[262] Background Microenvironmental Changes in Atypical Hyperplasia of the Breast

John K Schoolmeester, Lynn C Hartmann, Marlene H Frost, Daniel W Visscher. Mayo Clinic, Rochester, MN

Background: Benign breast disease (BBD), encompassing nonproliferative changes, proliferative disease without atypia, and atypical hyperplasia (AH), has been proven an important risk factor for subsequent development of breast cancer. The comprehensive identification of these background microenvironmental changes in AH and whether they collectively represent a precursor state, contribute to or create the conditions necessary for development of epithelial atypia has not been previously studied.
Design: Background microenvironmental changes were assessed in 47 randomly selected biopsies with AH (25 atypical lobular hyperplasia, 22 atypical ductal hyperplasia) from women enrolled in our BBD cohort. This cohort consists of 9087 women, aged 18-85, who had a benign breast biopsy between 1967-1991. Each biopsy was evaluated for nonproliferative changes, proliferative disease without atypia, AH, and the presence of calcifications in benign or atypical ducts in a single slide.

Background Microenvironmental ChangesALH, n=25ADH, n=22
Nonproliferative Changes2217
Columnar Cell Lesions20 (7 CC, 9 CH, 4 FEA)19 (2 CC, 6 CH, 11 FEA)
Sclerosing Adenosis1111
Moderate-Florid Usual Ductal Hyperplasia65
Radial Scar and/or Papilloma510
Two Proliferative Lesions1113
Three Proliferative Lesions11
Greater than Three Proliferative Lesions23
Calcifications Associated with Benign Ducts98
Calcifications Associated with Atypical Ducts611
CC=Columnar Change, CH=Columnar Hyperplasia, FEA=Flat Epithelial Atypia

Conclusions: 1. Columnar cell lesions and sclerosing adenosis are the most common background alterations in the setting of AH.
2. The frequency and quantity with which AH is associated with proliferative lesions are essentially equal.
3. FEA is more frequent in the setting of ADH than ALH.
4. In comparison to ALH, calcifications associated with atypical ducts are more common in ADH.
5. The frequency of sclerosing adenosis and columnar cell lesions, particularly FEA, in AH, implies their pathogenesis is non-random and develops out of a limited set of precursors.
Category: Breast

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 27, Monday Morning


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