A 56 years old female underwent needle localized excision after an abnormal breast biopsy
Contributed By: Kamaljeet Singh MD
Ductal carcinoma in situ
The answer is Tubular Carcinoma.
Tubular carcinoma (with FEA)
The histological sections show tubular carcinoma (TAC) arising in a setting of flat epithelial atypia (FEA). TAC is a special histological subtype of invasive breast carcinoma. It is considered a favorable histologic subtypes (like cribriform, and type A mucinous). TAC is composed of well-formed rounded to angular glands lined by single layer of low nuclear grade neoplastic cells. The tubules are consistently accompanied by a moderately cellular and slightly edematous reactive spindle cell stroma. Tumor cells display apical snouts. TAC are positive for estrogen receptor and negative for HER2. Per WHO the diagnosis of TAC require that > 90% of the tumor be composed of tubules.
TAC have better prognosis than stage matched grade 1 IDC, NST and long term outcome of TAC is similar to age-matched women without breast cancer.
Reference: WHO classification of Tumours Editorial Board. Breast tumours. Lyon (France): IARC; 2019 (pages 119-120).