MICROINVASIVE PROTOCOL FOR PREOPERATIVE DIAGNOSIS OF MINOR SALIVAR GLANDS MEC ALLOWING TARGETED SURGICAL THERAPY

Abstract

<h3>Background</h3> Mucoepidermoid carcinoma (MEC) is the most common intraoral malignancy and is mainly located between hard and soft palate. Its surgical therapy could be difficult and depends on location, dimension, infiltration, and histologic grading. <h3>Objective</h3> The aim is to report the importance of a clinicopathologic protocol for microinvasive preoperative diagnosis, grading, and staging of MEC to sketch out a targeted surgical therapy in intraoral difficult locations. <h3>Methods</h3> In 64 cases of intraoral MEC treated between 2000 and 2019 at the Oro-maxillo-facial Surgery Unit of Policlinico-University-Hospital of Bari (Italy), the following preoperative protocol was performed: clinical examination, high-definition intraoral ultrasonography, radiological assessment (rxOPT, computed tomography/magnetic resonance imaging), microinvasive biopsy with fine-needle aspiration biopsy/fine-needle aspiration cytology with HeE, PAS+/−Alcian stains, and immunohistochemical panel (high-/low-molecular-weight cytokeratins, calponin, smooth muscle actin, S-100, Ki-67). Surgery was targeted for each patient and guided from histopathologic data and consisted of conservative excision with wide margins for low-grade MEC and demolitive resection with neck dissection for high-grade MEC. <h3>Results</h3> Application of our protocol gave a 100% preoperative histologic diagnosis and grading. Forty-one cases were low-grade MEC (29 female and 12 male patients, mean age = 37; site: 33 palate, 4 cheek, 2 lip, and 2 tongue); 23 were high-grade MEC (16 female and 7 male patients, mean age = 41; site: 19 palate, 1 cheek, 2 lip, and 1 tongue), and 4 were clear cells. <h3>Conclusions</h3> Preoperative fine-needle aspiration biopsy/fine-needle aspiration cytology for histologic diagnosis of MEC is mandatory in order to make decisions on the type of surgical treatment to avoid over- or undertreatment.