Gastric leiomyosarcoma: CT observations.

The abdominal CT examinations of seven patients with gastric leiomyosarcoma (GLMS), proven by surgical or endoscopic biopsy or both in five patients and percutaneous aspiration biopsy in two, are reviewed. In the six patients studied prior to therapy, CT demonstrated that each of the primary gastric tumors was spherical or ellipsoidal, large (mean diameter 15 cm), and predominantly exogastric in location. Additional CT features of the primary tumor included necrosis in all six masses, a distinct gastric mural attachment in four, bubbles of gas or an air-fluid level or both in three, and mucosal ulceration in two. Direct tumor invasion of nearby organs was suggested by CT in four of the six patients, the spleen and pancreas representing the most frequent sites. Intraperitoneal spread of tumor was present in two patients; necrotic liver metastases accompanied three of the six primary tumors and were found in an additional patient examined 4 years after gastric resection. By accurately reflecting the biological behavior of GLMS, CT is an ideal imaging modality for studying this unusual neoplasm. Differential diagnosis and specificity of the CT findings are discussed.