[Case of testicular carcinoid].

This is a case report of testicular carcinoid in a 37-year-old male who was admitted to hospital because of a gradual enlargement of the right testis. Macroscopically, the well-demarcated and solid lesion tumor was yellow-tan in color and confined to the testis. Microscopically, the proliferating tumor cells were arranged in a predominantly insular or lobular growth pattern admixed with cord- or ribbon-like areas. Teratomatous elements were not found. Grimelius stain revealed argyrophilic granules in the tumor cells, and, immunohistochemically, neuroendocrine markers and gastrointestinal hormones were diffusely postive in the tumor cells. From these features, we made a conclusive diagnosis of testicular carcinoid.