Complex fibroadenoma

Complex fibroadenoma is a sub type of fibroadenoma harboring one or more of the following features:

• epithelial calcifications
• papillary apocrine metaplasia
• sclerosing adenosis and 
• cysts larger than 3 mm

Epidemiology

Complex fibroadenomas tend to occur in older patients (median age, 47 years) compared with simple fibroadenomas (median age, 28.5 years).

Pathology

They fall under the broad group of adenomatous breast lesions. Complex fibroadenomas are often smaller than simple fibroadenomas (1.3 cm compared with 2.5 cm in simple fibroadenomas). When histopathology on core biopsy reveals a higher-risk lesion, such as atypical lobular hyperplasia, excisional biopsy may be indicated to rule out malignancy.

The clinical relevance is not clear. 

Radiographic features

There are no clear cut mammographic or sonographic features that distinguish complex from simple fibroadenomas.

Complications

There are numerous reports that the general risk of developing cancer in the breast parenchyma is elevated among women with complex fibroadenomas; these women are 3.1-3.7 times more likely to develop breast cancer than women in the general population (compared with a relative risk of 1.9 times in women with non-complex fibroadenomas). ~50% of these tend to be lobular carcinoma in situ (LCIS), ~20%  infiltrating lobular carcinoma, ~20% ductal carcinoma in situ (DCIS), and the remaining 10% are infiltrating ductal carcinoma .