Contributed by Eizaburo Sasatomi MD, PhD and Rafael Medina-Flores MD
Published on line in October, 2004
A 71 year old man underwent a radical orchiectomy for a left solid testicular mass.
The resection specimen (79 grams) showed a solid, firm, well-circumscribed nodule measuring 0.8 x 0.7 x 0.5 cm close to the lower pole of the left testicle. The cut surface of the nodule was homogeneously yellowish-tan, slightly bulging and smooth. There was no necrosis or hemorrhage.
Low-power examination revealed a well-demarcated, non-encapsulated tumor with an expansile pattern of growth (Fig. 1). There were several small and medium sized blood vessels in and around the tumor nodule, which appeared to be encased rather than a neoplastic component of the tumor. At higher power, the tumor consisted of a solid growth of polygonal cells with abundant, slightly granular, eosinophilic cytoplasm and distinct cell borders (Fig. 2). The nuclei were round with a single prominent nucleolus. There was some variation in nuclear size and shape, but mitotic figures were absent (Figs 3 & 4). A few cells showed cytoplasmic lipofuscin pigment granules (Figure not shown). No intracellular crystalloid structures were detected on H&E slides. The tubular basement membrane was thickened, and some tubules showed luminal obliteration. Spermatogenesis was within the normal range for the patient's age (Fig 5).
The tumor cells were strongly and diffusely positive for inhibin (Fig. 6), calretinin (Fig. 7), vimentin (Fig. 8), and focally positive for synaptophysin (Fig. 9). High molecular weight cytokeratins AE1/3 (Fig. 10), low-molecular-weight cytokeratins CAM 5.2 (Fig. 11), melan A, chromogranin, alpha - fetoprotein (AFP), estrogen receptor, and progesterone receptor were all negative. Ki-67 staining was virtually absent in the tumor tissue.