Pediatric and Developmental Pathology 17, 487-490, 2014 DOI: 10.2350/14-06-1510-CR. 1 © 2014 Society fo r Pediatric Pathology
Benign Cystic Mesothelioma Associated with Ipsilateral Renal Agenesis: A Case Report and Review of Literature D iana M
urro, 1*
A parna H arbhajanka , 1 B rett M ahon , 1
and
D aniel D eziel2
'Departm ent of Pathology, Rush University Medical Center, 1750 W. Harrison St., Suite 573 Jelke, Chicago, IL60612 d e p a rtm e n t o f Surgery, Rush University Medical Center, 1750 W. Harrison St., Suite 785 Jelke, Chicago, IL 60612
Received June 17, 2014; accepted September 4, 2014; published online September 10, 2014.
ABSTRACT
CASE REPORT
Benign Cystic Mesothelioma (BCM) is an uncommon peritoneal lesion that usually occurs in reproductive age females with a history of abdominal surgery. Occasional expression of estrogen and progesterone receptor in these cells may explain female predilection. Reports of BCM in males are rare. We describe a case of BCM associated with ipsilateral renal agenesis in a young male without any surgical history. The cyst lining stained positive for cytokeratin, Wilms Tumor-1, epithelial membrane anti gen, CD10, estrogen receptor, and progesterone receptor, and negative for PAX-8. Only three cases of BCM associated with congenital renal anomalies have been reported. To the best of our knowledge, this is the first case of BCM associated with ipsilateral renal agenesis in an adult male and the first male case of BCM displaying estrogen and progesterone receptor positivity. Such a case reveals the presence of congenital anomalies should be considered in patients with BCM.
A 26-year-old man with a history of hypertension, currently not on any medications, presented to the Emergency Department with worsening abdominal and right flank pain of 1 month’s duration. Physical exam revealed mild right lower quadrant and right costoverte bral angle tenderness without abdominal distention. Due to clinical suspicion for nephrolithiasis or appendicitis, initial computerized tomography (CT) without contrast was performed, followed by CT with contrast media. CT studies (Fig. 1) revealed a large, well-defined, homoge nous complex cystic mass with multiple septations along the posterior aspect of the inferior right hepatic lobe and left abdomen and pelvis. No normal right kidney was visualized, although a rounded 7- X 6.6-cm thick-walled multiseptated cystic collection was present in the right renal fossa. There were additional cystic structures in the left anterior pelvis and a moderate amount of ascitic fluid. The appendix was visualized and appeared normal. Differential diagnoses included biliary cystadenoma, cystadenocarcinoma, pyogenic hepatic abscess, mildly complex hepatic cysts, multicystic dysplastic kidney, and mucinous peritoneal cysts. The patient was unaware of any prior diagnosis of renal agenesis. The patient underwent exploratory laparotomy to reveal fluid in the midabdomen, left abdomen, and pelvis, likely from previously ruptured cysts. A partially solid, multicystic mass, very adherent to the left peritoneum in the midabdomen, extended down toward the pelvis lateral to the colon. The appendix was identified and was grossly normal. Intraoperative frozen section examinations re vealed that the cysts were negative for malignancy. No right kidney or right ureter was present. There was a multicystic mass in the right retroperitoneum extending up over the psoas muscle, behind the right lobe of the liver and hepatoduodenal ligament, and up toward the apex of the diaphragm. Right pelvic cysts (4.6 X 4.2 X 3.5 cm in greatest dimension), peritoneal cysts (7 X 6.5 X 1 cm), and liver
benign cystic mesothelioma, peritoneal cysts, renal agenesis Key words:
INTRODUCTION
Benign cystic mesothelioma (BCM), also known as peritoneal inclusion cysts, is an uncommon condition characterized by peritoneal, multilocular, thin-walled, fluid-filled cysts. BCM is most often reported in women of reproductive age with a history of prior abdominal surgery [1-6], pelvic inflammatory disease, endometriosis [4-6], or leiomyomata [5]. Although benign, these cysts have a tendency to recur after surgical removal [1,3,5-7]. Only 20% of BCM cases have been reported in adult males [1]. Coexisting renal anomalies have been reported in only 3 other cases: a boy with contralateral renal agenesis [1], a teenage female with an extrarenal pelvis, and another teenage female with a horseshoe kidney [4], *Corresponding author, e-mail: [email protected]
Figure 1. A b d o m in a l co m p u te rize d to m o g ra p h y revealed m u ltis e p ta te d cysts (a rro w ) and absence o f th e rig h t kidn ey (circle).
cysts (9.5 X 5 X 2.5 cm) were submitted for histological analysis. Grossly, the specimens were pale, thin-walled, multi-loculated cysts with thin gelatinous and hemor rhagic contents. Extensive sampling revealed that the diameters of the individual cysts ranged from 2.5-5.5 cm, and wall thickness ranged from 0.1-0.3 cm. Hematoxylin and eosin-stained sections showed fibrous-walled cysts with variable lining (Fig. 2A). Some cysts had no surface lining, while others had squamous lining ranging from cuboidal to a hobnailed appearance (Fig. 2B). The cyst walls showed robust fibroblastic activity and prominent vasculature. No smooth muscle layer was seen. Immunohistochemistry was performed (Fig. 2C,D). The lining cells were positive for CK5, AE1/AE3, CD10, Wilms Tumor-1 (WT-1), p63, epithelial membrane antigen (EMA), calretinin, and D2-40 and negative for Pax8, CD31, CD34, mucin, and prostate specific antigen (PSA). Some epithelial cells were estrogen receptor (ER) positive, and progesterone receptor (PR) showed focal positivity. Stromal cells showed calretinin positivity. These findings were consistent with a diagnosis of BCM.
Figure 2. A. H em atoxylin and eosin stain show ed m u ltip le cysts w ith a va riab le lin in g , in c lu d in g fla tte n e d lin in g cells and areas o f squam ous m etaplasia (o rig in a l m a g n ific a tio n X40). B. Some o f th e lin in g cells had a h o b n a ile d appearance (o rig in a l m a g n ific a tio n X400). C. The lin in g cells w ere positive fo r CK5 and (D) estrogen rece pto r (im m un osta in, o rig in a l m a g n ific a tio n X200).
488
D.
M
urro et a l .
Table 1.
Peritoneal cysts associated with renal agenesis
C ase
A ge (years)
Sex
T ype o f cyst
Im m unostaining
Renal agenesis location
Present case
26
M
Mesothelial
Right
Devaraju and colleagues [14] Hodgins and Hancock [11] Stojsic and colleagues [1]
28 30 11
M M M
Mullerian Metanephric Mesothelial
CK5, AE1/AE3, CD 10, WT-1, EMA NR NR Calretinin, CK5/6, HBME1, EMA
Right Right Right
NR indicates not reported; WT-1, Wilms tumor-1; and EMA, epithelial membrane antigen.
Five weeks later, the patient was doing well without new complaints. Physical exam revealed no abnormali ties, but he was counseled to continue follow-up, as his cysts were likely to recur. DISCUSSION This case was clinically and pathologically consistent with previously reported cases of BCM [1-7]. The presence of a mesothelial lining was confirmed by immunopositivity with calretinin [1,6], AE1/AE3 [1,2,5,7], CK5 [1,4], CD10 [8], WT-1 [9], and EMA [1] and negativity for CD31, CD34 [6], Pax8 [10], and PSA [10]. Gross features of BCM include translucent, thin-walled cysts filled with hemor rhagic or serous fluid [3,4,7]. Histologically, these cysts are lined by flat or cuboidal cells [2,3,7], with possible squamous metaplasia [2,3,7] or chronic inflammation [4.7] . The exact pathogenesis of BCM is unclear. BCM has been considered both a true neoplastic lesion and a reactive lesion resulting from chronic peritoneal irritation [1.3.6.7] . Because a few reports have associated BCM with familial Mediterranean fever [3], there may be a genetic component. However, analysis was performed in only 1 case, which revealed a normal karyotype and negative breast cancer gene (BRCA) mutation status in a woman whose sister was also a BCM patient [3], Although these lesions are benign, their recurrence rate is approximately 50% [1,2], The differential diagnosis includes cystic lymphan gioma, mullerian duct cysts, urogenital cysts, and malignant mesothelioma. Cystic lymphangiomas have chylous contents, and the walls contain smooth muscle and lymphoid aggregates [4-7]. Additionally, immunostaining is positive for vascular markers such as CD31 and CD34 [6] and negative for cytokeratin [7]. Mullerian cysts are lined by serous or mucinous epithelium [6], Immunostaining of the cyst lining is Pax8 positive [10] and CD 10 negative [8], Urogenital cysts are lined by cuboidal to columnar epithelium [2,11]. The walls contain fibrous tissue and smooth muscle, and primitive renal structures may be present [11]. Malignant mesothelioma can be distinguished from BCM by the presence of stromal invasion [5], high cellularity, nuclear atypia, and mitotic activity [5-7]. Due to the predilection of BCM to affect women of reproductive age, it has been suggested that BCM is
hormone dependent [3,6]. A case of BCM that regressed with tamoxifen treatment was reported in a young female, and the authors postulated that sensitivity to peripheral estrogen sources may explain recurrence of this lesion [12]. Sporadic estrogen and/or progesterone receptor positivity by immunohistochemistry has been previously reported in female patients [3,6]. In a study of 17 BCM cases, Sawh and colleagues noted ER and/or PR positivity in 3 female cases [6]. Three of the 4 male cases were tested for ER and PR expression by immunohistochem istry, and all 3 were negative. The authors suggested that the pelvic peritoneal lining cells may acquire ER and PR by metaplasia. ER and PR negativity was also reported in BCM in an 11-year-old boy [11], To the best of our knowledge, ours is the first case of BCM with ER and PR positivity in a male. Unilateral renal agenesis occurs when the ureteric bud fails to form the ureter, renal pelvis, and collecting duct in the fifth week of gestation [13]. Without stimulation from the ureteric bud, the metanephrogenic cap does not form normal renal tissue [11]. Thus, congenital absence of the kidney often results in ipsilateral absence of the ureter [11], The single kidney undergoes compensatory glomerular hyperfiltration, lead ing to renal injury that presents at a median age of 15 years [11]. A review by Westland and coworkers revealed that hypertension was present in 16% of patients with unilateral renal agenesis [13]. Since our patient presented with hypertension at such a young age, perhaps his right renal agenesis was the underlying cause. He had no other known medical conditions and no history of prior surgery, and no abdominal imaging was performed prior to his presentation in the emergency department. Renal agenesis associated with peritoneal cysts has been sporadically reported in the literature (Table 1). Devaraju and colleagues reported renal agenesis associ ated with mullerian cysts in a 28-year-old woman [14], and Hodgins and Hancock reported metanephric cysts associated with renal agenesis in a 30-year-old man [11], However, only 3 cases of BCM associated with various congenital renal abnormalities have been reported, and all occurred in pediatric patients [1,4]. One paper reported contralateral renal agenesis associated with BCM in an 11-year-old boy [1] and the other 2 reported an extrarenal pelvis and a horseshoe kidney in adolescent females [4], Perhaps the positive immunostaining with WT-1 in our
B e n ig n C y s t ic M
e s o t h e l io m a a n d
R e n a l A g e n e s is
489
case might explain this association. Unfortunately, most cases o f BCM in the literature have not discussed WT-1 staining. WT-1 was negative in the case o f BCM associated with contralateral renal agenesis [1] and not tested in the 2 other cases [4], The only other case of BCM associated with a coexisting congenital abnormality was reported in an 11-month-old male with right lung congenital cystic adenomatoid malformation [15]. Although the pathogenesis of BCM is attributed to chronic pelvic irritation or prior surgery, cases have been reported in patients without prior abdominal events [1,4,6,7,15,16], including 4 pediatric patients with coexisting congenital disorders [1,4,15], Therefore, a possible develop mental origin of BCM has been postulated [1], with pathogenesis attributed to peritoneal layer developmental abnormalities similar to hamartomatous conditions [16]. Unilocular mesothelial cyst pathogenesis has been attributed to improper posterior parietal development after bowel rotation, and similar cysts have been noted in the round ligament, splenic capsule, pleura, and pericardium [7]. Though BCM is rarely reported in young patients with no history of abdominal events, prior cases may have been misdiagnosed as lymphangioma [15]. Our patient could be another case that supports a developmental etiology of BCM. REFERENCES 1. Stojsic Z, Jankovic R, Jovanovic B, Vujovic D, Vucinic B, Bacetic D. Benign cystic mesothelioma of the peritoneum in a male child. J Pediatr Surg 2012;47:e45-e49. 2. Pantanowitz L, Botero M. Giant mesenteric cyst: a case report and review of the literature. Internet J Pathol 2001; 1(2). 3. Tangjitgamol S, Erlichman J, Northrop H, Malpica A, Wang X, Lee E, Kavanagh JJ. Benign multicystic peritoneal mesothelioma: case reports in the family with diverticulosis and literature review. Int J Gynecol Cancer 2005;15:1101-1107.
490
D. M u r r o
et a l .
4. Amesse LS, Gibbs P, Hardy J, Jones KR, Pfaff-Amesse T. Peritoneal inclusion cysts in adolescent females: a clinicopathological characterization of four cases. J Pediatr Adolesc Gynecol 2009; 22:41-48. 5. Dzieniecka M, Kaluzynski A. Benign multicystic peritoneal mesothelioma (BMPM): case report and review of the literature. Pol J Pathol 2011;2:122-124. 6. Sawh RN, Malpica A, Deavers MT, Liu J, Silva EG. Benign cystic mesothelioma of the peritoneum: a clinicopathologic study of 17 cases and immunohistochemical analysis of estrogen and proges terone receptor status. Hum Pathol 2003;34:369-374. 7. Ross MJ, Welch WR, Scully RE. Multilocular peritoneal inclusion cysts (so-called cystic mesotheliomas). Cancer 1989;64:1336-1346. 8. Hattori H. Ciliated cyst of probable mullerian origin arising in the posterior mediastinum. Virchows Arch 2005;446:82-84. 9. Langerak AW, Williamson KA, Miyagawa K, Hagemeijer A, Versnel MA, Hastie ND. Expression of the Wilms’ tumor gene WT1 in human malignant mesothelioma cell lines and relationship to platelet-derived growth factor A and insulin-like growth factor 2 expression. Genes Chromosomes Cancer 1995;12:87-96. 10. Tong G, Memeo L, Colarossi et al. Pax8 and Pax2 immunostaining facilitates the diagnosis of primary epithelial neoplasms of the male genital tract. Am J Surg Pathol 2011;35:1473-1483. 11. Hodgins TE, Hancock RA. Retroperitoneal cyst and congenital absence of ipsilateral kidney. Urology 1976;8:590-592. 12. Letterie GS, Yon JL. The antiestrogen tamoxifen in the treatment of recurrent benign cystic mesothelioma. Gynecol Oncol 1998;70:131— 133. 13. Westland R, Schreuder MF, Ket JCF, van Wijk JAE. Unilateral renal agenesis: a systematic review on associated anomalies and renal injury. Nephrol Dial Transplant 2013;28:1844-1855. 14. Devaraju S, Nerli RB, Hiremath MB. A large mullerian duct cyst presenting as an abdominal mass with ipsilateral renal agenesis: an unusual presentation. Nephrourol Mon 2012;4:640-643. 15. Terry NE, Fowler CL. Benign cystic mesothelioma in a child. J Pediatr Surg 2009;44:e9-el 1. 16. Shakya VC, Agrawal CS, Karki S, Sah PL, Poudel P, Adhikary S. Benign cystic mesothelioma of the peritoneum in a child— case report and review of the literature. J Pediatr Surg 2011 ;46: e23-e26.
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Benign Cystic Mesothelioma Associated with Ipsilateral Renal Agenesis: A Case Report and Review of Literature D iana M
urro, 1*
A parna H arbhajanka , 1 B rett M ahon , 1
and
D aniel D eziel2
'Departm ent of Pathology, Rush University Medical Center, 1750 W. Harrison St., Suite 573 Jelke, Chicago, IL60612 d e p a rtm e n t o f Surgery, Rush University Medical Center, 1750 W. Harrison St., Suite 785 Jelke, Chicago, IL 60612
Received June 17, 2014; accepted September 4, 2014; published online September 10, 2014.
ABSTRACT
CASE REPORT
Benign Cystic Mesothelioma (BCM) is an uncommon peritoneal lesion that usually occurs in reproductive age females with a history of abdominal surgery. Occasional expression of estrogen and progesterone receptor in these cells may explain female predilection. Reports of BCM in males are rare. We describe a case of BCM associated with ipsilateral renal agenesis in a young male without any surgical history. The cyst lining stained positive for cytokeratin, Wilms Tumor-1, epithelial membrane anti gen, CD10, estrogen receptor, and progesterone receptor, and negative for PAX-8. Only three cases of BCM associated with congenital renal anomalies have been reported. To the best of our knowledge, this is the first case of BCM associated with ipsilateral renal agenesis in an adult male and the first male case of BCM displaying estrogen and progesterone receptor positivity. Such a case reveals the presence of congenital anomalies should be considered in patients with BCM.
A 26-year-old man with a history of hypertension, currently not on any medications, presented to the Emergency Department with worsening abdominal and right flank pain of 1 month’s duration. Physical exam revealed mild right lower quadrant and right costoverte bral angle tenderness without abdominal distention. Due to clinical suspicion for nephrolithiasis or appendicitis, initial computerized tomography (CT) without contrast was performed, followed by CT with contrast media. CT studies (Fig. 1) revealed a large, well-defined, homoge nous complex cystic mass with multiple septations along the posterior aspect of the inferior right hepatic lobe and left abdomen and pelvis. No normal right kidney was visualized, although a rounded 7- X 6.6-cm thick-walled multiseptated cystic collection was present in the right renal fossa. There were additional cystic structures in the left anterior pelvis and a moderate amount of ascitic fluid. The appendix was visualized and appeared normal. Differential diagnoses included biliary cystadenoma, cystadenocarcinoma, pyogenic hepatic abscess, mildly complex hepatic cysts, multicystic dysplastic kidney, and mucinous peritoneal cysts. The patient was unaware of any prior diagnosis of renal agenesis. The patient underwent exploratory laparotomy to reveal fluid in the midabdomen, left abdomen, and pelvis, likely from previously ruptured cysts. A partially solid, multicystic mass, very adherent to the left peritoneum in the midabdomen, extended down toward the pelvis lateral to the colon. The appendix was identified and was grossly normal. Intraoperative frozen section examinations re vealed that the cysts were negative for malignancy. No right kidney or right ureter was present. There was a multicystic mass in the right retroperitoneum extending up over the psoas muscle, behind the right lobe of the liver and hepatoduodenal ligament, and up toward the apex of the diaphragm. Right pelvic cysts (4.6 X 4.2 X 3.5 cm in greatest dimension), peritoneal cysts (7 X 6.5 X 1 cm), and liver
benign cystic mesothelioma, peritoneal cysts, renal agenesis Key words:
INTRODUCTION
Benign cystic mesothelioma (BCM), also known as peritoneal inclusion cysts, is an uncommon condition characterized by peritoneal, multilocular, thin-walled, fluid-filled cysts. BCM is most often reported in women of reproductive age with a history of prior abdominal surgery [1-6], pelvic inflammatory disease, endometriosis [4-6], or leiomyomata [5]. Although benign, these cysts have a tendency to recur after surgical removal [1,3,5-7]. Only 20% of BCM cases have been reported in adult males [1]. Coexisting renal anomalies have been reported in only 3 other cases: a boy with contralateral renal agenesis [1], a teenage female with an extrarenal pelvis, and another teenage female with a horseshoe kidney [4], *Corresponding author, e-mail: [email protected]
Figure 1. A b d o m in a l co m p u te rize d to m o g ra p h y revealed m u ltis e p ta te d cysts (a rro w ) and absence o f th e rig h t kidn ey (circle).
cysts (9.5 X 5 X 2.5 cm) were submitted for histological analysis. Grossly, the specimens were pale, thin-walled, multi-loculated cysts with thin gelatinous and hemor rhagic contents. Extensive sampling revealed that the diameters of the individual cysts ranged from 2.5-5.5 cm, and wall thickness ranged from 0.1-0.3 cm. Hematoxylin and eosin-stained sections showed fibrous-walled cysts with variable lining (Fig. 2A). Some cysts had no surface lining, while others had squamous lining ranging from cuboidal to a hobnailed appearance (Fig. 2B). The cyst walls showed robust fibroblastic activity and prominent vasculature. No smooth muscle layer was seen. Immunohistochemistry was performed (Fig. 2C,D). The lining cells were positive for CK5, AE1/AE3, CD10, Wilms Tumor-1 (WT-1), p63, epithelial membrane antigen (EMA), calretinin, and D2-40 and negative for Pax8, CD31, CD34, mucin, and prostate specific antigen (PSA). Some epithelial cells were estrogen receptor (ER) positive, and progesterone receptor (PR) showed focal positivity. Stromal cells showed calretinin positivity. These findings were consistent with a diagnosis of BCM.
Figure 2. A. H em atoxylin and eosin stain show ed m u ltip le cysts w ith a va riab le lin in g , in c lu d in g fla tte n e d lin in g cells and areas o f squam ous m etaplasia (o rig in a l m a g n ific a tio n X40). B. Some o f th e lin in g cells had a h o b n a ile d appearance (o rig in a l m a g n ific a tio n X400). C. The lin in g cells w ere positive fo r CK5 and (D) estrogen rece pto r (im m un osta in, o rig in a l m a g n ific a tio n X200).
488
D.
M
urro et a l .
Table 1.
Peritoneal cysts associated with renal agenesis
C ase
A ge (years)
Sex
T ype o f cyst
Im m unostaining
Renal agenesis location
Present case
26
M
Mesothelial
Right
Devaraju and colleagues [14] Hodgins and Hancock [11] Stojsic and colleagues [1]
28 30 11
M M M
Mullerian Metanephric Mesothelial
CK5, AE1/AE3, CD 10, WT-1, EMA NR NR Calretinin, CK5/6, HBME1, EMA
Right Right Right
NR indicates not reported; WT-1, Wilms tumor-1; and EMA, epithelial membrane antigen.
Five weeks later, the patient was doing well without new complaints. Physical exam revealed no abnormali ties, but he was counseled to continue follow-up, as his cysts were likely to recur. DISCUSSION This case was clinically and pathologically consistent with previously reported cases of BCM [1-7]. The presence of a mesothelial lining was confirmed by immunopositivity with calretinin [1,6], AE1/AE3 [1,2,5,7], CK5 [1,4], CD10 [8], WT-1 [9], and EMA [1] and negativity for CD31, CD34 [6], Pax8 [10], and PSA [10]. Gross features of BCM include translucent, thin-walled cysts filled with hemor rhagic or serous fluid [3,4,7]. Histologically, these cysts are lined by flat or cuboidal cells [2,3,7], with possible squamous metaplasia [2,3,7] or chronic inflammation [4.7] . The exact pathogenesis of BCM is unclear. BCM has been considered both a true neoplastic lesion and a reactive lesion resulting from chronic peritoneal irritation [1.3.6.7] . Because a few reports have associated BCM with familial Mediterranean fever [3], there may be a genetic component. However, analysis was performed in only 1 case, which revealed a normal karyotype and negative breast cancer gene (BRCA) mutation status in a woman whose sister was also a BCM patient [3], Although these lesions are benign, their recurrence rate is approximately 50% [1,2], The differential diagnosis includes cystic lymphan gioma, mullerian duct cysts, urogenital cysts, and malignant mesothelioma. Cystic lymphangiomas have chylous contents, and the walls contain smooth muscle and lymphoid aggregates [4-7]. Additionally, immunostaining is positive for vascular markers such as CD31 and CD34 [6] and negative for cytokeratin [7]. Mullerian cysts are lined by serous or mucinous epithelium [6], Immunostaining of the cyst lining is Pax8 positive [10] and CD 10 negative [8], Urogenital cysts are lined by cuboidal to columnar epithelium [2,11]. The walls contain fibrous tissue and smooth muscle, and primitive renal structures may be present [11]. Malignant mesothelioma can be distinguished from BCM by the presence of stromal invasion [5], high cellularity, nuclear atypia, and mitotic activity [5-7]. Due to the predilection of BCM to affect women of reproductive age, it has been suggested that BCM is
hormone dependent [3,6]. A case of BCM that regressed with tamoxifen treatment was reported in a young female, and the authors postulated that sensitivity to peripheral estrogen sources may explain recurrence of this lesion [12]. Sporadic estrogen and/or progesterone receptor positivity by immunohistochemistry has been previously reported in female patients [3,6]. In a study of 17 BCM cases, Sawh and colleagues noted ER and/or PR positivity in 3 female cases [6]. Three of the 4 male cases were tested for ER and PR expression by immunohistochem istry, and all 3 were negative. The authors suggested that the pelvic peritoneal lining cells may acquire ER and PR by metaplasia. ER and PR negativity was also reported in BCM in an 11-year-old boy [11], To the best of our knowledge, ours is the first case of BCM with ER and PR positivity in a male. Unilateral renal agenesis occurs when the ureteric bud fails to form the ureter, renal pelvis, and collecting duct in the fifth week of gestation [13]. Without stimulation from the ureteric bud, the metanephrogenic cap does not form normal renal tissue [11]. Thus, congenital absence of the kidney often results in ipsilateral absence of the ureter [11], The single kidney undergoes compensatory glomerular hyperfiltration, lead ing to renal injury that presents at a median age of 15 years [11]. A review by Westland and coworkers revealed that hypertension was present in 16% of patients with unilateral renal agenesis [13]. Since our patient presented with hypertension at such a young age, perhaps his right renal agenesis was the underlying cause. He had no other known medical conditions and no history of prior surgery, and no abdominal imaging was performed prior to his presentation in the emergency department. Renal agenesis associated with peritoneal cysts has been sporadically reported in the literature (Table 1). Devaraju and colleagues reported renal agenesis associ ated with mullerian cysts in a 28-year-old woman [14], and Hodgins and Hancock reported metanephric cysts associated with renal agenesis in a 30-year-old man [11], However, only 3 cases of BCM associated with various congenital renal abnormalities have been reported, and all occurred in pediatric patients [1,4]. One paper reported contralateral renal agenesis associated with BCM in an 11-year-old boy [1] and the other 2 reported an extrarenal pelvis and a horseshoe kidney in adolescent females [4], Perhaps the positive immunostaining with WT-1 in our
B e n ig n C y s t ic M
e s o t h e l io m a a n d
R e n a l A g e n e s is
489
case might explain this association. Unfortunately, most cases o f BCM in the literature have not discussed WT-1 staining. WT-1 was negative in the case o f BCM associated with contralateral renal agenesis [1] and not tested in the 2 other cases [4], The only other case of BCM associated with a coexisting congenital abnormality was reported in an 11-month-old male with right lung congenital cystic adenomatoid malformation [15]. Although the pathogenesis of BCM is attributed to chronic pelvic irritation or prior surgery, cases have been reported in patients without prior abdominal events [1,4,6,7,15,16], including 4 pediatric patients with coexisting congenital disorders [1,4,15], Therefore, a possible develop mental origin of BCM has been postulated [1], with pathogenesis attributed to peritoneal layer developmental abnormalities similar to hamartomatous conditions [16]. Unilocular mesothelial cyst pathogenesis has been attributed to improper posterior parietal development after bowel rotation, and similar cysts have been noted in the round ligament, splenic capsule, pleura, and pericardium [7]. Though BCM is rarely reported in young patients with no history of abdominal events, prior cases may have been misdiagnosed as lymphangioma [15]. Our patient could be another case that supports a developmental etiology of BCM. REFERENCES 1. Stojsic Z, Jankovic R, Jovanovic B, Vujovic D, Vucinic B, Bacetic D. Benign cystic mesothelioma of the peritoneum in a male child. J Pediatr Surg 2012;47:e45-e49. 2. Pantanowitz L, Botero M. Giant mesenteric cyst: a case report and review of the literature. Internet J Pathol 2001; 1(2). 3. Tangjitgamol S, Erlichman J, Northrop H, Malpica A, Wang X, Lee E, Kavanagh JJ. Benign multicystic peritoneal mesothelioma: case reports in the family with diverticulosis and literature review. Int J Gynecol Cancer 2005;15:1101-1107.
490
D. M u r r o
et a l .
4. Amesse LS, Gibbs P, Hardy J, Jones KR, Pfaff-Amesse T. Peritoneal inclusion cysts in adolescent females: a clinicopathological characterization of four cases. J Pediatr Adolesc Gynecol 2009; 22:41-48. 5. Dzieniecka M, Kaluzynski A. Benign multicystic peritoneal mesothelioma (BMPM): case report and review of the literature. Pol J Pathol 2011;2:122-124. 6. Sawh RN, Malpica A, Deavers MT, Liu J, Silva EG. Benign cystic mesothelioma of the peritoneum: a clinicopathologic study of 17 cases and immunohistochemical analysis of estrogen and proges terone receptor status. Hum Pathol 2003;34:369-374. 7. Ross MJ, Welch WR, Scully RE. Multilocular peritoneal inclusion cysts (so-called cystic mesotheliomas). Cancer 1989;64:1336-1346. 8. Hattori H. Ciliated cyst of probable mullerian origin arising in the posterior mediastinum. Virchows Arch 2005;446:82-84. 9. Langerak AW, Williamson KA, Miyagawa K, Hagemeijer A, Versnel MA, Hastie ND. Expression of the Wilms’ tumor gene WT1 in human malignant mesothelioma cell lines and relationship to platelet-derived growth factor A and insulin-like growth factor 2 expression. Genes Chromosomes Cancer 1995;12:87-96. 10. Tong G, Memeo L, Colarossi et al. Pax8 and Pax2 immunostaining facilitates the diagnosis of primary epithelial neoplasms of the male genital tract. Am J Surg Pathol 2011;35:1473-1483. 11. Hodgins TE, Hancock RA. Retroperitoneal cyst and congenital absence of ipsilateral kidney. Urology 1976;8:590-592. 12. Letterie GS, Yon JL. The antiestrogen tamoxifen in the treatment of recurrent benign cystic mesothelioma. Gynecol Oncol 1998;70:131— 133. 13. Westland R, Schreuder MF, Ket JCF, van Wijk JAE. Unilateral renal agenesis: a systematic review on associated anomalies and renal injury. Nephrol Dial Transplant 2013;28:1844-1855. 14. Devaraju S, Nerli RB, Hiremath MB. A large mullerian duct cyst presenting as an abdominal mass with ipsilateral renal agenesis: an unusual presentation. Nephrourol Mon 2012;4:640-643. 15. Terry NE, Fowler CL. Benign cystic mesothelioma in a child. J Pediatr Surg 2009;44:e9-el 1. 16. Shakya VC, Agrawal CS, Karki S, Sah PL, Poudel P, Adhikary S. Benign cystic mesothelioma of the peritoneum in a child— case report and review of the literature. J Pediatr Surg 2011 ;46: e23-e26.
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