Differential Diagnosis for the 1-month-old Boy
- Single most likely diagnosis
- B) Cryptorchidism: This is the most likely explanation for the finding, as the boy has a history of bilateral descended testes at birth, but now has an empty left scrotum and a palpable nodule in the left groin that can be pulled into the scrotum. Cryptorchidism, or undescended testes, is a common condition in preterm infants, and the fact that the testis can be pulled into the scrotum suggests that it is not truly undescended, but rather retractile or at risk for becoming undescended.
- Other Likely diagnoses
- C) Retractile testis: This is a possible explanation, as the testis can be pulled into the scrotum, suggesting that it may be retractile. However, the fact that the testis is not currently in the scrotum and is instead in the groin suggests that cryptorchidism may be a more likely diagnosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- D) Testicular torsion: Although this is unlikely given the age of the patient and the fact that the testis can be pulled into the scrotum, testicular torsion is a medical emergency that requires prompt attention. It is essential to consider this diagnosis, even if it is unlikely, to avoid missing a potentially life-threatening condition.
- Rare diagnoses
- A) Androgen insensitivity: This is a rare condition that affects the development of male genitalia. While it could potentially explain the finding of an undescended testis, it is unlikely given the lack of other signs or symptoms suggestive of androgen insensitivity.
- E) Vanishing testes syndrome: This is a rare condition in which one or both testes are absent or atrophic. While it could potentially explain the finding of an empty scrotum, it is unlikely given the presence of a palpable nodule in the groin that can be pulled into the scrotum.