Rare Case of Docetaxel-Induced Myositis Detected on Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in a Patient with Carcinoma Breast.

We report an extremely rare case of acute inflammatory myopathy during combination chemotherapy with docetaxel and transtuzumab for metastatic breast carcinoma in a 44-year-old female patient. Despite the significant response in the follow-up fluorodeoxyglucose (FDG) positron emission tomography/computed tomography, of the underlying malignancy to the chemotherapeutic regimen, there was diffusely increased FDG uptake in the upper and lower limb muscles with associated painful, proximal muscle weakness. These symptoms regressed after the discontinuation of docetaxel and the administration of corticosteroids, suggesting it to be the drug-induced myositis.