title: Extragonadal seminoma presenting as a large mass in the pelvic cavity without c-kit-activating mutations.
abstract: Extragonadal germ cell tumors are relatively rare tumors, which usually occur in the mediastinum or retroperitoneum. In this report, we present a case of primary seminoma arising in the pelvic cavity. A 58-year-old man with urinary retention and abdominal distension was admitted to our hospital. Computed tomography and magnetic resonance imaging demonstrated a large mass in the pelvic cavity. Histological examination of the specimens obtained by open biopsy revealed seminomatous malignant cells. Immunohistochemical studies detected vimentin, placental alkaline phosphatase and c-kit. Taking these results together with the patient's other clinical manifestations, this case was diagnosed as extragonadal seminoma without c-kit-activating mutations, and chemotherapy followed by radiation therapy was successful. Primary seminoma in the pelvic cavity is extremely rare, but should be considered a cause of pelvic mass formation.
authors.affiliation: Department of Clinical Investigation, National Hospital Organization National Kochi Hospital, 1-2-25 Asakuranishimachi, Kochi 780-8077, Japan.
authors.forename: Takahira
authors.initials: T
authors.lastname: Kuno
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Shinohara
authors.forename: Kotaro
authors.initials: K
authors.lastname: Kasahara
authors.forename: Aoi
authors.initials: A
authors.lastname: Matsuoka
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Keishi
authors.initials: K
authors.lastname: Naruse
authors.forename: Hironobu
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000469:Alkaline Phosphatase / Q000302:isolation & purification; D003125:Colostomy; D003937:Diagnosis, Differential; D058851:GPI-Linked Proteins / Q000302:isolation & purification; D006801:Humans; D007150:Immunohistochemistry; D007415:Intestinal Obstruction / Q000601:surgery; D007527:Isoenzymes / Q000302:isolation & purification; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010386:Pelvic Neoplasms / Q000737:chemistry / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000302:isolation & purification*; D018239:Seminoma / Q000737:chemistry / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D016896:Treatment Outcome; D016055:Urinary Retention / Q000209:etiology; D014746:Vimentin / Q000302:isolation & purification
chemical_list: D058851:GPI-Linked Proteins; D007527:Isoenzymes; D014746:Vimentin; D019009:Proto-Oncogene Proteins c-kit; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental