Granular cellular tumors are unusual lesions that can occur in the gastrointestinal tract, where they localize most commonly to the esophagus followed by the colon.

We report a case of a young man with a sub-epithelial lesion of the ascending colon, removed by endoscopic submucosal dissection. Histological examination revealed a granular cellular tumor without features of malignancy. We present a systematic review of the English literature evaluating granular cellular tumors of lower gastrointestinal tract.

These tumors are usually asymptomatic and discovered incidentally during endoscopy performed for other reasons. Though their histological behavior is usually benign, 1-2% are malignant. Therefore, it is important that these lesions are excised and adequately pathologically characterized.

Granular cell tumor (GCT) was first described by Abrikossof in 1926. This tumor is a benign neoplasm of unclear histogenesis that is generally believed to be of nerve sheath origin. GCT is not common and most often affects the tongue, skin, and soft tissue, although it may occur anywhere in the body. Gastrointestinal tract involvement, and especially that of the colon, is very rare. This usually benign tumor appears as a submucosal nodule, measuring less than 2 cm in diameter and is often found incidentally during colorectal examinations. We describe the case of a 27-year-old man with a GCT in the cecum that was detected after a screening colonoscopy. Endoscopic examination revealed a yellowish submucosal tumor, 0.7 cm in diameter. An endoscopic mucosal polypectomy was done for histological confirmation and treatment.

Although colorectal granular cell tumors (GCTs) are rare, their incidental finding has increased as the use of diagnostic colonoscopy has become more common. Here we describe the case of a 41-yr-old man with a GCT in the descending colon that was detected after a screening colonoscopy. Endoscopic examination revealed a yellowish submucosal tumor, 13x12 mm in diameter, in the descending colon. Endoscopic mucosal resection (EMR) followed by histological examination revealed that the tumor was composed of plump histiocyte-like cells with an abundant granular eosinophilic cytoplasm and small round nuclei. The tumor cells expressed S-100 protein and stained with periodic acid-Schiff, but were negative for desmin and cytokeratin. The resected tumor was diagnosed as a GCT. Colonoscopists should consider the possibility of GCT in the differential diagnosis of yellowish submucosal tumors of the colon. In such patients, EMR seems to be a feasible and safe approach for diagnosis and treatment.

Granular cell tumors are rare, invariably benign, and often solitary tumors, which infrequently involve the gastrointestinal tract. We report the unique presentation of a granular cell tumor of the internal anal sphincter in a 75 year-old female. The tumor was detected during investigation of new rectal bleeding and was excised using a transanal approach and sphincter repair. At five-year follow-up the patient reported normal continence to stool and flatus and demonstrated no evidence of tumor recurrence. Immunohistochemical studies cite the Schwann neural cell as the origin of the granular cell tumor. Cytoplasmic features include acidophilic, p-aminosalicylic acid-positive, diastaseresistant granules. Granular cell tumors may be located anywhere in the body, but anorectal involvement is rare. In our own search of the world literature, no other cases were reported specifically to involve the anal sphincter. Granular cell tumors are usually detected incidentally but may be symptomatic, especially when the anorectal region is involved. Symptoms include perianal discomfort and bleeding. Adequate local excision is effective for both diagnosis and treatment of anorectal granular cell tumors. Careful follow-up should be performed after excision because of the risk of recurrence.

Granular cell tumors are uncommon, usually benign tumors that can be located anywhere in the body. They commonly occur in the oral cavity and in subcutaneous tissue. In the gastrointestinal tract, granular cell tumors are uncommon and are quite rare in the colon. To date, 55 patients diagnosed with granular cell tumors of the colon have been reported in the literature, only 15 had multiple tumors. We describe the case of a 38-year-old man with a family history of colon cancer who was diagnosed with multiple colonic granular cell tumors after a screening colonoscopy. This seems to be the first report of this type. However, in our patient, the diagnosis of colonic granular cell tumors was incidental and there is no data that correlates adenomas or colorectal cancer with granular cell tumors of the colon. Finally, since granular cell tumors are usually benign, we suggest a conservative approach to patients with multiple granular cell tumors of the colon by means of endoscopic resection and a strict endoscopic follow-up.