A case of primary micropapillary carcinoma of the jejunum

Micropapillary carcinoma (MPC) has been recently reported as a variant of invasive breast carcinoma. MPC is also known to be an aggressive variant of adenocarcinoma, and it is associated with poor prognosis and a high propensity for lymphovascular invasion and lymph node metastases. MPC of the breast, urinary bladder, and lung has been reported relatively frequently; however, there have been few reports on gastrointestinal MPC. Furthermore, MPC of the small bowel has not been reported yet. Here we report a case of MPC of the jejunum. A female septuagenarian was admitted because of anorexia and weight loss. We established a diagnosis of primary jejunal cancer and resected the duodenum and a part of the jejunum. Histologically, the tumor consisted of adenocarcinoma with moderate to poor differentiation. Among the carcinoma cells, approximately 10% formed small papillary neoplastic cell clusters surrounded by clear spaces, suggesting a diagnosis of MPC. We present the details of the case along with a review of relevant literature.