From One Cancer to Two

A 59-year-old woman with an ulcerated right breast lesion was diagnosed with ER-positive invasive ductal carcinoma. Staging ¹⁸FFDG PET/CT revealed intense uptake in the breast, axillary nodes, a large hypermetabolic pulmonary mass, mediastinal lymphadenopathies, and bone lesions. Because of this metabolic pattern, ¹⁸FFES PET/CT was performed, demonstrating ¹⁸FFES-avid bone metastases but no uptake in the lung mass. Biopsy confirmed a BRAF V600E-mutated lung adenocarcinoma. ¹⁸FFES PET/CT proved crucial in differentiating synchronous primary malignancies from metastatic spread and guiding targeted therapy with dabrafenib-trametinib.