Expression of programmed death‐1 in cutaneous extranodal natural killer/T‐cell lymphoma and its effect on clinical findings and biological behaviour

Abstract

Higher PD-1 positivity is associated with small-cell-predominant cutaneous ENKTL. However, PD-1 expression has no prognostic value in cutaneous ENKTL.

A case of cutaneous extranodal natural killer/T‐cell lymphoma clinically and histopathologically mimicking interface dermatitis

“…4 Kim et al also reported in both primary and secondary cutaneous ENKTL that cellulitis or abscess-like swellings and subcutaneous nodules are common. 3 In general, ENKTL is clinically distinct from mycosis fungoides as it often shows compartmentalisation within the skin. 1 However, our current patient presented with diffuse erythematous papulopatches on his trunk without ulceration or palpable nodules.…”

“…When the skin is involved, these cancers manifest a variety of clinical morphologies including cellulitis or abscess-like lesions, nodular lesions, ulceration, plaques and purpuric patches. 3,4 Among these presentations, cellulitis or abscess-like lesions and nodular lesions are classic morphologies. 3 Histopathologically, ENKTL shows a multinodular localisation at vascular structures or diffuse dermal and subcutaneous infiltration with angiocentricity and angiodestruction.…”

“…3,4 Among these presentations, cellulitis or abscess-like lesions and nodular lesions are classic morphologies. 3 Histopathologically, ENKTL shows a multinodular localisation at vascular structures or diffuse dermal and subcutaneous infiltration with angiocentricity and angiodestruction. Massive necrosis and a predominant subcutaneous involvement can also be observed.…”

“…Most of the infiltrate is comprised of medium to large NK or T cells with occasional pleomorphism. 3 Epidermotropism is also observed in some cases and thus confers a differential diagnosis of epidermotropic lymphocytic infiltration. 5 Although most of the atypical lymphocytes in ENKTL lesions are CD56 + cells, CD56 -ENKTL tumours with variable expression of CD7, CD8, TIA-1 and granzyme have been reported.…”

PD‐1 and PD‐L1 expression in Kaposi sarcoma: A comparative study according to the pathological stage and clinical characteristics

“…Programmed death‐1 (PD‐1) and PD ligand‐1 (PD‐L1) expression are related to clinical behavior in various cutaneous malignancies including squamous cell carcinoma, 6,7 melanoma, 8 NK/T‐cell lymphoma, 9 and thymic epithelial tumors 10 . Recent studies of cutaneous warts revealed that PD‐L1 promotes host immune dysfunction and thereby facilitates the development of recalcitrant warts 7 .…”