Diffuse malignant biphasic peritoneal mesothelioma with cystic areas.
We report a case of peritoneal biphasic mesothelioma with cystic areas in a patient with professional exposure to asbestos. It showed focal epithelial glandular and papillary proliferations, also presenting fluid filled cysts, whose wall consisted of a proliferation of spindle cells. Atypia and mitoses were very scanty. EMA, vimentin, CK5/6, D2-40, calretinin and P53 were positive and desmin was negative in both epithelial and spindle areas, including the ones surrounding the cystic spaces. These findings gave an essential aid in the differential diagnosis with a benign cystic mesothelioma and with a cystic epithelial mesothelioma with secondary pseudosarcomatous myofibroblastic proliferation. The presence of cystic areas in a malignant mesothelioma could make difficult the diagnosis. A large amount of tumour tissue is necessary for confirming the biphasic histotype, an aggressive histotype, even in the presence of mild histological features and of some others favourable clinical prognostic indices as in this case. To our knowledge this is the first case of malignant peritoneal biphasic mesothelioma with cystic features reported in the literature.


BACKGROUND
Cystic Mesothelioma, Immunohistochemistry, Malignant Mesothelioma, Peritoneal Diseases, Mesothelial Neoplasms.
Daniela
D
Cabibi
Roberta
R
Tutino
Giuseppe
G
Salamone
Gianfranco
G
Cocorullo
Antonino
A
Agrusa
Gaspare
G
Gulotta
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001064:Appendicitis / Q000175:diagnosis; D001194:Asbestos / Q000009:adverse effects; D001201:Ascites / Q000209:etiology; D014408:Biomarkers, Tumor / Q000032:analysis; D002945:Cisplatin / Q000008:administration & dosage; D003424:Crohn Disease / Q000175:diagnosis; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D008297:Male; D008654:Mesothelioma / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D018261:Mesothelioma, Cystic / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D000086002:Mesothelioma, Malignant; D016273:Occupational Exposure; D000068437:Pemetrexed / Q000008:administration & dosage; D010534:Peritoneal Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*
D014408:Biomarkers, Tumor; D000068437:Pemetrexed; D001194:Asbestos; D002945:Cisplatin