Hamartoma of the breast: an underrecognized disease?

Hamartomas of the breast are benign tumors composed primarily of dense, fibrous tissue with variable amounts of fat and associated ducts. A 48-year-old woman had noted a lump in her right breast for a number of years. She came to our clinics because of the recent progressive enlargement of this lump. Physical examination revealed a large, mobile, round, painless mass in the lower inner quadrant of the right breast. There were no palpable axillary lymph nodes. Mammography showed a circumscribed, 4.5 x 2.5 cm mass with a radiolucent periphery and moderately radiopaque center. On the basis of the clinical and mammographic findings, hamartoma of the breast was highly suspected. A lumpectomy was performed and histological examination of the specimen revealed overgrowth of mammary lobules and ductules, forming a well-circumscribed lesion with admixed fat tissue. Hamartoma of the breast was confirmed. With the awareness of this entity and good correlation of imaging findings, the clinical diagnosis of hamartoma of the breast should not be difficult. If careful attention is paid to the clinical information, histological underdiagnosis of hamartoma of the breast can be avoided.