Primary cutaneous CD8+ positive aggressive epidermotropic T- cell lymphoma is a rare and poorly characterized variant of cutaneous lymphoma still considered a provisional entity in the latest 2016 World Health Organization Classification of Cutaneous lymphomas. We sought to better characterize and provide diagnostic and therapeutic guidance of this rare cutaneous lymphoma. Thirty-four patients with a median age of 77 years (range 19 – 89 years) presented primarily with extensive annular necrotic plaques or tumor lesions with frequent mucous membrane involvement. The 5-year survival was 32% with a median survival of 12 months. A subset of 17 patients had a prodrome of chronic patches prior to the development of aggressive ulcerative lesions. We identified cases with lack of CD8 or αβ T-cell receptor expression yet with similar clinical and pathological presentation. Allogeneic stem cell transplantation provided partial or complete remissions in 5/6 patients. We recommend the term primary cutaneous aggressive epidermotropic cytotoxic T-cell lymphoma as this more broad designation better describes this clinical-pathologic presentation which allows the inclusion of cases with CD8 negative and/or αβ/γδ T-cell receptor chain double positive or double negative expression. We have identified early skin signs of chronic patch/plaque lesions that are often misdiagnosed as eczema, psoriasis, or MF. Our experience confirms the poor prognosis of this entity and highlights the inefficacy of our standard therapies with the exception of allogeneic stem cell transplantation in selected cases.

Background Mycosis fungoides (MF) in young patients is rare and may have atypical presentations. There are limited data in these patients. Objective Determine the clinical outcome and prognosis of young patients with MF. Methods A search of our institutional cancer registry database was conducted for patients diagnosed with MF at ≤ 30 years of age. Results Our study includes 74 patients (median age at diagnosis= 25.5 years). Most patients (n=65, 88%) presented with early stage disease and variants of MF (n=44, 59%) leading to a median delay in diagnosis of 2.5 years. Hypopigmented MF (n=27, 36.5%) was the most common variant affecting predominantly African-American (44.4% vs.19%, p= 0.02) and younger age group (20 vs. 26 years, p<0.001). All patients with hypopigmented MF presented with early stage disease and were less likely to develop progressive disease (PD) compared to other variants (11% vs. 34%, p= 0.03). Overall, nineteen patients (26%) developed PD during median follow-up of 3.5 years which was associated with advanced stage disease (89% vs. 17%, p<0.0001), older age (>20 years) [31% vs. 13%, p=0.08 (NS)], African-American race (52.6% vs. 20%, p= 0.0090) and poikilodermatous presentation (p<0.01). The overall survival was favorable (97.2% and 95.9% at 5 and 10 years) despite delay in diagnosis and atypical presentation. Conclusions PD is associated with older age, African-American race, the poikilodermatous variant, and advanced-stage disease. The hypopigmented variant is a common presentation in young patients and has an indolent disease course. Our study confirms an overall favorable prognosis in young patients with MF.

We identified dermoscopic features that are specific to the diagnosis of poroma. Overall, however, the prevalence of these features was low. Significant clinical and dermoscopic variability is a hallmark of these uncommon tumours, which are most prevalent on non-acral sites.

Background Primary cutaneous CD4+ small–medium pleomorphic T cell lymphoma (SMPTCL) is a low‐grade cutaneous T cell lymphoma. Its clinical and histopathologic features are comparable with those of CD8+ lymphoid proliferations (LPs) of the ear and acral sites. Objectives We performed a retrospective analysis of patients with CD4+ SMPTCL or CD8+ LP to elucidate the clinical course, prognosis, and outcomes. Methods Demographic, clinical, and treatment data were reviewed. Histopathologic data based on architectural, cytomorphologic, and immunohistochemical features were assessed. Immunohistochemical staining for T and B cell markers was evaluated. Results A total of 25 patients including 22 with CD4+ SMPTCL and three with CD8+ LP were identified. All patients presented with a single lesion, predominantly on the head, neck, or upper trunk (84%). No patients showed extracutaneous disease at any evaluation. The most common histopathologic changes showed a dense nodular infiltrate of small cells with hyperchromatic nuclei without significant follicular or adnexal involvement. Patients were treated with excision (48%), local radiation (28%), or topical or intralesional steroids (24%). All patients achieved complete resolution of disease. Five patients demonstrated cutaneous relapse at new sites. Conclusions The CD4+ SMPTCL/CD8+ LP subgroup usually presents with solitary lesions and demonstrates an indolent clinical course. Typical presentation, classic histopathology, widespread expression of follicular T helper cell markers, and loss of a T cell antigen are diagnostic features of CD4+ SMPTCL, whereas monomorphous CD8+ infiltrate without follicular T helper cell markers is consistent with CD8+ LP. Local skin‐directed therapy is appropriate in these patients.