Differential Diagnosis

• Single most likely diagnosis
  • Breast engorgement: This condition is very common in the postpartum period, especially in the first few weeks after delivery. The symptoms of "rock solid" breasts, exquisite tenderness, and difficulty expressing milk are classic for breast engorgement. The fact that the infant prefers to nurse on the left breast because milk cannot be expressed from the right breast also supports this diagnosis.
• Other Likely diagnoses
  • Mammary vein phlebitis: Also known as Mondor's disease, this condition is characterized by thrombophlebitis of the superficial veins of the breast. The prominent venous dilation and axillary fullness on the right side could be indicative of this condition. However, it is less common than breast engorgement.
  • Acute mastitis: Although the patient's temperature is normal, mastitis can occur without fever. The tenderness and fullness could be consistent with mastitis, but the lack of breast discoloration and systemic symptoms makes it less likely.
• Do Not Miss
  • Intraductal breast carcinoma: Although rare in young women, breast cancer can present with similar symptoms, including a palpable mass or axillary fullness. It is essential to consider this diagnosis to avoid missing a potentially life-threatening condition.
  • Lymphoma: Like breast cancer, lymphoma is rare but can present with axillary fullness or breast symptoms. It is crucial to keep this diagnosis in mind, especially if the patient's symptoms do not improve with treatment for more common conditions.
• Rare diagnoses
  • Other vascular conditions: Conditions like arterial thrombosis or vasculitis could potentially cause similar symptoms, but they are rare and would typically be associated with additional systemic symptoms or risk factors.