Polymorphous Low-Grade Adenocarcinoma: A Rare Type of Parotid Neoplasm

Abstract

Polymorphous low-grade adenocarcinoma is an unusual tumour that has been described as occurring in the minor salivary glands, particularly of the palate. It has also been called terminal duct carcinoma, lobular carcinoma, papillary lowgrade adenocarcinoma and trabecular adenocarcinoma. Adenocarcinomas of the salivary glands are heterogenous group both in terms of histomorphology and clinical course and the pathologist can misdiagnose this tumor as pleomorphic adenoma or adenoid cystic carcinoma. As well, despite an infiltrative growth pattern, which frequently results in perineural invasion, this tumor has a low local recurrence rate and remarkable infrequency of local or distant metastasis. In order to provide appropriate therapy for polymorphous low-grade adenocarcinoma, oral head and neck surgeons must be familiar with this neoplasm. We describe a patient with polymorphous low-grade adenocarcinoma arising in the parotid gland that was originally diagnosed as pleomorphic adenoma in fine needle aspiration biopsy.

Keywords

• parotid gland
• polymorphous low-grade adenocarcinoma.