Acinic cell carcinoma (salivary glands)
Acinic cell carcinomas of the salivary glands are rare malignant neoplasms that account for 1-3% of all salivary gland tumours.
Pathology may superficially resemble normal serous (acinar) cells of the salivary glands. It is considered a low-grade, indolent malignancy, but with a tendency to recur after excision 4.
The majority arise in the parotid gland (81-98% 3) and they may be bilateral and multicentric.
Imaging findings in acinic cell carcinoma are non-specific and there is an overlap with benign tumors such as Warthin tumor and pleomorphic adenoma 6.
- non-specific appearance
- hypoattenuating regions of central necrosis
- irregular enhancing solid component
- non-specific appearance
- T2 hyperintense cystic/necrotic component
- solid component is also mildly T2 hyperintense
- irregular solid component that enhances on the postcontrast sequence
Features that might suggest malignancy include:
- rapid increase in size
- clinical history of pain
Treatment and prognosis
Surgical excision is considered the standard of care. Acinic cell carcinomas may recur in up to 35% of patients 5.
Possible differential considerations include:
- Warthin tumour: much more common
- pleomorphic adenoma: much more common
- mucoepidermoid carcinoma: more common than acinic cell
- adenoid cystic carcinoma: more common than acinic cell
- 1. Habermann CR, Arndt C, Graessner J et-al. Diffusion-weighted echo-planar MR imaging of primary parotid gland tumors: is a prediction of different histologic subtypes possible?. AJNR Am J Neuroradiol. 2009;30 (3): 591-6. doi:10.3174/ajnr.A1412 - Pubmed citation
- 2. Harnsberger HR, Osborn AG. Differential diagnosis of head and neck lesions based on their space of origin. 1. The suprahyoid part of the neck. AJR Am J Roentgenol. 1991;157 (1): 147-54. doi:10.2214/ajr.157.1.2048510 - Pubmed citation
- 3. Vidyadhara S, Shetty AP, Rajasekaran S. Widespread metastases from acinic cell carcinoma of parotid gland. Singapore Med J. 2007;48 (1): e13-5. Pubmed citation
- 4. FRCPath CDMFMD. Diagnostic Histopathology of Tumors: 2 Volume Set: Expert Consult - Online and Print, 4e (DIAGNOSTIC HISTOPATHOLOGY OF TUMORS (FLETCHER)). Churchill Livingstone. ISBN:1437715346. Read it at Google Books - Find it at Amazon
- 5. FCCP ATSMDFACP. Atlas of Diagnostic Oncology: Expert Consult - Online and Print. Mosby. ISBN:0323059058. Read it at Google Books - Find it at Amazon
- 6. Suh SI, Seol HY, Kim TK et-al. Acinic cell carcinoma of the head and neck: radiologic-pathologic correlation. J Comput Assist Tomogr. 2005;29 (1): 121-6. Pubmed citation