Challenges in Breast Pathology: A Review of the Most Common Problems Encountered in a Subspecialty Consult Service Over 1 Year-Retrospective Review of 553 Specimens.

Aims. To identify the most common reasons for consultation to a large specialty breast pathology service at a major institution. To provide insight into the overall challenges in practicing breast pathology. Methods. The anatomic pathology database at one institution was searched for all breast consultations received in 2021, excluding in-house patients and patients who were transferring care. Results. A total of 553 patients met the criteria (n = 553) from a variety of academic and private practices. For each patient, the paperwork from the submitting institution was reviewed to identify the specific question, and subsequently classified into 14 categories. The reason for the consultation request was not provided for 78 (14%) patients, and a review of the outside diagnoses, where applicable, was performed. In summary, the top 5 reasons for consultation were: (1) assistance with classification of atypical intraductal epithelial proliferations (32%); (2) evaluation for the presence of (micro-)invasive carcinoma (14%); (3) evaluation of fibroepithelial (12%), (4) papillary (11%), and (5) spindle cell lesions (7%). Conclusion. We show an ongoing educational and practice gap for pathologists who most commonly struggle with classifying atypical precursor lesions, specifically when these are small and focal, or bordering on intraductal carcinoma (32%, 177/553). The second most common reason for consultation was classifying invasive carcinomas as microinvasive and subtypes (total of 20.4%, 113/553). As such, our data supports the continued need for rigid and clear criteria for diagnosing threshold lesions (namely atypical hyperplasias) and intraductal carcinoma of the breast.