Breast tissue inclusions in axillary lymph nodes.

This report describes a female of 54 years with a past history of repeated breast biopsies all showing benign epithelial hyperplasia. The patient subsequently had a simple mastectomy and axillary lymph node biopsy. No evidence of malignancy was found in the specimen but there were numerous foci of epithelial hyperplasia in the breast and one axillary lymph node was extensively replaced by similar tissue. The danger of mistaking benign inclusions in lymph nodes for metastatic malignancy, particularly in tissue examined by cryostat section, is emphasized. The possible aetiology of such lesions is briefly discussed.