Granular cell myoblastoma of the breast: a report of 2 cases.

Two cases of granular cell myoblastoma of the breast are presented occurring in women aged 20 and 22 years. The clinical findings, mammographic and naked eye appearances suggested carcinoma. The difficulties of diagnosis and the pathogenesis of this rare tumour are discussed. A definitive histological diagnosis of an apparently malignant breast lump, particularly in a young woman, is mandatory before proceeding to major surgery.