Cytophotometric analysis of nuclear DNA-content in so-called obliterating mastopathy with epithelial hyperproliferation

INTRODUCTION: Histogenesis, microscopic appearance, and clinical significance of so-called "obliterating mastopathy with epithelial hyperproliferation" are described. This focal lesion, which was recently re-evaluated by Hamperl (1975), may simulate scirrhous carcinoma in X-ray mammography. In histologic specimens similarities to special types of tubular carcinomas may cause problems in differential diagnosis. In order to gain a better insight into their behavior, cytophotometric DNA-analysis was applied to 10 selected cases. MATERIALS AND METHODS: DNA-determination was performed on Feulgen stained sections by means of a Leitz microspectrophotometer MPV 1. The plug technique was used after careful focussing of cell nuclei. Intraductal and extraductal epithelial proliferations have been analyzed in separate series. RESULTS: In four series of extraductal pseudoinfiltration and in six series of intraductal hyperproliferation, normoploid DNA-patterns were found. One series of apocrine metaplasia and one of atypical intraductal proliferation were read as borderline cases, but one case of atypical apocrine metaplasia revealed an aneuploid DNA-pattern, thus indicating the malignant nature of the lesions. DISCUSSION: "Obliterating mastopathy with epithelial hyperproliferation" is regarded a high risk disease which may progress to invasive carcinoma. According to the gross morphologic appearance of the focal lesions, the term "pseudoscirrhus" is proposed. Therapeutic approach depends mainly on the degree of epithelial hyperproliferation and cellular atypia. Focal lesions should be removed by wide excision, whereas in cases of multicentric development, subcutaneous mastectomy and plastic augmentation is recommended.