Teaching Case

Eczematous skin lesion on the left breast.

The patient consulted with an eczematous skin lesion at the left breast. She underwent a mammography and an ultrasonography which showed a suspicious lesion in the left breast. Because the clinical examination did not reveal a palpable mass, ultrasonography was repeated, and again showed the lesion in the left breast. The patient underwent surgical biopsy followed by tumorectomy. Histological examination revealed regions of fibrocystic disease with epithelial hyperplasia and some regions of radial scar formation. There were no malignant cells found in the biopsied tissue.

Radial scar is a benign hyperplastic proliferative disease of the breast. It can develop out of benign proliferative disorders such as adenosis, hyperplasia and papilloma by inflammation and slow infarction in these lesions. Histopathologically radial scars contain hyperplastic tissue cells and a central fibrous core, with spiculated peripheral borders, mimicking infiltrating carcinoma. Clinical examination of the breast containing regions of radial scar is often normal, although in about 25% of cases radial scar can be palpable. Mammography of radial scar shows an irregularly outlined, lobulated or spiculated mass. Some radial scars appear solid in the center, but in most cases the center is radiolucent. Sometimes a fatty content is found in the center of a radial scar. Microcalcifications, which are only rarely associated with radial scar, are located within the surrounding breast parenchyma and have a benign appearance. On ultrasonography the radial scar is ill-defined and disturbs the architecture of surrounding breast parenchyma. The lesion is round, oval or lobulated. Variable internal echoes can be found. Some radial scars show retroacoustic attenuation. The differential diagnosis includes malignant diseases, such as invasive ductal carcinoma, invasive lobular carcinoma and tubular carcinoma, and benign disorders, such as early hematoma, early abscess formation, fat necrosis and postsurgical scar. Diagnosis of radial scar always needs histological proof. According to literature data about 19% of nonpalpable breast carcinomas have radiographic features identical to radial scar. Because of the higher risk for tubular carcinoma follow-up of patients treated for radial scar is necessary.