Differential Diagnosis for Visual Impairment, Galactorrhea, Gynaecomastia, and Decreased Libido

• Single Most Likely Diagnosis
  • Pituitary Adenoma: This condition is the most likely diagnosis given the combination of symptoms. Pituitary adenomas, especially prolactinomas, can cause an overproduction of prolactin, leading to galactorrhea and gynaecomastia. Large adenomas can also compress the optic chiasm, resulting in visual impairment. Additionally, the hormonal imbalance can affect libido.
• Other Likely Diagnoses
  • Hypothalamic Disorders: Conditions affecting the hypothalamus can disrupt the normal functioning of the pituitary gland, leading to similar symptoms. However, these are less common than pituitary adenomas.
  • Thyroid Disorders: Certain thyroid conditions can cause galactorrhea and changes in libido, though they are less directly linked to visual impairment and gynaecomastia compared to pituitary issues.
• Do Not Miss Diagnoses
  • Pituitary Apoplexy: Although less common, pituitary apoplexy is a medical emergency that requires immediate attention. It involves sudden hemorrhage or infarction of the pituitary gland, which can present with sudden onset of headache, visual impairment, and acute endocrine deficiency. Missing this diagnosis could be fatal.
  • Craniopharyngioma: These are rare, benign brain tumors that occur near the pituitary gland and can cause similar symptoms by compressing or infiltrating the pituitary and surrounding structures.
• Rare Diagnoses
  • Lymphocytic Hypophysitis: An autoimmune condition that can cause inflammation of the pituitary gland, leading to a variety of endocrine symptoms. It is rare and more commonly seen in women, especially during pregnancy.
  • Granular Cell Tumor of the Pituitary: A rare, usually benign tumor that can cause symptoms by compressing the pituitary gland or stalk, affecting hormone production.