Intracapsular (in situ) carcinoma ex pleomorphic adenoma with unusual clinical and histological features.

Carcinoma ex pleomorphic adenoma poses a challenge to diagnosis and treatment. Herein we describe an extremely unusual case, which presented initially as an intracapsular carcinoma ex pleomorphic adenoma in the right parotid gland. The first recurrence, after an interval of 8 years, showed only recurrence of the benign component. Five years later, a myoepithelial carcinoma arose from the same site. No ductal carcinoma as seen in the initial intracapsular carcinoma ex pleomorphic adenoma was identified. This case report elucidates the atypical clinical behaviour and interesting histological features encountered within this group of salivary neoplasm.