Case Report of Denovo Musculoskeletal Metastasis from Hormonal Positive and Her2 Negative Receiving CDK4 Inhibitor

摘要

Skeletal muscle metastasis from breast cancer is a very rare presentation. We reported a case with breast cancer metastatic to skeletal muscle, bone, peritoneum and lymph node at presentation detected in FDG PET-CT. A Core needle biopsy was performed from the left breast tail lesion. Immunohistochemistry showed hormonal positivity, Her2 negativity with low KI67. Patient was treated with combined CDK4 inhibitor and non-steroidal aromatase inhibitors with regressive course in the PET-CT after the 1st 3 months. More studies should investigate the prognosis and proper management of skeletal muscle metastasis in breast cancer.