Polymorphous low-grade adenocarcinoma of seromucous glands of the nasopharynx. A report of a case and a discussion of the morphologic and immunohistochemical features.

Polymorphous low-grade adenocarcinoma (PLGA) is a minor salivary gland neoplasm that is characterized by morphologic variability, cytologic uniformity, and an infiltrating growth pattern. To date, this entity has been identified either within the confines of the oral cavity or, rarely, in the nasal cavity. The authors report a case of PLGA that arose in the nasopharynx of a 44-year-old female, representing the first documented occurrence of this tumor outside the oral cavity or the sinonasal tract. The histopathologic and immunohistochemical differentiation from pleomorphic adenoma and adenoid cystic carcinoma is discussed.