Synchronous metaplastic breast carcinoma and lung adenocarcinoma: a rare case and review of the literature.

Synchronous primary cancers occur in 1.7% of breast cancer cases and metaplastic breast cancer (MBC) occurs in less than 1% of breast cancer cases. We present a previously healthy 66-year-old woman diagnosed with MBC after surgical resection of a presumed cyst. A second primary cancer, multifocal lung adenocarcinoma, was discovered during the staging process for her MBC. Remarkably she had not experienced pulmonary or constitutional symptoms at the time of diagnosis. She received chemotherapy with paclitaxel and carboplatin, followed by immunotherapy with nivolumab. At 24 months of follow-up after her initial diagnosis, she was breast cancer-free with stable pulmonary nodules. This case highlights that rather than assuming multifocal lesions represent metastasis, biopsies should be considered as clinical management could be significantly altered in the presence of a synchronous cancer. Furthermore, platinum-based chemotherapy agents have potential to be considered in the treatment of MBC.

Muscle oxidative phosphorylation quantitation using creatine chemical exchange saturation transfer (CrCEST) MRI in mitochondrial disorders.

Systemic mitochondrial energy deficiency is implicated in the pathophysiology of many age-related human diseases. Currently available tools to estimate mitochondrial oxidative phosphorylation (OXPHOS) capacity in skeletal muscle in vivo lack high anatomic resolution. Muscle groups vary with respect to their contractile and metabolic properties. Therefore, muscle group-specific estimates of OXPHOS would be advantageous. To address this need, a noninvasive creatine chemical exchange saturation transfer (CrCEST) MRI technique has recently been developed, which provides a measure of free creatine. After exercise, skeletal muscle can be imaged with CrCEST in order to make muscle group-specific measurements of OXPHOS capacity, reflected in the recovery rate (τCr) of free Cr. In this study, we found that individuals with genetic mitochondrial diseases had significantly (P = 0.026) prolonged postexercise τCr in the medial gastrocnemius muscle, suggestive of less OXPHOS capacity. Additionally, we observed that lower resting CrCEST was associated with prolonged τPCr, with a Pearson's correlation coefficient of -0.42 (P = 0.046), consistent with previous hypotheses predicting that resting creatine levels may correlate with 31P magnetic resonance spectroscopy-based estimates of OXPHOS capacity. We conclude that CrCEST can noninvasively detect changes in muscle creatine content and OXPHOS capacity, with high anatomic resolution, in individuals with mitochondrial disorders.