Fine-Needle Aspiration of Parotid Gland Sialoblastoma. Two New Cases and Literature Review.

Sialoblastoma is an exceedingly rare, low-grade malignancy, most frequently arising in the parotid gland. Only four case reports detailing the cytomorphology of this neoplasm exist in the English literature. Here, we describe the cytological features, histopathology, and clinical data of sialoblastomas presented at birth in two additional patients. Both neoplasms were initially examined by fine-needle aspiration (FNA) followed by surgical excision of the tumors. Smears showed hypercellularity and basaloid round to oval cells isolated or arranged in three-dimensional clusters. Papillary and acinar configurations, metachromatic pink stromal fragments, and hyaline globules were also present. One case was diagnosed as a neoplasm of unclear malignant potential and the second as malignant.