Abstract
Background : Primary squamous cell carcinoma of the salivary gland is extremely rare and is known to be associated with a very poor prognosis. Herein, we report the cytological features of a diagnostically difficult case of primary salivary gland squamous cell carcinoma with intracytoplasmic vacuoles, which resembled a mucoepidermoid carcinoma.
Case : A 65-year-old man presented to a physician with a swelling on the right mandible, which he had first noticed about a month earlier. Fine needle aspiration cytology revealed orange G-philic keratinized cells and strongly light green-stained cells in Papanicolaou stain, based on which the lesion was diagnosed as a squamous cell carcinoma. However, it was difficult to distinguish it from mucoepidermoid carcinoma because the tumor cells contained intracytoplasmic vacuoles. Histological examination showed moderately to poorly differentiated squamous cell carcinoma without any evidence of mucus production. Electron-microscopic examination of a formalin-fixed tissue specimen revealed dilated endoplasmic reticula, suggestive of intracytoplasmic vacuoles.
Conclusion : It is important to distinguish squamous cell carcinoma with intracytoplasmic vacuoles from mucoepidermoid carcinoma.
