HAMARTOMA OF THE BREAST, AN UNDERRECOGNIZED BREAST LESION - A CLINICOPATHOLOGICAL AND RADIOGRAPHIC STUDY OF 25 CASES

This study investigated the clinical, radiographic, and pathologic fea tures of breast hamartoma, The patients ranged in age from 18 to 89 ye ars, with a mean age of 45 years, and a median age of 43 years, Sevent y-five percent of the patients were asymptomatic, other than reporting a breast lump. In two patients, the lesions recurred at 7 and 18 mont hs after the initial resection. The clinical diagnoses were fibroadeno ma in 10 cases, carcinoma in 5 cases, hamartoma in 4 cases, and phyllo des tumor and lipoma in 2 other cases. Mammograms were available in 12 cases, the majority of which showed a well-defined mass of homogeneou s density. Grossly, these lesions were oval to round, well-circumscrib ed masses, ranging in size from 1 to 7 cm in maximum dimension (mean, 3.9 cm). The microscopic appearance of these tumors corresponded to th eir gross appearance, Lesions that were grossly firm, rubbery, and whi te consisted largely of dense fibroconnective tissue with variable amo unts of glandular elements with little adipose tissue, Softer, pale, y ellow lesions contained more adipose tissue, A consistent and importan t diagnostic feature was the presence of both lobules and ducts, in co ntrast to fibroadenoma in which lobules are often absent or rare. The current trend of mammographic breast screening has made us aware that mammary hamartomas are not uncommon. These lesions may go unrecognized by the pathologist because they show all the constituents of normal b reast tissue and may be reported as ''no pathological diagnosis'' or ' 'normal breast tissue,'' which are inappropriate diagnoses for a lesio n that presents as a palpable and a well-circumscribed mass.