Contrast-enhanced ultrasonography combined with superb microvascular imaging for preoperative diagnosis of sporadic intra-abdominal desmoid-type fibromatosis: A case report.

We herein report a case of sporadic intra-abdominal desmoid-type fibromatosis in which contrast-enhanced ultrasonography (US) combined with superb microvascular imaging (SMI) was useful for preoperative diagnosis. 18-Fluorodeoxyglucose positron emission tomography performed for systematic screening for lung cancer revealed an abnormal accumulation in the abdominal cavity. Transabdominal US showed a tumor with a mixture of hypoechoic and hyperechoic areas. Contrast-enhanced US combined with SMI revealed dendritic blood flow signals and no abnormal vascular network within the tumor. Macroscopic examination of the resected specimen revealed a white tumor with relatively clear boundaries. Microscopic examination revealed spindle cells with poor atypia proliferating in bundles with collagenous stromal cells. Immunohistochemistry showed nuclear localization of beta-catenin within the tumor cells. From these findings, we finally diagnosed intra-abdominal desmoid-type fibromatosis. Contrast-enhanced US combined with SMI is useful for diagnosing intra-abdominal desmoid-type fibromatosis.