Fig. 16

68-year-old female with primary melanoma in the upper back (1 mm Breslow thickness, no ulceration, mitotic rate < one, no peri-neural or lymphovascular invasion) with negative sentinel node biopsy at diagnosis (5 years ago) who developed self-detected right axillary metastasis one year later (images not provided). Axillary nodal dissection demonstrated 1/9 lymph nodes involved with 8 mm deposit and 0.3 mm extra-nodal extension (stage IIIB) BRAF V600K. Started on ICI (Ipilimumab and Nivolumab) afterwards and developed multifocal acquired demyelinating sensory and motor neuropathy treated with steroids, plasmapheresis and rituximab. Surveillance ¹⁸F-FDG PET/CT (A) showed new small pulmonary nodules (not evident on MIP),red arrows axial fused image(G and H); which were confirmed to be metastatic melanoma on wedge resection. MRI brain also showed small new cerebral metastases (stage IV-M1b). Treatment subsequently changed to Dabrafenib and Trametinib, which was poorly tolerated with recurrent episodes of fever, myalgia and fatigue. Surveillance ¹⁸F-FDG PET/CT scans were performed 3 monthly afterwards; the 1st follow-up ¹⁸F-FDG PET/CT showed an enlarged spleen with multiple foci of moderately increased FDG uptake (red arrow - B). The treatment regimen changed to 4 days on and 3 days off; however, this was also poorly tolerated and the patient was switched to Encorafenib and binimetinib with subsequent scans showing a mild interval splenic enlargement and reversal of the spleen to liver activity (blue arrows – D,E). The patient remained in CMR on subsequent scan and reversal of spleen to hepatic activity normalised