Fine-needle aspiration biopsy of low-grade cribriform cystadenocarcinoma of the salivary gland.

Low-grade cribriform cystadenocarcinoma (LGCCC) is a rare tumor, defined in the 2005 WHO classification as a primary salivary duct tumor. Previously, the neoplasm had been recognized as a variant of salivary duct carcinomas. A 56-year-old Japanese woman noticed a mass in the left subaural region. On radiological examinations, a multicystic tumor was seen in the left parotid gland. Fine-needle aspiration biopsy was performed. The smears revealed several characteristic cytologic features. The tumor cells were arranged in irregular overlapping and showed inconspicuous nuclear atypia with variable-sized and irregularly shaped cytoplasmic vacuoles. Based on these findings, a cystic tumor with uncertain malignancy was diagnosed. A parotidectomy was performed, because the tumor was slowly growing and contained solid components on the radiological images. Based on the histologic findings, along with immunohistochemistry, LGCCC was diagnosed based on resemblance to breast low-grade ductal carcinoma in situ and intraductal proliferation of tumor cells. This is the first report of the cytomorphological findings of LGCCC.