Glomus tumors are mesenchymal tumors composed of modified smooth muscle cells representing a neoplastic counterpart of the perivascular glomus bodies. They are most common in the skin and subcutaneous tissue, but also occur in the viscera. In the gut, they are almost exclusively found in the stomach. There have been only seven previous cases reported in the literature of glomus tumor in the colon, 3 of which were in the anorectal area. We report the fourth case of glomus tumor in the anorectum, and 7th in the colon. A 68 year old female was referred for abdominal–perineal resection of a locally advanced rectal carcinoma after neo-adjuvant chemotherapy/radiation. The tumor showed marked therapy response with minimal residual tumor. From the pericolonic fat, a small nodule, 0.3 cm, was found, considered to be a lymph node. On histologic examination, this nodule was composed of a vascular lesion, where dilated blood vessels were associated with small collections of bland cells. The morphology and immunohistochemistry were consistent with a glomus tumor.
Glomus tumors are generally benign, though rare cases have resulted in metastasis and death: histological features such as cellular atypia, mitosis and lymphovascular invasion do not predict malignant behavior.
Ethics: This study has been performed according to the declaration of Helsinki. In our institution, case reports do not require an ethics board review, and hence none was obtained for this pathology based case report.
