Benign cystic mesothelioma associated with ipsilateral renal agenesis: a case report and review of literature.

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 antigen, 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.

Diagnosis and treatment of benign multicystic peritoneal mesothelioma.

Benign multicystic peritoneal mesothelioma (BMPM) is a rare cystic mesothelial lesion that occurs predominantly in reproductive aged women. A 56-year-old Caucasian male was admitted to our surgical department with a chief complaint of a painful mass in his right lower abdomen for almost 2 years. The physical examination revealed a palpable painful mass. Computed tomography demonstrated an irregular, cystic tumor in his right lower abdomen. There was no obvious capsule or internal septations. No enhancement after intravenous administration of contrast was noted. An exploratory laparotomy was performed, and a multicystic tumor and adherent to the caecum was noted. The walls of the cysts were thin and smooth, filled with clear fluid, and very friable. An en bloc resection of the tumor, including appendix and caecum, was performed. Histological examination revealed multiple cysts lined with flattened simple epithelial cells, and the capsule walls of the cysts were composed of fibrous tissue. Immunohistochemical analysis documented positive expression of mesothelial cells and calretinin. The final diagnosis was BMPM. The patient was well at 6-mo follow-up. BMPM is exceedingly rare lesion. A complete resection of the tumor is required. The diagnosis of BMPM is based on pathological analysis.

Benign cystic mesothelioma of the peritoneum: a clinicopathologic study of 17 cases and immunohistochemical analysis of estrogen and progesterone receptor status.

Benign cystic mesothelioma (BCM) is an uncommon lesion of the peritoneum occurring predominantly in women of reproductive age. Although most patients are managed by surgical resection, a reported high incidence of cyst recurrence has led to the use of hormonal therapy in isolated cases in an attempt to control cyst size and relieve local symptoms. To date, the estrogen receptor (ER) and progesterone receptor (PR) status of BCM has not been evaluated. Here we present our experience with 17 cases (13 women, 4 men) of BCM seen over a 19-year period, including an immunohistochemical analysis of ER and PR status in 14 cases. All lesions showed typical morphological features of BCM, and calretinin immunostaining was positive in 14 of 14 cases. Five patients experienced either 1 or 2 tumor recurrences, and no patients died of disease. One case was diffusely positive for ER only, 1 case was focally positive for PR only, and 1 case was focally positive for both ER and PR. Although immunohistochemical detection of female sex hormone receptors in BCM is uncommon, the focal presence of ER and/or PR in some lesions does provide weak biologic support for the use of hormonal manipulation as a therapeutic option. Hum Pathol 34:369-374.

Cystic, peritoneal mesothelioma in a dog.

A 10-year-old, spayed female beagle was presented with a 2.5-year history of ascites. The ascitic fluid was a modified transudate with no abnormal cells present. Cardiac and hepatic functions were normal. Abdominal ultrasonography revealed cystic abnormalities of the peritoneal serosal surfaces. On exploratory laparotomy, the parietal and visceral peritonea were covered with variably sized, thin-walled cysts containing serous fluid. Histopathological, immunohistochemical, and ultrastructural analyses of the lesions were consistent with a diagnosis of cystic, peritoneal mesothelioma.