Differential Diagnosis for Nipple Discharge
- Single most likely diagnosis
- Intraductal Papilloma: This is the most likely diagnosis given the presentation of scant reddish-brown nipple discharge from a single breast, which is a classic symptom of intraductal papilloma. The discharge is often bloody or serosanguinous, and the absence of a palpable mass does not rule out this diagnosis.
- Other Likely diagnoses
- Ductal Ectasia: This condition can cause nipple discharge, which may be greenish, blackish, or bloody. It is more common in perimenopausal or postmenopausal women but can occur at any age.
- Fibrocystic Changes: While more commonly associated with breast pain and lumpiness, fibrocystic changes can occasionally cause nipple discharge, especially if there is a dominant cyst or fibroadenoma.
- Hyperprolactinemia: Given the patient's history of schizophrenia and treatment with antipsychotics, which can elevate prolactin levels, hyperprolactinemia is a plausible cause for the nipple discharge. However, it would typically be bilateral.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Breast Cancer: Although the mammography is normal, breast cancer, especially ductal carcinoma in situ (DCIS) or invasive cancer, can present with nipple discharge. The family history of breast cancer increases the index of suspicion.
- Pituitary Tumor: A prolactinoma or other pituitary tumor could cause hyperprolactinemia leading to nipple discharge. This is particularly important given the patient's psychiatric history and potential for medication-induced hyperprolactinemia.
- Rare diagnoses
- Galactorrhea due to Other Endocrine Disorders: Conditions like thyroid disorders or adrenal insufficiency can cause hyperprolactinemia and subsequent galactorrhea, though these would be less common.
- Breast Infections or Abscesses: Though typically associated with more pronounced symptoms of infection (e.g., pain, redness, swelling), an abscess or infection could potentially cause nipple discharge, especially if it involves the ductal system.