Pattern and spectrum of morphology referrals in breast pathology consultation

Summary Aims We aimed to identify common reasons for second opinion breast pathology referrals at the Pathology Department, Singapore General Hospital, focusing on queries and diagnostic issues raised by referring clinicians and pathologists. Methods Request forms for breast pathology consultations were retrieved from a specialist’s correspondence files consisting of pathologists’ referrals, and from centralised laboratory records, comprising clinician-initiated referrals. Clinical and histomorphological queries raised by the referrals were collated. Results Of 299 cases evaluated, clinician-initiated referrals ( n =137, 46%) included requests for review of overall histopathology to confirm carcinoma subtype ( n =47), grade ( n =2), size ( n =4), lymphovascular invasion ( n =1) and confirm hormonal receptor and c-erbB-2 assays ( n =33). Also required were: comparison of recurrent with previous lesions ( n =8); settling discrepant diagnoses between two or more prior pathology reports ( n =4); verification of microinvasion ( n =6), in situ carcinomas ( n =6) or atypical ductal hyperplasias ( n =4); delineation of benign ( n =8) and spindle cell lesions ( n =3); to establish a breast origin of metastatic lesions ( n =5); and distinction of carcinoma from lymphoma ( n =2). Pathologist-initiated referrals ( n =162, 54%) sought arbitration between borderline proliferative lesions ( n =46) and papillary lesions ( n =34); verification of microinvasion ( n =23), stromal lesions ( n =16), and carcinoma subtype ( n =13), especially if the patient was young ( n =5); clarification of metaplastic changes ( n =4) and lobular neoplasia ( n =8); and comparison of fibroepithelial lesions ( n =11). Conclusions Clinicians sought a second opinion mainly to verify histological diagnoses and report important pathological details for staging and confirmation of hormonal receptor and c-erbB-2 status prior to therapy. Borderline breast lesions are worrisome for both clinicians and pathologists in view of implications for management.