Incidental Finding of Ductal Carcinoma in Situ: On Histopathology Report of Fibroadenoma

Breast cancer remains one of the most common causes of cancer and cancer-related death in women. Invasive ductal carcinoma (ICD) of breast and fibroadenoma are rarely found as coexist. There are no pathognomonic symptoms or signs to distinguish both diseases. A 28-year-old woman presented with a palpable lump in the right breast, upper outer quadrant. Mammography showed an oval mass associated with two small microcalcifications within the lump. Breast ultrasound (US) revealed a 2.5 cm×2.5 cm oval mass. On Fine Needle Aspiration Cytology (FNAC), the initial biopsy of the lump suggested fibroadenoma; however, the mass was diagnosed as a fibroepithelial lesion. Per-operatively the mass was found suspicious for malignancy, as there were pockets of dark discolored tissue within the lump. The lump was removed with 1cm clearance. Histopathological examination of the specimen revealed small lesions of ductal carcinoma in situ (DCIS) within the fibro adenomatous tissue. This case highlights the diagnostic challenges of identifying coexisting carcinomas within fibroadenoma tumours and emphasizes the necessity for increased awareness among radiologists regarding this possibility.