Small bowel volvulus revealing advanced jejunal gastrointestinal stromal tumor with diffuse metastases: a case report

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, with 25-30% arising from the small intestine. While GISTs commonly present with abdominal pain or gastrointestinal bleeding, they may rarely manifest as acute surgical emergencies such as small bowel volvulus (SBV). Presentation with diffuse metastatic disease, including umbilical involvement (Sister Mary Joseph's nodule), at initial diagnosis is exceptionally uncommon.

A 60-year-old woman presented with acute abdominal pain, vomiting, and obstipation for 2 days. Clinical examination revealed a soft, non-tender, distended abdomen with preserved bowel sounds. Imaging revealed small bowel obstruction with the characteristic whirlpool sign, a pelvic mass, diffuse peritoneal deposits, a Sister Mary Joseph's nodule, and a hepatic lesion. Emergency laparotomy revealed a 13.0 × 7.5 × 6.5 cm jejunal mesenteric mass causing a 180° anticlockwise volvulus with widespread peritoneal, omental, and umbilical nodules. Segmental jejunal resection with jejunojejunal anastomosis was performed for symptom palliation. Histopathology confirmed spindle-cell GIST, positive for CD117 and DOG1, with a mitotic count of 1/5 mm² and a Ki-67 index of 3%. The tumor was staged as pT4 Nx M1 and categorized as high-risk. The patient recovered uneventfully and was started on treatment with imatinib mesylate.

SBV secondary to GIST is rare and typically occurs in the presence of large extramural tumors that act as a lead point for mesenteric rotation. This case highlights the insidious biological behavior of GISTs, wherein prolonged asymptomatic growth may culminate in advanced metastatic disease at presentation, despite low proliferative indices. The presence of Sister Mary Joseph's nodule further signifies advanced intra-abdominal dissemination and poor prognostic implications.

GISTs should be considered in cases of unexplained SBV. This case emphasizes the diagnostic challenges, the need for prompt surgical palliation, and the role of systemic tyrosine kinase inhibitors in advanced presentation of GIST.