Fig. 1

Gross and H&E staining specimens: a showed a tumor located in the hilum of the testis with a maximum diameter of 13.0 cm. It was close to the testicular tunica albuginea with an unclear boundary, as indicated by the red arrow. b Showed that tumor cells in this area were spiked and constituted slit-like branched tubules, with hyperchromatic and pleomorphic nuclei (magnified ×200). c Showed tumor cells arranged in an acinar-like structure. Normal and abnormal mitoses were indicated by white and black arrows, respectively (magnified ×400). d Showed atrophied seminiferous tubules surrounded by tumor cells (magnified ×200)