Differential Diagnosis for Clear Fluid Nipple Discharge

• Single Most Likely Diagnosis
  • Galactorrhea: This condition is characterized by the spontaneous flow of milk or a milk-like substance from the breast, which can be clear, and is not associated with childbirth or nursing. It's often related to hormonal imbalances, particularly prolactin levels, but can also be caused by certain medications, thyroid disorders, or pituitary tumors.
• Other Likely Diagnoses
  • Ductal Ectasia: A condition where the milk ducts in the breast become widened, leading to a discharge that can be clear, green, or black. It's more common in older women and can be associated with periductal mastitis.
  • Intraductal Papilloma: A small, benign tumor that grows in the milk ducts of the breast. It can cause a clear or bloody discharge and is usually found in women between the ages of 40 and 50.
• Do Not Miss Diagnoses
  • Breast Cancer: Although less common, clear nipple discharge can be a symptom of breast cancer, particularly if it's associated with other signs like a lump, skin changes, or axillary lymphadenopathy. Intraductal carcinoma, such as ductal carcinoma in situ (DCIS), can present with nipple discharge.
  • Pituitary Tumor: A prolactinoma, a type of pituitary adenoma, can cause an increase in prolactin levels, leading to galactorrhea. It's crucial to diagnose and treat pituitary tumors due to their potential to cause significant morbidity.
• Rare Diagnoses
  • Neurofibromatosis: A genetic disorder that can cause tumors to form on nerve tissue, including in the breast, potentially leading to clear nipple discharge.
  • Thyroid Disorders: Certain thyroid conditions, such as hypothyroidism, can lead to an increase in prolactin levels, resulting in galactorrhea. However, this is less common compared to other causes of clear nipple discharge.