Polymorphous low-grade adenocarcinoma of the parotid gland. Case report and review of the literature.

Polymorphous low-grade adenocarcinoma (PLGA) is difficult to diagnose both clinically and histologically due to its indolent presentation, and because of its morphological diversity that includes several microscopic patterns. The aggressive biologic behavior seen in minor salivary glands as compared to major glands is apparently associated histologically to a predominance of the papillary pattern in the former. Biologic behavior of PLGA in the major salivary glands is uncertain, as some cases have developed recurrences and metastases independently of the presence of a papillary pattern. A case of PLGA originated de novo in parotid gland is presented a 60 year-old male, treatment was surgically excised through superficial parotidectomy and to postoperative radiotherapy (46 Gy). Forty-eight months later the patient is alive with no signs of recurrence, as well as a review of the literature, with particular emphasis in its differential diagnosis and biological behavior.