Radiological diagnosis

Gastric Leiomyosarcoma

Ultrasound [Figure - 2] shows a hypoechoic mass, posterior and to the left of the body of the stomach. No communication to the gastric lumen is seen. The barium study [Figure - 2],[Figure - 3] shows evidence of an extrinsic pressure effect on the greater curvature of the stomach, suggestive of a predominantly extraluminal mass which communicates with the lumen of the stomach through an irregular cavity in the region of the fundus.

The CT [Figure - 4] shows a poorly enhancing mass with a central cavity communicating with the lumen of the stomach and indenting the body and fundus of the stomach. The fat planes between the mass and the spleen are lost.

The presence of an external mass indenting the stomach with evidence of communication with the stomach lumen via an irregular cavity on the barium meal study prompted a diagnosis of leiomyosarcoma. The irregular cavity and the large size of the mass on CT established the malignant nature of the mass. A differential diagnosis that was entertained was a peri-gastric abscess. However, non-opacification of the walls of the cavity on CECT ruled this out.

Surgery confirmed the diagnosis of a large extrinsic mass arising from the fundus of the stomach and infiltrating the pancreas and the spleen with a few peri-gastric lymph nodes. A total gastrectomy was done for the patient. Histopathological analysis of the excised specimen confirmed the diagnosis of leiomyosarcoma.

Leiomyosarcomas are rare gastric tumors that arise from the smooth muscle and are estimated to represent 1-3% of gastric malignancies [1]. Clinical presentation includes abdominal pain, a palpable mass and gastro-intestinal hemorrhage in cases of ulceration. They are predominantly extramural, projecting into the perigastric spaces and only a small portion of these mural tumors project into the gastric lumen. It is the intraluminal portion, which ulcerates [2].

The diagnosis of leiomyosarcoma is based on histological evidence either from endoscopically obtained biopsy or surgically obtained biopsy. The typical findings include pleomorphism and the presence of mitotic figures along with hypercellularity and tumor necrosis [3]. The most common site of metastases is the liver. Direct extension into the omentum, retroperitoneum and adjacent organs like the pancreas can also occur [2].[8]