Diagnosis of myeloid sarcoma involving salivary glands by fine-needle aspiration cytology and flow cytometry: report of four cases.

Myeloid sarcoma involving salivary glands is extremely rare. Here, we report four cases of this rare occurrence, diagnosed by fine-needle aspiration biopsy. All of four patients had previous diagnoses of myeloid neoplasms. They presented with a solitary mass in the parotid or submandibular salivary gland. The cytological evaluation of the aspirates revealed scattered salivary gland acini admixed with dispersed atypical cells. In three cases, the atypical cells appeared to be heterogeneous, intermediate to large in size, and have folded nuclei with fine chromatin. In another case the atypical cells were monotonous and had round nuclei with fine chromatin. The myeloid lineage of the atypical cells was demonstrated by flow cytometric analysis. High clinical suspicion, careful cytological evaluation, and concurrent ancillary studies are essential for establishing a diagnosis of myeloid sarcoma.