Immune privilege disruption in folliculotropic mycosis fungoides: investigation of major histocompatibility complex antigen expression.

BACKGROUND: Folliculotropic mycosis fungoides (FMF) is a cutaneous T-cell lymphoma mainly affecting the hair follicle, which seems to represent a place of immune privilege phenomenon. OBJECTIVES: To explore a possible role of immune privilege (IP) in FMF analyzing the major histocompatibility complex (MHC) expression. METHODS: Immunohistochemistry for HLA-G and MHC-II was performed to formalin-fixed paraffin-embedded cutaneous skin biopsies of FMF patients (n = 43), conventional mycosis fungoides (CMF; n = 13), alopecia areata (AA; n = 13), and normal scalp skin (NS; n = 12). RESULTS: HLA-G expression was lower in FMF (34%: 14/41) and CMF (18%: 2/11) groups compared to alopecia areata (92%:11/12) and normal scalp skin group (100%: 12/12). MHC-II expression in hair follicle was greater in the FMF group (18/42: 43%) compared to AA (0%) and NS (0%). HLA-G and MHC-II expression in cellular infiltrate had no difference among FMF and CMF groups and was different compared to the AA group. CONCLUSIONS: Our data support the hypothesis of disruption of immune privilege based on the lower expression of HLA-G and higher expression of MHC-II in the follicular epithelium in mycosis fungoides compared to alopecia areata and normal scalp skin. The lack of difference between FMF and CMF groups did not support the role of these molecules as a driver of folliculotropism. The expression of MHC molecules seems to be different between neoplastic and inflammatory infiltrates. The definitive significance of expression of the MHC molecules remains unclear, and more studies are necessary to fully understand the role of these molecules in cutaneous lymphomas.

Folliculotropic mycosis fungoides: clinical and epidemiological evaluation in a single center in Brazil.

BACKGROUND: Folliculotropic mycosis fungoides (FMF) is a rare variant of mycosis fungoides with clinical peculiarities, refractoriness to conventional treatments, and worse prognosis when compared to classic mycosis fungoides. OBJECTIVE: To evaluate the clinical and epidemiological characteristics of FMF patients in a single center in Brazil. METHODS: Data were retrospectively collected from patients with FMF who attended the Cutaneous Lymphoma Clinic, University of São Paulo Medical School, between 1987 and 2013. RESULTS: Thirty-three patients were included (median age 46 years old at diagnosis; 20 male; 27 white). The median disease duration before diagnosis was 3 years. Regarding stage at diagnosis, 61% had advanced stage disease (≥IIb). Follicular papules were reported in 66% and alopecia in 59% of the cases. The most involved regions were limbs, followed by trunk and head. Pruritus was present in 81% of the patients. The median time of patients' follow-up was 38 months. At the last follow-up visit, 67% of the patients were alive with active disease, 27% deceased, and 6% were in complete remission. Four patients had large cell transformation. At the time of diagnosis, 25% of the patients showed eosinophilia. LIMITATIONS: Retrospective study with partial unavailable data. CONCLUSIONS: The characteristics of our patients with FMF correlated with aspects previously described in the literature, which were at a more advanced stage at diagnosis and had a less favorable outcome. Pruritus is a very common complaint. Large cell transformation should be monitored as it is implicated in poor prognosis.

CD30(+) cutaneous lymphoproliferative disorders with pseudocarcinomatous hyperplasia are associated with a T-helper-17 cytokine profile and infiltrating granulocytes.

BACKGROUND: The pathogenetic mechanism of CD30(+) cutaneous lymphoproliferative disorders (CLPD) associated with pseudocarcinomatous hyperplasia (PCH) and granulocytic inflammation surrounding atypical CD30(+) lymphocytes remains unclear. OBJECTIVE: We sought to characterize clinical and pathological findings of a cohort of patients with PCH associated with CD30(+) CLPD and to analyze the cytokine profile of the atypical lymphocytes. METHODS: We retrospectively reviewed medical records and pathological material of CD30(+) CLPD with PCH. Immunohistochemistry for T-helper (Th)17 cytokine profile was performed. RESULTS: In all, 25 patients with a median age of 52 years were included. The median follow-up was 3.7 years. Histologically, an infiltrating pattern of PCH was observed in 14 cases with a neutrophilic-rich infiltrate (P = .21), and epidermal pattern in 11 cases with eosinophil-rich infiltrate (P = .03). Th17 or Th22 cytokines were detected in tumor cells in 81% cases tested. Tumor cells expressed Th17 transcription factor retinoic acid receptor (ROR)-related orphan receptor gamma-2 in 2 of 7 samples tested and 1 was positive for aryl hydrocarbon receptor. LIMITATIONS: This is a retrospective study of a small sample. CONCLUSIONS: PCH in CD30(+) CLPD is associated with Th17/Th22 cytokine expression in the atypical lymphocytes. Although these lesions commonly regress spontaneously and are associated with an indolent course, some cases develop a generalized process and tumor progression.

Dyschromatosis symmetrica hereditaria of late onset?

Dyschromatosis symmetrica hereditaria (DSH), also known as reticulated acropigmentation of Dohi, is an autosomal dominant disease with high penetrance, characterized by hypo- and hyperpigmented macules of varying sizes on the dorsal of the extremities with reticulated pattern. This paper presents a female patient with typical dermatological lesions, but only diagnosed in adulthood. It is necessary to perform differential diagnosis with other pigmentary disorders. This entity is not very common in South America, and the vast majority of cases were described in Japanese population. Since it is a benign disease, it is important to be aware of this diagnosis in order to establish the correct conduct for these patients.

The role of molecular analysis in cutaneous lymphomas.

The purpose of this review is to summarize the most important molecular techniques for the diagnosis of cutaneous lymphomas. When making a diagnosis, we are looking for the solid clinicopathological correlation. Molecular analysis includes immunophenotyping and clonality analysis, and is important for 2 principal reasons: (1) to confirm the diagnosis in cases where the clinical and/or pathological presentations are nondiagnostic, and (2) to further characterize the nature of the lymphoma. More specifically, we are trying to discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and we are also attempting to subclassify the tumor. Recently, many techniques have provided a more accurate diagnosis of cutaneous lymphomas and some prognostic implications, including polymerase chain reaction, fluorescence in situ hybridization, and flow cytometry. Fluorescence in situ hybridization is not routinely used in the diagnosis of cutaneous lymphoma, but many studies have shown potential future applications in various areas. Other techniques, such as comparative genomic hybridization, are still confined to the research arena, but have added some insight into the molecular pathogenesis of cutaneous T-cell lymphoma.

Cutaneous γδ T-cell lymphomas: a spectrum of presentations with overlap with other cytotoxic lymphomas.

We reviewed our multicenter experience with gamma-delta (γδ) T-cell lymphomas first presenting in the skin. Fifty-three subjects with a median age of 61 years (range, 25 to 91 y) were diagnosed with this disorder. The median duration of the skin lesions at presentation was 1.25 years (range, 1 mo to 20 y). The most common presentation was deep plaques (38 cases) often resembling a panniculitis, followed by patches resembling psoriasis or mycosis fungoides (10 cases). These lesions tended to ulcerate overtime (27 cases). Single lesions or localized areas of involvement resembling cellulitis or pyoderma were reported in 8 cases. The most common anatomic site of involvement was the legs (40 cases), followed by the torso (30 cases) and arms (28 cases). Constitutional symptoms were reported in 54% (25/46) of the patients, including some with limited skin involvement. Significant comorbidities included autoimmunity (12 cases), other lymphoproliferative disorders (5 cases), internal carcinomas (4 cases), and viral hepatitis (2 cases). Lymphadenopathy (3/42 cases) and bone marrow involvement (5/28 cases) were uncommon, but serum lactose dehydrogenase (LDH) was elevated in 55% (22/39) of the patients. Abnormal positron emission tomography and/or computed tomography scans in 20/37 subjects mostly highlighted soft tissue or lymph nodes. Disease progression was associated with extensive ulcerated lesions resulting in 27 deaths including complications of hemophagocytic syndrome (4) and cerebral nervous system involvement (3). Median survival time from diagnosis was 31 months. Skin biopsies varied from a pagetoid pattern to purely dermal or panniculitic infiltrates composed of intermediate-sized lymphocytes with tissue evidence of cytotoxicity. The most common immunophenotype was CD3+/CD4⁻/CD5⁻/CD8⁻/BF1⁻/γ-M1+/TIA-1+/granzyme-B+/CD45RA-/CD7-, and 4 cases were Epstein-Barr virus positive. This is the largest study to date of cutaneous γδ T-cell lymphomas and demonstrates a variety of clinical and pathologic presentations with a predictable poor outcome.

Current understanding of cutaneous lymphoma: selected topics.

Recent epidemiology studies have identified a steady increase in the incidence of cutaneous lymphomas over the past few decades. Although possible explanations for this increased incidence include heightened awareness of these conditions as well as a more refined diagnostic acuity by dermatologists and pathologists, an increase secondary to environmental factors cannot be discounted. Our understanding of cutaneous lymphomas keeps evolving. Consequently, our knowledge and understanding of cutaneous lymphomas requires reconsideration of past dogma and critical revision of the new proposals. In this article, some hot topics and important new findings in the field are reviewed.