Myoid hamartoma of the breast: case report and review of the literature.

Hamartoma is a mass of disorganized but mature specialized cells or tissue indigenous to the particular site. They can occur anywhere in the body, and their common sites of occurrence include lungs, skin, hypothalamus, spleen, and kidneys, of which lungs are the most common. We report a rather unusual, largely unrecognized case of myoid hamartoma of the breast. They constitute approximately 3.9%-4.8% of breast tumors. Myoid hamartomas belong to a spectrum of benign breast lesion of dual origin, containing myoepithelial and myofibroblastic components in varying proportions. They are usually asymptomatic but can present as well-circumscribed masses that do not possess specific diagnostic histologic features, and diagnosis is, therefore, difficult. In contrast to many other benign or malignant breast lesions, the diagnosis of hamartoma can easily be missed. Herein, we discuss the importance of radiologic, immunohistochemical studies and histopathologic findings in the diagnosis of a myoid hamartoma. Extensive review of the literature has been done for this purpose, and we highlight the clinical presentation and therapeutic aspects of this breast lesion.