Figure Legends
Figure 1A . Maculopapular rash, grade 3. The patient received pembrolizumab for stage IV non-squamous non-small cell lung cancer. Histopathology reveals vacuolar degeneration at the dermal-epidermal junction, perivascular infiltration of lymphocytes and eosinophils, and necrotic keratinocytes (hematoxylin-eosin [HE]; A2: ×10 original magnification, A3: ×200 original magnification, A4, 5: ×400 original magnification).
Figure 1B . Erythema multiforme, grade 2. The patient received nivolumab for stage IV squamous non-small cell lung cancer. Histopathology reveals vacuolar degeneration at the dermal-epidermal junction and perivascular infiltration of lymphocytes and eosinophils, histopathologically resembling maculopapular rash (HE; B2: ×10 original magnification, B3: ×200 original magnification).
Figure 1C . Lichenoid reaction, grade 1. The patient received nivolumab for metastatic melanoma. Histopathology reveals the lichenoid infiltration of lymphocytes and a few eosinophils, and the epidermis exhibited acanthosis, a thickened granular layer, orthokeratotic hyperkeratosis, and spongiosis (HE; C3: ×10 original magnification, C4: ×100 original magnification).
Figure 1D . Psoriasiform reaction, grade 2. The patient received atezolizumab for stage IV non-squamous non-small cell lung cancer. Histopathology reveals epidermal hyperkeratotic parakeratosis and acanthosis without a granular layer, elongation of rete ridges and dermal papilla, mild vacuolar degeneration at the dermal-epidermal junction, and perivascular infiltration of lymphocytes, eosinophils, and neutrophils in the upper dermis (HE; D2: ×10 original magnification, D3: ×100 original magnification).
Figure 1E . Bullous pemphigoid, grade 1. The patient received pembrolizumab for metastatic melanoma. Histopathology reveals subepidermal bulla with eosinophils and perivascular infiltration of lymphocytes and eosinophils (HE; E2: ×10 original magnification, E3: ×100 original magnification). A direct immunofluorescence test revealed the linear deposition of IgG (E4).
Figure 1F . Scleroderma-like reaction, grade 1. The patient received nivolumab for stage IV gastric adenocarcinoma. Histopathology reveals increased amount of thick collagen fibers that packed sweat glands (HE; F2: ×10 original magnification, F3: ×100 original magnification).
Figure 1G . Stevens-Johnson syndrome, grade 3. The patient received nivolumab for stage IV non-squamous non-small cell lung cancer. Histopathology reveals epidermal necrosis with numerous necrotic keratinocytes, acantholytic bullae, infiltration of lymphocytes and eosinophils, and parakeratotic hyperkeratosis (HE; G2: ×10 original magnification, G3: ×100 original magnification, G4: ×400 original magnification).