A 45-year-old electrical engineer presents to your clinic, complaining of spots on his scrotum. He first noticed the spots several months ago, and they have gotten bigger. He denies any pain with urination or with sexual intercourse. He has had no fever, night sweats, weight gain, or weight loss. His past medical history consists of a vasectomy 10 years ago and mild obesity. He is on medication for hyperlipidemia. He denies any tobacco or illegal drug use and drinks alcohol socially. His mother has Alzheimer's disease and his father died of leukemia. On examination he appears relaxed and has unremarkable vital signs. On visualization of his penis, he is circumcised and has no lesions on his penis. Visualization of his scrotum shows three yellow nodules 2-3 millimeters in diameter. During palpation they are firm and nontender. What abnormality of the male genitalia is this most likely to be?
Correct Answer: D
Rationale: The correct answer is D: Epidermoid cysts. These cysts typically present as firm, non-tender nodules on the scrotum, consistent with the patient's presentation. The history of gradual growth without associated symptoms supports this diagnosis. Additionally, the lack of pain with urination or sexual intercourse rules out sexually transmitted infections like condylomata acuminata (choice A) and syphilitic chancre (choice B). Peyronie's disease (choice C) involves penile curvature and fibrous plaques, not scrotal nodules. In summary, the patient's presentation, physical examination findings, and absence of specific symptoms point towards epidermoid cysts as the most likely diagnosis.