Benign Recurrent Pleomorphic Adenoma of the Parotid Gland with Perineural Space Invasion

https://doi.org/10.4068/cmj.2017.53.3.236 C Chonnam Medical Journal, 2017 Chonnam Med J 2017;53:236-237 Corresponding Author: Luca Roncati Department of Diagnostic and Clinical Medicine and of Public Health, Institute of Pathology, University of Modena and Reggio Emilia, Policlinico Hospital, I-41124 Modena (MO), Italy Tel: +390594224812, Fax: +390594224998, E-mail: [email protected] Article History: Received August 24, 2017 Accepted September 4, 2017 FIG. 1. Recurrent pleomorphic adenoma of the parotid gland: the tumor recurs inside the salivary tissue (A, yellow asterisks), it shows a typical myxoid appearance and a plurinodular growth pattern on panoramic histological view, and it involves the surgical margin (A, red arrows), highlighted by ink marking. Some neoplastic nests (A, yellow circle) spread along the perineural spaces (A, hematoxylin & eosin, 1.25×). At higher magnification, this phenomenon (B, yellow circle) is best appreciated (B, hematoxylin & eosin, 10×). Both neoplastic nests and nerves (C, black arrows) are brown-stained by immunohistochemistry for S100 protein (C, polyclonal, 10×); however, nerves (D, black arrows) are not reactive for pancytokeratins, which reveal in brown only the neoplastic nests (D, clone MNF116, 20×). Benign Recurrent Pleomorphic Adenoma of the Parotid Gland with Perineural Space Invasion