Metastasizing Pleomorphic Adenoma: A Rare Entity

Metastatic pleomorphic adenoma (MPA) is rare and one of the outcomes of long-standing pleomorphic adenoma (PA). Due to its rarity, its prevalence is not well understood. While PA usually presents in the second decade of life, earlier onset may increase the risk of MPA. In cases of recurrent PA, a high suspicion for MPA is advised, and full-body imaging is recommended to detect metastasis. Enucleation is not recommended due to its association with higher recurrence rates, and total surgical excision, such as parotidectomy, is preferred. Chemotherapy and radiation are ineffective for MPA, and surgical excision is the primary treatment. Despite surgical intervention, recurrence and metastasis can still occur, with a reported 50% mortality rate at five years and a World Health Organization (WHO) report indicating that 40% of patients die from the disease. Hereby, we report a patient who presented with a recurrent parotid gland PA that metastasized to the ipsilateral lymph node nine years after the initial treatment.