Fine needle aspiration cytology of a trabecular adenoma of the parotid gland.

: What is believed to be the first description of the cytologic presentation of a trabecular adenoma of the parotid gland in a fine needle aspirate is reported in the case of a 52-year-old woman. The cytologic findings included translucent spherical bodies surrounded by small round cells with a thin rim of cytoplasm and round-to-oval nuclei in Papanicolaou-stained specimens. The cells, which varied little in size, formed densely packed clusters. In May-Grunwald-Giemsa-stained preparations, mucoid globules were seen surrounded by palisading tumor cells. Nuclear anaplasia was not seen. The aspiration cytologic and even the histologic appearance of trabecular adenoma can closely mimic that of adenoid cystic carcinoma, which was the preoperative diagnosis in this case. Because the treatment of these two entities is different, it is important that trabecular adenoma be considered in the differential diagnosis. The observations in this case indicate that tinctorial properties of the intercellular substance may aid in differentiating between these two neoplasms in fine needle aspirates.