Primary leiomyosarcoma of the parotid gland: Aspiration cytology with emphasis on differential diagnosis

Abstract

AbstractMost salivary gland neoplasms are of epithelial origin. Sarcomas of the parotid gland, including leiomyosarcoma, are exceedingly rare mesenchymal tumours. A definitive diagnosis of leiomyosarcoma is challenging on cytomorphology alone. We herein describe a case of a 41‐year‐old woman who presented with parotid gland swelling. The patient was previously diagnosed with leiomyosarcoma of the parotid gland on histopathology. Fine needle aspiration cytology was done from this recurrent swelling. Cytomorphology combined with cell block immunocytochemistry was fruitful in confirming the tumour recurrence. Primary and recurrent/metastatic leiomyosarcoma of the parotid gland is a rarity and cannot be distinguished on cytology. Such a distinction is based on the known history of prior malignancy, which was forthcoming in the present case, or after an exhaustive work‐up. Pertinent clinical history and radiology provide leads for the cytopathologist. They must be sought so that immunocytochemistry can be applied judiciously and a precise/nearly precise cytological diagnosis rendered, as it guides patient management. The diagnosis is challenging on cytology as the spindle cell lesions of the parotid gland range from reactive to benign to malignant tumours.