Path. Res. Pract. 187,103-106 (1991)
Tcaching Cases
Peritoneal Benign Cystic Mesothelioma _J. Hidvegi, F. Schneider, B. Rohonyi, L. Flautner and L. Szlavik 2nd Department of Pathology and 1st Department of Surgery, Semmelweis University, Medical School, Budapest; Department of Pathology and Department of Surgery, Town Hospital Sopron, Hungary
SUMMARY
A case of a benign cystic peritoneal mesothelioma is reported. A 25-year-old woman presented a 8-year history of recurrent tumor and five operations because of that. On the basis of this case and of 18 cases proved by electron microscopy reported by others, the clinicopathological features and the problems of differential diagnosis are discussed. The ultrastructural examination is essential for the diagnosis of cystic mesothelioma.
Introduction Peritoneal cystic mesothelioma is a tumor first recognized by Mennemeyer and Smith in ultrastructural studies 7 • It has been considered as benign, although it recurs more frequently than the morphologically similar lymphangioma 1,8,10. Cystic mesothelioma is a rare tumor and its clinicopathological features are still poorly defined 3 • The number of adequately documented reported cases is less than twenty3,11. This paper is a report on a recurrent case of peritoneal benign cystic mesothelioma in a young woman. On the basis of the reported cases the clinicopathological features and the morphological differential diagnosis of cystic peritoneal mesothelioma are discussed. Case Report A 33-year-old woman was first examined in 1980 at the Department of Gynecology of the Town Hospital in Sopron at the age of 25 because of a pelvic mass. At surgery a cystic tumor the size of a woman's fist was found involving the omentrum maior. Resection was performed. The pathologic diagnosis was lymphangioma multicysticum. In 1984 she was admitted to the Department of Surgery of the Town Hospital in Sopron because of severe abdominal pain. A resistant mass the size of a woman's fist was palpated in the abdomen. Laparotomy revealed © 1991 by Gustav Fischet Verlag, Stuttgart
several foci of multiple cysts contammg a clear fluid spreading all over the omentum maior, pelvic peritoneum, surface of the uterus and both ovaries. The cystic mass was resected together with part of the omentum. The pathologic diagnosis was lymphangioma cavernosum. In 1985 she was readmitted to the Department of Surgery of the Town Hospital in Sopron with an 8 months' history of abdominal pain. She had lost three pounds in the three weeks prior to admission. In the lower abdomen a woman-fist-sized resistance was noted. Similar to the previous one laparotomy revealed numerous foci of multiple cysts covering both the parietal and visceral peritoneum, surface of the uterus and both ovaries. Resection of the tumor mass, total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. The pathologic diagnosis was Iymphangiomatosis peritonei. Two years later (March 1987) the patient was admitted to the 1st Department of Surgery, Semmelweis Medical University, Budapest because of persistent abdominal pain. At laparotomy the multiple cysts covering the pelvic peritoneum were removed. The pathologic diagnosis was lymphangioma cavernosum. Eight months after the last surgery (October 1987) the patient again experienced abdominal pain and she reported to the 1st Department of Surgery, Semmelweis Medical University. At laparotomy numerous cysts covering the pelvic peritoneum and part of the omentum were resected. The macroscopic features of the cystic tumors removed in the course of the five laparotomies were similar. They 0344-0338/91/0187 -0103 $3.5 DID
104 .
J. Hidvegi et al.
consisted of numerous thin-walled cysts measuring
5-50 mm in diameter, containing water-clear translucent
liquid material. Small pieces of specimens were embedded in paraffin. The preparations were stained with haematoxylin and eosin, periodic acid Schiff (PAS) and alcian blue at pH 2.5. Sections for electron microscopy were prepared from formalin fixed specimens obtained at the last surgery. Histological specimens were made available from all surgically removed tumors. They all had similar features. Numerous variably sized thin-walled cysts separated by fibrous or myxoid connective tissue stroma containing a few lymphocytes and eosinophil polymorphs were
observed. The cysts were lined predominantly with a single layer of flat endothelial-like cells with elongated nuclei (Fig.1A). Both the eosinophilic cystic content and the cells exhibited negative PAS and alcian blue reactions. Ultrastructural examination revealed numerous short microvilli at the luminal border. The tumor cells lay upon a well-defined continuous basal lamina. Cell boundaries were often tightly apposed with prominent desmosomes. The cytoplasm contained abundant tonofilaments which were connected to desmosomes at the cell periphery (Fig. 2). Following the ultrastructural examination the epithelium of the cysts was re-examined by light microscopy. In a
Fig. 1. A: Multiple thin-walled cysts separated by fibrous stroma containing some lymphocytes and eosinophilic polymorphs. Eosinophilic content is seen in the lumen. The cysts were lined predominantly by flattened cells, but there are some hobnail cells, too (~). HE, x 100. - B: Inset: Hobnail cells with brush-like cell processes. HE, x 1000.
Fig. 2. Numerous surface microvilli (MV), prominent belt of desmosomes (D) and welldeveloped continuous basal lamina (BL). TEM, x 43200.
Peritoneal Benign Cystic Mesothelioma . 105 Table 1. Reported cases with final diagnosis of benign cystic peritoneal mesothelioma Cases references
Mennemeyer (7) 1
Moore (8) 1
Katsube (3) 1 2 3 4 5
Dumke (1) 1 2
Schneider (10)
1 2 3 4
Nirodi (9) 1 2
Marshall (6) 1
Sienkowski (11) 1 2
Our case 1
Sex
Age years
Follow up No. recidives/ (years) first re- No. surgeries cidive (years)
Localization abdomi- pelvic nal
Diagnostic errors
F
27
2/0.25
2/3
+
lymphangioma
M
73
20/6
4/5
+
non-specific reactive proliferative process, lymphangioma
F F F F F
23 30 44 28 35
6/5 8 8/6 2 2
1/2 0/1 2/3 0/1 0/1
F M
74 46
3/3
?
0/1 1/2
F F F F
43 28 24 26
2 3 1 0.3/0.3
0/1 0/1 0/1 1/2
+ + + +
F F
26 42
2/1 1
2/3 0/1
+ +
F
43
0.5
0/1
+
M M
35 45
0.5 3
0/1 0/1
+
F
33
8/4
4/5
+
few foci there were hobnail cells with brush-like cell processes (Fig. 1B inset). The final pathologic diagnosis was benign cystic mesothelioma of the peritoneum. Discussion There are three well-characterized types of mesothelial tumors occuring in the peritoneum: malignant tubulopapillary mesothelioma, cystic mesothelioma and adenomatoid tumor. Of these variants, the cystic mesothelioma is one of the rarest 1,3,6,9. In Table 1, the clinical and pathologic data of the reported cases and our case of peritoneal cystic mesothelioma are summarized. Before Mennemeyer's and Smith's ultrastructural studies 7 reported cases could have presumably been benign cystic mesotheliomas on the basis of their light microscopic features; they were nonetheless excluded because of poor clinical history 2, 4, 5. Most patients (14 of the 18) were women. The age of the patients varied from 23-74 years, with an average of 35
+ + + + +
endometriosis serous cystadeno-carcinoma
+ +
pseudomyxoma peritonei
+ lymphangioma
years. Two-thirds of cases (12 of the 18) occurred as pelvic neoplasms. The case report here was located in the omentum. The most common clinical symptoms were pain and abdominal and/or pelvic mass. In some cases surgery resulted in definite cure. Recurrence occurred in nearly half of the cases. It should be strongly stressed that in 7 of 11 cases without recurrence the follow-up time was under 4 years. In our case the recurrence occurred 4 years after the first surgery and further recurrences developed at shorter intervals. Therefore the 7 cases with no recurrence within 4 years represent insufficient evidence for the absence of recurrence. Cystic mesothelioma of the peritoneum seems to be a borderline lesion between the adenomatoid tumor and malignant tubulopapillary mesothelioma 1. One-third of cases were initially misdiagnosed. Benign cystic mesothelioma must be differentiated from uncommon macroscopic and microscopic features of lymphangioma, pseudomyxoma peritonei, endometriosis and ovarian cystadenocarcinoma.
106 .
J. Hidvegi et al.
Specific ultrastructural features (presence of microvilli on the luminal surface, continuous basal lamina and tight desmosomal junctions) are required for the reliable diagnosis of this mesothelial neoplasm. The first two and last specimens of our patient showed the presence of some hobnail cells with brush-like cell processes in the light microscope. This should have suggested a mesothelial tumor. The pathologist should remember this entity and in case of doubt ultrastructural investigation should be made to provide a correct diagnosis. References 1 Dumke K, Schnoy N, Specht G, Buse H (1983) Comparative light and electron microscopic studies of cystic and papillary tumors of the peritoneum. Virchows Arch (Path Anat) 399: 25-39 2 Jacobson E (1974) Benign papillary peritoenal cystosis simulating serous cystadenocarcinoma of the ovary. Am] Obstet Gynecol118: 575-576 3 Katsube Y, Mukai K, Silverberg SG (1982) Cystic mesothelioma of the peritoneum. Cancer 50: 1615-1622
4 Krieger ]S, Fisher ER, Richards MR (1952) Multiple mesothelial cysts of the peritoneum. Am] Surg 84: 328-330 5 Lascano EF, Villamayor RD, Llauro]L (1960) Loose cysts of the peritoneal cavity. Ann Surg 152: 836-844 6 Marshall RM, Gould VE, King ME, ]ensik S, Chejfec G (1985) Multicystic abdominal peritoneal tumor presenting as an enlarging incisional hernia. Ultrastruct Path 8: 249-256 7 Mennemeyer R, Smith M (1979) Multicystic peritoneal mesothelioma. A report with electron microscopy of a case mimicking intraabdominal cystic hygroma (lymphangioma). Cancer 44: 692-698 8 Moore ]H, Crum CP, Chandler ]G, Feldman PS (1980) Benign cystic mesothelioma. Cancer 45: 2395-2399 9 Nirodi NS, Lowry DS, Wallace R] (1984) Cystic mesothelioma of the pelvic peritoneum. Two case reports. Br ] Obstet Gynecol91: 201-204 10 Schneider V, Partridge ]R, Gutierrez F, Hurt WG, Maizels MS, Demay RM (1983) Benign cystic mesothelioma involving the female genital tract: report of four cases. Am ] Obstet Gynecol 145: 355-359 11 Sienkowski IK, Russel A], Dilly SA, Djazaer B (1986) Peritoenal cystic mesothelioma: an electron microscopic and immunohistochemical study of two male patients. ] Clin Pathol 39:440-445
Received October 11, 1988 . Accepted in revised form March 13, 1990
Key words: Peritoneal tumor - Mesothelioma - Cystic tumor - Hobnail cells Dr. ]udit Hidvegi, 2nd Dept. of Pathology, Semmelweis University, Medical School, Budapest, Hungary
Letters to the Case M. Brockmann and K.-M. Muller Bochum, FRG Large unilocular or multilocular cysts are rare outside the pelvic peritoneum. The multilocular cysts can include parts of the visceral and parietal peritoneum. They are usually attached to the peritoneum and, in some cases, fill the whole peritoneal cavity4. Loose cysts of the peritoneal cavity have been described additionallylo. The majority of benign abdominal cystic lesions have been classified as lymphangiomas l . To our knowledge Hamdi et a1. 6 and Plaut l6 were the first authors assuming a part of the peritoneal cysts histogenetically to be derived from the mesothelium. This hypothesis has been proved by ultrastructural investiga-
tions l4 . Although the tumors are rare, some mainly casuistic communications are already existing tl , 13, 17. A relatively great confusion is to be observed in differential diagnosis between lymphangioma and benign cystic peritoneal mesothelioma 2 . This diagnostic question, however, is essential in so far as there are only rare recurrences in lymphangiomas compared to benign cystic mesotheliomas. Cystic mesotheliomas most commonly occur in adult females. The cystic lymphangiomas are more often diagnosed in males and a significant number of cases in children are reviewed 3 . Pain, although an inconstant
Tcaching Cases
Peritoneal Benign Cystic Mesothelioma _J. Hidvegi, F. Schneider, B. Rohonyi, L. Flautner and L. Szlavik 2nd Department of Pathology and 1st Department of Surgery, Semmelweis University, Medical School, Budapest; Department of Pathology and Department of Surgery, Town Hospital Sopron, Hungary
SUMMARY
A case of a benign cystic peritoneal mesothelioma is reported. A 25-year-old woman presented a 8-year history of recurrent tumor and five operations because of that. On the basis of this case and of 18 cases proved by electron microscopy reported by others, the clinicopathological features and the problems of differential diagnosis are discussed. The ultrastructural examination is essential for the diagnosis of cystic mesothelioma.
Introduction Peritoneal cystic mesothelioma is a tumor first recognized by Mennemeyer and Smith in ultrastructural studies 7 • It has been considered as benign, although it recurs more frequently than the morphologically similar lymphangioma 1,8,10. Cystic mesothelioma is a rare tumor and its clinicopathological features are still poorly defined 3 • The number of adequately documented reported cases is less than twenty3,11. This paper is a report on a recurrent case of peritoneal benign cystic mesothelioma in a young woman. On the basis of the reported cases the clinicopathological features and the morphological differential diagnosis of cystic peritoneal mesothelioma are discussed. Case Report A 33-year-old woman was first examined in 1980 at the Department of Gynecology of the Town Hospital in Sopron at the age of 25 because of a pelvic mass. At surgery a cystic tumor the size of a woman's fist was found involving the omentrum maior. Resection was performed. The pathologic diagnosis was lymphangioma multicysticum. In 1984 she was admitted to the Department of Surgery of the Town Hospital in Sopron because of severe abdominal pain. A resistant mass the size of a woman's fist was palpated in the abdomen. Laparotomy revealed © 1991 by Gustav Fischet Verlag, Stuttgart
several foci of multiple cysts contammg a clear fluid spreading all over the omentum maior, pelvic peritoneum, surface of the uterus and both ovaries. The cystic mass was resected together with part of the omentum. The pathologic diagnosis was lymphangioma cavernosum. In 1985 she was readmitted to the Department of Surgery of the Town Hospital in Sopron with an 8 months' history of abdominal pain. She had lost three pounds in the three weeks prior to admission. In the lower abdomen a woman-fist-sized resistance was noted. Similar to the previous one laparotomy revealed numerous foci of multiple cysts covering both the parietal and visceral peritoneum, surface of the uterus and both ovaries. Resection of the tumor mass, total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. The pathologic diagnosis was Iymphangiomatosis peritonei. Two years later (March 1987) the patient was admitted to the 1st Department of Surgery, Semmelweis Medical University, Budapest because of persistent abdominal pain. At laparotomy the multiple cysts covering the pelvic peritoneum were removed. The pathologic diagnosis was lymphangioma cavernosum. Eight months after the last surgery (October 1987) the patient again experienced abdominal pain and she reported to the 1st Department of Surgery, Semmelweis Medical University. At laparotomy numerous cysts covering the pelvic peritoneum and part of the omentum were resected. The macroscopic features of the cystic tumors removed in the course of the five laparotomies were similar. They 0344-0338/91/0187 -0103 $3.5 DID
104 .
J. Hidvegi et al.
consisted of numerous thin-walled cysts measuring
5-50 mm in diameter, containing water-clear translucent
liquid material. Small pieces of specimens were embedded in paraffin. The preparations were stained with haematoxylin and eosin, periodic acid Schiff (PAS) and alcian blue at pH 2.5. Sections for electron microscopy were prepared from formalin fixed specimens obtained at the last surgery. Histological specimens were made available from all surgically removed tumors. They all had similar features. Numerous variably sized thin-walled cysts separated by fibrous or myxoid connective tissue stroma containing a few lymphocytes and eosinophil polymorphs were
observed. The cysts were lined predominantly with a single layer of flat endothelial-like cells with elongated nuclei (Fig.1A). Both the eosinophilic cystic content and the cells exhibited negative PAS and alcian blue reactions. Ultrastructural examination revealed numerous short microvilli at the luminal border. The tumor cells lay upon a well-defined continuous basal lamina. Cell boundaries were often tightly apposed with prominent desmosomes. The cytoplasm contained abundant tonofilaments which were connected to desmosomes at the cell periphery (Fig. 2). Following the ultrastructural examination the epithelium of the cysts was re-examined by light microscopy. In a
Fig. 1. A: Multiple thin-walled cysts separated by fibrous stroma containing some lymphocytes and eosinophilic polymorphs. Eosinophilic content is seen in the lumen. The cysts were lined predominantly by flattened cells, but there are some hobnail cells, too (~). HE, x 100. - B: Inset: Hobnail cells with brush-like cell processes. HE, x 1000.
Fig. 2. Numerous surface microvilli (MV), prominent belt of desmosomes (D) and welldeveloped continuous basal lamina (BL). TEM, x 43200.
Peritoneal Benign Cystic Mesothelioma . 105 Table 1. Reported cases with final diagnosis of benign cystic peritoneal mesothelioma Cases references
Mennemeyer (7) 1
Moore (8) 1
Katsube (3) 1 2 3 4 5
Dumke (1) 1 2
Schneider (10)
1 2 3 4
Nirodi (9) 1 2
Marshall (6) 1
Sienkowski (11) 1 2
Our case 1
Sex
Age years
Follow up No. recidives/ (years) first re- No. surgeries cidive (years)
Localization abdomi- pelvic nal
Diagnostic errors
F
27
2/0.25
2/3
+
lymphangioma
M
73
20/6
4/5
+
non-specific reactive proliferative process, lymphangioma
F F F F F
23 30 44 28 35
6/5 8 8/6 2 2
1/2 0/1 2/3 0/1 0/1
F M
74 46
3/3
?
0/1 1/2
F F F F
43 28 24 26
2 3 1 0.3/0.3
0/1 0/1 0/1 1/2
+ + + +
F F
26 42
2/1 1
2/3 0/1
+ +
F
43
0.5
0/1
+
M M
35 45
0.5 3
0/1 0/1
+
F
33
8/4
4/5
+
few foci there were hobnail cells with brush-like cell processes (Fig. 1B inset). The final pathologic diagnosis was benign cystic mesothelioma of the peritoneum. Discussion There are three well-characterized types of mesothelial tumors occuring in the peritoneum: malignant tubulopapillary mesothelioma, cystic mesothelioma and adenomatoid tumor. Of these variants, the cystic mesothelioma is one of the rarest 1,3,6,9. In Table 1, the clinical and pathologic data of the reported cases and our case of peritoneal cystic mesothelioma are summarized. Before Mennemeyer's and Smith's ultrastructural studies 7 reported cases could have presumably been benign cystic mesotheliomas on the basis of their light microscopic features; they were nonetheless excluded because of poor clinical history 2, 4, 5. Most patients (14 of the 18) were women. The age of the patients varied from 23-74 years, with an average of 35
+ + + + +
endometriosis serous cystadeno-carcinoma
+ +
pseudomyxoma peritonei
+ lymphangioma
years. Two-thirds of cases (12 of the 18) occurred as pelvic neoplasms. The case report here was located in the omentum. The most common clinical symptoms were pain and abdominal and/or pelvic mass. In some cases surgery resulted in definite cure. Recurrence occurred in nearly half of the cases. It should be strongly stressed that in 7 of 11 cases without recurrence the follow-up time was under 4 years. In our case the recurrence occurred 4 years after the first surgery and further recurrences developed at shorter intervals. Therefore the 7 cases with no recurrence within 4 years represent insufficient evidence for the absence of recurrence. Cystic mesothelioma of the peritoneum seems to be a borderline lesion between the adenomatoid tumor and malignant tubulopapillary mesothelioma 1. One-third of cases were initially misdiagnosed. Benign cystic mesothelioma must be differentiated from uncommon macroscopic and microscopic features of lymphangioma, pseudomyxoma peritonei, endometriosis and ovarian cystadenocarcinoma.
106 .
J. Hidvegi et al.
Specific ultrastructural features (presence of microvilli on the luminal surface, continuous basal lamina and tight desmosomal junctions) are required for the reliable diagnosis of this mesothelial neoplasm. The first two and last specimens of our patient showed the presence of some hobnail cells with brush-like cell processes in the light microscope. This should have suggested a mesothelial tumor. The pathologist should remember this entity and in case of doubt ultrastructural investigation should be made to provide a correct diagnosis. References 1 Dumke K, Schnoy N, Specht G, Buse H (1983) Comparative light and electron microscopic studies of cystic and papillary tumors of the peritoneum. Virchows Arch (Path Anat) 399: 25-39 2 Jacobson E (1974) Benign papillary peritoenal cystosis simulating serous cystadenocarcinoma of the ovary. Am] Obstet Gynecol118: 575-576 3 Katsube Y, Mukai K, Silverberg SG (1982) Cystic mesothelioma of the peritoneum. Cancer 50: 1615-1622
4 Krieger ]S, Fisher ER, Richards MR (1952) Multiple mesothelial cysts of the peritoneum. Am] Surg 84: 328-330 5 Lascano EF, Villamayor RD, Llauro]L (1960) Loose cysts of the peritoneal cavity. Ann Surg 152: 836-844 6 Marshall RM, Gould VE, King ME, ]ensik S, Chejfec G (1985) Multicystic abdominal peritoneal tumor presenting as an enlarging incisional hernia. Ultrastruct Path 8: 249-256 7 Mennemeyer R, Smith M (1979) Multicystic peritoneal mesothelioma. A report with electron microscopy of a case mimicking intraabdominal cystic hygroma (lymphangioma). Cancer 44: 692-698 8 Moore ]H, Crum CP, Chandler ]G, Feldman PS (1980) Benign cystic mesothelioma. Cancer 45: 2395-2399 9 Nirodi NS, Lowry DS, Wallace R] (1984) Cystic mesothelioma of the pelvic peritoneum. Two case reports. Br ] Obstet Gynecol91: 201-204 10 Schneider V, Partridge ]R, Gutierrez F, Hurt WG, Maizels MS, Demay RM (1983) Benign cystic mesothelioma involving the female genital tract: report of four cases. Am ] Obstet Gynecol 145: 355-359 11 Sienkowski IK, Russel A], Dilly SA, Djazaer B (1986) Peritoenal cystic mesothelioma: an electron microscopic and immunohistochemical study of two male patients. ] Clin Pathol 39:440-445
Received October 11, 1988 . Accepted in revised form March 13, 1990
Key words: Peritoneal tumor - Mesothelioma - Cystic tumor - Hobnail cells Dr. ]udit Hidvegi, 2nd Dept. of Pathology, Semmelweis University, Medical School, Budapest, Hungary
Letters to the Case M. Brockmann and K.-M. Muller Bochum, FRG Large unilocular or multilocular cysts are rare outside the pelvic peritoneum. The multilocular cysts can include parts of the visceral and parietal peritoneum. They are usually attached to the peritoneum and, in some cases, fill the whole peritoneal cavity4. Loose cysts of the peritoneal cavity have been described additionallylo. The majority of benign abdominal cystic lesions have been classified as lymphangiomas l . To our knowledge Hamdi et a1. 6 and Plaut l6 were the first authors assuming a part of the peritoneal cysts histogenetically to be derived from the mesothelium. This hypothesis has been proved by ultrastructural investiga-
tions l4 . Although the tumors are rare, some mainly casuistic communications are already existing tl , 13, 17. A relatively great confusion is to be observed in differential diagnosis between lymphangioma and benign cystic peritoneal mesothelioma 2 . This diagnostic question, however, is essential in so far as there are only rare recurrences in lymphangiomas compared to benign cystic mesotheliomas. Cystic mesotheliomas most commonly occur in adult females. The cystic lymphangiomas are more often diagnosed in males and a significant number of cases in children are reviewed 3 . Pain, although an inconstant
