Cytodiagnosis of unusual metastases in parotid gland

J Oral Maxillofac Pathol. 2021 Jan-Apr;25(1):171-176. doi: 10.4103/jomfp.JOMFP_267_20. Epub 2021 May 14.

Abstract

Documentation of metastatic lesions in the parotid gland diagnosed by fine-needle aspiration cytology (FNAC) is limited in the cytopathology literature. The metastases within the parotid masquerades clinically as primary neoplasm of parotid. The authors of present case report intent to highlight the importance of FNAC in the diagnosis of metastases in parotid. These diagnoses enable the search for the locations of unknown primaries. The nodules within the parotid masquerading as primary neoplasm have undergone FNAC in five cases. The cytomorphological interpretation of the smears was performed. The diagnosis on cytology was compared with subsequent histological evaluation of the suggested primary neoplasm. FNAC in the five cases revealed the following cytodiagnosis: metastases of ductal carcinoma (2), melanoma (1), deposits of small cell carcinoma (1) and metastases of clear cell renal cell carcinoma (RCC) (1). There was complete concordance when these cytodiagnoses were compared with histological evaluation from the suggested sites of primaries as well-differentiated ductal carcinoma of the breast (2), melanoma of the scalp (1), small cell carcinoma of the lung (1) and clear cell RCC of the kidney (1). The metastases within the parotid can masquerade as primary neoplasm. The cytomorphological patterns and features of metastases are similar to that of their primary neoplasm. Therefore, FNAC over the nodules within the parotid unsuspected for metastases provides valuable information to search for primary neoplasm.

Keywords: Fine-needle aspiration cytology; metastases; parotid gland.

Publication types

  • Case Reports