Minerva Stomatologica 2020 Dec 16

DOI: 10.23736/S0026-4970.20.04441-6

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English

Extranodal B-cell marginal zone lymphoma arising in the context of a lympho-epithelial cyst of the parotid gland in a patient with clonal B-cell lymphocytosis: report of the first case

Giorgio TONI ¹, Immacolata COZZOLINO ¹, Giuseppe COLELLA ², Virginia TIRINO ³, Pierluigi MARIANI ⁴, Luigi LAINO ⁴ ✉, Andrea RONCHI ¹, Renato FRANCO ¹

¹ Pathology Unit, Department of Mental and Physical Health and Preventive Medicine, University of Campania L. Vanvitelli, Naples, Italy; ² Maxillo-Facial Unit, Multidisciplinary Department of Medical, Surgical and Dental Specialities, University of Campania L. Vanvitelli, Naples, Italy; ³ Biotechnology, Medical Histology and Molecular Biology Unit, Department of Experimental Medicine, University of Campania L. Vanvitelli, Naples, Italy; ⁴ Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, University of Campania Luigi Vanvitelli, Naples, Italy

BACKGROUND: Primary salivary gland lymphomas are unusual, accounting for 2.5% to 4.5% of salivary gland tumours. More than 90% are non-Hodgkin lymphomas (NHLs) and extranodal marginal zone lymphoma (EMZL) is the most common histotype.
METHODS: A patient with a history of CD5-negative and CD23-negative clonal B-cell lymphocytosis presented a nodule in the deeper left parotid region, discovered accidentally during a follow-up for the lymphocytosis. Ultrasounds and Magnetic resonance imaging showed multiple nodules, the biggest of about 1.5 centimetres, partly solid and partly cystic. US-guided fine needle aspiration cytology and flow cytometry were executed. Final diagnosis of a monoclonal B-cell lymphoproliferative disorder was rendered, and the patient underwent to partial left parotidectomy.
RESULTS: Histological examination and immunohistochemistry allowed to formulate the final diagnosis of an extranodal non-Hodgkin B-cell marginal zone lymphoma (MZL) occurring in the context of a lympho-epithelial cyst was rendered. The 2 years clinical and instrumental follow-up was uneventful.
CONCLUSIONS: The diagnostic evaluation of a LEC has to include the possibility of a concurrent EMZL, mainly in case of high risk biological and clinical conditions like CBL.

KEY WORDS: Lympho-epithelial cyst; Clonal lymphocytosis; Marginal zone lymphoma; B-cell lymphoma