Type of publication:
*Venkatasami, M ; *Harrison, K
Oral Surgery, Oral Medicine, Oral Pathology & Oral Radiology; Jul 2021; vol. 132 (no. 1)
Background: Acinic cell carcinoma (ACC) is a rare, low-grade tumor, accounting for about 5% of all primary salivary gland malignancies. ACCs predominate in the parotid gland, are seen in the fifth and sixth decades of life, and have a female predilection. Well-differentiated and low-grade tumors are associated with a favorable prognosis.
Description: We report a case of a 16-year-old female patient presenting with a right parotid lump that had been slowly increasing over the past year. Clinical examination revealed a 1.5-cm right parotid nodule with no facial nerve involvement and presence of cervical lymphadenopathy. Her past medical history was unremarkable.
Findings: Radiological investigations revealed a well-circumscribed, lobulated lesion in the anterior right parotid gland with presence of reactive lymph nodes bilaterally. Fine-needle aspiration showed granular cells with a differential diagnosis of oncocytoma, Warthin's tumor, or acinic cell carcinoma. Histologic examination showed a multinodular appearance with some marked granular cytoplasm with oncolytic and lymphoid infiltrate. The results of immunohistochemistry were negative for S100 and positive with DOG-1. There were widespread periodic acid-Schiff diastase-resistant granules throughout the tumor cells, with a Ki67 proliferation index of approximately 5%.
Outcome: The tumor was completely excised, and the patient made a full recovery and was considered to have a good long-term prognosis.
Conclusions: This is an unusual case of ACC seen in this age group and gender, where less than 4% of cases of ACC have been reported in patients younger than 20. It is important to consider differential diagnoses of salivary gland pathology, such as ACC, in the young female patient.