Myoepithelioma presenting as a midline cystic tongue lesion: Cytology, histology, ancillary studies, and differential diagnosis

Abstract

Salivary gland myoepithelioma (ME) is a neoplasm derived from myoepithelial cells that lacks the ductal and broad mesenchymal differentiation seen in the vast majority of mixed tumors. This report describes the cytologic findings of a cystic ME presenting in the midline of the dorsal tongue, a site where no salivary glands are generally present. The tumor was well circumscribed and composed of sheets of monotonous epithelioid cells without ductal cells. The cells were positive for S-100 protein and ultrastructurally had features of myoepithelial cells. The fine needle aspiration (FNA) biopsy findings, differential diagnosis, histology, immunohistochemistry, and electron microscopic features of this interesting and uncommon neoplasm are presented. To the best of our knowledge, there have been no cytologic reports of ME of the tongue.

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

“…We describe the cytomorphology of epithelioid myoepithelioma on FNAB and consider the challenges in rendering the correct diagnosis. The cytologic features of the epithelioid variant has only been described in a single case report, 8 and to the best of our knowledge, this is the first report of an epithelioid myoepithelioma of the parotid gland on FNAB.…”

“…Only a few reports describing the cytologic features of myoepithelioma on fineneedle aspiration biopsy (FNAB) are noted in the literature, with mixed, spindle cell, clear cell, plasmacytoid and epithelioid variants having been described. [4][5][6][7][8] Because of the varied morphology, the lack of established cytologic criteria, and the vast differential diagnosis, diagnosing myoepithelioma on FNAB is difficult. We describe the cytomorphology of epithelioid myoepithelioma on FNAB and consider the challenges in rendering the correct diagnosis.…”

Myoepithelioma of the Salivary Glands

“…Moreover, the cytologic findings have been reported rarely. 1,2,[4][5][6][7][8]10 So far no specific cytologic findings have been described that enabled us to diagnose myoepithelioma with certainty. The cytologic diagnosis of myoepithelioma is not straightforward since myoepithelial cells assume different morphologic forms, such as plasmacytoid, spindle, clear and epithelioid.…”

“…3,9,[11][12][13] There have been only a few reports regarding the fine needle aspiration (FNA) diagnosis of myoepithelioma of the salivary glands. 1,2,[4][5][6][7][8]10 However, there is no report describing the specific, characteristic cytologic findings that can enable a diagnosis of myoepithelioma to be made. In an attempt to de- It is difficult to differentiate myoepithelioma from cellular pleomorphic adenoma on FNA smears.…”

Zystisches Myoepitheliom

“…De las Casas et al [2] berichten über einen 1,5 cm großen zystischen Tumor im vorderen Zungenrücken, welcher nach histologischer Aufarbeitung als zystisches Myoepitheliom diagnostiziert wurde. Wie im vorliegenden Fall wurde eine epitheliale Auskleidung der zystischen Komponente nicht nachgewiesen.…”