Published online Jan 14, 2018. doi: 10.3748/wjg.v24.i2.303
Peer-review started: August 31, 2017
First decision: September 20, 2017
Revised: October 3, 2017
Accepted: October 26, 2017
Article in press: October 26, 2017
Published online: January 14, 2018
Primary benign schwannoma of the mesentery is extremely rare. To date, only 9 cases have been reported in the English literature, while mesenteric schwannoma with ossified degeneration has not been reported thus far. In the present study, we present the first giant ossified benign mesenteric schwannoma in a 58-year-old female. Ultrasound, computed tomography and magnetic resonance imaging were used, but it was still difficult to determine the definitive location and diagnose the mass. By laparotomy, a 10.0 cm × 9.0 cm × 9.0 cm giant mass was found in the mesentery and was then completely resected. Microscopically, the tumour located in the mesentery mainly consisted of spindle-shaped cells with a palisading arrangement. Some areas of the tumour were ossified, and a true metaplastic bone formation was observed, with the presence of bone lamellae and osteoblasts. Immunohistochemical investigation of the tumour located in the mesentery showed that the staining for the S-100 protein was strongly positive, while the stainings of SMA, CD34, CD117 and DOG-1 were negative. The cell proliferation index, measured with Ki67 staining, was less than 3%. Finally, a giant ossified benign mesenteric schwannoma was diagnosed. After surgery, the patient was followed up for a period of 43 mo, during which she remained well, with no evidence of tumour recurrence.
Core tip: To date, only 9 cases of mesenteric schwannomas have been reported in the English literature; an ossified mesenteric schwannoma has not been reported. In the present study, we present the first giant ossified benign mesenteric schwannoma. It was challenging to determine the location and obtain a precise diagnosis of the mesenteric schwannoma prior to surgery. We completely resected the mesenteric schwannoma by laparotomy. In this paper, a literature review was conducted to deepen our understanding of mesenteric schwannomas.