title: A large retroperitoneal malignant solitary fibrous tumor.
abstract: We report on a large, retroperitoneal, malignant, solitary fibrous tumor (SFT) with high proliferation activity. A 43-year-old man was admitted to our department complaining of a palpable mass. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a large retroperitoneal tumor occupying the entire abdominal cavity. A laparotomy was performed for diagnosis and treatment, which revealed a tumor in the retroperitoneum but with no invasion to the surrounding organs, thereby allowing safe macroscopic excision. Histologically, the tumor was composed of spindle-shaped cells with patternless pattern and a hemangiopericytomatous appearance. Moreover, immunohistochemical staining was positive for CD34, vimentin, Bcl-2, and CD99 and negative for desmin, S-100p, and smooth muscle actin (AMA). The tumor exhibited high cellularity, moderate mitotic activity, pleomorphism, necrosis, and hemorrhagic changes. In addition, the Ki-67 labeling index was 37%. These findings confirmed the diagnosis of malignant SFT with high proliferation activity. Subsequently, adjuvant doxorubicin plus ifosfamide chemotherapy was performed. No signs of recurrence were observed 12 months after the surgery.
authors: Department of Surgery, Yamatotakada Municipal Hospital, Yamatotakada, Nara, Japan.
authors: Tomoaki
authors: T
authors: Yoh
authors: Ritsuko
authors: R
authors: Sata
authors: Atsushi
authors: A
authors: Kobayashi
authors: Seidai
authors: S
authors: Wada
authors: Yuya
authors: Y
authors: Nakamura
authors: Tatsushi
authors: T
authors: Kato
authors: Hiroyuki
authors: H
authors: Nakayama
authors: Ryuji
authors: R
authors: Okamura
mesh_terms: D000328:Adult; D003131:Combined Modality Therapy; D003952:Diagnostic Imaging; D006801:Humans; D008297:Male; D012187:Retroperitoneal Space; D054364:Solitary Fibrous Tumors / Q000175:diagnosis / Q000473:pathology / Q000628:therapy*
keywords: Ki67; Malignant solitary fibrous tumor; Retroperitoneum