Aggressive cutaneous T-cell lymphomas

Gamma/Delta Phenotype in Primary Cutaneous T-cell Lymphomas and Lymphoid Proliferations: Challenges for Diagnosis and Classification

Primary cutaneous T-cell lymphomas pose a diagnostic challenge for dermatopathologists, hematopathologists, and general surgical pathologists. Recognition of gamma/delta phenotype in cutaneous T proliferations has been enhanced by the availability of antibodies against TCRgamma and delta for immunohistochemistry. Thus, reporting gamma/delta phenotype in a cutaneous T-cell lymphoid proliferation may indicate a significant change in therapy and a challenge for dermatologists and oncologists who treat these patients. Herein, we discuss primary cutaneous gamma/delta T-cell lymphoma, its differential diagnosis, and other skin lymphoid proliferations that may show gamma/delta phenotype. Awareness of the occurrence of gamma/delta phenotype in both T-cell lymphomas and benign lymphoid proliferations involving skin is crucial for a better interpretation of histopathologic findings. Integration of clinical presentation, morphology, immunoprofile, and molecular findings is key for a correct diagnosis and appropriate therapy of lesions displaying gamma/delta T-cell phenotype.

Acneiform Presentations of Folliculotropic Mycosis Fungoides

BACKGROUND

Folliculotropic mycosis fungoides (FMF) is a variant of cutaneous T-cell lymphoma that has clinical overlap with a variety of inflammatory follicular unit disorders. However, we describe distinctive presentations of FMF with acneiform features that can be diagnostically challenging, leading to diagnostic delay.

OBJECTIVE

To highlight the importance of histopathologic and immunohistochemical evaluation for diagnostic confirmation of presumed inflammatory follicular unit-based disorders that are unusual in presentation or unresponsive to standard therapies.

METHODS

A cross-sectional retrospective study of 5 consecutive patients with a histopathologic diagnosis of FMF was conducted. The clinical, histopathologic, immunophenotypic, and molecular genetic features of cases are presented.

RESULTS

We describe 5 patients with clinical and histopathologic presentations of FMF masquerading as hidradenitis suppurativa, furunculosis, or acne vulgaris (age range 34-66 years, 4:1 female to male). Clinical morphologies included open and closed comedones, inflammatory pustules, papules and nodules, follicular papules with keratotic plugging, cysts, and scarring involving the face, trunk, and intertriginous areas. All patients failed to respond to standard therapies, including topical and oral antibiotics, topical and oral retinoids, or topical corticosteroids, before receiving the diagnosis of FMF. Lesional skin biopsies showed a perifollicular CD4-positive T-lymphocytic infiltrate with pilotropism, intrafollicular mucin deposition, foreign-body granulomatous inflammation, acute inflammation, and follicular epithelial necrosis. None had concurrent systemic mycosis fungoides.

LIMITATIONS

Small retrospective cohort study.

CONCLUSION

We present these cases to expand the clinical and histopathologic spectrum of FMF that may strikingly resemble acneiform disorders and to highlight the importance of diagnostic reconsideration with histopathologic evaluation.

Cutaneous Lymphoproliferative Disorders: What's New in the Revised 4th Edition of the World Health Organization (WHO) Classification of Lymphoid Neoplasms

Cutaneous lymphoproliferative disorders remain a challenging aspect of dermatopathology, in part due to the rarity of the entities and extreme variability in clinical outcomes. Although many of the entities remain unchanged, the approach to some of them has changed in the new 2016 classification scheme of the World Health Organization. Chief among these are Epstein-Barr virus-associated lymphoproliferative disorders such as Epstein-Barr virus-associated mucocutaneous ulcer and hydroa vacciniforme-like lymphoproliferative disorder, primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma, primary cutaneous acral CD8+ T-cell lymphoma, primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder, and breast implant-associated anaplastic large cell lymphoma. In addition, translocations and gene rearrangements such as those involving the 6p25.3 locus have started to inform diagnosis and classification of anaplastic large cell lymphoma and lymphomatoid papulosis. In this review, we will examine what is new in the diagnostic toolbox of cutaneous lymphoproliferative disorders.

Acute Cutaneous Necrosis: A Guide to Early Diagnosis and Treatment

Acute cutaneous necrosis is characterised by a wide range of aetiologies and is associated with significant morbidity and mortality, warranting complex considerations in management. Early recognition is imperative in diagnosis and management of sudden gangrenous changes in the skin. This review discusses major causes of cutaneous necrosis, examines the need for early assessment, and integrates techniques related to diagnosis and management. The literature, available via PubMed, on acute cutaneous necrotic syndromes was reviewed to summarise causes and synthesise appropriate treatment strategies to create a clinician’s guide in the early diagnosis and management of acute cutaneous necrosis. Highlighted in this article are key features associated with common causes of acute cutaneous necrosis: warfarin-induced skin necrosis, heparin-induced skin necrosis, calciphylaxis, pyoderma gangrenosum, embolic phenomena, purpura fulminans, brown recluse spider bite, necrotising fasciitis, ecthyma gangrenosum, antiphospholipid syndrome, hypergammaglobulinemia, and cryoglobulinemia. This review serves to increase recognition of these serious pathologies and complications, allowing for prompt diagnosis and swift limb- or life-saving management.