Acinic cell carcinoma of the salivary glands

Acinic cell carcinoma is a malignant epithelial neoplasm of the salivary glands defined in the WHO head and neck classification by serous acinar differentiation, with a recurrent NR4A3 rearrangement noted on the parent page; the most common presentation is a well-defined painless solid mass, diagnosis is complicated by its similarity to benign tumours, imaging has no clear characteristics, radical surgery is the best treatment, the role of radiotherapy remains controversial and literature on chemotherapy for metastatic disease is insufficient (Eur Arch Otorhinolaryngol 2020). In 2,362 National Cancer Database cases, most patients were women (61.3 percent) with a median age of 54; age over 70, high grade, size over 3 cm, four or more positive nodes and T4 stage were significant adverse prognosticators (Oral Oncology 2018).

How it differs from its parent: the salivary gland page covers all types; acinic cell carcinoma is the low-grade type with the best outlook after adenoid cystic and mucoepidermoid carcinoma are set aside, with a defined high-grade transformed variant that changes the plan.

How common: the third or fourth most common salivary malignancy; no UK share in the sources read.

Treatment: parotidectomy with facial nerve preservation where possible and neck dissection for node-positive or high-grade disease; postoperative radiotherapy for high grade, positive margins or nodes; systemic therapy for metastatic disease has no evidence base and follows the parent page (Eur Arch Otorhinolaryngol 2020).