Aspiration cytology of mediastinal seminoma: report of a case with emphasis on the diagnostic role of aspiration cytology, cell block and immunocytochemistry.

摘要

BACKGROUND: Medigstinal seminoma ia an uncommon tumor that occurs primarily in young males. We present a case of mediastinal seminoma in an elderly male diagnosed on fine needle aspiration (FNA) tytology. CASE: A 62-year-old male was admitted to our hospital because of anterior chest pain for 2 weeks. Chest computed tomography revealed a huge, lobulated mass in the anterior mediastinum. Aspirate smears were highly cellular. The tumor cells appeared singly or in loose groups of a few cells in a markedly necrotic background without lymphocytic or tigroid characteristics. Well-preserved cells were relatively uniform, large and polygonal, with round or ovoid nuclei, 2 1 prominent nucleoli and a mild to moderate amount of clear, occasionally vacuolated cytoplasm. The chromatin wasfinely granular. Mitotic figures were frequently found. The cell block section showed solid nests of tumor cells with cytologic features similar to those in the smears, supported by loose, fibrous stroma infiltrated by some lymphocytes. Immunocytochemically the tumor showed diffuse reactivity for c-kit and appearedfocally positive for placentalike alkaline phosphatase and was uniformly negative for pancytokeratin, CAM 5.2 low-molecular-weight cytokeratin, CD5, CD30, alpha-fetoprotein and leukocyte common antigen. CONCLUSION: A confident diagnosis of mediastinal seminoma can be established by FNA cytology, cell block and immunocytochemistry.