It is the routine procedure today to include an inspection and palpation of the external genitalia during the course of a physical examination. Such a practice will usually reveal the presence of any testicular irregularity or nodularity that is indicative of the probable presence of a tumor of the testis. In this case the testicular tumor was first manifest by the presence of a large solitary metastatic mass in the left retroperitoneum, and the primary tumor could not be detected on physical examination. REPORT OF A CASE A 55-year-old white male office worker consulted one of us (H. S.) because of a painless swelling of his left lower extremity of three weeks' duration. Examination revealed a large, hard mass occupying the left lower quadrant. Roentgenographic gastrointestinal studies and barium enema showed no abnormality of the gastrointestinal tract but did show a space-occupying mass in the left lower quadrant. An excretory