Intracapsular carcinoma ex-pleomorphic adenoma of the parapharyngeal space: report of two cases and review of the literature.

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.