Preoperative Diagnosis of Ductal Carcinoma In Situ Arising Within a Mammary Fibroadenoma: A Case Report

Abstract

Fibroadenoma is the most common form of benign breast tumor and the most common breast tumor in women under 30 years of age. However, carcinoma arising within a fibroadenoma is unusual, with over 100 cases reported in the literature. Histological diagnosis is typically unexpected. A 46-year-old female with no family history of breast malignancies was admitted for an elastic hard lump in the upper-outer quadrant of her right breast. At a clinic that she visited previously, her condition was diagnosed by core needle biopsy with four specimens showing fibroadenoma with borderline atypical ductal hyperplasia at pathology. Excisional biopsy was recommended for pathological diagnosis. The patient requested a definitive diagnosis and alternative treatment to tumorectomy. More biopsy specimens were needed for pathological diagnosis; therefore, ultrasonography-guided vacuum-assisted core needle biopsies were obtained, confirming ductal carcinoma in situ with questionable microinvasion of intracanalicular- and pericanalicular-type fibroadenoma. Right breast-conserving surgery and sentinel lymph node biopsy were immediately performed for radical therapy. We present this case to increase awareness of this entity and stress the need for histological evaluation of some breast masses.

Invasive Breast Carcinoma Occuring Within Fibroadenoma: Case Report

“…7,10 Carcinoma occuring within a fibroadenoma is a very rare condition. 1,3,5 The incidence of carcinoma occuring within fibroadenoma is between 0.1-0.3%, and mean age is 44 years (range from 15 to 83 years) and higher from single fibroadenoma. 1,3 The age of our case is compatible with literature.…”

“…Doppler USG often shows marginal vascularities surrounding the mass, and slightly increased vascularity in fibroadenomas is different from cancers from the vascular infiltration into the mass. 1 The mammographic features of carcinoma originating within a fibroadenoma include round, oval or lobulated mass, margin irregularity, suspicious linear or pleomorphic calcifications. 12 Fibroadenomas are seen as a focal round or oval shaped mass with smooth margins at MRI 12 .…”

“…1 The detection of malignancy occuring within a fibroadenoma can be difficult. 2,10 Although malignant transformation of a fibroadenoma is very rare, fibroadenoma in a woman with a positive family history may have greater clinical importance than fibroadenoma occuring in a woman with no additional risk factors.…”

“…[1][2][3][4] They are the second most common tumours of the breast after carcinoma and the most common benign tumours of the breast in adolescent girls and young women. 1,3 Malignant transformation of fibroadenoma to carcinoma is very rare (equal or less than 0.5%), and the mean age is fifth decade.…”

“…[1][2][3][4] They are the second most common tumours of the breast after carcinoma and the most common benign tumours of the breast in adolescent girls and young women. 1,3 Malignant transformation of fibroadenoma to carcinoma is very rare (equal or less than 0.5%), and the mean age is fifth decade. 2,[4][5][6][7] The most common malignant histologic type coexistence with fibroadenoma is lobular carcinoma in situ (66.9%), followed by ductal carcinoma in situ (12.4%), invasive ductal carcinoma (11%), and invasive lobular carcinoma (3.4%).…”