Which condition is NOT a differential diagnosis for mastitis?

Mastitis is an infection of the breast tissue that results in breast pain, swelling, warmth, and redness, and can sometimes lead to systemic symptoms such as fever and chills. It is important to consider various differential diagnoses when evaluating a patient with breast symptoms.

The conditions that are typically considered in the differential diagnosis of mastitis include severe engorgement, breast abscess, and plugged duct.

Severe engorgement can occur when the breasts are overly full, which can lead to pain and inflammation that may mimic mastitis. A breast abscess is a localized collection of pus that can arise from untreated mastitis and has similar clinical presentations. A plugged duct may lead to similar symptoms of breast pain and could potentially progress to mastitis if not resolved.

Cystic fibrosis, however, is a genetic disorder primarily affecting the lungs and digestive system due to thick, sticky mucus production. While cystic fibrosis can have some impact on different organ systems, it is not a condition typically associated with breast tissue inflammation or symptoms of mastitis. Thus, it does not fit into the differential diagnoses for mastitis, making it the correct answer in this context.