Author reply

Abstract

We appreciated the opportunity to respond to the letter from Dr. Brodie and her colleagues. Our study demonstrated 85% sensitivity for stereotactic needle core biopsy (SNCB) in the diagnosis of radial scars (RS), with a specified technique that widely sampled the center and periphery of the lesion. None of the 4 cases of ductal carcinoma in situ (DCIS) associated with the 55 RS sampled were missed because either DCIS and/or atypical ductal hyperplasia (ADH), which both mandated excision, were diagnosed by SNCB. In the series reported by Quinn et al., most RS (21 of 30 cases) were sampled using ultrasound-guided needle core biopsy (UNCB). To our knowledge, their technique was not described. Our findings do not support using UNCB, which was found to be insufficiently sensitive in the diagnosis of RS or the associated pathology (63% sensitivity reported for the diagnosis of RS and 60% sensitivity reported for ADH/RS). The technique of SNCB permits sampling of the lesion periphery, usually the site of associated pathology,1, 2 whereas UNCB samples the central focus of the RS. SCNB also facilitates taking a large number of core samples, which is important for obtaining a representative sample of the associated pathology.3, 4 We reviewed the literature3 regarding the association between RS and malignancy, which demonstrated discrepancies largely between the low rates detected by population screening and the high rates reported in some case series. The findings presented by Quinn et al. do not appear to be typical of mammographic population screening. ADH is commonly associated with RS and the problem of interobserver variance in reporting ADH versus low-grade DCIS is well recognized. Forty-two of the 75 RS cases in our study were excised elsewhere and the pathology was later reviewed in our program. These cases therefore were independently double reported. Comparison of the external and internal reports showed no major discrepancies with regard to diagnoses. For the purpose of this response, an unselected review of half of the RS cases reported internally was performed by another specialist breast pathologist. This review resulted in no cases of ADH being reclassified as DCIS. However, approximately 30% of the cases previously interpreted as ADH were reclassified as ductal epithelial hyperplasia of the usual type. Jennifer N. Cawson M.P.H.*, Prue Hill Ph.D. , Michael Henderson M.D. , * Breast Screen Department St. Vincent's Hospital University of Melbourne Fitzroy, Victoria, Australia, Department of Pathology St. Vincent's Hospital University of Melbourne Fitzroy, Victoria, Australia, Department of Surgery St. Vincent's Hospital University of Melbourne Fitzroy, Victoria, Australia Department of Surgical Oncology Peter MacCallum Cancer Institute East Melbourne, Victoria, Australia.