RESUMEN
The mammary hamartoma is a poorly recognised benign breast neoplasm. For diagnosis one usually correlates the clinical, mammographic, gross and histologic features. This study of fifteen cases emphasises the histomorphologic criteria for diagnosis especially in the absence of mammographic picture, viz. a clinically palpable, well encapsulated mass which on histology shows normal breast epithelium admixed with fat, fibrous tissue and other mesenchymal elements. The epithelium in the hamartomas studied showed changes seen in normal breast especially in the progestational phase of the menstrual cycle. The stroma was either densely collagenous, hyalinised or cellular and admixed with fat in various proportion in thirteen cases, muscle in two cases and thick muscular arteries in four cases. It also showed pseudoangiomatous hyperplasia in seven cases. The importance of this change and probable evolution is discussed therein.