Background: Few cases of GIST bigger than 15 cm have been reported in medical literature, all primarily in elderly patients. We report an unusual case, in which a giant gastric GIST - in a young patient - presented as spontaneous intratumoral bleeding followed by intraluminal rupture.
Case presentation: A 37-year-old man was admitted with an acute onset of abdominal pain. CT showed a 32 x 25 cm mass with some cystic lesions and areas of calcification. Twelve hours after admission the patient presented with an episode of upper GI bleeding, and a significant decrease of tumor size and hemoglobin level. An upper endoscopy showed a large bulge in the posterior aspect of the gastric wall, and a small ulcer with continuous bleeding coming from a central orifice. A subtotal gastrectomy was carried out. Pathological examination showed a giant gastric GIST measuring 32 x 25 x 21 cm and weighing 3.750 g. Immunohistochemical staining demonstrated positive reactivity to C-kit protein, CD34, and alpha-smooth muscle actin; but negative reactivity to S-100 protein.
Conclusion: Intratumoral bleeding is a very rare presentation of GIST; preoperative diagnosis is always made difficult by the absence of pathognomonic signs or symptoms. Emergency local excision with negative margins associated with adjuvant therapy with imatinib mesylate remains the main modality of treatment for high risk GISTs.