Monoclonal rearrangement of the T cell receptor gamma-chain in lichenoid pigmented purpuric dermatitis of gougerot-blum responding to topical corticosteroid therapy

The color of skin: brown diseases of the skin, nails, and mucosa

Brown diseases comprise disorders leading to hyperpigmentation in skin and nails. Melasma is an acquired skin disorder that is characterized by brownish macules that typically occur on the face. Schamberg disease, also known as progressive pigmented purpura, is characterized by brown pigmentation with pepper spots on their edges. We summarize the epidemiology, pathogenesis, histologic features, and treatment choices for additional brown diseases, including melasma, pigmented purpuric dermatoses, postinflammatory hyperpigmentation, drug-induced hyperpigmentation, and pigmentations due to systemic or physiologic conditions.

Pathology of T-cell lymphomas: diagnosis and biomarker discovery

T-cell lymphomas are a group of predominantly rare hematologic malignancies that tend to recapitulate different stages of T-cell development, in a similar way that B-cell lymphomas do. As opposed to B-cell lymphomas, the understanding of the biology and the classification of T-cell lymphomas are somewhat rudimentary, and numerous entities are still included as 'provisional categories' in the World Health Classification of hematolopoietic malignancies. A relevant and useful classification of these disorders have been difficult to accomplish because of the rarity nature of them, the relative lack of understanding of the molecular pathogenesis, and their morphological and immunophenotypical complexity. Overall, T-cell lymphomas represent only 15 % of all non-Hodgkin lymphomas. This review is focused on addressing the current status of the categories of mature T-cell leukemias and lymphomas (nodal and extranodal) using an approach that incorporates histopathology, immunophenotype, and molecular understanding of the nature of these disorders, using the same philosophy of the most recent revised WHO classification of hematopoietic malignancies.

Pigmented purpuric dermatosis: classification by phenotypic and molecular profiles

The categorization of pigmented purpuric dermatosis (PPD) as a form of cutaneous lymphoid dyscrasia has been suggested. Phenotypic and molecular studies were done on 43 patients with PPD. The molecular studies used a capillary gel electrophoresis T-cell receptor beta multiplex polymerase chain reaction assay. There were 2 principal categories: polyclonal PPD represented by 22 cases and monoclonal variants comprising 21 cases. Monoclonal cases had extensive skin lesions. An identical restricted T-cell repertoire independent of time and location was observed. Approximately 40% of the monoclonal cases had clinical and pathologic features of mycosis fungoides (MF). In the polyclonal variant, disease outside the lower extremities was uncommon; there were no patients with MF. Striking reductions in CD7 and CD62L were seen in both groups. PPD is a form of cutaneous T-cell lymphoid dyscrasia, based on the frequency of monoclonality, the preservation of persistent T-cell clonotypes, and extent of pan-T-cell marker loss. Stratification of lesions of PPD according to the molecular profile may be of significant value prognostically and influence therapeutic intervention.

CCR4 Expression by Atypical T Cells in Systemic Pilotropic Lymphoma: Its Behavior under Treatment with Interferon Gamma, Topical PUVA and Systemic Retinoid

We describe an 88-year-old Japanese patient with pilotropic T cell lymphoma involving the peripheral blood as well as lymph nodes. This patient presented with multiple red follicular papules, confluent, infiltrated erythematous plaques and nodules. Moreover, he was conspicuous for the presence of total alopecia of the scalp and eyebrows. Histopathologically, the lesional skin showed dense follicular and perifollicular infiltrates of atypical lymphocytes. The flow cytometry disclosed the presence of weakly CD4+ CCR4+ cell populations that would not be detected in the peripheral blood from healthy controls. The patient responded well to topical PUVA and systemic etretinate (retinoid-PUVA) and intravenous IFN-gamma. Parallel with the decrease in atypical cells in the peripheral blood, the percentage of weakly CD4+ CCR4+ T cells declined. However, about 1 week after we discontinued this treatment because of the side effects, the lymph node swelling became prominent, and, 4 weeks later, the patient died before restarting any specific chemotherapy.