case_images: PMC10350685_01
case_images: Summary of key events in the clinical course of patient 1. (A) Timeline from the cancer diagnosis. "0" is the time when metastatic non-small cell lung cancer (mNSCLC) was confirmed by the biopsy. (B) Timeline of neurological symptoms. (C) Summary of the systemic treatments. (D) Serial skin photos and PET images assess disease status. (a) Extensive Gottron's papules in hands before ICI treatment. (b) PET before ICI treatment showed increased radiotracer uptakes in lung, cervical, and mediastinal lymph nodes. (c) Resolution of skin rash after ICI and IVIG treatment. (d) Resolution of all FDG-avid tumor lesions after ICI treatment.
case_images: fonc-13-1199195-g001.jpg
case_images: PMC10350685_01_fonc-13-1199195-g001.jpg
case_images: f1
case_images: The erythematous papular rash was first present in the extremities, head, and trunk, accompanied by pruritus and burning pain, which worsened after sun exposure ( Figure 1D  (a)). Figure 1D ). Further testing revealed elevated creatine kinase (CK, 885 U/L), high positive anti-transcription intermediary factor 1 gamma (TIF 1-gamma) antibody (154 units), and myositis-specific anti-p155/140 antibody ( Table 1 ). Two months later, he started IVIG 2 g/kg every 4-6 weeks for the autoimmune disease while taking PD-1 inhibitor pembrolizumab 200 mg IV every 3 weeks ( Figure 1 ). After 11 months of combined treatment, the rash resolved ( Figure 1D ), muscle strength returned to normal (MRC grade 5/5), and neck pain resolved. PET/CT scan demonstrated resolution of essentially all previously active tumor lesions while his neurological symptoms were controlled, so the IVIG was reduced to maintenance dose at 2 g/kg every 3 months while pembrolizumab was maintained at 200 mg IV every 3 weeks ( Figure 1 ).
case_images: PMC10350685_02
case_images: Summary of key events in the clinical course of patient 2. (A) Timeline from the cancer diagnosis. "0" is the time when metastatic melanoma was confirmed by the biopsy. (B) Timeline of neurological symptoms. (C) Summary of the systemic treatments. (D) Serial neurological responses after treatments. (E) Serial PET images assess disease status. (a) Right pelvic mass (8.5 x 5.4 cm), hypermetabolic right retroperitoneal and iliac/inguinal lymph nodes. (b) to (c), Continued improvement in pelvic lymphadenopathy, but new mediastinal and bilateral hilar lymphadenopathy (d) No evidence of residual, recurrent, or metastatic tumor.
case_images: fonc-13-1199195-g002.jpg
case_images: PMC10350685_02_fonc-13-1199195-g002.jpg
case_images: f2
case_images: PET/CT scan showed a hypermetabolic right retroperitoneal soft tissue mass of 8.4 x 3.5 x 8.7 cm and several hypermetabolic right retroperitoneal and iliac/inguinal lymph nodes suggestive of nodal metastasis ( Figure 2 ). The patient was treated with targeted therapy dabrafenib 150 mg twice daily and trametinib 2 mg daily ( Table 1 ,  Figure 2 ). EMG/NCS study after 10 months of targeted therapeutics together with monthly IVIG treatment also demonstrated mild improvement of neuropathy ( Figure 2 ,  Table 2 ). Simultaneously, the frequency of maintenance IVIG was reduced from every 4 weeks to every 8 weeks for 21 months due to the concern that frequent IVIG infusions might reduce the anti-tumor effect of the PD-1 inhibitor nivolumab ( Figure 2 ). Surveillance PET/CT scans showed that the patient achieved complete remission (CR) after 19 cycles of nivolumab and has remained in CR since then ( Figure 2 ). At the time of this submission, the patient has been in remission from both melanoma and neuropathy for 12 months ( Figure 2 ).