A case of mucoepidermoid carcinoma located in the left forearm of a middle-aged pregnant woman.

In this article, we described a mucoepidermoid carcinoma (MEC) located in the left forearm of a 39-year-old pregnant woman. Here, the patient had a superficial tip size apophysis nearly 3 years, which begin to sustained growth after pregnant in 2012, and stopped growth after childbirth. MEC is a rare malignant tumor. Previously reports showed it mainly arise from the salivary, bronchial, thyroid, breast, lacrimal gland and conjunctiva. Here, we reported a case of MEC arising from the forearm gland for the first time. Histological finding showed a cystic and solid tumor in fibrous tissue below the squamous epithelium, and some columnar or cuboidal mucous cells covering on the epidermal cells or mixed with epidermal cells included in the tumor tissues. Also, Focal hyperplasia epidermal cells with round or oval nucleus in center were distributed in small pieces but no keratosis. The tumor tissues were immunopositive for CEA, P63, ki-67 (10%), CK7 and CK5/6, and immunonegative for CK20 and GCDFP-15. This case is a low-grade MEC and the patient's postoperative recovery is smooth.