title: A Case of Solitary Well-Differentiated Papillary Mesothelioma with Invasive Foci in the Pleura.
abstract: Well-differentiated papillary mesothelioma (WDPM) is a rare, distinct tumor consisting of mesothelial cells with a papillary architecture, bland cytological features, and a tendency toward superficial spread without invasion. Rare cases with superficial invasion are termed WDPM with invasive foci. We report a case of solitary WDPM with invasive foci in the pleura. A 61-year-old woman presented with a lung adenocarcinoma. A small papillary lesion measuring 29 × 10 × 8 mm was incidentally found in the parietal pleura during a lobectomy for the lung adenocarcinoma. The fibrovascular core of the small papillary lesion was surrounded by a single layer of cuboidal cells with mild to moderate atypia and large nucleoli. Atypical mesothelial cells focally invaded the submesothelial layer. The cells of the papillary lesion were positive for cytokeratins and mesothelial markers. The Ki67 index was <1 %. The lesion did not show p16 loss on fluorescence in situ hybridization. We could not detect atypical mesothelial cells in the specimen from an extrapleural pneumonectomy. WDPM with invasive foci is prone to multifocality; however, our case represents a solitary case in the pleura.
authors.affiliation: Department of Laboratory Medicine and Pathology, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.|Department of Molecular Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Department of Surgery, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Hyung-Eun
authors.initials: HE
authors.lastname: Yoon
authors.affiliation: Department of Surgery, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Norimasa
authors.initials: N
authors.lastname: Ito
authors.affiliation: Department of Internal Medicine, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Tsuji
authors.affiliation: Department of Surgery, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Funakoshi
authors.affiliation: Department of Surgery, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Utsumi
authors.affiliation: Department of Surgery, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakaguchi
authors.affiliation: Department of Molecular Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Tsujimura
authors.affiliation: Department of Laboratory Medicine and Pathology, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Kasai
authors.affiliation: Department of Pathology, Tokyo Women's Medical University Yachiyo Medical Center, Yachiyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hiroshima
authors.affiliation: Department of Surgery, National Hospital Organization Kinki-chuo Chest Medical Center, Sakai, Osaka, Japan.
authors.forename: Akihide
authors.initials: A
authors.lastname: Matsumura
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000473:pathology*; D008654:Mesothelioma / Q000473:pathology*; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D010997:Pleural Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: pleura; solitary lesion; stromal invasion; well-differentiated papillary mesothelioma