Differential Diagnosis for a Painful Scrotal Nodule in a 15-Year-Old Male
Single Most Likely Diagnosis
- Epididymitis: This is an inflammation of the epididymis, a tube at the back of the testicle that stores and carries sperm. It's often caused by a bacterial infection and can present with sudden onset of pain and swelling, which could be mistaken for a nodule. The pain and potential for acute presentation make it a leading consideration.
Other Likely Diagnoses
- Spermatocele: A spermatocele is a benign cystic accumulation of sperm that arises from the head of the epididymis. It can cause a painful nodule if it becomes inflamed or ruptures, although it's more commonly painless.
- Varicocele: This refers to an enlargement of the veins within the scrotum, similar to varicose veins. While often asymptomatic and discovered incidentally, a varicocele can become painful, especially if it's new or has recently increased in size.
- Hydrocele: A hydrocele is an accumulation of serous fluid in a body cavity, particularly in the tunica vaginalis testis or along the spermatic cord. This condition can cause scrotal swelling and, if sudden, might be perceived as a painful nodule.
Do Not Miss Diagnoses
- Testicular Torsion: Although testicular torsion typically presents with severe, acute testicular pain and elevation of the testis (the "bell clapper" deformity), it's a medical emergency that requires immediate attention. Delayed diagnosis can result in loss of the testicle.
- Malignancy (Testicular Cancer): While rare in this age group, testicular cancer can present as a painless testicular mass. However, some types, like choriocarcinoma, can cause acute pain due to hemorrhage or rapid growth.
Rare Diagnoses
- Dermoid Cyst or Teratoma: These are types of germ cell tumors that can occur in the testes or along the spermatic cord, presenting as a mass. They are less common and might not always be painful but could cause discomfort if they become large or inflamed.
- Filarial Infection (Filariasis): In endemic areas, filarial infections can cause lymphatic obstruction leading to scrotal swelling and potentially painful nodules, although this would be uncommon in a 15-year-old without travel history to endemic areas.
- Scrotal Calcinosis: This is a rare condition characterized by the deposition of calcium in the scrotal skin, leading to multiple, small, hard nodules. It's usually painless but could be considered if other diagnoses are ruled out.