Acinic Cell Carcinoma Of Parotid Gland Surrounded By Prominent Lymphoid Tissue, Diagnostic Dilemma In F N A C , A Case Report.

摘要

Acinic cell carcinoma is a rare salivary gland cancer comprises 1% to 3% of all salivary gland tumors. The majority is located in the parotid gland (86.3% in largest study) but many examples in the minor salivary gland have been recorded. Cases have been reported where acinic cell carcinoma located within intraparotid lymph nodes.[1] We hereby report a case where a 40 year old male had a right sided parotid swelling-for 2 years. Introduction Acinic cell carcinoma is a rare salivary gland cancer comprises 1% to 3% of all salivary gland tumors. The majority is located in the parotid gland (86.3% in largest study) but many examples in the minor salivary gland have been recorded. Cases have been reported where acinic cell carcinoma located within intraparotid lymph nodes.[1] We hereby report a case where a 40 year old male had a right sided parotid swelling-for 2 years. FNAC was performed and the diagnosis was suggestive of chronic sialadenitis with a advice for biopsy and histopathological examination to exclude acinic cell neoplasm as in FNA smear the cellularity was high with plenty of normal looking salivary acinar cells and lymphocytes in the background. Later on biopsy was performed and histopathology showed the features of acinic cell carcinoma with prominent lymphoid tissue in the periphery of the tumor. Case report A 40 year male presented to the surgical OPD with a right sided parotid swelling for 2 years. It was 4x3.5x3 cm in size, firm in consistency and nontender in palpation. As advised by the surgeon the patient attended in the department of pathology for Fine Needle Aspiration Cytology. FNAC was performed. Smears showed high cellularity. There were cohesive clusters of acinar cells some with central fibro vascular core. They resembled normal salivary acinar epithelial cells with finely vacuolated cytoplasm but nuclei were slightly larger than normal. Background showed mildly pleomorphic medium sized bare nuclei; lymphocyte like (Figure-1).Considering the cytomorphological features our preliminary diagnosis was chronic sialadenitis with an advice of urgent biopsy and histopathological examination to exclude acinic cell neoplasm as cellularity was very high with anisonucleosis. A superficial parotidectomy was done and the specimen was sent for histopathological examination. Grossly the tumour size was 3x3x2.5 cms. Cut section showed an encapsulated mass with a solid, friable grayish white cut surface. The microscopic appearance showed a solid pattern of growth with a capsule at the periphery. The characteristic acinar cells known as acinic cells were round to polygonal in shape, nuclei showed mild to moderate enlargement and pleomorphism and cytoplasm were granular and basophilic. Lymphoid tissue well encapsulated was prominent at the periphery of the tumor (Figure-2). The histopathological diagnosis was given as “Acinic cell carcinoma surrounded by prominent lymphoid component”.