Giant solitary fibrous tumor of the pelvis successfully treated with preoperative embolization and surgical resection: a case report

Abstract

Solitary fibrous tumors (SFTs) rarely develop in the pelvis. When they do arise, they are usually treated using surgery, although SFTs are often very large by the time of diagnosis, which makes surgical excision difficult. We report a case of a 63-year-old man who was referred to our hospital for the treatment of a giant tumor of the pelvis. Computed tomography (CT) revealed a 30 × 25 × 19 cm sized hypervascular tumor that almost completely filled the pelvic cavity. The diagnosis of SFT was made by CT-assisted needle biopsy. The feeding arteries of the tumor were embolized twice. The first embolization aimed to reduce the tumor volume, while the second one was planned a day prior to the surgery to obtain hematostasis during the operation. Tumor resection was then performed. The blood loss during the operation was 440 ml, and there was no uncontrollable bleeding. The postoperative course was uneventful. No recurrence of SFT was observed during a 2-year follow-up.

Figure 1

Preoperative computed tomography (CT), angiography before embolization, and plain CT after embolization with lipiodol and N-butyl-2-cyanoacrylate. (A), (B) Preoperative CT showed a giant pelvic mass lesion, measuring 30 × 25 × 19 cm. (C) Angiography of the left iliac artery revealed that the mass was mainly supplied by the left obturator artery (black arrow), left internal pudendal artery (white arrow), and left superior vesical artery (red arrow). (D), (E), (F) CT after embolization showed that lipiodol and N-butyl-2-cyanoacrylate were well distributed to the left obturator artery (black arrow), left internal pudendal artery (white arrow), and left superior vesical artery (red arrow), demonstrating successful embolization of the target vessels.

Figure 2

Macroscopic, microscopic, and immunohistological tumor findings. (A) Gross appearance of the resected tumor. (B) Microscopic findings were of a disordered arrangement of spindle cells (×100, original magnification). (C) Immunohistochemical staining revealed that tumor cells were positive for CD34 (×200, original magnification).