Metastatic pancreatic islet cell carcinoma with peptic ulcer disease and hypercalcemia

CLINICOPATHOLOGIC CONFERENCES

Metastatic Pancreatic Islet Cell Carcinoma with Peptic Ulcer Disease and Hypercalcemia

Stenographic reports, edited by Philip E. Cryer, M.D. and John M. K&sane, M.D., of weekly clinicopathologic conferences held in Barnes and Wohl Hospitals, are published in each issue of the Journal. These conferences are participated in jointly by members of the Departments of Internal Medicine, Radiology and Pathology of Washington University School of Medicine. A 62 year old woman was admitted to Barnes Hospital for the fifth time on May 25, 1976, because of symptomatic hypercalcemia. She died on July 18, 1976. During surgery for a subcapsular hematoma of the spleen in 1958, the patient was found to have a carcinoma of the pancreas. Because of a hemorrhage in the upper gastrointestinal tract due to duodenal ulcers, she required a laparotomy in 1968. Hepatic metastases were noted. Subsequent review of tissue specimens from the pancreatic tumor and the hepatic metastases confirmed that this was a pancreatic islet cell carcinoma. In 1968, diabetes mellitus was also diagnosed. The family history was positive for diabetes. Recurrent peptic ulcer disease refractory to medical therapy led to vagotomy and hemigastrectomy (Billroth II anastomosis) in 1971. The patient was admitted to the Washington University School of Medicine Clinical Research Center for the first time on April 8, 1974, with a three to four month history of fatigability, weakness, weight loss and polyuria without major glycosuria. Findings included (1) hypercalcemia (14.3 f 0.2” mg/lOO ml), marked osteopenia, normal bone scans, peripheral serum parathyroid hormone (PTH) levels at the upper limit of normal (8 @Ieq/ml) and serum PTH levels of 12.1 to 13.6 ~1 eq/ml in the large neck veins, and 4.6 to 9.9 ~1 eq/ml in the right atrium and inferior vena cava; (2) hypergastrinemia (2,420 f 410 pg/ml) and a 1.O cm anastomotic peptic ulcer demonstrated on an x-ray series of the upper gastrointestinal tract: (3) renal insufficiency; (4) anemia; and (5) diabetes mellitus. The morning plasma cortisol level was suppressed to 3.9 pg/lOO ml after the administration of dexamethasone at 2400 hours, fasting plasma glucagon concentrations were normal as were the serum thyroxine, potassium and sodium concentrations, and the urinary excretion of 5hydroxyindoleacetic acid. There was no hypoglycemia during a 24-hour glucose and insulin profile (hourly samples). * Standard error.

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PANCREATIC ISLET CELL CARCINOMA, PEPTIC ULCER DISEASE AND HYPERCALCEMIA

After a brief discharge, pending the results of laboratory determinations, the patient was readmitted on May 13, 1974, and parathyroidectomy (removal of three glands and biopsy of a fourth) was performed two days later. The parathyroid tissue was histologically normal, and the serum calcium concentration was unaffected. Measures designed to temporarily limit the patient’s hypercalcemia (including a single dose of mithramycin, two short courses of oral phosphate and a one month course of calcitonin therapy) were instituted and therapy with streptozotocin (in weekly doses of 0.5, 0.5, 0.75, 1.O, 1.O and 1.O g) was instituted. Following streptozotocin therapy, the serum calcium concentration decreased to normal (10.3 f 0.3 mg/lOO ml) with resolution of symptoms, and the serum gastrin level fell to near normal (549 f 27 pg/ml; the upper limit of normal in that laboratory is 300 pg/ml) with disappearance of the anastomotic peptic ulcer. There was no change in the creatinine clearance (24 ml/min), hematocrit value (26 per cent) or fasting serum glucose concentration (110 mg/lOO ml) following treatment with streptozotocin. The patient felt remarkably well over the ensuing 18 months. She gained weight and was able to return to her usual activities including light house and garden work. She was electively readmitted on January 5, 1975. Findings then included mild hypocalcemia (6.8 f 0.1 mg/ 100 ml) with mildly elevated serum PTH levels (10 to 17 I.LIeq/ml) and normal serum gastrin levels (227 f 22 pg/ml); no ulcerations were demonstrable on an x-ray series of the upper gastrointestinal tract. The serum gastrin concentration did not increase during a calcium infusion. She was again electively readmitted on July 28, 1975. The serum calcium concentrations were normal (10.3 f 0.2 mg/ 100 ml) but inappropriately high for her degree of renal impairment, the serum PTH level was unmeasurably low and serum gastrin levels remained normal (149 f 15 pg/ml). The creatinine clearance, hematocrit value and fasting plasma glucose concentrations were essentially unchanged. Subjectively, the patient continued to do well until late December 1975, 18 months after her initial course of streptozotocin therapy, when fatigability, weakness, anorexia, weight loss and polyuria recurred. She was readmitted on January 3, 1976. Findings included hypercalcemia (13.3 f 0.2 mg/lOO ml) with unmeasurable serum PTH concentrations and normal serum gastrin levels (126 f 12 pg/ml). Bone scans disclosed no abnormalities, liver scans demonstrated multiple filling defects, and no gastrointestinal ulcerations were demonstrable roentgenographically. Therapy with streptozotocin, in doses of 0.5 and 1.O g one week later, was followed by an increase in the serum calcium concentration to 17.6 mg/lOO ml. A single dose of mithramycin was given. After a sharp decrease, the

serum calcium level plateaued and then started a gradual but progressive decline to normal (9.1 f 0.1 mg/ 100 ml), again with resolution of symptoms. However, the initial post-streptozotocin increment in serum calcium was mirrored by a decrement in the creatinine clearance to a nadir of 10 and 11 ml/min with only partial recovery to 15 and 16 ml/min at the time of discharge. This second remission was short-lived. The patient was admitted for the fifth time on May 25, 1976, with anorexia, nausea, weight loss, polyuria, weakness and confusion. She also complained of leg pain (which persisted and became increasingly severe during the remainder of her course) and pain over the left 10th rib. She was thin, pale and generally weak, and there was tenderness over the left 10th rib. The liver span was 12 cm by percussion; there were no abdominal masses. The initial serum calcium concentration was 19.4 mg/lOO ml. It decreased to 14.6 mg/lOO ml after an infusion of saline solution. The serum PTH was unmeasurable, serum prostaglandins E (PGE) and F (PGF) levels were 362 and 140 pg/ml, respectively (both within the normal range), and gastrin levels were 84 and 93 pg/ml. The serum thyroxine was 5.8 pg/ 100 ml and the plasma cortisol41 cLg/lOO ml. Chest films showed no changes aside from a fracture of the left 10th rib without evidence of metastases. The hematocrit value was 31 per cent, the white blood cell count 10,300/ mm3 and the serum alkaline phosphatase 164 mlU/ml. Creatinine clearances were 17 and 16 ml/min, and the tubular reabsorption of phosphate was 17 and 26 per cent. The administration of streptozotocin, in four weekly doses of 0.5 g each, was begun on May 29, 1976. Serum calcium concentrations were 15.2, 13.2, 11.8 and 12.1 mg/ 100 ml on June 4,9, 18 and 28, respectively. However, there was little clinical improvement, and a single dose of mithramycin (1 .O mg) was given on June 28. The serum calcium concentration decreased to 9.0 and 8.7 mg/lOO ml on the following two days and ranged from 9.0 to 10.2 mg/lOO ml (seven determinations) over the remaining 18 days of her course. The creatinine clearances were 14 and 14 ml/min on July 8 and 9. The corresponding values for tubular reabsorption of phosphate were 56 and 79 per cent. The serum alkaline phosphatase increased progressively reaching a peak of 5 15 mlU/ml, and the serum albumin decreased progressively to 2.7 g/100 ml. The patient’s clinical course was one of progressive deterioration. Although her mental status cleared with correction of her hypercalcemia, she remained anorectic, continued to lose weight and became progressively weaker. She required meperidine therapy for relief of leg pain. Plaque-like and then hemorrhagic skin lesions appeared over the lower extremities.

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between the tibia and fibula (Figure 2). Such metastatic calcification is caused by hyperparathyroidism, but it is also reported in hypoparathyroidism, massive bone destruction due to me&static tumors, multiple myeloma or leukemia, and in sarcoidosis and hypervitaminosis D. Dr. Kipnis: This patient does not represent a diagnostic problem in terms of the histopathology since we know that she had a pancreatic islet cell carcinoma with hepatic metastases. Her clinical course illustrates a portion of the remarkable panorama of symptoms which can occur in patients with islet cell tumors. We now recognize that the majority of islet cell tumors produce biologically active materials. With our increasing analytic capacity, an increasing number of humoral products have been detected in such patients. One of the early patients studied at this institution presented with Cushing’s syndrome due to the secretion of ACTH from an islet cell tumor; evidence of the ectopic secretion of five additional hormones was recognized at that time

[Il.

Figure 1. Compression spot film of gastroenterostomy showing large ulcer niche (arrows).

site

Dermal calcification was seen in a biopsy specimen of one of these lesions. She became progressively obtunded and died on July 18, 1976. CLINICAL DISCUSSION Dr. David Kipnis: Before we begin the discussion, Dr. Levitt will present the pertinent x-ray films. Dr. Robert Levitt: An examination of the upper gastrointestinal tract was performed during the first Barnes Hospital admission in April 1974. On a compression spot film of the gastroenterostomy site from that study, a large ulcer niche was identified (Figure 1). Ulcers were not seen on a series of films of the upper gastrointestinal tract obtained after the first course of streptozotocin therapy. On the final admission in May 1976, a film of the lower leg was obtained because of leg pain. On that film, faint calcifications were seen in the soft tissue

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Dr. Cryer, in addition to producing a variety of secretory products and corresponding clinical syndromes, islet cell tumors are a component of the multiple endocrine neoplasia syndrome. Would you discuss this and then focus on the mechanism of this patient’s major problem, her hypercalcemia? Dr. Philip Cryer: Some of the hormones known to be produced from islet cell tumors include insulin, resulting in hypoglycemia; glucagon, which may result in hyperglycemia; gastrin, resulting in peptic ulcer disease; vasopressin, resulting in hyponatremia; and ACTH, resulting in Cushing’s syndrome. The “pancreatic cholera” syndrome (watery diarrhea, hypokalemia and achlorhydria) also occurs in patients with islet cell tumors. Patients with this syndrome often have elevated serum levels of vasoactive intestinal peptide [2] and/or PGE [3]. Elevated levels of other peptides, such as gastric inhibitory peptide and human pancreatic polypeptide, have been reported in patients with islet cell tumors. Lastly, hypercalcemia may occur. Of these possibilities, the patient under discussion had two: (1) hypergastrinemia with peptic ulcer disease (the Zollinger-Ellison syndrome) and (2) hypercalcemia. Islet cell tumors are a component of multiple endocrine neoplasia, type I (MEN I): pituitary tumor (often functional), hyperparathyroidism and islet cell tumor. Multiple endocrine neoplasia, type II (MEN II) includes hyperparathyroidism, medullary carcinoma of the thyroid and pheochromocytoma whereas multiple endocrine neoplasia, type Ill (MEN Ill or llr,) includes medullary carcinoma of the thyroid, pheochromocytoma, mucosal neuromas and a marfanoid habitus [4]. Pancreatic islet cell tumors are not a feature of the latter two syndromes.

PANCREATIC

ISLE1 CELL CARCINOMA,

PEPTIC ULCER DISEASE

AND HYPERCALCEMIA

Hypercalcemia is commonly caused by cancer or primary hyperparathyroidism, although it can be caused by a variety of disorders, such as thyrotoxicosis, immobilization of patients with accelerated bone turnover (e.g., Paget’s disease), vitamin D or A intoxication, the milk-alkali syndrome, Addison’s disease and, rarely, sarcoidosis. None of the latter was present in this patient in whom the differential diagnosis was between primary hyperparathyroidism and hypercalcemia due to her known carcinoma. In general, cancer causes hypercalcemia either by primary bone involvement by the tumor (e.g., multiple myeloma) or by secondary bone involvement with metastases or, in the absence of metastases, with the systemic production of a humoral substance which acts on bone. These distinctions are, in a sense, artificial since it is now known [5] that myeloma cells release a humoral substance which causes bone resorption (osteoclast activating factor, OAF) and, it is reasonable to suspect, that carcinomatous metastases to bone may produce a similar substance so that it is possible that all cancer-related hypercalcemia is humoral, if not hormonal. Systemic humoral agents produced from cancers and recognized to cause hypercalcemia include parathyroid hormone (PTH) and/or PTH-like peptides [6] and prostaglandins 171. There were several reasons to suspect that this patient had primary hyperparathyroidism. First, there is the recognized association between islet cell tumors and primary hyperparathyroidism mentioned earlier (MEN I). Second, the clinical findings-hypercalcemia, hypophosphatemia, a very low tubular reabsorption of phosphate and marked osteopenia-were consistent with that diagnosis. Third, PTH was measurable in the serum, and there was an apparent PTH gradient from the major neck veins. Parenthetically, similar gradients have been found in normocalcemic patients [8] as well as in hypercalcemic patients with primary hyperparathyroidism [9]. Now it has been seen in a hypercalcemic patient without primary hyperparathyroidism. This underscores the critical importance of sampling from small thyroidal veins if venous catheterization is used to localized hyperfunctional parathyroid tissue [ 10,l l]. Lastly, from a practical point of view, neck exploration with the operational diagnosis of primary hyperparathyroidism was in the patient’s best interest since the probability of cure was high if that diagnosis was correct. Retrospectively, it is clear that the patient did not have primary hyperparathyroidism and that her hypercalcemia is best attributed to the production of a hypercalcemic substance from her islet cell tumor. That was suspected on the basis of the recognized potential of islet cell tumors to produce hypercalcemia, as mentioned earlier, and in view of the fact that the serum PTH levels were not clearly elevated. It was strongly

Figure 2. Close-up film of lower leg showing faint calcifications in the soft tissue between the tibia and fibuia.

supported by the failure of parathyroidectomy to correct the hypercalcemia and even more strongly by the response of the hypercalcemia to therapy with streptozotocin. The nature of the hypercalcemic substance is unclear. It did not appear to be PTH although the use of other PTH antiserums might have demonstrated elevated levels of a PTH molecule in the serum. Similarly, it was probably not a prostaglandin in view of the normal serum prostaglandin levels. Streptozotocin has been used most extensively in patients with insulin secreting islet cell carcinomas [ 121. It has, however, been used effectively in patients whose islet cell carcinomas secrete other humoral substances. The patient under discussion represents,

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to my knowledge, the third reported case of streptozotocin-responsive hypercalcemia [ 13- 151. Furthermore, her serum gastrin levels fell to normal and her clinical Zollinger-Ellison syndrome totally resolved after streptozotocin therapy [ 151. Reduction in serum gastrin levels and resolution of this clinical syndrome have recently been observed in other patients [ 16-201. Resolution of the pancreatic cholera syndrome [21], with normalization of serum vasoactive intestinal peptide levels [22,23], following streptozotocin therapy has been reported. Suppression of glucagon secretion [ 12,241 and of ACTH secretion [25] has also occurred following streptozotocin therapy of patients with islet cell tumors, In addition to the vascular calcifications pointed out by Dr. Levitt, painful, plaque-like and then hemorrhagic cutaneous lesions developed in this patient similar to those in the syndrome of tissue necrosis and vascular calcification noted by Gipstein and co-workers [26] in patients with chronic renal failure. Our patient had renal insufficiency but, in contrast to most patients with renal failure, was hypercalcemic and not hyperphosphatemic. The common feature was elevated levels of parathyroid hormone or, in our patient, a substance which behaved like parathyroid hormone. It is of note that healing of the skin lesions followed removal of parathyroid tissue in seven of the 10 patients with renal failure [26]. Dr. Kipnis: It has been nearly five years since Raisz and colleagues [27] described osteoclast activating factor, a soluble mediator released from phytohemagglutinin-activated normal peripheral blood leukocytes, which promotes the resorption of calcium from fetal long bones prelabeled with 45Ca. This material not only promotes calcium resorption but also inhibits collagen synthesis in bone [28]. Thus, the effects of osteoclast activating factor on bone are remarkably similar td those of parathyroid hormone. A biologically active material chemically indistinguishable from osteoclast activating factor has been demonstrated in supernatant fluids from cultures of human myeloma [5] and lymphoma [29] cells. This, coupled with the morphologic observation of osteoclasts on bone resorbing surfaces adjacent to areas of heavy myeloma cell infiltration [5], strongly suggests that calcium mobilization from bone and hypercalcemia in patients with tumors, such as myeloma, is mediated by osteoclast activating factor released from the malignant cells. I would suspect that other tumors release materials with biologic activity similar to that of osteoclast activating factor into the circulation and that these materials mediate the development of hypercalcemia. Therefore, I would agree that a major mechanism of the severe hypercalcemia in the patient under discussion, especially when she was hypercalcemic with no measurable serum PTH, was the secretion of a hypercalcemic material from her islet cell carcinoma.

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It is a general principle that, even when deprivedof their tropic stimulus, endocrine glands continue to release their hormones, albeit at markedly reduced rates. This could conceivably explain the apparent serum PTH gradient between the neck veins and the veins more remote from the parathyroid glands observed in our patient. Nonetheless, one would not expect to find peripheral serum PTH levels in the high normal range in a patient with hypercalcemia due to nonparathyroid factors. Thus, the finding of a serum PTH level of 8 ~1 eq/ml early in this patient’s course raises the possibility that her tumor may have also been secreting a PTHrelated molecule initially. After her first course of streptozotocin therapy, however, PTH was not detectable in her serum despite recurrent hypercalcemia. Prostaglandins as mediators of hypercalcemia were mentioned earlier. Prostaglandins of the E series have been shown to stimulate bone resorption in vitro [30], and PGE2 may be the mediator of hypercalcemia in two tumor-bearing, hypercalcemic animal models. There have been reports of elevated serum PGE levels [31] and increased excretion of a major prostaglandin E metabolite (PGE-M) [7] in hypercalcemic patients with hypercalcemia. Seyberth and co-workers [ 71 found that inhibition of prostaglandin synthesis, by the administration of indomethacin or aspirin, reduced both the urinary PGE-M excretion and the serum calcium concentration in six such patients. It is worth emphasizing that the serum calcium response to drugs such as indomethacin, if a response occurs, is usually apparent within 48 to 72 hours. Recognizing this, a short trial of indomethacin therapy was considered early in this patient’s course. However, she had an active anastomotic peptic ulcer at that time and, because of its gastric irritant effect, indomethacin was not administered. Subsequently, she was found to have normal serum PGE levels at a time when she was hypercalcemic. Dr. Jaffe, the serum PGE levels in this patient were measured in your laboratory. Would you care to comment on prostaglandins in hypercalcemia before you discuss serum gastrin measurements and the diagnosis of the Zollinger-Ellison syndrome, which was another clinical problem in this patient? Dr. Bernard Jaffe: To extend the observations that Dr. Kipnis has described, a number of investigators besides Dr. Oates and his group have screened large numbers of patients with hypercalcemia associated with malignancy. Although the Oates group believes very strongly that their gas chromatographic-mass spectroscopic data measuring urinary excretion of prostaglandin metabolites is better than any other diagnostic test, the general experience has been that measurement of circulating concentrations of native prostaglandins has been as good or almost as good a diagnostic technic. At a recent prostaglandin meeting, a poll was taken in an attempt to establish the frequency of prostaglan-

PANCREATIC

TABLE I

ISLET CELL CARCINOMA,

Interpretation of Levels of Gastrin

PEPTIC ULCER DISEASE AND HYPERCALCEMIA

-__--___

Normal

Mildly Elevated

Elevated

Controls Duodenal ulcer Postresection

Gastric ulcer Gastric carcinoma Primary hyperparathyroidism Postvagotomy Vitiligo

Obstructing duodenal ulcer Retained gastric antrum Secondary hyperparathyroidism Pheochromocytoma Atrophic gastritis and pernicious anemia Zollinger-Ellison syndrome

Rheumatoid arthritis

din-induced hypercalcemia. This poll involved investigators who measured both urinary metabolites and circulating prostaglandins. There was general agreement that approximately one third of the patients with hypercalcemia, neoplasia and normal serum PTH levels had hyperprostaglandinemia. Similarly, among hypercalcemic patients with malignancy, therapy with indomethacin lowered the serum calcium level in one third of the patients. Although indomethacin therapy was uniformly successful in lowering the serum calcium level in hyperprostaglandinemic hypercalcemic patients, the degree of success of indomethacin therapy depended upon the presence or absence of bone metastases. Among hyperprostaglandinemic hypercalcemic patients without bone metastases, indomethacin therapy normalized serum calcium within 48 hours. On the other hand, in similar patients who had bone metastases, indomethacin caused a significant fall in serum calcium levels but they did not reach the normal range. Now, let us direct our attention to gastrin. When measurements of gastrin first became available at Washington University eight years ago, the distinction between patients with the Zollinger-Ellison syndrome and those with the usual form of peptic ulcer disease seemed relatively simple. Patients with the ZollingerEllison syndrome had serum gastrin’ levels at least tenfold normal, or at least 1,000 pg/ml. With further experience, this differentiation has become less clear, and interpretation of the meaning of the gastrin levels has become more difficult. In most laboratories, including ours, the upper limit of normal for serum gastrin is 100 pg/ml and mean basal levels are approximately 40 pg/ml under normal circumstances. Patients with duodenal ulcer disease have normal fasting levels of serum gastrin. In contrast, patients with gastric ulcers and relative hypochlorhydria have somewhat elevated gastrin levels, presumably due to lack of inhibition of release of gastrin by gastric acid. In addition, patients with primary hyperparathyroidism have slightly elevated levels of serum gastrin. In our series, resection of the parathyroid glands with a resultant normalization of serum calcium has returned serum gastrin levels to normal. Finally, gastric carcinoma has been associated

with slightly elevated serum gastrin levels. As seen in Table I, significantly elevated gastrin levels have been described in patients with obstructing duodenal ulcer disease. Distention of the stomach results in accentuated release of gastrin, and this is readily reversible by nasogastric suction. If an elevated gastrin level in a patient with obstructing ulcer disease is difficult to interpret, this uncertainty can be clarified by remeasuring the levels of gastrin after three days of gastric decompression at which time the serum gastrin level should have returned to normal. Secondary hyperparathyroidism, particularly due to renal disease, has been shown to result in very elevated gastrin levels, frequently exceeding 1,000 pg/ml. Since a large amount of the gastrin circulating is of the “big” variety, the gastrin level following dialysis is usually unchanged. Hypergastrinemia in this instance is primarily due to failure of renal inactivation, but it is not related to abnormalities in the renal excretion of gastrin. Chronic atrophic gastritis with or without parietal cell antibodies has been associated with gastrin levels in the range of the Zollinger-Ellison syndrome, but since these patients are hypochlorhydric, they are easy to distinguish from patients with the Zollinger-Ellison syndrome. A number of much less common causes for hypergastrinemia have been reported, including pheochromocytoma, vitiligo, retained gastric antrum following gastric resection and rheumatoid arthritis [32]. The final and most important cause of hypergastrinemia is the ZollingerEllison syndrome. Considerable experience with measurement of serum gastrin in patients with the Zollinger-Ellison syndrome has demonstrated that approximately one third of patients with ulcerogenic tumors have gastrin levels of less than 500 pg/ml. In these patients, confirmation of the diagnosis of the Zollinger-Ellison syndrome requires a stimulation test. The tests suggested include calcium infusion and the secretin challenge. Calcium infusion is performed utilizing a dose of 4 mg calcium/kg/hour. Gastrin levels are measured at 30 minute intervals. In our experience, in conjunction with Drs. Way and Deveney in San Francisco and Jones in Durham, calcium infusion increased serum gastrin by more than 450 pg/ml in 22 of 24 patients with the Zol-

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TABLE II

Suggested Subdivision of the Zollinger-Ellison Syndrome Zollinger-Ellison

Feature

Absent

Antral G-cells

Hyperplastic Very high Short

Serum gastrin Clinical history

Type 2

Type 1

Tumor

Syndrome

Gastrinoma (pancreas or duodenum) or islet hyperplasia Normal High Long

linger-Ellison syndrome. In addition to two false-negative results, we noted intermediate responses in four patients with questionable Zollinger-Ellison syndrome. The secretin challenge is performed by administering an intravenous bolus of secretin, 2 U/kg. Normally, secretin causes either a decrease or a slight increase (less than 50 pg/ml) in serum gastrin. On the other hand, the secretin challenge has been diagnostic (an increase of more than 100 pg/ml) in all our patients with the Zollinger-Ellison syndrome, with no false-negative or false-positive reactions observed [ 331. Because of its better specificity, safety and rapidity (serum levels of gastrin are measured at 2, 5, 15 and 30 minutes), we advocate the use of the secretin challenge in confirming the diagnosis in patients suspected of having the Zollinger-Ellison syndrome. Finally, I think a word about antral G-cell hyperplasia is in order. Polak and her associates [34] suggested that antral G-cell hyperplasia was a variant of the Zollinger-Ellison syndrome. The differentiating points suggested are listed in Table II. According to the observations described by Straus and Yalow [35], antral G-cell hyperplasia can be diagnosed by the response to a high protein meal. An exaggerated response in serum gastrin to a meal challenge associated with negative secretin and calcium tests is said to be characteristic of antral Gcell hyperplasia. Theoretically, this syndrome should be curable by antrectomy alone. I want to emphasize that my view, and I think the majority view, is that antral G-cell hyperplasia is an extremely rare clinical entity and is, in fact, a variant of peptic ulcer disease rather than of the Zollinger-Ellison syndrome. Dr. Kipnis: Thank you very much. It is of interest that in the last year of her life this patient had normal serum gastrin levels despite recurrent episodes of hypercalcemia. This, again, suggests that something rather dramatic occurred subsequent to streptozotocin therapy. Dr. Presant, would you briefly review the current state of chemotherapy of patients with islet cell tumors? Dr. Cary Presant: One should first emphasize that the

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primary modality of treatment of patients with islet cell tumors, no matter what they secrete, is surgery. Surgery is the only curative therapy which exists. Once metastatic disease is present, symptoms may develop due either to secretion of substances, as have been discussed, or to tumor involvement itself. Palliative chemotherapy is required in these patients. Standard palliative therapy has been streptozotocin, an experimental drug available in most medical centers through the National Cancer Institute [ 121. Streptozotocin is a nitrosourea much like CCNU (CeeNU) which is now available as a standard chemotherapy agent. Streptozotocin differs from most other nitrosoureas in several points. First, streptozotocin has been found to produce permanent diabetes in laboratory animals. It was for that reason that streptozotocin was first used in patients with insulin-secreting islet cell carcinomas. Streptozotocin therapy produces a decrease in insulin secretion in 60 to 70 per cent of such patients. About 50 per cent of the patients have a decrease in measured tumor area after streptozotocin therapy. In 20 per cent of these patients, there is a complete disappearance of all tumor, in another 20 per cent there is a greater than 50 per cent decrease in measured tumor area and in the remainder there are lesser degrees of antitumor response. These responses last a median of about one year. Streptozotocin also differs from other nitrosoureas because it almost never produces myelosuppression. Rarely, a mild granulocytopenia is observed, but it is never dose-limiting. However, streptozotocin is markedly nephrotoxic. In 65 per cent of patients, some type of renal abnormality develops; and this, occasionally, is a fatal complication. In the patient discussed, it was a very difficult decision to give her streptozotocin initially and to continue streptozotocin in the face of impaired renal function. The initial type of renal toxicity which is usually produced is proteinuria. This can then be followed either by azotemia, which occurs in from 10 to 20 per cent of the patients, or by evidence of proximal tubular dysfunction such as a Fanconi syndrome or renal tubular acidosis, which also is seen in from 10 to 20 per cent of cases. After stopping therapy with the drug, renal toxicity in some patients is completely reversible, whereas in some patients there is a permanent decrease in renal function. Another hazard in streptozotocin therapy is that streptozotocin responses can be very rapid. Following rapid necrosis of tumor, one can have massive release of any of the secretory products which have been discussed. For example, in a patient who has an insulinsecreting tumor, marked hypoglycemia may develop within 3 hours of administration. Such reactions require prompt and persistent supportive care. In the patient being discussed a hypercalcemic response developed

PANCREATIC ISLET CELL CARCINOMA. PEPTIC ULCER DISEASE AND HYPERCALCEMIA

after the second dose during her second course of streptozotocin therapy, most likely due to release of a hypercalcemic substance from the tumor. All patients eventually become refractory to further steptozotocin therapy or experience toxicity which prevents further therapy. Some reports suggest that adriamycin or 5-fluorouracil may be effective in some of these patients. However, the patient discussed herein failed to respond to a combination of those two drugs given near the end of her course. Dr. Kipnis: It is of interest that between 1958 and 1968 this woman had a known carcinoma of the pancreatic islets which produced negligible clinical symptoms. From 1968 through mid-1974, she had recurrent peptic ulcer symptoms attributable to the hypersecretion of gastrin from her tumor. It was not until early 1974, 16 years after the initial diagnosis, that symptomatic and severe hypercalcemia developed. Was this simply a reflection of gradually increasing tumor mass or was there a mutational change in the tumor cells? Furthermore, after her first course of streptozotocin therapy her serum gastrin levels fell to normal and remained normal despite recurrent and, again, streptozotocinresponsive, hypercalcemia. Were there two populations of tumor cells, one totally obliterated by streptozotocin and the other only partially so, or was there a druginduced mutational change in the hormone secretory capacity of a homogeneous population of tumor cells? It would be of interest to study tumor cells from the original pancreatic biopsy specimen (1958) the biopsy specimen of the hepatic metastases (1968) and the postmortem specimen (1976) for hormone content and ultrastructural appearance. In summary, this patient had a metastatic islet cell carcinoma with peptic ulcer disease due to gastrin hypersecretion, and hypercalcemia due to secretion of an unidentified substance from her tumor. Both the hypergastrinemia and the hypercalcemia were controlled with streptozotocin therapy. She had chronic renal insufficiency, at least in part attributable to nephrocalcinosis, with a corresponding anemia. She had some further impairment of renal function associated with her second course of streptozotocin therapy but had a symptom-free interval thereafter. For unclear reasons, she remained anorectic after her third hypercalemic episode and became progressively debilitated. I suspect she died of pneumonia or pulmonary embolism. PATHOLOGIC DISCUSSION Dr. Richard Lynch: This patient had extensive metastatic calcification of the viscera, blood vessels and skin. The calcification was advanced and was readily apparent at the time of gross examination. There was signifimt calcification in the myocardium and focally

Figure 3. photomicrograph of liver showing smooth pushing margin of metastatic is/et cell carcinoma (right half of photo) separated from hepatic parenchyma (left) by a fibrous capsule. Masson stain; original magnification X 250, reduced by 29 per cent.

in the connective tissue adjacent to the atrioventricular node. The most severely involved organs were the lungs in which calcification of the vasculature and the alveolar walls was marked. Active bone resorption and the changes of osteitis fibrosa were seen in the samples of vertebrae examined. There were two occult lesions for which there were no clinical correlates: left renal thrombosis and acute pancreatitis with fat necrosis. The malignant islet cell tumor was confined to the liver in which it occurred as multiple nodules, some of which were extensively calcified. The slow growth of this neoplasm was reflected by the presence of a smooth pushing margin and a prominent connective tissue capsule (Figure 3). The neoplastic cells were well-differentiated, and mitotic figures were absent. As is often the case with endocrine neoplasms, the morphologic features are not as reliable prognosticators of the degree of malignancy as is the case with most nonendocrine neoplasms. At this point I would like to stop and have Dr. Greider present the results of the special studies that she conducted on this patient’s tumor. Dr. Marie Greider: The histologic pattern of the tumor was typical of a pancreatic ulcerogenic tumor of the Zollinger-Ellison syndrome. The tumor did not contain alpha, beta or delta cells as determined by specific tinctorial stains. There are no specific tinctorial stains for gastrin cells. We stained cryostat sections of fresh-frozen tissue and formalin-fixed, paraffin-embedded sections for gastrin by the direct and indirect immunofluorescent staining technics. We used antibodies to human synthetic gastrin prepared by Dr. McGuigan. The tumor cells did not stain by either of

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Figure 4. Electron micrograph of part of a tumor cell that contains numerous secretory granules in a diameter range of 150 to 200 nm. An edge of the nucleus is in the upper right corner. Magnification X 24,000.

these methods although a small population of islet cells in cryostat sections of human autopsy pancreas did stain. The negative staining reaction of the tumor is not unusual. We have observed a positive reaction in only one of four tumors previously studied by these methods. We do have some interesting results with our electron microscopic studies. The granules in ZollingerEllison tumors are different from alpha, beta and delta

cell granules. They are smaller, do not have a crystalline pattern as do beta granules, do not have a halo area around a very dense core as do alpha granules and are denser than delta granules. Figure 4 illustrates the tumor cells of this patient. The specific granules were very numerous in most cells and were of the size that we normally see in Zollinger-Ellison tumors. The other cytologic features also indicate that this was an endocrine tumor. Dr. Lynch: I would like to comment further about the point Dr. Kipnis raised regarding a change in the phenotype of this patient’s neoplasm. A similar phenomenon occurs in some patients with immunoglobulinproducing tumors. On the basis of a structural analysis of the immunoglobuliris, it is clear that some examples of myeloma with two paraproteins reflect neoplastic growth of two different, unrelated clones of B cells, whereas some cases are examples of a monoclonal neoplasm in which cells of a single clone are producing different immunoglobulins. At least in myeloma, then, the two possible models suggested by Dr. Kipnis have both been confirmed. Final diagnoses: Malignant islet cell tumor of the pancreas, metastatic to the liver; metastatic calcification in the liver, heart, lungs, kidney, stomach, adrenals, thyroid, breast, pituitary, blood vessels, basal ganglia, and skin; osteitis fibrosa; fracture 10th rib, recent; acute and chronic pyelonephritis, focal: aspiration pneumonia, left lower lobe; nephrosclerosis, moderate; thrombosus and subtotal occlusion of left renal vein, old; acute pancreatitis with fat necrosis, focal; superficial colitis consistent with chemotherapy effect: double collecting system, right kidney; atherosclerosis, mild; cholelithiasis; fibrocystic disease of the breast. EDITORS’ NOTE: The initial portion of this patient’s course has been reported [ 151.

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