Acute regression of a melanocytic neoplasm.

Immune-mediated regression of melanocytic neoplasms is predominantly lymphocytic, driven by CD8+ anti-tumoral T-cells and, rarely, natural killer cells. Histopathologic features of regression include effacement of the epidermis, replacement of tumor cells by a fibrotic stroma, varying degrees of chronic inflammation (usually lymphocytes) and melanophages, as well as vascular ectasia and angioplasia. The understanding of regression and the complex immune response in melanoma has led to the development of targeted immunotherapy in melanoma. Here, we report a case of near-complete regression of a melanocytic neoplasm associated with neutrophilic and eosinophilic inflammation, suggesting a non-traditional pathway of regression that has yet to be explored.

Syphilitic Folliculitis: A Case Report With Demonstration of Spirochetes Showing Follicular Epitheliotropism.

ABSTRACT: We report a case of a 59-year-old man presenting with a widespread follicular-based papular rash with a several-month history of myalgias, lymphadenopathy, fatigue, and weight loss who was diagnosed with acute syphilitic folliculitis by tissue biopsy analysis with immunohistochemical demonstration of spirochetes in hair follicle epithelium. Serologic analysis also showed evidence of Treponema sp. infection. Owing to the rising number of syphilis cases in the last decade, it is important to recognize classic cutaneous findings of syphilis in addition to unusual presentations such as syphilitic folliculitis.

Eczematous dermatitis in primary immunodeficiencies: A review of cutaneous clues to diagnosis.

Primary immunodeficiency Disorders (PIDD) are a varied group of heritable disorders characterized by defects in components of the innate and/or adaptive arms of the immune system. Although diagnosing these disorders is often challenging, the skin is a readily accessible and easily assessable organ that may provide clues to a diagnosis of PIDD. Specifically, many immunodeficiencies are associated with characteristic cutaneous eruptions that, based on their morphology, distribution and symptomatology, may suggest a specific underlying diagnosis. This review will discuss an approach to identifying and managing PIDDs that typically present with eczematous dermatitis.

Cutaneous manifestations of angioimmunoblastic T-cell lymphoma.

Angioimmunoblastic T-cell lymphoma (AITL) is a rare form of non-Hodgkin lymphoma often accompanied by autoimmune and paraneoplastic phenomena. Up to 50% of patients with AITL present with skin manifestations. This case series highlights two cases of AITL presenting with unusual cutaneous findings: one with a medium-vessel vasculitis and another with a chronic urticarial eruption. Clinicians should consider AITL in the differential diagnosis of vasculitis or urticaria refractory to standard treatment.