2000 年 39 巻 6 号 p. 543-544
Cytological findings of Leydig cell tumor of the testis are described. A 61-year-old male presented with left scrotal swelling and no hormonal manifestations. The castrated left testis contained a 4.6×4.1 cm, well-defined, yellowishbrown mass. Imprint cytological specimens showed polygonal, weakly cohesive tumor cells with round nuclei, fine granular chromatin, small nucleoli and light-green stained cytoplasm. Lipofuscin pigments were observed but no Reinke's crystals were found. The tumor cells were positive for cytokeratin and α-inhibin. Clinical information and consideration of related diagnoses are essential for the diagnosis of this tumor and α-inhibin immunostaining is helpful.