Intracapsular Carcinoma Ex-Pleomorphic Adenoma of the Parapharyngeal Space: Report of Two Cases and Review of the Literature

Abstract

Background Carcinoma ex-pleomorphic adenoma of the parapharyngeal space is an exceedingly rare entity. Methods The clinical records of two patients with primary carcinoma ex-pleomorphic adenoma of the parapharyngeal space surgically treated at two different centers were retrospectively analyzed. Results Despite ultrasound-guided fine-needle aspiration cytology and magnetic resonance imaging, the correct diagnosis was preoperatively missed in both cases. Excision was obtained through a transcervical-transparotid approach in 1 case and a minimally-invasive endoscopic-assisted transcervical approach in the other. Definitive histology was consistent with intracapsular carcinoma ex-pleomorphic adenoma. Adjuvant radiotherapy was performed in the case with macroscopic malignant degeneration; both patients are alive and free from disease 36 months after surgery. Conclusions Carcinoma ex-pleomorphic adenoma of the parapharyngeal space is a rare disease, and definitive diagnosis may be challenging. Surgery is the mainstay of treatment, but adjuvant radiotherapy also may be required in the presence of specific risk factors.