NEUROENDOCRINE CARCINOMA AFFECTING THE PAROTID GLAND: CASE REPORT WITH IMMUNOHISTOCHEMICAL STUDY

Abstract

Salivary gland neuroendocrine carcinoma (sgNEC) is a rare malignant neoplasm characterized by rapid tumor growth, commonly affecting older male patients and frequently observed on the parotid gland. These tumors can be classified as primary or metastatic sgNEC. A 57-year-old White woman sought medical care for facial swelling and odynophagia. On clinical examination, a painful large nodule located on the right parotid gland was noted, as well as regional lymphadenopathy. Imaginologic analysis revealed a large and irregular mass infiltrating the parotid gland. Core needle biopsy was performed, and the histopathologic analysis revealed features of poorly differentiated sgNEC. Immunohistochemistry showed strong immunopositivity for anti-synaptophysin and chromogranin. Mindbomb 1 labeling index was approximately 30%. The antineoplastic treatment consisted of chemotherapy and adjuvant radiotherapy, and there was no tumor recurrence after 36 months of follow-up. Although rare, sgNEC must be considered in differential diagnosis of parotid gland swellings. Salivary gland neuroendocrine carcinoma (sgNEC) is a rare malignant neoplasm characterized by rapid tumor growth, commonly affecting older male patients and frequently observed on the parotid gland. These tumors can be classified as primary or metastatic sgNEC. A 57-year-old White woman sought medical care for facial swelling and odynophagia. On clinical examination, a painful large nodule located on the right parotid gland was noted, as well as regional lymphadenopathy. Imaginologic analysis revealed a large and irregular mass infiltrating the parotid gland. Core needle biopsy was performed, and the histopathologic analysis revealed features of poorly differentiated sgNEC. Immunohistochemistry showed strong immunopositivity for anti-synaptophysin and chromogranin. Mindbomb 1 labeling index was approximately 30%. The antineoplastic treatment consisted of chemotherapy and adjuvant radiotherapy, and there was no tumor recurrence after 36 months of follow-up. Although rare, sgNEC must be considered in differential diagnosis of parotid gland swellings.