title: Microcystic variant of localized malignant mesothelioma accompanying an adenomatoid tumor-like lesion.
abstract: The case of a 70-year-old man with a hitherto undescribed pleural mesothelioma is reported. The tumor was localized in the left lung apex and had invaded the parietal pleura. Histologically, the tumor was characterized by a proliferation of epithelioid cells and the formation of microcysts. The tumor cells were positive for calretinin and vimentin, and possessed abundant microvilli, indicating a mesothelial cell origin for the tumor. A high Ki-67 index and mitotic index, and the recurrence of the tumor after surgery, indicated malignancy. Based on the evidence, we propose that the tumor is a microcystic variant of a localized malignant mesothelioma.
authors.affiliation: Department of Surgical Pathology, Niigata University Hospital, Asahimachi-dori, Japan. umezu@med.niigata-u.ac.jp
authors.forename: Hajime
authors.initials: H
authors.lastname: Umezu
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Kuwata
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ebe
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Naito
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yamato
authors.forename: Takaaki
authors.initials: T
authors.lastname: Ishiyama
authors.forename: Masanori
authors.initials: M
authors.lastname: Tsuchida
authors.forename: Mina
authors.initials: M
authors.lastname: Okuizumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Naoya
authors.initials: N
authors.lastname: Koizumi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D018254:Adenomatoid Tumor / Q000473:pathology*; D000368:Aged; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018261:Mesothelioma, Cystic / Q000378:metabolism* / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D009378:Neoplasms, Multiple Primary; D016609:Neoplasms, Second Primary; D010997:Pleural Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000648:ultrastructure