A 42-year-old asymptomatic woman presented for routine health checkup. Abdominal examination was unremarkable. The laboratory tests were normal. The chest radiograph, upper gastrointestinal endoscopy and abdominal computed tomography showed no abnormal findings. A colonoscopy was performed. A hepatic flexure polypoid mass (8 × 8 mm in diameter), covered with normal-appearing mucosa, was identified (Figure 1A). Polypectomy of polyp was performed using snare. Histologically, a circumscribed proliferation of nests of histiocyte-like cells with finely granular eosinophilic cytoplasm was confirmed in the submucosa (Figure 1B). No feature of malignancy was found. Immunohistochemical examination identified granular cell tumor with positivity for S100 (Figure 1C), SOX10 (Figure 1D), CD68 (Figure 1E). The tumor was finally diagnosed as granular cell tumor occurred in the colon by pathologic confirmation. Granular cell tumor is a typically benign tumor with a risk of malignant transformation, rarely occurs in the colon without specific symptoms, which should be differentiated from leiomyoma, lipoma, and stromal tumor [1,2]. Granular cell tumor occurs commonly among those middle-aged women, which is found incidentally during colonoscopy. Granular cell tumors may be removed by endoscopic mucosal resection or snare polypectomy to avoid aggressive surgical interventions. The postoperative course was uneventful. The patient elected to undergo annual surveillance.

The authors have no conflicts of interest to declare.

The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Written informed consent was obtained from the patient for publication of this “GI Image”. Board institutional approval was not required.

Collection of data and writing: Yong-Xin Yang; Manuscript preparation: Yong-Xin Yang; Final approval of the manuscript: Wei Liu.