Scalp metastasis of pulmonary blastoma - a rare entity: Cytomorphology with differential diagnoses.

Pulmonary blastomas are exceptionally rare tumors. These tumors behave aggressively, with a propensity to metastasize to the brain and mediastinum. A definitive diagnosis of pulmonary blastoma is challenging to obtain on cytomorphology alone. However, in a known case of primary pulmonary blastoma, any newly developing lesion at any anatomical site should be carefully evaluated for metastasis. We herein describe a case of a 59-year-old female who presented with a scalp lesion. Fine-needle aspiration cytology was done from the scalp swelling. Cytomorphology supplemented with immunocytochemistry on cell block confirmed the diagnosis of a metastatic pulmonary blastoma.