Myoid hamartoma of the breast that proved difficult to diagnose: a case report

Naruhiko Mizuta,Aya Imai,Midori Morita,Mitsuhiko Mizuta,Mari Soshi,Katsuhiko Nakatsukasa,Mariko Goto,Tetsuya Taguchi,Eiichi Konishi,Koichi Sakaguchi,Satoru Yasukawa

doi:10.1186/1477-7819-10-12

Naruhiko Mizuta, Aya Imai + Show 9 more

Open Access

https://doi.org/10.1186/1477-7819-10-12

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Abstract

Myoid hamartomas of the breast are extremely rare breast lesions, with a poorly understood pathogenesis. We describe the case of a 38-year-old premenopausal woman who presenting with a mass in the left breast. Mammography revealed an oval mass that was partly indistinct, and ultrasonography showed a hypoechoic mass with a slightly irregular margin. Bilateral breast dynamic magnetic resonance imaging was performed for a more detailed evaluation. The images showed rapid initial enhancement and a microlobulated margin. Because the suspicion of malignancy was strong at that time, core needle biopsy was performed. Histologically, the tumor was identified as fibroadenoma. A case of myoid hamartoma of the breast that proved difficult to diagnose is reported, and discussed with reference to the literature.

Highlights

Hamartoma is an uncommon breast tumor that histologically contains lobular breast tissue with various admixtures of fibrous, fibrocystic, and adipose tissue [1,2]
We report a case of myoid hamartoma of the breast that proved difficult to diagnoses because the findings on morphological evaluation employing various imaging modalities were different from the histological findings of core needle biopsy
The smooth muscle tissue stained diffusely positive for smooth-muscle actin (SMA), vimentin, desmin, and Discussion Breast hamartomas comprise about 0.7-5% of all benign breast masses, and their main characteristic is the variety of tissue they contain [4]

Summary

Background

Hamartoma is an uncommon breast tumor that histologically contains lobular breast tissue with various admixtures of fibrous, fibrocystic, and adipose tissue [1,2]. Myoid hamartoma is an extremely rare subtype containing an additional smooth muscle component [3]. Both radiographic correlations and immunohistochemical studies are important to diagnose myoid hamartoma and avoid confusion with other breast diseases. We report a case of myoid hamartoma of the breast that proved difficult to diagnoses because the findings on morphological evaluation employing various imaging modalities were different from the histological findings of core needle biopsy. Hematoxylin and eosin staining showed benign ductal and lobular units, adipose tissue, fibrous stroma and bundles of elongated spindle cells in a disorganized pattern (Figure 5a). The smooth muscle tissue stained diffusely positive for smooth-muscle actin (SMA), vimentin, desmin, and

Discussion

Conclusion

17. Rosser RJ