A Rare Case of Recurrent Myoid Hamartoma Mimicking Malignancy: Imaging Appearances

Abstract

Myoid hamartoma is an uncommon type of breast hamartoma and its recurrence is very rare. We report the imaging appearance of an unusual case of recurrent myoid hamartoma of the breast mimicking malignancy in a 43-year-old woman. Although the mammographic and ultrasonographic findings have long been described in the literature, MR finding with a dynamic study has not, to the best of our knowledge, been reported previously.

Genetic Characterization of Myoid Hamartoma of the Breast

“…Myoid (muscular) hamartoma of the breast was described 2 years later by Davies and Riddell (6) as a subtype of breast hamartoma characterized by the presence of smooth muscle cells. It is a very rare benign lesion of which only few cases have been reported (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). The pathogenesis is unknown and nothing is known about their genetic constitution.…”

A Male Patient With Breast Hamartoma: An Uncommon Finding

“…However, in a study of 14 breast hamartomas in both males and females, one was found to have irregular borders and three showed myoid differentiation [10]. Myoid hamartomas belong to an uncommon subtype of breast hamartoma with low recurrence [11]. These hamartomas have smooth muscle cells that are histologically normal but irregularly and randomly distributed.…”

“…Surgical removal is an option for patients if the hamartoma leads to discomfort but is not mandatory in one with well-demarcated borders and halted growth. However, even with surgical excision, there are rare cases of hamartomas that result in recurrence [11].…”

Myoid Hamartoma of the Breast: A Case Report

“…Myoid hamartoma, first described by Davies and Riddell in 1973, is an extremely rare subtype that is characterized by the presence of histologically normal, but irregular, randomly distributed, smooth muscle cells [3]. The exact incidence of myoid hamartoma is not yet known, and there have been no more than 50 cases of myoid hamartoma described in the literature, mainly in case reports [3][4][5][6][7][8][9][10][11][12][13]. In general, it is considered that the smooth muscle component in myoid hamartomas originates from the myoepithelium, stromal myofibroblasts, walls of the blood vessels, or stromal stem cells [4][5][6]10].…”

“…The exact incidence of myoid hamartoma is not yet known, and there have been no more than 50 cases of myoid hamartoma described in the literature, mainly in case reports [3][4][5][6][7][8][9][10][11][12][13]. In general, it is considered that the smooth muscle component in myoid hamartomas originates from the myoepithelium, stromal myofibroblasts, walls of the blood vessels, or stromal stem cells [4][5][6]10]. Since the inception of regular breast cancer screening programs, the number of diagnosed myoid hamartomas is expected to increase; therefore, increased awareness of this rare disease is required to decrease the potential for pathological misdiagnoses.…”