Sclerosing lobular hyperplasia manifesting as a palpable mass of the breast in young black women.

Sclerosing lobular hyperplasia is defined as a lesion of the breast characterized solely by prominent hyperplasia of the lobules and sclerosis of the intralobular stroma. The extra-lobular connective tissue may or may not be fibrosed. To ascertain the frequency of this condition, the histologic sections of all benign breast lesions diagnosed at Howard University Hospital between January 1, 1980, and June 30, 1982, were reviewed. The patient population of the hospital is almost entirely black. Among a total of 590 benign breast lesions, 18 cases of sclerosing lobular hyperplasia were found. The mean age of the patients was 28.3 years. The patients generally complained of a painless or slightly tender lump in the breast, of one or two month's duration. The masses appeared finely nodular and varied in size from 0.8 X 1.2 cm to 3.5 X 5.0 cm. Some microscopic sections from patients with sclerosing lobular hyperplasia revealed incipient (lobule-sized) fibroadenoma. On re-examination of the available sections of 101 fibroadenomas, 47 (46.5 per cent) were found to be surrounded by breast tissue exhibiting focal sclerosing lobular hyperplasia. Apparently, sclerosing lobular hyperplasia is often overgrown by fibroadenoma, and the presenting symptoms are those of the dominant tumor rather than those of the preceding condition.