Polymorphous Low-Grade Adenocarcinoma in the Lung: A Case Report

Although uncommon, it is well recognized that salivary gland-type tumors can occur as primary lung tumors, probably arising from minor salivary-type glands lining the bronchial tree. Polymorphous low-grade adenocarcinoma (PLGA) is a rare tumor that usually originates from oral minor salivary glands. There are only 2 reported cases showing metastasis to the lung; however, a primary lung tumor has not been reported so far. In this report we describe the clinical and pathological features of another case of PLGA involving the lung, but in a patient with no evidence of a previous oropharyngeal primary. While our case probably represents another example of metastatic PLGA to the lung, to our knowledge, it is the first description of a PLGA involving the lung in the absence of a history of a previous primary oral salivary gland tumor.