False-positive amplified Mycobacterium tuberculosis direct tests in skin specimens of leprosy.

The amplified Mycobacterium tuberculosis (M tuberculosis) direct test (MTD) is reported to be a highly sensitive (92.6%) and specific (100%) test for the detection of M tuberculosis. We report two cases of human leprosy in which false-positive amplified MTD testing on skin biopsies led to initial misdiagnoses of cutaneous M tuberculosis.

Mycophenolate mofetil in dermatology.

UNLABELLED: Mycophenolate mofetil (MMF) is the prodrug of mycophenolic acid (MPA), a medication used to treat psoriasis in the 1970s until side effects and the concern of carcinogenesis led to its discontinuation. The prodrug, MMF, emerged decades later in the transplant field. Dermatologists have since used MMF off-label to treat various inflammatory skin conditions, with most research concentrating on its use in psoriasis, autoimmune blistering disorders, dermatitides, and connective tissue disorders. The appeal of MMF is predicated upon its lymphocyte specificity and consequent decreased toxicity profile. These attributes may make it a preferable treatment option. Its use in the field of dermatology is currently limited by a lack of randomized controlled trials, potential unknown side effects, and cost of treatment. In reviewing both current literature and our own clinic records, MMF appears to be a promising therapeutic option for the treatment of cutaneous inflammatory diseases. LEARNING OBJECTIVE: After completing this learning activity, participants should be able to summarize the history and pharmacology of mycophenolate mofetil as an immunosuppressant; recognize its potential role in the treatment of dermatologic conditions, including general dosing guidelines, use in pregnancy and pediatrics, and potential adverse effects; and identify future considerations and developing areas of research regarding the use of mycophenolate mofetil in dermatology.

Treatment with 5-fluorouracil and celecoxib displays synergistic regression of ultraviolet light B-induced skin tumors.

Standard chemotherapeutic agents used for the treatment of pre-cancerous skin lesions and non-melanoma skin cancers are not completely effective. Several studies have suggested that repeated inflammatory sunburn reactions, which include the induction of cyclooxygenase-2 (COX-2) and the subsequent production of prostaglandins, play a role in skin cancer development. COX-2 inhibition has been demonstrated to be a potent means of preventing skin cancer development in mice; however, COX-2 inhibitors alone are not effective as chemotherapeutic agents. Data in a variety of cancer types suggest greater efficacy in treating tumors with combination chemotherapies. Therefore, we hypothesized that a combination of the chemotherapeutic agent 5-fluorouracil (5-FU) and the COX-2 inhibitor and anti-inflammatory drug celecoxib would act synergistically to regress tumors in a murine model of ultraviolet light B- (UVB-) induced carcinogenesis. We found that topical treatment with 5-FU and celecoxib together was up to 70% more effective in reducing the number of UVB-induced skin tumors than 5-FU treatment alone. Our data suggest that more effective chemotherapy regimens can be developed to treat the millions of pre-cancerous and cancerous skin lesions that arise every year, which could ultimately lead to a significant reduction in costs and cosmetic defects (scarring) associated with surgical interventions.

Cutaneous marginal zone B-cell lymphoma in the setting of fluoxetine therapy: a hypothesis regarding pathogenesis based on in vitro suppression of T-cell-proliferative response.

INTRODUCTION: Drugs may be an important cause of atypical lymphocytic infiltration. Oftentimes, these infiltrates are in the context of pseudolymphomata. We report a patient who developed lymphocytoma cutis temporally associated with initiation of fluoxetine therapy that later went on to develop cutaneous marginal zone B-cell lymphoma. The response of peripheral blood lymphocytes to fluoxetine and other drugs was examined in an attempt to ascertain the potential role for drugs in the propagation of these infiltrates. MATERIALS AND METHODS: Routine light microscopic analysis and phenotypic studies were performed on tissue obtained from a skin biopsy. Lymphocyte mitogenic studies were carried out using increasing concentrations of fluoxetine, bupropion, and two anticonvulsants. RESULTS: An initial biopsy was consistent with lymphocytoma cutis. The patient stopped fluoxetine associated with lesional regression. The lesions recurred despite being off fluoxetine; a repeat biopsy was compatible with marginal zone lymphoma. Lymphocyte proliferation assays revealed a suppressive effect on T-lymphocyte proliferation at physiologic concentrations. Other tested drugs did not have a similar suppressive effect. CONCLUSIONS: Fluoxetine may be associated with pseudolymphomata and marginal zone lymphoma. The inhibitory effects on T-lymphocyte function and more specifically T-suppressor function may lead to excessive antigen-driven B-cell proliferation.

CD34 expression in primary cutaneous malignant melanoma: apropos of a case and review of the aberrant melanoma phenotype.

BACKGROUND: The histological diagnosis of malignant melanoma can be challenging. Immunohistochemical techniques may define a critical role in certain cases, specifically in establishing a primary diagnosis of melanoma. CD34 is a hemopoietic stem cell antigen expressed in bone marrow and endothelial cells, and may also be expressed in vascular and spindle cell tumors; it is generally negative in malignant melanoma. CASE REPORT: An 83-year-old white female presented with a 3-4 mm area on her right upper back, which had been present for several years. Histologic sections showed a polypoid distortion by sheets and nodules of transformed amelanotic melanocytes lying in intimate apposition to an attenuated epidermis without a concomitant radial growth phase. Tumor cells were extensively S-100 and CD34 positive and showed focal immunoreactivity with melan-A and HMB-45. DISCUSSIONS: We present a case of malignant melanoma of nodular subtype, which strongly expressed CD34. The spectrum of abnormal phenotypes in malignant melanoma is reviewed, and a possible explanation for the presence of CD34 is discussed. This case demonstrates the potential of malignant melanoma to express CD34, defining an infrequently recognized aberrant phenotype. Whether or not expression of this marker is associated with a more aggressive clinical course remains to be determined.