Fine-needle aspiration biopsy findings in epithelioid myoepithelioma of the parotid gland: A case report

Abstract

We describe the fine-needle aspiration biopsy findings in a case of epithelioid myoepithelioma of the parotid gland in a 24-yr-old male. The cytologic features of myoepithelioma of the parotid gland are only documented in a few case reports and we believe the cytologic description of the epithelioid variant has been described in only one other case. The differential diagnosis with other salivary gland neoplasms is discussed.

Fine-needle aspiration findings in epithelioid myoepithelioma of the parotid gland: A diagnostic pitfall

“…Reports have shown positivity for alpha SMA, S-100 protein, CK, vimentin, desmin, p63, calponin, smooth muscle myosin heavy chain and glial fibrillary acidic protein[4] and negativity for EMA. [3] The positivity for p63, SMA, S-100, CK and HMWCK confirmed the diagnosis of myoepithelioma in our case.…”

“…[3] The criteria for classifying a myoepithelioma on morphology alone is somewhat subjective composed predominantly of myoepithelial cells, with (less than 10%) or without duct-like structures or the presence of myxoid stroma. [4] Hence, immunohistochemical and/or ultrastructural studies is essential at arriving correct diagnosis.…”

The key radiologic and cytomorphologic features of oncocytic and oncocytoid lesions of the salivary gland

“…Lesions may demonstrate a pure morphology throughout or may be mixed. Lesions with a spindle cell component are more likely to demonstrate a dense collagenous to mucoid background on FNAC than pure plasmactyoid lesions, and myoepitheliomas may demonstrate a fibrillary chondromyxoid background similar to that in pleomorphic adenoma …”

“…Lesions with a more prominent epithelioid component may be mistaken for PA, particularly when an extensive stromal background is present. Unlike myoepitheliomas, however, PAs will demonstrate a ductal component in addition to a myoepithelial component . When a purely spindle cell component is present, the differential is broad and includes several soft tissue lesions, such as those of smooth muscle or nerve sheath origin.…”

Epithelioid Myoepithelioma of the Accessory Parotid Gland: Pathological and Magnetic Resonance Imaging Findings

“…Because of this morphologic diversity, it is usually difficult to definitively diagnose myoepithelioma by FNAC before surgery [9], although Das et al [10] reported a case of a successful preoperative parotid myoepithelioma diagnosis via a cytological examination and immunohistochemistry. The main differential diagnoses of myoepithelioma include PA, adenoid cystic carcinoma, other salivary tumors without obvious ductal differentiation, and mesenchymal tumors.…”