case_images: PMC4376918_01
case_images: Representative images of histopathology from the right radical orchiectomy. a The testis contained a well-circumscribed tumor measuring 1.5 cm, no involvement of the spermatic cord, and negative surgical margins. The tumor showed anastomosing nests of large cells infiltrating between benign seminiferous tubules. HE. x100. b A higher-magnification image illustrates large cells with vesicular chromatin, large nucleoli, and abundant cytoplasm. HE. x400.
case_images: cro-0008-0133-g01.jpg
case_images: PMC4376918_01_cro-0008-0133-g01.jpg
case_images: F1
case_images: The tumor was composed of irregularly infiltrating and anastomosing nests of large cells with vesicular chromatin, large nucleoli, and abundant cytoplasm (fig. 1), similar to the tumor in the lung biopsy.
case_images: Representative images of immunohistochemistry performed on the testicular mass. Immunoperoxidase stains show strong reactivity for pan-keratin (a), CK 5/6 (b), p63 (c), and polyclonal CEA (d). This phenotype supports the diagnosis of metastatic squamous cell carcinoma. x200.
case_images: cro-0008-0133-g02.jpg
case_images: PMC4376918_01_cro-0008-0133-g02.jpg
case_images: F2
case_images: TTF-1 and napsin-A were negative. This pattern supported the diagnosis of metastatic squamous cell carcinoma rather than a new testicular primary (fig. 2).