Neuroendocrine Tumor of the Small Intestine Diagnosed With Transabdominal Ultrasonography: A Case Report

Background: Tumors of the small intestine are rare. In addition, clinical symptoms are nonspecific, and neoplasm-related symptoms occur late. Methods: We report a case of neuroendocrine tumor of the small intestine that was diagnosed early with transabdominal ultrasonography (US). The patient was a 61-year-old man. Abdominal contrast-enhanced computed tomography (CT) was performed because the patient complained of abdominal pain. The CT showed a tumor lesion in the mesentery. Transabdominal US was undertaken to evaluate this tumor lesion, and a tumor lesion of the small intestine was found nearby. A diagnosis of lymph node metastasis of a small intestine tumor was made as a preoperative diagnosis. A laparotomy was performed with partial resection of the ileum, together with the small intestine mesentery, including an enlarged lymph node. Results: Histologic examination revealed neuroendocrine tumor of the ileum and lymph node metastasis. Transabdominal US is useful in the diagnosis of small-intestine NET.