Differential Diagnosis for Unilateral Tender Breast Mass in a Breast Feeder

• Single most likely diagnosis
  • Duct ectasia: This condition is characterized by the dilation of the milk ducts, often accompanied by inflammation and the formation of small cysts. It can cause a tender mass, especially if it involves and is attached to the areola, which aligns with the symptoms described. Duct ectasia is more common in lactating women, making it a likely diagnosis in this context.
• Other Likely diagnoses
  • Breast lactating adenoma: This is a benign tumor that can develop during pregnancy or lactation. It presents as a palpable mass and can be tender. Given the patient's status as a breast feeder, this diagnosis is plausible.
  • Intraductal papilloma: Although less common, an intraductal papilloma could cause a tender mass if it becomes large enough or if there is associated ductal ectasia. However, it typically presents with nipple discharge rather than a palpable mass attached to the areola.
• Do Not Miss diagnoses
  • Breast abscess: This is an infection of the breast tissue that can form a mass, often accompanied by significant pain, redness, and warmth. While less likely given the description of many small cysts, an abscess could be deadly if missed due to the risk of sepsis, especially in a lactating woman.
  • Inflammatory breast cancer: Although rare, this aggressive form of breast cancer can mimic inflammatory conditions of the breast, including duct ectasia or an abscess. It's crucial to consider this diagnosis to ensure timely treatment if present.
• Rare diagnoses
  • Fibroadenoma: While fibroadenomas are common benign breast tumors, they are less likely in this scenario due to the specific involvement of the areola and the presence of many small cysts, which is not typical for fibroadenomas.
  • Other rare conditions such as granulomatous mastitis or diabetic mastopathy could also present with a breast mass but are less likely given the clinical context provided.