Abstract
Desmoid tumor is commonly known as a slow-growing tumor. We report herein a case of sporadic, rapidly growing, intraabdominal desmoid tumor arising from the gastrosplenic ligament. A 54-year-old man showed a round tumor 2 cm in diameter near the greater curvature of the stomach on screening abdominal CT. One year later, the tumor had grown rapidly to 10 cm, and thus the patient was referred to our hospital. Diagnostic investigations suggested that the tumor had arisen from the gastric muscularis propria layer with extraluminal extension, and laparoscopic and hand-assisted tumor resection with splenectomy was performed. Microscopic histopathological findings revealed that the tumor mainly consisted of proliferative collagen fibers and spindle cells without atypia, and the tumor capsule originated from the gastrosplenic ligament. Immunohistochemistry of the resected specimen indicated the tumor cells were positive for β-catenin and negative for c-kit, desmin, and S-100, consistent with desmoid tumor. The patient has survived without evidence of tumor recurrence as of 21 months after surgery. It is necessary to consider that desmoid tumor has a potential to grow rapidly, despite the difficult preoperative diagnosis.
