ANATOMIC PATHOLOGY Single Case Report
A Rare Lymphoepithelial Cyst of the Pancreas MICHAEL P. DiCORATO, M.D., AND ALAN R. SCHNED, M.D.
and the primary importance of its recognition is in the distinction from cystic malignant neoplasms. (Key words: Lymphoepithelial cyst; Pancreas; Pseudocysts; Epithelial inclusion cyst) Am J Clin Pathol 1992; 98:188-191
Most cystic lesions of the pancreas can be classified into the two categories of pseudocysts and cystic neoplasms.1,2 Among the neoplasms are mucinous and serous cystadenomas and cystadenocarcinomas. The pseudocysts generally develop as a result of ductal obstruction secondary to cancer, stones, inflammation, or parasites. Far rarer are various congenital cysts, including dermoid cysts, enterogenous cysts, and the cysts associated with the polycystic syndromes and cystic fibrosis.1'3 We report a lymphoepithelial cyst (LEC) of the pancreas that, by virtue of its keratinaceous contents, resembles a dermoid cyst but is distinguished by a prominent lymphoid component. To our knowledge, this report represents only the fourth case of LEC described in the literature, and only the third in the English language.4"6 Our case is unique in that it was situated entirely within the pancreatic parenchyma.
provement in platelet count. His past medical history indicated no alcoholism, gallbladder disease, or previous pancreatitis. In January 1989, as part of a workup for recurrent thrombocytopenia, a computerized axial tomography scan showed a 3-cm mass in the tail of the pancreas, in addition to two small accessory spleens. Radiographic studies showed that the lesion was a spherical low attenuation mass with an enhancing rim, and thus was considered to be of cystic density (Fig. 1). Two subsequent computed axial tomography scans in June and August demonstrated no interval change in the size of the mass; however, it was thought that these studies could not distinguish pseudocyst from cystic neoplasm. Physical examination showed that the liver span was 12 cm. No masses were palpated in the liver or pancreas, and the abdomen was not tender. Serum amylase and liver function studies were unremarkable. At laparotomy, a smooth, encapsulated, well-circumscribed mass was found completely within the tail of the pancreas. Surrounding pancreatic tissue was compressed but did not appear to be infiltrated by tumor. The remaining section of the pancreas was unremarkable. No adhesions were present. The tail of the pancreas was amputated without difficulty and a multilobulated mass of accessory splenic tissue and adipose also was removed. After operation, the patient had an uncomplicated recovery, with a steady increase in the platelet count to 287,000 at the time of discharge 7 days after surgery. On follow-up examination 6 weeks later, the platelet count had again decreased to 45,000. At 24 months after surgery, the platelet count remains low, and there has been no evidence of recurrent or metastatic tumor.
CASE REPORT The patient was an asymptomatic 43-year-old man with a history of idiopathic thrombocytopenic purpura since 1971. This was treated with splenectomy in 1971, with initial normalization of his platelet count. No unusual trauma in the region of the pancreas was reported during this operation. Subsequent medical intervention for recurrent thrombocytopenia included corticosteroid therapy, with only temporary im-
PATHOLOGIC FINDINGS
The resected specimen consisted of compressed, nonindurated pancreatic parenchyma surrounding an irregFrom the Department of Pathology, Dartmouth-Hitchcock Medical ular, uniloculated cystic structure measuring 3 X 3 X 1.5 Center, Hanover, New Hampshire, and Veterans Affairs Medical Center, cm, with a poorly defined margin and soft, tan-white, White River Junction, Vermont. foul-smelling contents (Fig. 2). Microscopically, the cyst Received October 22, 1991; accepted for publication November 20, was lined by a keratinizing stratified squamous epithelium 1991. that was several cell layers thick (Fig. 3). A granular cell Address reprint requests to Dr. Schned: Laboratory (113), Veterans layer was present. The contents of the cyst consisted of Affairs Medical Center, White River Junction, Vermont 05009. 188
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
Reported is a case of a rare lymphoepithelial cyst of the tail of the pancreas that developed in a young man with no symptoms. To the authors' knowledge, it is the first case described to be entirely situated within the pancreas, thus confirming its pancreatic origin. Biologic behavior appears to be entirely benign,
DiCORATO AND SCHNED Lymphoepithelial
189
of the Pancreas
laminated, poorly cohesive keratinaceous material and eosinophilic debris containing many acicular cholesterol clefts. The cyst wall was surrounded by a dense lymphocytic infiltrate with scattered germinal centers and some small clusters of epithelioid histiocytes. In a few areas, the cyst wall was ruptured and partly replaced by multinucleated foreign body-type giant cells. Areas of dense hyalinized scarring surrounded the rupture sites. The adjacent pancreatic parenchyma was partly compressed. There was no significant inflammation, atrophy, or scarring. DISCUSSION True non-neoplastic cystic lesions of the pancreas are rare. These consist primarily of congenital cysts, either
FIG. 2. The completely intrapancreatic cyst is lined by an ill-defined wall of varying thickness and contains soft, tan-white, granular material, which extrudes from the cut surface (above).
Vol.
enterogenous or dermoid, and the cysts seen in the various polycystic syndromes or cystic fibrosis. Enterogenous cysts are true cysts lined by either gastric or intestinal epithelium, whereas dermoid cysts of the pancreas are similar to those found elsewhere in the skin and in other anatomic sites. 23 As such, they are lined by stratified squamous epithelium and often contain appendages, such as hair follicles, sweat and sebaceous glands, and even teeth. By contrast, the lesion herein described is devoid of adnexal structures and is characterized simply by a unilocular cyst containing keratinaceous material, lined by stratified squamous epithelium, and surrounded by prominent lymphoid tissue. It is very similar to the epidermal inclusion cyst except for the presence of a prominent lymphoid element. Lesions with a virtually identical appearance have been found in intraparotid lymph nodes, where they have been referred to as branchial cysts.7 Within the parotid gland itself, these lesions have been called lymphoepithelial cysts. 57 A thorough search of the literature has revealed only three previous case reports of a pancreatic LEC (Table 1). Truong and colleagues6 reported a 35-year-old man with abdominal pain and diarrhea. Endoscopic retrograde cholangiopancreatography showed external compression of the pancreatic duct, and computed axial tomography scan of the abdomen revealed a round mass measuring approximately 5 cm eccentrically protruding onto the surface of the body of the pancreas. This lesion was described as being at the upper and anterior border of the pancreas. Luchtrath and Schriefers4 previously presented the case of a 36-year-old man with weight loss and leukocytosis, who, by computed axial tomography scan and ultrasound, was found to have a multilocular cystic lesion closely associated with the pancreas. Most recently, Mockli
•No. 2
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
FIG. 1. The computed tomographic scan shows a cystic spherical low attenuation mass with an enhancingrimin the tail of the pancreas (arrow).
190
ANATOMIC PATHOLOGY Single Case Report TABLE 1. COMPARISON OF LYMPHOEPITHELIAL LESIONS
Authors
Age
Sex
DiCorato and Schned Truong and colleagues
43 35
M M
3 cm 5 cm
Luchtrath and Schreifers4 Mockli and Stein5
36
M
4 cm
72
M
15 cm
Associated Symptoms
Size
Location in Pancreas
Detection
None Abdominal pain, diarrhea None
Tail Body
CT scan CT scan
Pancreas
CT scan
Unknown
Tail
Autopsy
CT = computed tomograph; M = male.
It is interesting to consider the possible relationship between the LEC and the presence of longstanding idiopathic thrombocytopenic purpura in our patient. In the immediate post-operative period, the patient's peripheral platelet count increased steadily and rapidly to 287,000 from a preoperative low level of 42,000. Because the splenic tissue removed was minimal, consideration was given to the possibility that the lymphoid component of the pancreatic cyst may have played a role in the throm-
bocytopenia. Indeed, there is a precedent for a relationship between a pancreatic lesion and a hematologic effect, although both the pancreatic lesion (microcystic adenoma) and the hematologic condition (Evans' syndrome) differed from our case.8 Against any such relationship, however, are the facts that the cyst was not detected at the time of splenectomy many years earlier, and, more importantly, that the thrombocytopenia eventually recurred after the removal of the cyst. The main importance of the recognition of the LEC lies in distinguishing it from cystic neoplasms, namely mucinous cystadenoma and cystadenocarcinoma of the pancreas. In their series of 75 cases of cystadenomas and cystadenocarcinomas, Compagno and Oertel9 found the peak age of presentation to be 40 to 49 years, with women predominating (85%). In only 5% of their cases was the head of the pancreas involved. The cysts were most frequently multiloculated, and they averaged 10.5 cm in diameter. Associated epigastric pain and discomfort were present in 83%. In contrast, the LEC appears to be emerging as a smaller, uniloculated lesion (only one reported measuring more than 5 cm), most commonly affecting men younger than 45 years. Three of four reported cases have been asymptomatic. Like the cystadenoma and cystadenocarcinoma, the LEC appears to involve preferentially the body and tail of the pancreas. Further case descriptions will be important to confirm the salient clinical features. However, the LEC appears to be a distinct, albeit rare, pathologic entity, with a tendency to occur in young men, to localize peripherally in or near the tail of the pancreas, and to have no evidence or likelihood of becoming malignant. Acknowledgment. The authors thank Dr. Daniel Longnecker for reviewing the slides and for his support.
REFERENCES 1. Cubilla A, Fitzgerald P. Tumors of the exocrine pancreas. In: Hartmann WH, ed. Atlas of Tumor Pathology, Second Series, Fascicle 19. Bethesda, MD: Armed Forces Institute of Pathology, 1982, pp 185-194.
A.J.C.P. • August 1992
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
and Stein5 described the case of a 72-year-old man who died during heart surgery. Autopsy revealed a 4-cm cyst, an incidental finding, on the anterior surface of the tail of the pancreas. This smooth-walled cyst contained turbid serous fluid and was associated with the underlying pancreatic parenchyma. The cyst wall encompassed another smaller cyst. In all three previous cases, the microscopic descriptions and illustrations are virtually identical to our case. However, our case seems unique in that the entire lesion was completely incorporated within the pancreatic parenchyma. The importance of this feature is that it confirms that the lesion arises from the pancreatic parenchyma and does not involve the pancreas from an external origin. The actual histogenesis of this lesion, however, is uncertain. The two possibilities raised by Truong and colleagues6 include that the LEC represents an evolution from squamous metaplasia of an obstructed enlarged pancreatic duct, or that it is of branchial cleft origin. As noted above, similar, if not identical, lesions are uncommonly encountered within the parotid gland, and these are thought to arise from branchial cleft remnants. 7 By virtue of its remote anatomic location in the pancreas, however, the lesion described here is unlikely to have a branchial cleft connection. In our case, the patient's previous surgical manipulation in this area at the time of splenectomy raises the possibility of a relationship of the cyst to pancreatic trauma with possible pancreatic duct obstruction. Such an explanation, however, appears unlikely in light of the absence of any other ductal changes in the resected specimen and because the cyst was entirely intraparenchymal.
DiCORATO AND SCHNED
191
Lymphoepithelial Cyst of the Pancreas Truong LD, Rangdaeng S, Jordan P. Lymphoepithelial cyst of the pancreas. Am J Surg Pathol 1987; 11:899-903. Weidner N, Geisinger K, Sterling R, et al. Benign lymphoepithelial cysts of the parotid gland. Am J Clin Pathol 1986:85:395-401. Doll DC, List AF, Yarbro JW. Evans' syndrome associated with microcystic adenoma of the pancreas. Cancer 1987; 59:1366-1368. Compagno J, Oertel JE. Mucinous cystic neoplasms of the pancreas with overt and latent malignancy (cystadenocarcinoma and cystadenoma). Am J Clin Pathol 1978;69:573-580.
2. Howard JM. Cystic neoplasms and true cysts of the pancreas. Surg Clin North Am 1989;69:651-666. 3. Assawamatiyanont J, King A. Dermoid cysts of the pancreas. Am Surg 1977;43:503-504. 4. Luchtrath H, Schriefers K. Pankreaszyste unter dem bild einer sogenannten branchiogenen zyste. Der Pathologe 1985;6:217-219. 5. Mockli GC, Stein RM. Cystic lymphoepithelial lesion of the pancreas. Arch Pathol Lab Med 1990; 114:885-887.
The Heart in Tangier Disease Severe Coronary Atherosclerosis with Near Absence of High-Density Lipoprotein Cholesterol
Cardiac necropsy findings are described in a 72-year-old man with Tangier disease whose plasma total cholesterol levels averaged 70 mg/dL, low-density lipoprotein cholesterol level was 45 mg/dL, and high-density lipoprotein cholesterol level was 1.4 mg/dL, and who had coronary artery bypass grafting for severe atherosclerotic coronary artery disease. At necropsy, 24 of the 72 (33%) 5-mm segments of the 4 major (right, left main, left anterior descending, and left circumflex) native coronary arteries and 4 of the 27 (15%) 5-mm segments of the saphenous vein aortocoronary bypass conduits were narrowed by more than 75% in cross-sectional area by atherosclerotic plaques. The plaques
were composed primarily (91% to 97%) of fibrous tissue. Oil red O staining, polarized light microscopy, and electron microscopy revealed cholesterol deposits in the plaques and in the walls of coronary arteries, saphenous vein grafts, and aorta. Such deposits also were found in foam cells of histiocytic origin, fibroblasts in all four cardiac valves, and in Schwann cells of cardiac nerves. (Key words: Tangier disease; Atherosclerosis; High-density lipoprotein; Low-density lipoprotein; Coronary artery disease; Coronary artery bypass surgery) Am J Clin Pathol 1992; 98: 191-198
Tangier disease, a rare disorder of lipoprotein metabolism, is characterized by extremely low plasma levels of highdensity lipoprotein (HDL) cholesterol and low levels of total and low-density lipoprotein cholesterol. The low levels of HDL are due to rapid catabolism of HDL rather than to defective biosynthesis of HDL.' Patients with Tangier disease have accumulation of cholesteryl esters in various tissues, including tonsils, lymph nodes, thymus, bone marrow, intestinal mucosa, liver, spleen, skin, and
cornea. The disease is manifested by enlarged orange-yellow tonsils, splenomegaly, and peripheral neuropathy and is transmitted in an autosomal co-dominant mode. Little information is available on clinical and morphologic aspects of coronary artery disease in patients with genetic syndromes characterized by HDL deficiency, and no reports are available describing cardiovascular findings at necropsy in patients with Tangier disease. Such is the purpose of this report. REPORT OF A PATIENT
From the Pathology and Molecular Disease Branches, National Heart, Lung, and Blood Institute, National Institutes of Health. Bethesda. A 72-year-old white man, who had been an oil-refinery Maryland. Received August 28, 1991; received revised manuscript and accepted for publication February 28, 1992. Address reprint requests to Dr. Mautner: Pathology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Building 10, Room 2N-258, Bethesda, Maryland 20892.
worker, had a tonsillectomy at age 14 years because of markedly enlarged tonsils. He remained well until age 42 years, when he noted excessive fatigue. At age 43 years (in 1962), he was found to have malabsorption, thrombocytopenia, and splenomegaly that resulted in splenec-
Vol. 98 • No. 2
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
SUSANNE L. MAUTNER, M.D., JULIAN A. SANCHEZ, M.D., DANIEL J. RADER, M.D. GISELA C. MAUTNER, M.D., VICTOR J. FERRANS, M.D., PH.D., DONALD S. FREDRICKSON, M.D., H. BRYAN BREWER, JR., M.D., AND WILLIAM C. ROBERTS, M.D.
A Rare Lymphoepithelial Cyst of the Pancreas MICHAEL P. DiCORATO, M.D., AND ALAN R. SCHNED, M.D.
and the primary importance of its recognition is in the distinction from cystic malignant neoplasms. (Key words: Lymphoepithelial cyst; Pancreas; Pseudocysts; Epithelial inclusion cyst) Am J Clin Pathol 1992; 98:188-191
Most cystic lesions of the pancreas can be classified into the two categories of pseudocysts and cystic neoplasms.1,2 Among the neoplasms are mucinous and serous cystadenomas and cystadenocarcinomas. The pseudocysts generally develop as a result of ductal obstruction secondary to cancer, stones, inflammation, or parasites. Far rarer are various congenital cysts, including dermoid cysts, enterogenous cysts, and the cysts associated with the polycystic syndromes and cystic fibrosis.1'3 We report a lymphoepithelial cyst (LEC) of the pancreas that, by virtue of its keratinaceous contents, resembles a dermoid cyst but is distinguished by a prominent lymphoid component. To our knowledge, this report represents only the fourth case of LEC described in the literature, and only the third in the English language.4"6 Our case is unique in that it was situated entirely within the pancreatic parenchyma.
provement in platelet count. His past medical history indicated no alcoholism, gallbladder disease, or previous pancreatitis. In January 1989, as part of a workup for recurrent thrombocytopenia, a computerized axial tomography scan showed a 3-cm mass in the tail of the pancreas, in addition to two small accessory spleens. Radiographic studies showed that the lesion was a spherical low attenuation mass with an enhancing rim, and thus was considered to be of cystic density (Fig. 1). Two subsequent computed axial tomography scans in June and August demonstrated no interval change in the size of the mass; however, it was thought that these studies could not distinguish pseudocyst from cystic neoplasm. Physical examination showed that the liver span was 12 cm. No masses were palpated in the liver or pancreas, and the abdomen was not tender. Serum amylase and liver function studies were unremarkable. At laparotomy, a smooth, encapsulated, well-circumscribed mass was found completely within the tail of the pancreas. Surrounding pancreatic tissue was compressed but did not appear to be infiltrated by tumor. The remaining section of the pancreas was unremarkable. No adhesions were present. The tail of the pancreas was amputated without difficulty and a multilobulated mass of accessory splenic tissue and adipose also was removed. After operation, the patient had an uncomplicated recovery, with a steady increase in the platelet count to 287,000 at the time of discharge 7 days after surgery. On follow-up examination 6 weeks later, the platelet count had again decreased to 45,000. At 24 months after surgery, the platelet count remains low, and there has been no evidence of recurrent or metastatic tumor.
CASE REPORT The patient was an asymptomatic 43-year-old man with a history of idiopathic thrombocytopenic purpura since 1971. This was treated with splenectomy in 1971, with initial normalization of his platelet count. No unusual trauma in the region of the pancreas was reported during this operation. Subsequent medical intervention for recurrent thrombocytopenia included corticosteroid therapy, with only temporary im-
PATHOLOGIC FINDINGS
The resected specimen consisted of compressed, nonindurated pancreatic parenchyma surrounding an irregFrom the Department of Pathology, Dartmouth-Hitchcock Medical ular, uniloculated cystic structure measuring 3 X 3 X 1.5 Center, Hanover, New Hampshire, and Veterans Affairs Medical Center, cm, with a poorly defined margin and soft, tan-white, White River Junction, Vermont. foul-smelling contents (Fig. 2). Microscopically, the cyst Received October 22, 1991; accepted for publication November 20, was lined by a keratinizing stratified squamous epithelium 1991. that was several cell layers thick (Fig. 3). A granular cell Address reprint requests to Dr. Schned: Laboratory (113), Veterans layer was present. The contents of the cyst consisted of Affairs Medical Center, White River Junction, Vermont 05009. 188
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
Reported is a case of a rare lymphoepithelial cyst of the tail of the pancreas that developed in a young man with no symptoms. To the authors' knowledge, it is the first case described to be entirely situated within the pancreas, thus confirming its pancreatic origin. Biologic behavior appears to be entirely benign,
DiCORATO AND SCHNED Lymphoepithelial
189
of the Pancreas
laminated, poorly cohesive keratinaceous material and eosinophilic debris containing many acicular cholesterol clefts. The cyst wall was surrounded by a dense lymphocytic infiltrate with scattered germinal centers and some small clusters of epithelioid histiocytes. In a few areas, the cyst wall was ruptured and partly replaced by multinucleated foreign body-type giant cells. Areas of dense hyalinized scarring surrounded the rupture sites. The adjacent pancreatic parenchyma was partly compressed. There was no significant inflammation, atrophy, or scarring. DISCUSSION True non-neoplastic cystic lesions of the pancreas are rare. These consist primarily of congenital cysts, either
FIG. 2. The completely intrapancreatic cyst is lined by an ill-defined wall of varying thickness and contains soft, tan-white, granular material, which extrudes from the cut surface (above).
Vol.
enterogenous or dermoid, and the cysts seen in the various polycystic syndromes or cystic fibrosis. Enterogenous cysts are true cysts lined by either gastric or intestinal epithelium, whereas dermoid cysts of the pancreas are similar to those found elsewhere in the skin and in other anatomic sites. 23 As such, they are lined by stratified squamous epithelium and often contain appendages, such as hair follicles, sweat and sebaceous glands, and even teeth. By contrast, the lesion herein described is devoid of adnexal structures and is characterized simply by a unilocular cyst containing keratinaceous material, lined by stratified squamous epithelium, and surrounded by prominent lymphoid tissue. It is very similar to the epidermal inclusion cyst except for the presence of a prominent lymphoid element. Lesions with a virtually identical appearance have been found in intraparotid lymph nodes, where they have been referred to as branchial cysts.7 Within the parotid gland itself, these lesions have been called lymphoepithelial cysts. 57 A thorough search of the literature has revealed only three previous case reports of a pancreatic LEC (Table 1). Truong and colleagues6 reported a 35-year-old man with abdominal pain and diarrhea. Endoscopic retrograde cholangiopancreatography showed external compression of the pancreatic duct, and computed axial tomography scan of the abdomen revealed a round mass measuring approximately 5 cm eccentrically protruding onto the surface of the body of the pancreas. This lesion was described as being at the upper and anterior border of the pancreas. Luchtrath and Schriefers4 previously presented the case of a 36-year-old man with weight loss and leukocytosis, who, by computed axial tomography scan and ultrasound, was found to have a multilocular cystic lesion closely associated with the pancreas. Most recently, Mockli
•No. 2
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
FIG. 1. The computed tomographic scan shows a cystic spherical low attenuation mass with an enhancingrimin the tail of the pancreas (arrow).
190
ANATOMIC PATHOLOGY Single Case Report TABLE 1. COMPARISON OF LYMPHOEPITHELIAL LESIONS
Authors
Age
Sex
DiCorato and Schned Truong and colleagues
43 35
M M
3 cm 5 cm
Luchtrath and Schreifers4 Mockli and Stein5
36
M
4 cm
72
M
15 cm
Associated Symptoms
Size
Location in Pancreas
Detection
None Abdominal pain, diarrhea None
Tail Body
CT scan CT scan
Pancreas
CT scan
Unknown
Tail
Autopsy
CT = computed tomograph; M = male.
It is interesting to consider the possible relationship between the LEC and the presence of longstanding idiopathic thrombocytopenic purpura in our patient. In the immediate post-operative period, the patient's peripheral platelet count increased steadily and rapidly to 287,000 from a preoperative low level of 42,000. Because the splenic tissue removed was minimal, consideration was given to the possibility that the lymphoid component of the pancreatic cyst may have played a role in the throm-
bocytopenia. Indeed, there is a precedent for a relationship between a pancreatic lesion and a hematologic effect, although both the pancreatic lesion (microcystic adenoma) and the hematologic condition (Evans' syndrome) differed from our case.8 Against any such relationship, however, are the facts that the cyst was not detected at the time of splenectomy many years earlier, and, more importantly, that the thrombocytopenia eventually recurred after the removal of the cyst. The main importance of the recognition of the LEC lies in distinguishing it from cystic neoplasms, namely mucinous cystadenoma and cystadenocarcinoma of the pancreas. In their series of 75 cases of cystadenomas and cystadenocarcinomas, Compagno and Oertel9 found the peak age of presentation to be 40 to 49 years, with women predominating (85%). In only 5% of their cases was the head of the pancreas involved. The cysts were most frequently multiloculated, and they averaged 10.5 cm in diameter. Associated epigastric pain and discomfort were present in 83%. In contrast, the LEC appears to be emerging as a smaller, uniloculated lesion (only one reported measuring more than 5 cm), most commonly affecting men younger than 45 years. Three of four reported cases have been asymptomatic. Like the cystadenoma and cystadenocarcinoma, the LEC appears to involve preferentially the body and tail of the pancreas. Further case descriptions will be important to confirm the salient clinical features. However, the LEC appears to be a distinct, albeit rare, pathologic entity, with a tendency to occur in young men, to localize peripherally in or near the tail of the pancreas, and to have no evidence or likelihood of becoming malignant. Acknowledgment. The authors thank Dr. Daniel Longnecker for reviewing the slides and for his support.
REFERENCES 1. Cubilla A, Fitzgerald P. Tumors of the exocrine pancreas. In: Hartmann WH, ed. Atlas of Tumor Pathology, Second Series, Fascicle 19. Bethesda, MD: Armed Forces Institute of Pathology, 1982, pp 185-194.
A.J.C.P. • August 1992
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
and Stein5 described the case of a 72-year-old man who died during heart surgery. Autopsy revealed a 4-cm cyst, an incidental finding, on the anterior surface of the tail of the pancreas. This smooth-walled cyst contained turbid serous fluid and was associated with the underlying pancreatic parenchyma. The cyst wall encompassed another smaller cyst. In all three previous cases, the microscopic descriptions and illustrations are virtually identical to our case. However, our case seems unique in that the entire lesion was completely incorporated within the pancreatic parenchyma. The importance of this feature is that it confirms that the lesion arises from the pancreatic parenchyma and does not involve the pancreas from an external origin. The actual histogenesis of this lesion, however, is uncertain. The two possibilities raised by Truong and colleagues6 include that the LEC represents an evolution from squamous metaplasia of an obstructed enlarged pancreatic duct, or that it is of branchial cleft origin. As noted above, similar, if not identical, lesions are uncommonly encountered within the parotid gland, and these are thought to arise from branchial cleft remnants. 7 By virtue of its remote anatomic location in the pancreas, however, the lesion described here is unlikely to have a branchial cleft connection. In our case, the patient's previous surgical manipulation in this area at the time of splenectomy raises the possibility of a relationship of the cyst to pancreatic trauma with possible pancreatic duct obstruction. Such an explanation, however, appears unlikely in light of the absence of any other ductal changes in the resected specimen and because the cyst was entirely intraparenchymal.
DiCORATO AND SCHNED
191
Lymphoepithelial Cyst of the Pancreas Truong LD, Rangdaeng S, Jordan P. Lymphoepithelial cyst of the pancreas. Am J Surg Pathol 1987; 11:899-903. Weidner N, Geisinger K, Sterling R, et al. Benign lymphoepithelial cysts of the parotid gland. Am J Clin Pathol 1986:85:395-401. Doll DC, List AF, Yarbro JW. Evans' syndrome associated with microcystic adenoma of the pancreas. Cancer 1987; 59:1366-1368. Compagno J, Oertel JE. Mucinous cystic neoplasms of the pancreas with overt and latent malignancy (cystadenocarcinoma and cystadenoma). Am J Clin Pathol 1978;69:573-580.
2. Howard JM. Cystic neoplasms and true cysts of the pancreas. Surg Clin North Am 1989;69:651-666. 3. Assawamatiyanont J, King A. Dermoid cysts of the pancreas. Am Surg 1977;43:503-504. 4. Luchtrath H, Schriefers K. Pankreaszyste unter dem bild einer sogenannten branchiogenen zyste. Der Pathologe 1985;6:217-219. 5. Mockli GC, Stein RM. Cystic lymphoepithelial lesion of the pancreas. Arch Pathol Lab Med 1990; 114:885-887.
The Heart in Tangier Disease Severe Coronary Atherosclerosis with Near Absence of High-Density Lipoprotein Cholesterol
Cardiac necropsy findings are described in a 72-year-old man with Tangier disease whose plasma total cholesterol levels averaged 70 mg/dL, low-density lipoprotein cholesterol level was 45 mg/dL, and high-density lipoprotein cholesterol level was 1.4 mg/dL, and who had coronary artery bypass grafting for severe atherosclerotic coronary artery disease. At necropsy, 24 of the 72 (33%) 5-mm segments of the 4 major (right, left main, left anterior descending, and left circumflex) native coronary arteries and 4 of the 27 (15%) 5-mm segments of the saphenous vein aortocoronary bypass conduits were narrowed by more than 75% in cross-sectional area by atherosclerotic plaques. The plaques
were composed primarily (91% to 97%) of fibrous tissue. Oil red O staining, polarized light microscopy, and electron microscopy revealed cholesterol deposits in the plaques and in the walls of coronary arteries, saphenous vein grafts, and aorta. Such deposits also were found in foam cells of histiocytic origin, fibroblasts in all four cardiac valves, and in Schwann cells of cardiac nerves. (Key words: Tangier disease; Atherosclerosis; High-density lipoprotein; Low-density lipoprotein; Coronary artery disease; Coronary artery bypass surgery) Am J Clin Pathol 1992; 98: 191-198
Tangier disease, a rare disorder of lipoprotein metabolism, is characterized by extremely low plasma levels of highdensity lipoprotein (HDL) cholesterol and low levels of total and low-density lipoprotein cholesterol. The low levels of HDL are due to rapid catabolism of HDL rather than to defective biosynthesis of HDL.' Patients with Tangier disease have accumulation of cholesteryl esters in various tissues, including tonsils, lymph nodes, thymus, bone marrow, intestinal mucosa, liver, spleen, skin, and
cornea. The disease is manifested by enlarged orange-yellow tonsils, splenomegaly, and peripheral neuropathy and is transmitted in an autosomal co-dominant mode. Little information is available on clinical and morphologic aspects of coronary artery disease in patients with genetic syndromes characterized by HDL deficiency, and no reports are available describing cardiovascular findings at necropsy in patients with Tangier disease. Such is the purpose of this report. REPORT OF A PATIENT
From the Pathology and Molecular Disease Branches, National Heart, Lung, and Blood Institute, National Institutes of Health. Bethesda. A 72-year-old white man, who had been an oil-refinery Maryland. Received August 28, 1991; received revised manuscript and accepted for publication February 28, 1992. Address reprint requests to Dr. Mautner: Pathology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Building 10, Room 2N-258, Bethesda, Maryland 20892.
worker, had a tonsillectomy at age 14 years because of markedly enlarged tonsils. He remained well until age 42 years, when he noted excessive fatigue. At age 43 years (in 1962), he was found to have malabsorption, thrombocytopenia, and splenomegaly that resulted in splenec-
Vol. 98 • No. 2
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
SUSANNE L. MAUTNER, M.D., JULIAN A. SANCHEZ, M.D., DANIEL J. RADER, M.D. GISELA C. MAUTNER, M.D., VICTOR J. FERRANS, M.D., PH.D., DONALD S. FREDRICKSON, M.D., H. BRYAN BREWER, JR., M.D., AND WILLIAM C. ROBERTS, M.D.
