Differential Diagnosis

The patient presents with a 6-month history of loss of libido, loss of erections, change in semen volume, and testicular pain, along with laboratory results showing high SHBG, normal free testosterone, elevated FSH, and LH. Considering these symptoms and findings, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Hypogonadism: Given the patient's symptoms of loss of libido and erections, along with the laboratory findings, hypogonadism is a strong consideration. The elevated FSH and LH levels suggest primary hypogonadism, where the testes do not produce enough testosterone, leading to an increase in gonadotropin secretion in an attempt to stimulate the testes.

• Other Likely Diagnoses

  • Varicocele-related infertility: The presence of varicoceles, which are abnormal enlargements of the vein that is in the scrotum, can affect sperm production and quality, potentially leading to infertility. The patient's symptoms and the finding of varicoceles on ultrasound make this a plausible diagnosis.
  • Post-COVID-19 syndrome: Although less common, COVID-19 has been associated with a range of post-infection syndromes, including effects on the reproductive system. The temporal relationship between the patient's COVID-19 infection and the onset of symptoms suggests this as a possible contributing factor.
  • Testicular dysfunction: The patient's testicular pain and the ultrasound findings could indicate underlying testicular dysfunction, which might be contributing to the patient's symptoms and potential infertility.

• Do Not Miss Diagnoses

  • Testicular cancer: Although rare, testicular cancer can present with testicular pain, changes in testicular size, and hormonal imbalances. It is crucial to rule out testicular cancer due to its potential severity and the importance of early detection.
  • Pituitary or hypothalamic disorders: These can lead to secondary hypogonadism, characterized by low FSH and LH levels, which is not the case here. However, certain conditions like a pituitary adenoma could potentially cause an imbalance in hormone production, affecting gonadotropin secretion and, consequently, testicular function.
  • Infections or inflammation: Chronic infections or inflammatory conditions affecting the testes or epididymis could lead to the patient's symptoms and should be considered, especially given the recent history of COVID-19.

• Rare Diagnoses

  • Klinefelter syndrome: A genetic condition that affects male reproductive system development, often presenting with infertility, low testosterone, and elevated gonadotropins. However, it typically presents at a younger age and is associated with specific physical characteristics.
  • Autoimmune disorders: Certain autoimmune conditions can affect the testes, leading to inflammation and dysfunction. While rare, these should be considered in the differential diagnosis, especially if other causes are ruled out.