Epithelial atypia in biopsies performed for microcalcifications. practical considerations about 2,833 serially sectioned surgical biopsies with a long follow-up

Abstract

This study analyzes the occurrence of epithelial atypia in 2,833 serially sectioned surgical breast biopsies (SB) performed for microcalcifications (median number of blocks per SB:26) and the occurrence of subsequent cancer after an initial diagnosis of epithelial atypia (median follow-up 160 months). Epithelial atypia (flat epithelial atypia, atypical ductal hyperplasia, and lobular neoplasia) were found in 971 SB, with and without a concomitant cancer in 301 (31%) and 670 (69%) SB, respectively. Thus, isolated epithelial atypia were found in 670 out of the 2,833 SB (23%). Concomitant cancers corresponded to ductal carcinomas in situ and micro-invasive (77%), invasive ductal carcinomas not otherwise specified (15%), invasive lobular carcinomas (4%), and tubular carcinomas (4%). Fifteen out of the 443 patients with isolated epithelial atypia developed a subsequent ipsilateral (n = 14) and contralateral (n = 1) invasive cancer. The high slide rating might explain the high percentages of epithelial atypia and concomitant cancers and the low percentage of subsequent cancer after a diagnosis of epithelial atypia as a single lesion. Epithelial atypia could be more a risk marker of concomitant than subsequent cancer.

Fig. 1

a–d. ADH “mimicking DCIS.” a Tufts and short micropapillations with a broad base. b Pseudo-cribriform spaces. c Microlumen with incomplete polarization of surrounding epithelial cells. d Cellular bridges without cellular polarization. Cells are parallel to the axes (arrows)

Fig. 2

a–e. ADH corresponding to “mini DCIS.” a A solid mini DCIS focus measuring less than 2 mm in one TDLU. b Tufts and short micropapillations over the entire periphery of the duct with small free papillary tufts in the lumen. c Short micropapillations with a tight base. d True cribriform spaces. e Microlumen with complete polarization of surrounding epithelial cells

Fig. 3

a–c. Variants of cribriform patterns. Polarized cells arranged perpendicular to the axes. a Trabecular bars. b Cartwheel formations. c Roman bridges

Fig. 4

a and b. a Mild cytologic atypia. b Columnar cells with uniform ovoid nuclei, intraluminal calcifications

Fig. 5

Probability of developing subsequent invasive breast cancer in the group of 415 patients with epithelial atypia (dotted line: confidence interval 95%)