PeiPei Yang et.al. report the imaging and clinical features of a rare case of myopericytoma of the breast in a 63-year-old woman who presented with a mass in the left breast. Sonographic examination revealed 2 well-demarcated adjacent solid masses with prominent color signals in color doppler flow imaging. The lesions exhibited enhancement from the periphery to the center in contrast-enhanced ultrasound imaging. An ultrasound-guided fine-needle aspiration biopsy was done to find out the histological nature of the lesions. Subsequently, she underwent surgical excision of the masses.
A 63-year-old woman presented with a mass in the left breast for 3 months that had gradually enlarged during the last month. Physical examination revealed an approximately 5 × 4-cm immovable mass in the lower inner quadrant of her left breast, with no nipple discharge. No axillary lymphadenopathy was noted. She had undergone fibroadenoma resection in the right breast 10 years previously with no family history of breast cancer.
Sonographic examination demonstrated 2 well-demarcated heterogeneous hypoechoic adjacent solid masses of 4.2 × 1.5 cm and 2.0 × 1.2 cm in the left breast. Prominent color signals were noted within the 2 masses on color Doppler flow imaging. A syringe was used to inject 4.8 ml of SonVue suspension into the antecubital vein. On the resulting contrast-enhanced ultrasound images, the lesions exhibited enhancement from the periphery to the center. On magnetic resonance imaging (MRI) examination, the 2 lesions appeared hypointense on T1-weighted sequences and hyperintense on T2-weighted sequences. The time-signal intensity curve obtained from breast dynamic contrast-enhanced MRI showed a plateau (type II). After gadolinium administration, the large mass showed peripheral enhancement and central irregular low contrast enhancement, while the small mass showed overall intense homogeneous contrast enhancement.
An ultrasound-guided fine-needle aspiration biopsy revealed that the masses comprised oval-to-spindle-shaped cells with stroma and exhibited focal myxoid degeneration in their central regions. There were no atypia and mitotic cells.
The patient underwent surgical excision of the masses. The 2 masses were stuck together with well-circumscribed margins, but were not adherent to adjacent tissue. Histological examination revealed many thin-walled branching vessels surrounded by proliferative oval-to-spindle-shaped myoid cells in the peripheral area. On immunochemical staining, the cells were positive for smooth muscle actin and vimentin. Immunostaining for other proteins, including desmin, CK5/6, and S-100 protein, was negative. The proliferation index Ki-67 was about 10%. Anti-CD34 antibodies only labeled vascular endothelial cells. Specialized staining including Verhoeff-Van Gieson, Hematoxylin-Eosin, and Masson indicated small amounts of fibers and blood vessels. Overall, the final diagnosis was myopericytoma. The patient remains alive without tumor recurrence or metastasis during follow-up at 29 months after surgery.