A hypervascular malignant solitary fibrous tumor in the mesentery of the rectum with good response to preoperative radiation therapy

Abstract

Solitary fibrous tumor (SFT) is an uncommon neoplasm located in the pelvis. Here, we report a case of hypervascular malignant SFT in the mesentery of the rectum that showed a significant response to preoperative radiotherapy. A 36-year-old man presented to our department with constipation and dysuria. Abdominal computed tomography confirmed a large round neoformation (155 mm in the longest diameter) with an evident contrastenhanced periphery and a central necrotic area in the pelvis. Considering the results of the examinations, a pelvic neoplasm was strongly suspected. Due to the difficulty of safe gross total removal, a diagnostic laparotomy was indicated. Histologically, hypercellularity with spindleshaped cells and high mitotic activity was observed. Immunohistochemically, the tumor was positive for CD34, CD99, and bcl-2. The diagnosis of hypervascular malignant SFT was made. After the appropriate information had been given, the patient chose the use of preoperative radiotherapy. After local irradiation, the tumor size regressed to 105 mm in the longest diameter. Laparotomy revealed a tumor originating from the mesentery of the rectum, and the tumor was successfully excised. This case strongly suggested the potential applicability of preoperative radiotherapy for the safe gross total removal of a large pelvic SFT.

A diagnostic challenge; pelvic solitary fibrous tumor (SFT) mimicking Peri‐Anal gastrointestinal stromal tumor (GIST): A case report

“…SFTs typically affect men and women equally and in middle ages 5 with no specific symptoms typically until the tumor starts to compress peripheral structures. 3 It is similar to our study in that the patient has no significant complaints except some discomforts in her abdomen and peri-anal region. Although, the CT scan showed the compressing signs of the tumor on the external anal sphincter.…”

“…In the current study, we have also reported a rare case of grade II pelvic SFT. SFTs typically affect men and women equally and in middle ages 5 with no specific symptoms typically until the tumor starts to compress peripheral structures 3 . It is similar to our study in that the patient has no significant complaints except some discomforts in her abdomen and peri‐anal region.…”

“…Although, 50%–70% of SFTs are mentioned to originate from outside the thorax 16 . Herein, pelvic SFT is an extremely rare tumor, usually larger along with more malignant behaviors 3 . In the current study, we have also reported a rare case of grade II pelvic SFT.…”

Successful laparoscopic treatment of a giant solitary fibrous tumor of the mesorectum: A case report and literature review

“…A recent retrospective series demonstrated that 34% of all SFT occur in the abdominopelvic region and that the abdominopelvic cavity is a major primary site for SFT . However, a SFT that arises from the mesentery is unusual, and a SFT from the mesorectum is rarer still—we found only five reports describing such SFT .…”

“…A definitive preoperative diagnosis is important to differentiate SFT from other tumors because gastrointestinal stromal tumor can be treated with neoadjuvant chemotherapy. However, we resected this tumor without fine‐needle aspiration biopsy as it rarely provides enough tissue for a definitive diagnosis because of the heterogeneous distribution of cellular density within the tumor and because the tumor was considered to be resectable . We preoperatively planned a low anterior resection of the rectum but changed the procedure to tumor extirpation from the mesorectum because we judged the tumor could be resected without disturbing blood flow to the rectal wall.…”