Schwannoma of the rectum: A case report and literature review

Abstract

Schwannoma is a tumor originating from the Schwann cells. Gastrointestinal schwannomas are uncommon stromal tumors of the intestinal tract and, in particular, rectal schwannomas are extremely rare. In fact, it is well established that schwannomas appear more frequently in the stomach and in the small intestine, while location in the colon or in the rectum is uncommon. Reading the literature, only few cases of rectal schwannoma have been reported. Their diagnosis is confirmed by the immunohistochemical panel (S-100 protein). When these tumors are located in the colon and in the rectum, radical excision with wide margins is mandatory, due to their tendency to recur locally or become malignant, if left untreated. In the present study, we describe a case of a rectal schwannoma occured in a 72-year-old man, presented as a small polypoid lesion, which was successfully removed in toto by hot-biopsy, during the same endoscopy, due to the dimensons. No recurrence of the lesion was observed after 6 mo of follow-up.

Keywords: Immunohistochemistry; Rectum; S-100 protein; Schwannoma; Treatment.

Figure 1

In case of a rectal schwannoma, the colonoscopy disclosed evidence of a little polypoid lesion in the left lateral wall of the rectum.

Figure 2

In case of rectal schwannoma, the tumor, located in the submucosa, has a nodular well-defined structure (haematoxylin and eosin, ×20). The structure that consists in proliferation of Schwann-like cells, showing a palisading arrangement (A), being marked by S-100 protein (B).