Squamous Cell Carcinoma Arising from a Plemorphic Adenoma of the Parotid Gland: A Case Report and Literature Review

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Résumé

Introduction: The term “carcinoma ex pleomorphic adenoma” (CXPA) is used to denote the malignant transformation of a preexisting pleomorphic adenoma. This condition is uncommon, with an incidence ranging from 2% to 15% of malignant salivary gland tumors. The transformation of the lesion into squamous cell carcinoma is an exceptional histological variant. We present a rare case with a particularly prolonged course and complex multidisciplinary management in a setting with limited resources. Observation: A 74-year-old patient with no significant past medical history was admitted for a large, ulcerated, and nodular mass in the right parotid gland that had been present for more than 40 years. Imaging studies revealed a locally advanced tumor associated with cervical lymphadenopathy. The initial biopsy revealed a diagnosis of squamous cell carcinoma. Subsequent to the administration of neoadjuvant chemotherapy, a parotidectomy was performed in conjunction with a neck dissection and reconstruction utilizing a pectoralis major flap. A final histological examination confirmed the presence of squamous cell carcinoma arising from a pleomorphic adenoma. The patient underwent adjuvant treatment, which included radiation therapy and chemotherapy. The subsequent one-year follow-up revealed no evidence of recurrence. Conclusion: This case exemplifies the potential progression of overlooked pleomorphic adenomas and underscores the significance of a comprehensive histological diagnosis and early multidisciplinary management.1

Mots-clés

Carcinoma Ex Pleomorphic Adenoma, Squamous Cell Carcinoma, Parotid, Malignant Transformation, Histopathology