John M. Skaugen, M.D. and Rajiv Dhir, M.D.
The patient was a man in his early 30s who presented with 3 weeks of lower back pain and 1 week of right testicular pain. He was found to have a right testicular mass, which measured up to 3.0 cm by ultrasound. Lab work was also performed at this time (Table 1).
Table 1 - Selected laboratory data prior to surgery.
A right radical orchiectomy was then performed. Grossly, the tumor measured 3.2 x 2.9 x 2.4 cm and was confined to the tunica albuginea. It was grey-white to pink red, fleshy to friable and focally hemorrhagic with less than 5% necrosis (Figure 1). Representative microscopic images from both H&E sections (Figure 2) and immunohistochemical stains (Figure 3) are provided. What is the diagnosis?