11th April 2024

Miscellaneous

Lipomas are benign tumours made up of mature fat cells only. There is an absence of histologic elements of breast tissue. They are usually solitary, presenting as well-circumscribed, soft, non-tender masses. Core or excisional biopsy can be performed. There is no increased risk of subsequent breast cancer.

Fat necrosis typically occurs secondary to breast trauma or surgical intervention. Experienced radiologists can identify this pathology on ultrasound and/or mammogram. If the diagnosis is established, excision is not necessary. No increased risk of subsequent breast cancer. 

Periductal mastitis is an inflammatory condition affecting the subareolar ducts. The inflamed ducts are susceptible to secondary infection and formation of a subareolar abscess. Another rare inflammatory breast pathology affecting young women is idiopathic granulomatous mastitis. Breastfeeding women can develop lactational mastitis. If left untreated, this can progress to a secondary breast abscess. 

There are numerous congenital abnormalities of breast development. Polythelia, an accessory or supernumerary nipple, is seen in both sexes and is the most common variant of supernumerary breast components. An ectopic nipple may occur at any point from the axilla to the groin along the “milk streak.” Polymastia is accessory or supernumerary breast tissue. It is most commonly found in the axilla. Other rarer abnormalities include underdevelopment (hypoplasia), congenital absence (amastia) and the absence of breast tissue but a normal nipple-areola complex (amazia). 

Idiopathic granulomatous mastitis (IGM) is a benign, rare inflammatory disease of the breast. It typically affects younger women and presents as a unilaterally and peripheral breast lump. It can have malignant-like features on examination. Core needle biopsy shows non-necrotising granulomas. The most commonly isolated species is Corynebacterium kroppenstedtii.