 3.) After three and a half hours this had to be discontinued because of flushing of the face and upper trunk, vomiting, and explosive diarrhea. Blood serotonin increased sixfold from normal to 0.89 pg/ml in association with these symptoms. Postoperatively, after total thyroidectomy and left radical neck dissection, a repeated calcium infusion was performed. This time she had no symptoms and blood serotonin was within normal limits and did not change. The thyroid tumor contained serotonin in a concentration of 8.4 pg/gm wet weight. Case VI. The patient (LC), a twenty-four year old man, had a right adrenal pheochromocytoma removed in 1966. In 1969 he noted a mass in the left lobe of the thyroid. Six months later this had grown to the size of a grapefruit, and multiple lymph node and bone metastases and extensive subcutaneous deposits of tumor were present. A left thyroid lobectomy for palliation established the diagnosis of medullary carcinoma of the thyroid. Tissue contained calcitonin and prostaglandins on assay. The patient had no symptoms related to the carcinoid syndrome and urinary 5-HIAA was within normal limits. During a calcium infusion, no unusual symptoms occurred and blood serotonin remained within normal limits.
175
Kaplan, Jaffe, and Peskin
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Four other patients, one with diarrhea from a malabsorption syndrome, another with duodenal ulcer, a third with flushing after cheese ingestion, and lastly, an asymptomatic volunteer, experienced no untoward effects from calcium infusion and blood serotonin values remained normal.
Comments
Time (Hours)
Figure 1. Case I. JG, a patient with carcinoid syndrome from an ileal carcinoid tumor with metastases, was infused with calcium gluconate. Blood serotonin concentration increased and severe flushing and other symptoms ensued (*) necessitating discontinuation of the infusion. Normal blood serotonin is 0.1 to 0.3 pglml.
Case VII. The patient (PH), a seventeen year old girl, had multiple neurofibromatosis, cafk au lait spots, scoliosis, and an abdominal mass which was present for seven years but recently became tender. She had never experienced flushing, diarrhea, or any other carcinoid symptoms. Urinary 5-HIAA, however, was minimally elevated (22.8 mg/ 24 hr). A preoperative calcium infusion was accomplished with no abnormal symptoms; however, blood serotonin concentration rose from 0.15 to 0.41 pg/ml during the procedure. (Figure 4.) At operation, a vascular retroperitoneal tumor weighing 1,040 gm was removed. Microscopically it was classified as a ganglioneuroma with focal areas of malignant schwannoma. The tissue contained 0.2 pg/gm of serotonin.
0.6
R.T.
(
OVARIAN
CARCINOID .
,
120
Time (Hours)
Figure 2. Case Il. RT, a patient with carcinoid syndrome of ovarian origin, received calcium gluconate intravenously. Severe flushing and other symptoms occurred after two and a half hours (*). Blood serotonin became markedly elevated at this time.
176
Carcinoid tumors occur in the appendix, jejunoileum, rectum, duodenum, stomach, colon, ovary, biliary tract, and pancreas in decreasing order of frequency. Bronchial adenomas are microscopically of the carcinoid type in 85 per cent of cases, and one case of carcinoid of the larynx has been described. Of 3,718 cases of abdominal carcinoid tumors collected by Wilson et al [3], only 136 patients (3.7 per cent) had symptomatic endocrinologic activity and were classified as having the carcinoid syndrome. The tumors giving carcinoid symptoms are mostly from the jejunoileum followed in frequency by the ovary, stomach, appendix, colon, and duodenum. Unfortunately, in gastrointestinal carcinoids, endocrinologic manifestations almost always signify widespread metastatic disease to the liver. The liver contains large amounts of monamine oxidase, an enzyme needed in the first step of degradation of serotonin. On the other hand, the venous drainage of ovarian and bronchial carcinoids is systemic and bypasses the liver; hence, early disease without metastases may produce symptoms despite the fact that only 6 per cent had metastatic disease. Thus, ovarian teratomas offer a unique opportunity for surgical cure [3]. It is highly likely that not all carcinoids are endocrinologically active. There is only one recorded carcinoid syndrome associated with a rectal carcinoid [4]. However, many patients have symptoms which go undetected until far advanced disease is present. This results from two basic factors: (1) a lack of general appreciation of the multiplicity of variant symptoms produced by carcinoid tumors and (2) the lack of an entirely suitable screening procedure for diagnosis of the disease. Most patients with the “classical” carcinoid syndrome present with episodic watery diarrhea, abdominal cramps, and borborygmi. Intestinal obstruction, peptic ulcer, hepatomegaly, asthmatic symptoms, cutaneous flushing, or the murmurs of tricuspid insufficiency and/or pulmonary stenosis may also be present. The biochemical hallmark of the carcinoid syndrome has been a demonstration of excessive urinary excretion of 5-hydroxyindoleacetic acid. However, in some patients with full-blown carcinoid syndrome 5-HIAA may be normal [5]. Williams and associates [S], for example, recently studied eleven pa-
The American Journal of Surgery
Test for Diagnosing
tients with carcinoid syndrome. In three, large amounts of indolic acids (indoleacetic, indolelactic, indolepyruvic, and indoleacrylic) were present without elevation of the hydroxylated indolic derivatives. Thus, if the diagnosis is based exclusively on the urinary 5-HIAA levels, many carcinoids may be missed. Serotonin has been extracted from carcinoid tumors [7] and has been found to be elevated in the blood of many persons with the carcinoid syndrome [I]. The diarrhea has been attributed to action of this hormone or 5-hydroxytryptophan; however, episodes of flushing have not correlated well with elevations of these amines [5,8]. Several groups have demonstrated a rise of serum bradykinin concentration associated with induced flushing [9]; however, this has not been a consistent finding [IO]. Kallikrein, a bradykininreleasing enzyme, has been extracted from some carcinoid tumors [11]. Variant syndromes include metastatic gastric carcinoids which secrete large amounts of histamine and 5-hydroxytryptophan rather than serotonin [12]. Vivid, red patchy flushing may occur after meals and diarrhea may not be prominent. The urine in these instances contains serotonin and 5-hydroxytryptophan as well as 5-HIAA. Bronchial carcinoids may be endocrinologically asymptomatic but may present with very severe attacks of flushing which are prolonged and often associated with facial edema [13]. Heart lesions are predominantly left-sided in these patients. Bronchial tumors seem to be associated more frequently with acromegaly, pluriglandular adenomatosis, and Cushing’s disease than are other carcinoid tumors
[141. In several patients with carcinoid tumors, elevations of catecholamines and their metabolites have been found, but this is unusual [5]. An ectopic ACTHlike hormone and prostaglandins may also be present in some carcinoid tumors. Increased serotonin or its metabolites and hyperinsulinism, hyperglycemia, and the Zollinger-Ellison syndrome also have been reported in some patients [15]. Thus, a whole spectrum of syndromes may be associated with carcinoid tumors. Flushing and diarrhea often occur spontaneously in these patients, but they may also be precipitated by emotional stress, food, enemas, exercise, or abdominal palpation, as in one of our patients. Oral or intravenous alcohol and injections of epinephrine, norepinephrine, dopamine, and histamine have all been used as bedside provocative tests to induce flushing with some success [16]. In recent years it has been recognized that medullary carcinoma of the thyroid gland and carcinoid
Volume 123, February 1972
the Carcinoid
of the THYROID Postop
Syndrome
13.0
r
I_ 12.0 $ 11.0 10.0 6 9.0 ;
a0 y 10 p g 3
Ttme (Hours)
Figure 3. Case V. JH, a patient with medullary carcinoma of the thyroid with cervical node metastases, developed Nushing for the first time during calcium infusion (*) at which time blood serotonin was markedly increased (left). After extirpation of all known tumor, a repeated calcium infusion resulted in no untoward symptoms and blood serotonin values remained normal (right).
tumors have many features in common [17]. C cells, the cells of origin of medullary carcinomas, take up 5-hydroxytryptophan and convert it to serotonin. Argentaffin-staining cells have been demonstrated in these thyroid tumors. Moertel et al [18] described a syndrome of flushing and severe diarrhea associated with medullary carcinoma. Since that time, it has been recognized that about one third of patients with this type of thyroid cancer present with or subsequently have diarrhea which is often severe [19]. Like that of the carcinoid syndrome, the diarrhea appears to be related to hypermotility of the intestinal tract. At times, flushing is also associated with this symptom complex. Elevated blood and tissue levels of serotonin and prostaglandins have been found in
0.5
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NEUROGENIC
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Figure 4. Case VII. PH, a patient with neurofibromatosis and a retroperitoneal malignant neurogenic tumor, had no untoward effects from the calcium infusion. However, blood serotonin concentration became elevated. Serotonin was found to be present in the tumor.
177
Kaplan, Jaffe, and Peskin
patients with medullary carcinoma with diarrhea and the tumor has been demonstrated occasionally to contain kallikrein as well as an ectopic ACTH-like hormone. Recent studies also suggest that calcitonin, the hallmark of medullary thyroid cancers, may also be present in some carcinoid tumors [20]. These findings are in keeping with the hypotheses that both of these tumors are of neuroectodermal origin and are derived from the same primitive cell. This may also explain the presence and release of serotonin from the malignant retroperitoneal neurogenic tumor just described herein. Calcium infusion may offer .the prerequisites of specificity, safety, and ease of performance which qualify it as a new provocative test for endocrinologically active carcinoid tumors and other related neoplasms which contain and secrete serotonin. Using this method, each of two patients with the carcinoid syndrome (from tumors of ileal and ovarian origin) developed severe flushing and other manifestations of their symptom complex. One patient with medullary carcinoma of the thyroid who had borborygmi and occasional diarrhea had flushing for the first time in her life during induced hypercalcemia. Kinins were not measured but elevations of blood serotonin correlated well with the symptoms. Another patient with a retroperitoneal neurogenic tumor had no symptoms; however, blood serotonin concentrations also became elevated during the infusion. Finally, normal serotonin concentrations in basal and postinfusion states were found in a patient with a rectal carcinoid, in another in whom a recurrence of carcinoid from the appendix was suspected, and in several other patients who had flushing or diarrhea of other causes. Calcium infusion induces the release of calcitonin from medullary thyroid lesions and an associated decrease in cellular granularity [19]. It is, therefore, not completely unexpected that serotonin is released as well by increased concentrations of this divalent cation. Control of calcitonin secretion from C cells of normal thyroid tissue is closely related to serum calcium concentration. It remains to be determined if this stimulus is active in secretory regulation of normal Kultschitzky cells as well. Rasmussen [21] has recently hypothesized that intracellular calcium ion concentration as well as cyclic-AMP may be important factors in the control of many different hormonal secretions. The present observations support this concept.
Summary A new provocative test for the carcinoid syndrome is described and its use in a series of patients with various endocrinopathies detailed. Although the series of patients is small, it is hoped that additional
178
trials will confirm these results and allow the utilization of calcium infusion as an early and specific diagnostic aid for carcinoid and related tumors. Acknowledgment: We would like to thank Barbara J. Hill, Susan Locke, and David N. Toth for their expert technical assistance and Drs Cyril Costello, Bud Loeb, and David Wagner for permitting us to study their patients.
References 1. Udenfriend S, Weissbach H, Clark CT: The estimation of 5hydroxytryptamine (serotonin) in biological tissues. J Biol Chem 215: 337,1953. 2. Udenfriend S, Titus E, Weissbach H: The identification of 5hydroxy-3-indoleacetic acid in normal urine and a method for its assay. J Biol Chem 216: 449, 1955. 3. Wilson H, Cheek RC, Sherman RT, Storer EH: Carcinoid tumors. Curr Probl Surg Chicago, Yearbook Medical Publishers, 1970. 4. Saegesser F, Gross M: Carcinoid syndrome and carcinoid tumors of the rectum. AmerJ Procfol20: 27, 1969. 5. Levine RJ, Sjoerdsma A: Pressor amines and the carcinoid flush. Ann Int Med 58: 818, 1963. 6. Williams HE, Wilson KM, Trager W, Melmon KL: Tryptophanjnduced indoleaceticaciduria: a new variant of the carcinoid syndrome. C/ii, Res 19: 406, 1971. 7. Lembeck F: 5-Hydroxytryptamine in carcinoid tumors. Nature (London) 172: 910,1953. a. Robertson JIS, Peart WS, Andrews TM: The mechanism of facial flushes in the carcinoid syndrome. Quart J Med 31.1 103,1962. 9. Oates JA, Melmon K, Sjoerdsma A, Gillespie L, Mason DT: Release of a kinin peptide in the carcinoid syndrome. Lancet 1: 514,1964. 10. Dollinger MR, Gardner B: Newer aspects of carcinoid spectrum. Surg Gynec Obstet 122: 1335, 1966. 11. Melmon, K, Lovenberg W, Sjoerdsma A: Identification of lysyl-bradykinin as the peptide formed’in vitro by carcinoid tumor kallikrein. C/in Chim Acta 12: 292, 1965. 12. Oates JA, Sjoerdsma A: A unique syndrome associated with secretion of 5-hydroxytryptophan by metastatic gastric carcinoids. Amer J Med 32: 333, 1962. 13. Schneckloth RE, Mclsaac WM, Page IH: Serotonin metabolism in carcinoid syndrome with metastatic bronchial adenoma. JAMA 170: 1143,1959. 14. Williams ED, Celestin LR: The association of bronchial carcinoid and pluriglandular adenomatosis. Thorax 17: 120,1962. 15. Weichert RF I II, Roth LM, Harkin JC: Carcinoid-islet cell tumor of the duodenum and associated multiple carcinoid tumors of the ileum. Cancer 27: 910, 1971. 16. Adamson AR, Grahame-Smith DG, Peart WS, Starr M: Pharmacological blockade of carcinoid flushing provoked by catecholamines and alcohol. Lancef 1: 293, 1969. 17. Williams ED, Karim SMM, Sandler M: Prostaglandin secretion by medullary carcinoma of the thyroid-a possible cause of the associated diarrhea. Lancet 1: 22, 1966. 16. Moertel CG, Beahrs OH, Woolner LB, Tyce GM: “Malignant carcinoid syndrome” associated with noncarcinoid tumors. New Eng J Med 273: 244.1965. 19. Kaplan EL, Peskin GW: Physiologic implications of medullary carcinomaof the thyroid. Surg C/in N Amer 51: 125, 1971. 20. Beceiro J, Ouais S, Hill CS, Samaan NA: Serum calcitonin levels in medullary carcinoma of thyroid, hypercalcemia associated with malignancy and carcinoid tumors. C/in Res 19: 367,1971. 21. Rasmussen H: Cell communication, calcium ion and cyclic adenosine monophosphate. Science 170: 404,197O.
The American Journal of Surgery
Test for Diagnosing
Discussion Robert C. Hickey (Houston, Texas): 1 would like to ask the authors if the levels of calcitonin were measured in all of the patients studied. With medullary cancer and calcium intravenous infusion there may occur the syndrome described as well as a concomitant elevation of calcitonin. The cells of origin, for both tumors, are thought to be the same. Doctor Moore: Several years ago Dr Ben Eiseman and I observed that serotonin can release histamine. Did the authors find any alterations in histamine concentration that might account for some of the symptoms? Jack W. Cole (New Haven, Conn): Years ago it was very difficult to measure the level of serotonin in the blood and it was a fairly erratic determination. I wonder if Dr Kaplan would comment on this. Edwin L.Kaplan (closing): Doctor Hickey, we have tissue from several tumors and serum samples from all patients. Calcitonin was easily demonstrated by bioassay from the tumors of both patients with medullary carcinoma of the thyroid. Analyses of other tumors are in progress. Since the quantity of serum is limited, we plan to analyze the calcitonin content by radioimmunoassay. There are at least
Volume 123, February 1972
the Carcinoid
Syndrome
four groups of investigators in this country that have developed very sensitive immunoassays for measuring this polypeptide in man. Doctor Moore, the only humoral substance measured at this time was serotonin. Several groups have developed radioimmunoassays for bradykinin, and it would be helpful to know if blood kinin concentrations changed with calcium infusion as well. Similarly, histamine was not analyzed. Doctor Bernard ,Jaffe has done some preliminary work on prostaglandins utilizing a very sensitive radioimmunoassay for measuring these compounds which he developed. In several of our patients, serum prostaglandin concentrations did not change with calcium infusion. These findings are of interest since prostaglandins may be one of the factors responsible for diarrhea in endocrine syndromes. Finally, Dr Cole, the measurement of serotonin in blood is relatively complex. The upper limit of normal is 0.3 pg/ ml. Most of our normal patients fall within a range of 0.1 to 0.2 pg/ml. Therefore, we are able to measure normal subjects without great difficulty. Most people with advanced carcinoid syndrome have blood concentrations of 0.5 pg/ml. or greater. When values are borderline, the calcium infusion test should prove useful by further separating abnormal from normal values of blood serotonin.
179