Sclerosing lobular hyperplasia of the breast: imaging features in 15 cases.

OBJECTIVE: Sclerosing lobular hyperplasia is an infrequent benign lesion of the breast, defined as prominent hyperplasia of the lobules with sclerosis of the interlobular stroma. It commonly presents as a tumorlike mass clinically. Sclerosing lobular hyperplasia has been identified at biopsy at our institution with rare but increasing frequency. We reviewed the imaging features of 15 patients with biopsy-proven sclerosing lobular hyperplasia to determine if a characteristic imaging pattern could suggest this diagnosis.
MATERIALS AND METHODS: The mammograms and sonograms of all women with pathologically proved sclerosing lobular hyperplasia seen between January 1986 and June 1993 were retrospectively reviewed by two of the authors who were familiar with the pathologic diagnosis. Imaging findings that led to biopsy or were present on the preoperative studies were reviewed. The study included 15 patients ranging in age from 21 to 46 years old, with a mean age of 32 years. Seven were black, and eight were white. All women had mammograms, three patients had prior mammograms for comparison, and sonography was done in all but one case. Presenting symptoms included a recently discovered breast lump in eight patients, breast tenderness in one patient, and a clear nipple discharge in one patient. The other five were asymptomatic and had screening mammograms.
RESULTS: Eight patients (53%) had a well-defined mass on mammography, varying in size from 1.0 cm to 8.0 cm (mean, 3.7 cm). In one of these patients, the nodule was proved to be a fibroadenoma; sclerosing lobular hyperplasia was found only microscopically. Microcalcifications were present within the mass on mammography in one patient. Mammograms in two women showed asymmetric increased density compared with the opposite breast, and in five cases, the mammographic findings were interpreted as normal. Sonograms showed a solid, well-defined mass with either homogeneous or mixed echoes in 10 of 14 patients (71%). In only one of these nodules was acoustic enhancement present. In the other four women, sonograms were normal. No characteristic findings were identified that would suggest sclerosing lobular hyperplasia as a likely diagnosis preoperatively, and, in fact, in many cases a diagnosis of fibroadenoma was considered most probable.
CONCLUSION: The imaging findings of sclerosing lobular hyperplasia are not sufficiently characteristic to distinguish the lesion from fibroadenomas and well-circumscribed carcinomas.