Abstract
Background: We report a case of alveolar rhabdomyosarcoma with fine needle aspiration and imprint cytology findings as well as histological, immunohistochemical, and ultrastructural findings.
Case: A 33-year-old female presented with a left cheek mass. Fine needle aspiration of the nodule yielded cellular smears, mostly in large and small clusters of undifferentiated small round cells, with a few multinucleated giant cells. Imprint smears of the tumor contained many small round cells which had a high N/C ratio. Some mononuclear and bi/multinuclear tumor cells with abundant and dense cytoplasm were also seen. Histologically, the tumor consisted of solid and alveolar structures of many small round cells and a few eosinophilic multinuclear cells. Small focal clusters of eosinophilic bizarre giant cells were seen. Immunohistochemically, the tumor cells were positive for myogenic markers such as muscle specific actin (HHF 35), demsin, myoglobin, myo D 1, and myogenin. Diastase-sensitive PAS -positive glycogen granules were found in the tumor cells. Ultrastructurally, a few tumor cells had myofilaments with Z bands.
Conclusion: The cytological hallmarks of alveolar rhabdomyosarcoma were cellular smears composed predominantly of small round cells and a few mononuclear and bi/ multinuclear cells, having dense eosinophilic cytoplasm.
