- Email: [email protected]
Retroperitoneal Lipoma
RETROPERITONEAL LIPOMA RICHARD B. CATTELL AND KENNETH W. WARREN RETROPERITONEAL tumors, by virtue of their size, location and extent, frequently present confounding diagnostic possibilities and difficult surgical problems. It is not surprising, therefore, that these tumors frequently are approached with less aggressiveness than their true nature warrants. It is particularly true that retroperitoneal tumors of fatty origin are amenable to surgical treatment despite their remarkable size, their intimate visceral relationships and their malignant characteristics. These tumors tend to grow rapidly, to attain tremendous size, to become malignant and to recur locally following surgical excision. It has long seemed a physiologic paradox that these enormous fat stores could accumulate simultaneously with systemic wasting and progres~ sive cachexia. Some general characteristics of these tumors are demonstrated by a review of the following case records. of the Lahey Clinic. REPORT OF CASES I.-A woman, 55 years of age, was seen in the clinic in September, 1936, complaining of paroxysmal and exertional dyspnea, cough, swelling of the ankles and precordial distress. Examination revealed the patient to be obese, with auricular fibFillation and moderate hypertension. A smooth, round mass, approximately 10 cm. in diameter, was palpable in the right lower quadrant of the abdomen. A preoperative diagnosis was made of a mesenteric cyst. At operation, a large soft mass was found in the retroperitoneal space, pushing the cecum upward and medially. It was excised without difficulty. Microscopic analysis revealed a simple lipoma. Recovery was uneventful and there was no recurrence in eighteen months. CASE
CASE 2.-A woman, 61 years of age, first came to the clinic April 1, 1940. She had experienced epigastric distress and bloating of two years' duration. For several years before the onset of these symptoms she had been conscious of a gradual increase in abdominal girth. In May 1939, exploratory laparotomy had been performed elsewhere under a presumptive diagnosis of ovarian cyst. Abdominal exploration at that time revealed the presence of a massive retroperitoneal tumor, which was not removed because of its extensiveness. A biopsy showed the tumor to be a lipoma. Examination revealed the patient to be well developed, with a tremendous symmetrical enlargement of the abdomen. The tumor appeared to be fixed. On April 3, 1940, a retroperitoneal lipoma weighing 28 pounds was removed. On the first postoperative day the patient had a sudden, severe pain in the left chest which persisted for several minutes. A pulmonary infarct was suspected,
659
660
RICHARD B. CATTELL, KENNETH W. WARREN
and heparin was administered. The pain did not recur and recovery was not delayed. Microscopic diagnosis was lipoma. The patient was discharged from the hospital April 24, 1940, and when seen one year later she was well and free of obvious recurrence, although she had gained 30 pounds. She was next seen in the clinic on October 30, 1945, complaining of swelling of the abdomen and pressure distress in the upper part of the abdomen of seven months' duration. In addition, she had daily swelling of the ankles, particularly on the right side. Examination showed a massive, symmetrical swelling of the abdomen which appeared to be filled by a' soft solid mass. On December 3, 1945, a recurrent tumor, weighing 38% pounds, was removed from the retroperitoneal space. It was necessary to sacrifice the right kidney in order to remove the tumor. Convalescence was uneventful except for some abdominal cramps and diarrhea which appeared on the fourteenth day following operation. These symptoms subsided and the patient was discharged from the hospital December 28, 1945. The microscopic diagnosis was liposarcoma. The patient was last seen on November 15, 1946, at which time there wa~ no evidence of recurrence. Her general health was good. CASE 3.-A woman, 39 years of age, was seen in the clinic July 23, 1940. complaining of an abdominal tumor of eleven months' duration. The patient had experienced frequent backaches siRce the onset of the progressive abdominal swelliFlg. In May 1940, an abdominal exploratory operation had been performed elsewher~ with a preoperative diagnosis of ovarian cyst. No ovarian tumor was found, and it was concluded that the retroperitoneal growth was a cyst of the left kidney. Two weeks later the left kidney was explored; a large lipoma was found and a specimen taken but the tumor was not removed. The tumor continued to grow and the backaches became more severe. The patient lost 8 pounds prior to her initial visit to the clinic. Examination showed the patient to be thin and pale, with a large abdomen. A large mass filled most of the abdomen and extended into the pelvis. The tumor was nodular and filled the left flank. On August 13, 1940, the abdomen was explored and a massive retroperitoneal tumor was observed pushing the small intestine and ascending colon to the right. The transverse and descending colon ran along the left lateral border of the tumor. The growth was attached to the left kidney which was deliberately removed. The removed specimen, which was a lipoma of primitive cell type. weighed 20 pounds. Recovery was without incident. In October 1942, the patient returned because of an abdominal mass, which upon examination proved to be a fibroid uterus. Hysterectomy was performed October 15, 1942. There was no evidence of recurrence of the lipoma at that time. On September 22, 1944, radical mastectomy was done for carcinoma of the breast. Recent examination showed no signs of recurrence of either growth. CASE 4.-A woman, aged 64, was observed at the clinic April 12, 1945, complaining of flatulence, poor appetite and swelling of the ankles of five months' duration. The present illness had begun with nausea, vomiting and diarrhea, but these symptoms had been transient and had not recurred during the progression of the disease. The patient was a known diabetic under adequate insulin control.
RETROPERITONEAL LIPOMA
661
Physical examination revealed that the patient was well nourished. The veins were moderately distended over the abdominal wall. There was a large mass in the mid-abdomen extending into the left flank. Intravenous pyelograms demonstrated displacement of the left kidney upward and outward. The left ureter was not visualized. The preoperative diagnosis was a tumor of the left kidney. At operation, April 23, 1945, a large retroperitoneal tumor extending from the pelvis to the spleen was excised. The descending colon and sigmoid ran over the growth. The left ureter traversed the mass and was sacrificed, necessitating removal of the left kidney. Pathologic examination revealed a liposarcoma with a focus of bone formation. On the seventh postoperative day the patient had an insulin reaction, followed by left hemiplegia and coma. Death ensued four days later. Autopsy showed a gangrenous segment of small bowel secondary to a constricting band. Fragments of the liposarcoma remained in the retroperitoneal space. CASE 5.-A man, 64 years of age, was observed in the clinic on February 8, 1946, complaining of a lump in the right side of the scrotum of one year's duration. The mass first appeared in the right groin from whence it gradually grew into the right side of the scrotum. There were no attendant symptoms. Examination revealed a firm mass extending from the right inguinal ligament to the umbilicus. It appeared to be continuous with a similar mass in the scrotum. The testis was palpable but was connected with the growth. A clinical diagnosis was made of a fibrosarcoma of the right groin. On March 1, 1946, a preperitoneal lipomyxosarcoma weighing 950 gm. was excised, along with the right testis. The postoperative course was devoid of incidsnt and he was discharged from the hospital on March 17, 1946. He was seen on October 23, 1946, at which time he was free of obvious recurrence.
COMMENT
Physical and chemical analyses have failed to reveal differences in lipomatous and normal tissue fat which might account for the apparent unavailability of tumor fat for nutritional purposes. Hirsch and Wells reported the results of extensive chemical analyses of a huge retroperitoneal liposar-coma. They found that the tumor did not contain as much fat as the gross specimen suggested. Nevertheless, there was a significant amount of fat in a tumor of a patient showing extreme emaciation. Ewing assumes that "local conditions, possibly the character of the circulation, prevent the absorption of the lipoma in these instances." Lipomas are more common in the female, and are observed most frequently in patients between the ages of 40 and 60 years. They grow slowly and commonly attain considerable size before their presence is detected by the host. Even then, the symptoms are usually minimal and are related to mechanical inconvenience. The largest tumor on record, weighing 69 pounds, was reported by Hirsch and Wells, and it was not removed surgically. McConnell excised a retroperitoneal lipoma which weighed 65
662
RICHARD B. CArrELL, KENNETH W. WARREN
pounds. The tumor recurred six and one half years later, and the recurrent growth, weighing 27 pounds, was removed. Mayo and Dixon reported three cases in 1927, in which the tumors weighed 17.5, 18.5 and 3.5 pounds, respectively. McLaughlin and Sharpe reported 2 cases, one of which exhibited a tumor at autopsy, weighing 56 pounds. These growths arise most frequently in the paravertebral or perirenal fat, but they may occur at any point in the abdomen or pelvis. They may originate in the thigh and gain access to the retroperitoneal space through the femoral or obdurator canal. Not infrequently, they invade t'he mesentery of the ileum and surround the kidney. These tumors show a marked tendency toward malignant degeneration, and recur not infrequently in sarcomatous form even though the original tumor was apparently benign. It should be remembered in this regard that many of these tumors are extremely large and that failure to detect malignant areas may result from faulty sampling of the removed specimen. A rapid alteration in the progression of these tumors is highly suggestive of malignant disease and is usually accompanied by myxomatous degeneration. Hertzler concluded that "retroperitoneal lipomata represent a very embryonal type of tissue, and that rapid growth, myxoid and sarcomatous admixture are but manifestations of a primary impulse." The tumors exhibit, in their malignant states, a variety of histologic types, including lipomyxosarcoma, lipofibrosarcoma and true liposarcoma. One tumor observed at the clinic showed an area of bone formation which, according to Ewing, probably results from an area of necrosis followed by calcification and ossification. Perirenal lipomas, which account for a considerable portion of all retroperitoneal tumors of fatty origin, according to Hunt and Simon, may arise from the renal capsule or perirenal tissue. Some are multilobular, others cystic and many contain areas of sarcomatous degeneration. They may encompass the kidney and compress its blood supply to cause atrophy. Histologically, they are essentially connective tissue tumors, containing varying degrees of fat and fibrous connective elements, tending to malignant degeneration, and to recurrence following surgical removal. The malignant tumors are particularly resistant to radiation. SYMPTOMS
The symptoms, although variable, are generally meager and include swelling of the abdomen and the presence of an abdominal mass. Not infrequently, the growth reaches a considerable size without knowledge of the host. Vague pressure manifestations and mild gastrointestinal disorders are common in those instances in which the tumor is of sufficient size to compress or displace adjacent viscera. Severe symptoms are rare and include dyspnea, ascites, edema and persistent
RETROPERITONEAL LIPOMA
663
nausea and vomiting. Pfeiffer and Gandin reported a case in which marked compression of the vena cava was observed. With the advent of malignant degeneration, fatigue, loss of weight, anorexia and wasting occur. Urinary symptoms are rare, but may result from ureteral obstruction because of pressure. Acute symptoms such as severe pain, fever, tenderness, nausea and vomiting are rare and indicate a focus of degeneration or the mechanical embarrassment of adjacent abdominal viscera. In the series from the clinic, the symptoms of abdominal pain, flatulence, anorexia and edema of the ankles were those most commonly observed. Only 3 patients complained of abdominal tumor, and one had backache. DIAGNOSIS
The clinical recognition of these tumors is not easy but their presence should be suspected in an adult, particularly a woman, who gives a story of vague abdominal pressure, associated with a slow-growing abdominal mass of considerable size in whom visceral disease is evidently absent. The tumor is of soft-solid consistency, relatively fixed and tends to fill the abdominal cavity. The roentgenographic demonstration of an elevated diaphragm and the pyelographic delineation of a displaced kidney are valuable corroborative evidences of retroperitoneal tumors. Roentgenologic studies after a barium enema may show the bowel to be displaced anteriorly and medially. Differential diagnosis must comprehend ovarian cyst, pancreatic andni.esenteric :·cysts, retroperitoneal and intra-abdominal malignant disease, ascites, cirrhosis, splenomegaly and pregnancy. The specific elimination of these possibilities suggests strongly the presence of a retroperitoneal tumor. TREATMENT Most retroperitoneal lipomas are amenable to surgery, and every effort s·hould be made to excise the growth completely. They are thinly encapsulated and it is often necessary to remove them piecemeal. They frequently encircle the kidney and occasionally invade its parenchyma, necessitating nephrectomy. Exquisite care to avoid injury to the great vessels and retroperitoneal viscera should be exercised in every instance. The transperitoneal approach through a generous incision, with the patient under spinal anesthesia, affords the safest access to these tumors. The lumbar approach does not permit sufficient exposure of the mesentery of the bowel and the retroperitoneal structures. A transverse abdominal incision would be satisfactory. The hazards of surgical excision are considerable and the mortality varies from 20 to 25 per cent. This mortality relates to the enormous size of the tumorl', their intimacy with the great vessels and retroperitoneal viscera, and results primarily from hemorrhage and
664
RICHARD B. CATTELL, KENNETH W. WARREN
shock. Delayed postoperative complications, which contribute materially to the high mortality, include ileus, peritonitis, gangrene of the bowel, pneumonia and pulmonary embolism. Consequently, energetic measures directed toward the prevention of these complications must be pursued in every instance. PROGNOSIS
Without treatment, the growth of these tumors leads slowly to death. Following excision, recurrence is common and malignant degeneration is frequent, but it is possible in many instances to excise the recurrent growth and extend life significantly. The effectiveness of irradiation is doubtful. Stewart and Selman believe it is beneficial while Rheback and Houser, Barnard, and McLaughlin and Sharpe believe that it is of little value. The surgical excision of recurrent tumors is usually justifiable because of the slowgro",ing nature of the lesion. Irradiation may be employed in those cases proven inoperable by thorough exploratory operation. In this series of 5 patients who were subjected to six operations for retroperitoneal lipomas, there was one death. This patient, a diabetic, had an insulin reaction on the seventh postoperative day and died four days later from mesenteric thrombosis and paraplegia. Of the 4 survivors, one whose original tumor weighed 28Y2 pounds had a recurrence five years later. The recurrent tumor, a lipomyxosarcoma weighing 38Y2 pounds, was removed successfully, but with the sacrifice of the right kidney. The patient had no evidence of recurrence at the end of one year. Another individual survived an excision of a primitive-cell type of lipoma which weighed 20 pounds. Two years later she submitted to hysterectomy and four years following the original operation she had a radical mastectomy for carcinoma. She is well at present. . The 2 remaining survivors were well and free from recurrence eighteen months following operation. One of these individuals had a malignant tumor. SUMMARY AND CONCLUSIONS
Retroperitoneal lipomas may attain enormous size attended by meager symptoms. They are prone to malignant degeneration and are given to local recurrence following surgical excision. Despite these characteristics these tumors warrant vigorous surgical attack. <
REFERENCES 1. Barnard, L.: Primary liposarcoma of bone. Arch. Surg., 29:560-565 (Oct.) 1934. 2. Ewing, J.: Neoplastic Diseases. Ed. 3, Philadelphia, W. B. Saunders Co., 1934.
RETROPERITONEAL LIPOMA
665
3. Hertzler, A. E.: Clinical surgery by case histories. St. Louis, C. V. Mosby Co., 1920, 1130 pp. 4. Hirsch, E. F. and Wells, H. L.: Retroperitoneal liposarcoma. Am. J. M. Sc., 159:356 (Mar. 20) 1920. 5. Hunt, V. C. and Simon, H. E.: Perirenal and intrarenallipoma. Am. J. Surg., 4:390-395 (Apr.) 1928. 6. Mayo, C. H. and Dixon, C. F.: Retroperitoneal lipoma. Minnesota Med., 10:272-276 (May 27) 1927. 7. McConnell, G.: Recurrent liposarcoma of the kidney. J. M. Research, 19. . 225-235, 1908. 8. McLaughlin, C. W., Jr. and Sharpe, J. C.: Malignant fatty tumors of retro peritoneal region. Am. J. Surg., 41:512-518 (Sept.) 1938. 9. Pfeiffer, G. E. and Gandin, M. M.: Massive perirenal lipoma. J. Urol., 56:1227 (July) 1946. ' 10. Rehbock, D. J. and Hauser, H.: Liposarcoma of bone. Am. J. Cancer, 27:3744 (May) 1931. 11. Selman, W. A.: Report of a case of lipomyxosarcoma. Internat. Clin., 1:136, 1941. l2. Stewart, F. W.: Primary liposarcoma of bone. Am. J. Path., 7:87-94 (Mar.) 1931.
CASE 2.-A woman, 61 years of age, first came to the clinic April 1, 1940. She had experienced epigastric distress and bloating of two years' duration. For several years before the onset of these symptoms she had been conscious of a gradual increase in abdominal girth. In May 1939, exploratory laparotomy had been performed elsewhere under a presumptive diagnosis of ovarian cyst. Abdominal exploration at that time revealed the presence of a massive retroperitoneal tumor, which was not removed because of its extensiveness. A biopsy showed the tumor to be a lipoma. Examination revealed the patient to be well developed, with a tremendous symmetrical enlargement of the abdomen. The tumor appeared to be fixed. On April 3, 1940, a retroperitoneal lipoma weighing 28 pounds was removed. On the first postoperative day the patient had a sudden, severe pain in the left chest which persisted for several minutes. A pulmonary infarct was suspected,
659
660
RICHARD B. CATTELL, KENNETH W. WARREN
and heparin was administered. The pain did not recur and recovery was not delayed. Microscopic diagnosis was lipoma. The patient was discharged from the hospital April 24, 1940, and when seen one year later she was well and free of obvious recurrence, although she had gained 30 pounds. She was next seen in the clinic on October 30, 1945, complaining of swelling of the abdomen and pressure distress in the upper part of the abdomen of seven months' duration. In addition, she had daily swelling of the ankles, particularly on the right side. Examination showed a massive, symmetrical swelling of the abdomen which appeared to be filled by a' soft solid mass. On December 3, 1945, a recurrent tumor, weighing 38% pounds, was removed from the retroperitoneal space. It was necessary to sacrifice the right kidney in order to remove the tumor. Convalescence was uneventful except for some abdominal cramps and diarrhea which appeared on the fourteenth day following operation. These symptoms subsided and the patient was discharged from the hospital December 28, 1945. The microscopic diagnosis was liposarcoma. The patient was last seen on November 15, 1946, at which time there wa~ no evidence of recurrence. Her general health was good. CASE 3.-A woman, 39 years of age, was seen in the clinic July 23, 1940. complaining of an abdominal tumor of eleven months' duration. The patient had experienced frequent backaches siRce the onset of the progressive abdominal swelliFlg. In May 1940, an abdominal exploratory operation had been performed elsewher~ with a preoperative diagnosis of ovarian cyst. No ovarian tumor was found, and it was concluded that the retroperitoneal growth was a cyst of the left kidney. Two weeks later the left kidney was explored; a large lipoma was found and a specimen taken but the tumor was not removed. The tumor continued to grow and the backaches became more severe. The patient lost 8 pounds prior to her initial visit to the clinic. Examination showed the patient to be thin and pale, with a large abdomen. A large mass filled most of the abdomen and extended into the pelvis. The tumor was nodular and filled the left flank. On August 13, 1940, the abdomen was explored and a massive retroperitoneal tumor was observed pushing the small intestine and ascending colon to the right. The transverse and descending colon ran along the left lateral border of the tumor. The growth was attached to the left kidney which was deliberately removed. The removed specimen, which was a lipoma of primitive cell type. weighed 20 pounds. Recovery was without incident. In October 1942, the patient returned because of an abdominal mass, which upon examination proved to be a fibroid uterus. Hysterectomy was performed October 15, 1942. There was no evidence of recurrence of the lipoma at that time. On September 22, 1944, radical mastectomy was done for carcinoma of the breast. Recent examination showed no signs of recurrence of either growth. CASE 4.-A woman, aged 64, was observed at the clinic April 12, 1945, complaining of flatulence, poor appetite and swelling of the ankles of five months' duration. The present illness had begun with nausea, vomiting and diarrhea, but these symptoms had been transient and had not recurred during the progression of the disease. The patient was a known diabetic under adequate insulin control.
RETROPERITONEAL LIPOMA
661
Physical examination revealed that the patient was well nourished. The veins were moderately distended over the abdominal wall. There was a large mass in the mid-abdomen extending into the left flank. Intravenous pyelograms demonstrated displacement of the left kidney upward and outward. The left ureter was not visualized. The preoperative diagnosis was a tumor of the left kidney. At operation, April 23, 1945, a large retroperitoneal tumor extending from the pelvis to the spleen was excised. The descending colon and sigmoid ran over the growth. The left ureter traversed the mass and was sacrificed, necessitating removal of the left kidney. Pathologic examination revealed a liposarcoma with a focus of bone formation. On the seventh postoperative day the patient had an insulin reaction, followed by left hemiplegia and coma. Death ensued four days later. Autopsy showed a gangrenous segment of small bowel secondary to a constricting band. Fragments of the liposarcoma remained in the retroperitoneal space. CASE 5.-A man, 64 years of age, was observed in the clinic on February 8, 1946, complaining of a lump in the right side of the scrotum of one year's duration. The mass first appeared in the right groin from whence it gradually grew into the right side of the scrotum. There were no attendant symptoms. Examination revealed a firm mass extending from the right inguinal ligament to the umbilicus. It appeared to be continuous with a similar mass in the scrotum. The testis was palpable but was connected with the growth. A clinical diagnosis was made of a fibrosarcoma of the right groin. On March 1, 1946, a preperitoneal lipomyxosarcoma weighing 950 gm. was excised, along with the right testis. The postoperative course was devoid of incidsnt and he was discharged from the hospital on March 17, 1946. He was seen on October 23, 1946, at which time he was free of obvious recurrence.
COMMENT
Physical and chemical analyses have failed to reveal differences in lipomatous and normal tissue fat which might account for the apparent unavailability of tumor fat for nutritional purposes. Hirsch and Wells reported the results of extensive chemical analyses of a huge retroperitoneal liposar-coma. They found that the tumor did not contain as much fat as the gross specimen suggested. Nevertheless, there was a significant amount of fat in a tumor of a patient showing extreme emaciation. Ewing assumes that "local conditions, possibly the character of the circulation, prevent the absorption of the lipoma in these instances." Lipomas are more common in the female, and are observed most frequently in patients between the ages of 40 and 60 years. They grow slowly and commonly attain considerable size before their presence is detected by the host. Even then, the symptoms are usually minimal and are related to mechanical inconvenience. The largest tumor on record, weighing 69 pounds, was reported by Hirsch and Wells, and it was not removed surgically. McConnell excised a retroperitoneal lipoma which weighed 65
662
RICHARD B. CArrELL, KENNETH W. WARREN
pounds. The tumor recurred six and one half years later, and the recurrent growth, weighing 27 pounds, was removed. Mayo and Dixon reported three cases in 1927, in which the tumors weighed 17.5, 18.5 and 3.5 pounds, respectively. McLaughlin and Sharpe reported 2 cases, one of which exhibited a tumor at autopsy, weighing 56 pounds. These growths arise most frequently in the paravertebral or perirenal fat, but they may occur at any point in the abdomen or pelvis. They may originate in the thigh and gain access to the retroperitoneal space through the femoral or obdurator canal. Not infrequently, they invade t'he mesentery of the ileum and surround the kidney. These tumors show a marked tendency toward malignant degeneration, and recur not infrequently in sarcomatous form even though the original tumor was apparently benign. It should be remembered in this regard that many of these tumors are extremely large and that failure to detect malignant areas may result from faulty sampling of the removed specimen. A rapid alteration in the progression of these tumors is highly suggestive of malignant disease and is usually accompanied by myxomatous degeneration. Hertzler concluded that "retroperitoneal lipomata represent a very embryonal type of tissue, and that rapid growth, myxoid and sarcomatous admixture are but manifestations of a primary impulse." The tumors exhibit, in their malignant states, a variety of histologic types, including lipomyxosarcoma, lipofibrosarcoma and true liposarcoma. One tumor observed at the clinic showed an area of bone formation which, according to Ewing, probably results from an area of necrosis followed by calcification and ossification. Perirenal lipomas, which account for a considerable portion of all retroperitoneal tumors of fatty origin, according to Hunt and Simon, may arise from the renal capsule or perirenal tissue. Some are multilobular, others cystic and many contain areas of sarcomatous degeneration. They may encompass the kidney and compress its blood supply to cause atrophy. Histologically, they are essentially connective tissue tumors, containing varying degrees of fat and fibrous connective elements, tending to malignant degeneration, and to recurrence following surgical removal. The malignant tumors are particularly resistant to radiation. SYMPTOMS
The symptoms, although variable, are generally meager and include swelling of the abdomen and the presence of an abdominal mass. Not infrequently, the growth reaches a considerable size without knowledge of the host. Vague pressure manifestations and mild gastrointestinal disorders are common in those instances in which the tumor is of sufficient size to compress or displace adjacent viscera. Severe symptoms are rare and include dyspnea, ascites, edema and persistent
RETROPERITONEAL LIPOMA
663
nausea and vomiting. Pfeiffer and Gandin reported a case in which marked compression of the vena cava was observed. With the advent of malignant degeneration, fatigue, loss of weight, anorexia and wasting occur. Urinary symptoms are rare, but may result from ureteral obstruction because of pressure. Acute symptoms such as severe pain, fever, tenderness, nausea and vomiting are rare and indicate a focus of degeneration or the mechanical embarrassment of adjacent abdominal viscera. In the series from the clinic, the symptoms of abdominal pain, flatulence, anorexia and edema of the ankles were those most commonly observed. Only 3 patients complained of abdominal tumor, and one had backache. DIAGNOSIS
The clinical recognition of these tumors is not easy but their presence should be suspected in an adult, particularly a woman, who gives a story of vague abdominal pressure, associated with a slow-growing abdominal mass of considerable size in whom visceral disease is evidently absent. The tumor is of soft-solid consistency, relatively fixed and tends to fill the abdominal cavity. The roentgenographic demonstration of an elevated diaphragm and the pyelographic delineation of a displaced kidney are valuable corroborative evidences of retroperitoneal tumors. Roentgenologic studies after a barium enema may show the bowel to be displaced anteriorly and medially. Differential diagnosis must comprehend ovarian cyst, pancreatic andni.esenteric :·cysts, retroperitoneal and intra-abdominal malignant disease, ascites, cirrhosis, splenomegaly and pregnancy. The specific elimination of these possibilities suggests strongly the presence of a retroperitoneal tumor. TREATMENT Most retroperitoneal lipomas are amenable to surgery, and every effort s·hould be made to excise the growth completely. They are thinly encapsulated and it is often necessary to remove them piecemeal. They frequently encircle the kidney and occasionally invade its parenchyma, necessitating nephrectomy. Exquisite care to avoid injury to the great vessels and retroperitoneal viscera should be exercised in every instance. The transperitoneal approach through a generous incision, with the patient under spinal anesthesia, affords the safest access to these tumors. The lumbar approach does not permit sufficient exposure of the mesentery of the bowel and the retroperitoneal structures. A transverse abdominal incision would be satisfactory. The hazards of surgical excision are considerable and the mortality varies from 20 to 25 per cent. This mortality relates to the enormous size of the tumorl', their intimacy with the great vessels and retroperitoneal viscera, and results primarily from hemorrhage and
664
RICHARD B. CATTELL, KENNETH W. WARREN
shock. Delayed postoperative complications, which contribute materially to the high mortality, include ileus, peritonitis, gangrene of the bowel, pneumonia and pulmonary embolism. Consequently, energetic measures directed toward the prevention of these complications must be pursued in every instance. PROGNOSIS
Without treatment, the growth of these tumors leads slowly to death. Following excision, recurrence is common and malignant degeneration is frequent, but it is possible in many instances to excise the recurrent growth and extend life significantly. The effectiveness of irradiation is doubtful. Stewart and Selman believe it is beneficial while Rheback and Houser, Barnard, and McLaughlin and Sharpe believe that it is of little value. The surgical excision of recurrent tumors is usually justifiable because of the slowgro",ing nature of the lesion. Irradiation may be employed in those cases proven inoperable by thorough exploratory operation. In this series of 5 patients who were subjected to six operations for retroperitoneal lipomas, there was one death. This patient, a diabetic, had an insulin reaction on the seventh postoperative day and died four days later from mesenteric thrombosis and paraplegia. Of the 4 survivors, one whose original tumor weighed 28Y2 pounds had a recurrence five years later. The recurrent tumor, a lipomyxosarcoma weighing 38Y2 pounds, was removed successfully, but with the sacrifice of the right kidney. The patient had no evidence of recurrence at the end of one year. Another individual survived an excision of a primitive-cell type of lipoma which weighed 20 pounds. Two years later she submitted to hysterectomy and four years following the original operation she had a radical mastectomy for carcinoma. She is well at present. . The 2 remaining survivors were well and free from recurrence eighteen months following operation. One of these individuals had a malignant tumor. SUMMARY AND CONCLUSIONS
Retroperitoneal lipomas may attain enormous size attended by meager symptoms. They are prone to malignant degeneration and are given to local recurrence following surgical excision. Despite these characteristics these tumors warrant vigorous surgical attack. <
REFERENCES 1. Barnard, L.: Primary liposarcoma of bone. Arch. Surg., 29:560-565 (Oct.) 1934. 2. Ewing, J.: Neoplastic Diseases. Ed. 3, Philadelphia, W. B. Saunders Co., 1934.
RETROPERITONEAL LIPOMA
665
3. Hertzler, A. E.: Clinical surgery by case histories. St. Louis, C. V. Mosby Co., 1920, 1130 pp. 4. Hirsch, E. F. and Wells, H. L.: Retroperitoneal liposarcoma. Am. J. M. Sc., 159:356 (Mar. 20) 1920. 5. Hunt, V. C. and Simon, H. E.: Perirenal and intrarenallipoma. Am. J. Surg., 4:390-395 (Apr.) 1928. 6. Mayo, C. H. and Dixon, C. F.: Retroperitoneal lipoma. Minnesota Med., 10:272-276 (May 27) 1927. 7. McConnell, G.: Recurrent liposarcoma of the kidney. J. M. Research, 19. . 225-235, 1908. 8. McLaughlin, C. W., Jr. and Sharpe, J. C.: Malignant fatty tumors of retro peritoneal region. Am. J. Surg., 41:512-518 (Sept.) 1938. 9. Pfeiffer, G. E. and Gandin, M. M.: Massive perirenal lipoma. J. Urol., 56:1227 (July) 1946. ' 10. Rehbock, D. J. and Hauser, H.: Liposarcoma of bone. Am. J. Cancer, 27:3744 (May) 1931. 11. Selman, W. A.: Report of a case of lipomyxosarcoma. Internat. Clin., 1:136, 1941. l2. Stewart, F. W.: Primary liposarcoma of bone. Am. J. Path., 7:87-94 (Mar.) 1931.