Spontaneous partial regression of low-grade mucoepidermoid carcinoma of the maxilla

Malignant neoplasms of the nasal cavity and nasal sinuses are uncommon accounting for 3–5% of all head and neck tumors [1, 2]. The squamous carcinoma is the most frequent type, followed by the adenocystic carcinoma and the mucoepidermoid carcinoma (MEC). MEC is a malignant epithelial tumor composed of mucosecretory cells and epidermoid cells that originates in the minor salivary mucosal glands. It accounts for 13% of all malignant tumors of the maxillary sinuses, and is more common in females [1]. Histologically, we differentiate three types: those with low, high and intermediate degrees of malignancy according to the cellular proportions, with mucosal cells predominating in the low-grade type [3]. Spontaneous regression has been described in all types of cancers, although it is more frequent in some than others. We present a rare case of spontaneous partial regression of a lowgrade maxillary MEC, not previously described in this tumor, in a 50-year-old woman.