Table 3:
Summary of histopathologic diagnoses associated with inflammatory eruptions to checkpoint inhibitor therapy
| Clinical Diagnosis | Patients (no.) | Corresponding Histologic Diagnoses (no.) |
|---|---|---|
| Lichenoid | 16 | lichenoid interface dermatitis (15), scattered foci of histiocytes and lymphocytes with epidermal collarettes (lichen nitidus- like) (1) |
| Eczematous | 5 | eosinophilic spongiosis (5) |
| Maculopapular | 7 | dermal hypersensitivity reaction (5), acute vacuolar dermatitis (1), lichenoid interface dermatitis with eosinophils (1) |
| Psoriasiform | 4 | psoriasiform (4) |
| Immunobullous16 | 8 | subepidermal bulla with eosinophils (4), subepidermal bulla with focal interface changes (1), eosinophilic spongiosis (1), erosion of epidermis with eosinophils (1), subepidermal bulla with neutrophils (LABD, 1) DIF : linear IgG and C3 at the DEJ (5), linear IgG and C3 and IgA at the DEJ (LABD, 1) IIF : serum linear deposition of IgG at DEJ of monkey esophagus (2), serum intercellular staining of IgG and IgA on monkey esophagus with 1:10 dilution (IgA) and 1:80 dilution (IgG) dilutions (LABD, 1) |
| Prurigo nodularis | 1 | epidermal acanthosis and parakeratosis (1) |
| Grover’s-like | 2 | epidermal acantholysis and dyskeratosis (2) |
| Acneiform | 1 | suppurative and granulomatous folliculitis (1) |
| Granulomatous17 | 3 | naked granulomas within the dermis with multinucleated cells (sarcoidosis-like, 2), superficial and deep perivascular and interstitial infiltrate of histiocytes and lymphocytes with focal palisading (granuloma annulare-like, 1) |
| SJS-like | 2 | epidermal necrosis with numerous apoptotic keratinocytes and lymphoplasmacytic inflammation (SJS-like, 1), subcorneal pustules and mixed infiltrate with eosinophils and necrotic keratinocytes, and lichenoid interface dermatitis with necrotic keratinocytes (AGEP/SJS-like, 1). |
| PR-like | 1 | patchy papillary dermal mixed infiltrate with plasma cells/eosinophils with red cell extravasation (1) |
| PRP-like18 | 1 | epidermal acanthosis with orthokeratosis and parakeratosis, intact granular layer and mild spongiosis, perivascular inflammatory infiltrate within the superficial dermis (1) |