Gastrointestinal stromal tumor of small intestine

A 65-year-old man was referred to our hospital with a 5-day history of melena. Digital rectal examination showed the abdominal mass on the anterior wall of the rectum, about 6 cm from the anus. Laboratory test showed a hemoglobin level of 4.90 g/dL (normal range, 13.5 to 17.5 g/dL). A positive fecal occult blood test was confirmed. Coagulation function, blood platelets, CEA, and CA199 values were normal. Gastroscopy and colonoscopy showed no significant findings. Considering the findings in the patient's digital rectal examination, gadolinium-enhanced magnetic resonance imaging of the pelvic cavity was assessed and confirmed the abdominal mass between rectum and bladder (Fig. 1A), about 5.0 cm in diameter, which was further confirmed by colonoscopic ultrasonography. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed and findings on biopsy were consistent with gastrointestinal stromal tumors (GISTs). Therefore, an exploratory laparoscope was performed which detected the localization of the mass, about 1.80 m from the ileocecal region. The patient then underwent the mass excision and the bleeding point was completely removed (Fig. 1B and C). The intestine was not resected because of the potential benign lesion of GISTs. Histologic examination of the specimen revealed a spindle cell tumor (Fig. 1D). The lesion staining strongly immunoreactive for CD117 (Fig. 1E) and DOG1 (Fig. 1F) by immunohistochemistry was consistent with intermediate risk gastrointestinal stromal tumor of small intestine, which was further defined by a low proliferation index Ki67 around 5% in neoplastic cells (Fig. 1G). GISTs are the most common mesenchymal tumors of the gastrointestinal tract, with the most common sites of involvement being stomach, small intestine, colon, rectum, and esophagus. Gastrointestinal stromal tumor of small intestine have worse prognosis than those of comparable size and mitotic count arising in other organs.^, EUS-FNA is considered as a well tolerated and feasible endoscopic microsurgery to confirm a diagnosis of a suspected GIST. Neoadjuvant imatinib with surgical resection has been confirmed to be well tolerated and improved overall survival in patients with advanced disease. Adjuvant imatinib for 3 years was initiated in our patient with resection for primary disease. Follow-up double-balloon enteroscopy after 2 years confirmed no recurrence.

This work was supported by National Natural Science Foundation of China (31,600,134).