Faculty Bibliography

Cutaneous T cell lymphoma is a heterogeneous group of lymphomas characterized by the accumulation of malignant T cells in the skin. The molecular and cellular etiology of this malignancy remains enigmatic and what role antigenic stimulation plays in the initiation and/or progression of the disease remains to be elucidated. Deep sequencing of the tumor genome revealed a highly heterogeneous landscape of genetic perturbations and transcriptome analysis of transformed T cells further highlighted the heterogeneity of this disease. Nonetheless, using data harvested from high-throughput transcriptional profiling allowed us to develop a reliable signature of this malignancy. Focusing on a key cytokine signaling pathway, previously implicated in CTCL pathogenesis, JAK/STAT signaling, we used conditional gene targeting to develop a fully penetrant small animal model of this disease that recapitulates many key features of mycosis fungoides, a common variant of CTCL. Using this mouse model, we demonstrate that T cell receptor engagement is critical for malignant transformation of the T lymphocytes and that progression of the disease is dependent on microbiota.

The United States (US) Department of Defense(DoD) has been a leader in using telecommunicationstechnology to provide remote medical care. The DoDhas been using telemedicine for more than twentyyears to provide medical services to military personneldeployed throughout the world, and has largelyinfluenced the development of teledermatology. Theexperiences of early military teledermatology serviceshave yielded valuable lessons that have been essentialto the creation of successful civilian programs.

We report an HIV-negative, 55-year-old manwith recurrent Kaposi's sarcoma (KS) of the lowerextremities, who does not fit into any of thefour previously described variants of KS: classicKS, AIDS-related KS, iatrogenic KS, and AfricanendemicKS. There are reports in the literature ofchildhood-onset KS, which is thought to be dueto an inherited immune deficiency that confers ahigher susceptibility to human Herpesvirus-8 (HHV-8), which is the virus that is known to cause KS. Ourpatient may be affected with an inherited immunedeficiency that has predisposed him to KS, and thismutation also may account for his prostate andbladder cancer.

Primary cutaneous B cell lymphomas (PCBCL) are thesecond most common type of primary cutaneouslymphoma. The three main types of PCBCL areprimary cutaneous marginal-zone lymphoma(PCMZL), primary cutaneous follicle-centerlymphoma, and primary cutaneous diffuse largeB-cell lymphoma, leg type. PCMZL has an indolentcourse with a five-year survival rate approaching99%. Lesions most often present on the trunk or armas erythematous-to-violaceous papules, plaques, ornodules. Approximately one-half of patients havesolitary skin lesions. Treatment options includesurgery, radiation, and topical, intralesional orsystemic therapy. We present the case of a 33-yearoldHispanic woman with firm, pruritic, pink papuleson the forehead and cheeks, who was diagnosedwith PCMZL.

BACKGROUND: The histopathologic diagnosis of mycosis fungoides (MF) has classically relied on the presence of atypical epidermotropic T-lymphocytes predominating over spongiosis. However, in some cases of MF, prominent epidermal mucinosis in a spongiosis-like pattern mimics a spongiotic dermatitis. To our knowledge, only one series in the literature has thus far recognized the presence of epidermal mucinosis in MF. METHODS: We evaluated 30 skin biopsies from 18 patients with the clinical diagnosis of MF, which fulfilled all histopathologic criteria for patch- or plaque-stage MF, but also showed epidermal mucinosis in a spongiosis-like pattern. Fifteen specimens were studied by immunohistochemistry, and 7 were tested for T-cell receptor (TCR) gene rearrangements. Twenty biopsies of spongiotic dermatitides were included as controls. RESULTS: We confirmed the presence of epidermal mucinosis in all 30 cases of MF with a spongiosis-like pattern based on histopathologic criteria and the colloidal iron stain for mucin. Immunohistochemistry in 14 out of 15 specimens showed marked loss of pan-T-cell antigens CD5 and CD7; and TCR clonality was detected in 7 specimens from 6 patients, supporting the diagnosis of MF CONCLUSIONS: We report helpful histopathologic criteria for distinguishing MF with epidermal mucinosis in a spongiosis-like pattern from spongiotic dermatitis.