Colonic carcinoma metastatic to the left testis, epididymis & spermatic cord

836 Fig. 1. Histopathological examination revealed the colonic signet-ring cell carcinoma (arrow) (Hematoxylin-eosin staining; original magnification×200). Fig. 2A. CT showed the only hydrocele of tunica vaginalis (thin arrow) and the normal shape of testis (thick arrow) in the left scrotum during December 2010. Fig. 2B. CT showed a 6.8×4.5cm mixed density mass shadow with ill-defined margin in the left scrotum, and above which a cystic shadow with watery density in May 2014. CT diagnosis was left testis tumour (thick arrow) and hydrocele of tunica vaginalis (thin arrow). Fig. 3A-D. Immunohistochemistry (IHC) staining showed that the tumour cells were positive for cytokeratin (CK) 20 (A) (arrow), Villin (B) (arrow), caudal-related homeobox transcription factor 2 (CDX2) (C) (arrow), but negative for CK7 (D) (arrow) (DAB staining; original magnification ×200). Fig. 4A, B, C, D. Histopathological examination revealed metastatic colonic signet-ring cell carcinoma to the left tunica vaginalis testis (A) (arrow), tunica albuginea testis (B) (arrow), epididymis (C) (arrow) and spermatic cord (D) (arrow) (Hematoxylin-eosin staining; original magnification×200).