Changing clinical picture of mammary hamartoma

During a 6-year period, we identified 12 patients (age range: 16 to 72 years) with a histologic or mammographic diagnosis of mammary hamartoma. The lesion was found in 9 of 441 open breast biopsy specimens (2%) and was identified radiographically in 5 of 8,122 mammographic examinations (less than 1%). Two groups of patients were identified. Three patients under 30 years of age underwent the excision of small palpable lesions found on pathologic examination to be mammary hamartomas (group I). In nine patients over age 30, masses were identified or confirmed on mammography (group II). Five lesions showed the classic mammographic appearance of a mammary hamartoma (a circumscribed tumor of mixed soft tissue and fatty density), and the other four were indeterminate. Presentation in these older women who had a relatively high incidence of atypical mammographic findings mandates that biopsy be performed.