Langerhans cell sarcoma with lineage infidelity/plasticity: a diagnostic challenge and insight into the pathobiology of the disease.

Langerhans cell sarcoma is a very rare and aggressive tumor of Langerhans cell lineage, for which aberrant expression of T-cell-related antigens has not yet been reported in a primary skin tumor. The authors describe the first known case of a primary cutaneous Langerhans cell sarcoma with lineage infidelity and use comparative genomic hybridization to investigate the genetic composition of the tumor and detect DNA copy number alterations throughout its entire genome. The case involves a 62-year-old woman who presented with an irregular nodule on the forehead surrounded by smaller lesions in its vicinity. The clinical impression was melanoma with satellitosis. The biopsy specimen showed an epidermotropic tumor with moderate-to-marked cellular pleomorphism and significantly increased mitotic rate but no necrosis. The immunoprofile of the lesion was remarkable, as next to common Langerhans cell markers: Langerin, CD1a, S100, and CD4; it also exhibited an aberrant T-cell phenotype with the expression of CD2, CD3, and CD43. In addition, fascin and CD30 were also expressed, further exaggerating potential diagnostic pitfalls. Langerhans cell lineage was confirmed by the demonstration of characteristic Birbeck granules on electron microscopy. Whole genome analysis for copy number changes and loss of heterozygosity showed a complex karyotype with variable hyperdiploidy and numerous allelic imbalances. Significant findings included a homozygous deletion at 9p21 involving the CDKN2A and loss of heterozygosity at 17p involving TP53 gene, coupled with a TP53 missense mutation. Despite reexcision and multiagent systemic chemotherapy, the patient died of metastasis 2 years after diagnosis. This case is an outstanding example of lineage infidelity in a hematologic malignancy and the utilization of comparative genomic hybridization in characterizing its genetic abnormalities.

Use of tissue-engineered skin to study in vitro biofilm development.

BACKGROUND: Biofilms are aggregations of microorganisms that have been identified as potential pathogens in the chronicity of nonhealing wounds. OBJECTIVE To develop an in vitro wound model to study biofilms using Graftskin, a tissue-engineered skin equivalent. MATERIALS AND METHODS: Graftskin constructs were divided into sections, and wounds were created on each section. Bacterial suspensions with a concentration of 10(6) CFU/mL were prepared from cultures of pathogenic isolates of Pseudomonas aeruginosa and Staphylococcus aureus. A 25-microL aliquot of each suspension was deposited in the center of wounds created on the Graftskin. Sections were incubated at various time points, and a biopsy was then taken from the wounded and inoculated area. Sections were visualized with light (hematoxylin and eosin) and epifluorescent microscopy (calcofluor white and ethidium bromide). RESULTS Biofilm was observed on the wound model. Biofilm formation was dependent on time of Graftskin exposure to the bacteria. Biofilm was visualized in the S. aureus group at an earlier time point than in the P. aeruginosa group. CONCLUSIONS: We demonstrated biofilm formation in vitro using a wound model. This model may provide a basis on which future studies may explore therapeutic modalities to prevent and eradicate pathogenic bacterial biofilm. The authors have indicated no significant interest with commercial supporters.

The incidence of recurrent herpes simplex and herpes zoster infection during treatment with arsenic trioxide.

We report the incidence of varicella zoster virus (VZV) and herpes simplex virus (HSV) infection in patients with multiple myeloma and colon cancer who were treated with arsenic trioxide for their disease. In this report, we discuss the effects of arsenic on immune system, and suggest arsenic compounds as a possible predisposing factor for viral reactivation in these patients.

Laser-assisted tattoo removal with topical 5% imiquimod cream.

BACKGROUND: Laser-assisted tattoo removal is effective but can be costly and time-consuming and can result in disfiguring scars and pigment alterations. Imiquimod, an immune response modifier, may play a role in tattoo removal. OBJECTIVE: The objective was to evaluate the safety and efficacy of topical 5% imiquimod cream used daily in conjunction with laser therapy to remove unwanted tattoos. MATERIALS AND METHODS: Twenty subjects with two similar tattoos were enrolled in this randomized, prospective, double-blinded, case-controlled study. Tattoos were treated with either imiquimod or placebo daily and laser therapy every 4 to 6 weeks for a total of six sessions. The primary efficacy parameter was tattoo clearance (5-point scale, poor through complete). Secondary efficacy parameters included textural changes (5-point scale, minimal through severe), pain during and between laser procedures, and undesirable pigment alterations. RESULTS: Nineteen subjects completed the study. The mean score for tattoo clearance with imiquimod versus placebo was 3.2 versus 2.9 and, for textural changes, was 1.37 versus 1.21 (differences not statistically significant). There was no difference in subjective pain during and between laser sessions and no undesirable pigment alterations were reported. Adverse reactions were more frequent with imiquimod compared to placebo. CONCLUSION: Topical imiquimod is an ineffective adjunct to laser-assisted tattoo removal.

Eruptive dermatosis papulosa nigra as a possible sign of internal malignancy.

A 42-year-old black woman presented with dermatosis papulosa nigra lesions of 15 years' duration. Coincident with the diagnosis of symptomatic iron-deficiency anemia about 1 year ago, she reported an "explosion" in number and size of the lesions progressing from her face to her trunk and arms. Physical examination revealed numerous 1-5-mm, black, smooth, verrucous papules predominantly on the forehead, malar region of the face, neck, and upper trunk (Figs 1 and 2). The lesions on the back were situated in a "Christmas tree" pattern and included two 1-cm papules. She had multiple 1-mm papules on the upper arms. A biopsy confirmed the diagnosis of dermatosis papulosa nigra, showing parakeratosis, acanthosis, hyperpigmentation, thick interwoven tracts of epithelial cells, and horn cysts. Given the eruptive nature of her disease, the possibility of an underlying malignancy was entertained. Six weeks later, she went to the emergency room for severe weakness; a colonoscopy revealed an ascending colon adenocarcinoma with a negative metastatic work-up.

Comparing 18- versus 12-mm spot size in hair removal using a gentlease 755-nm alexandrite laser.

BACKGROUND: Laser epilation is based on the principle of selective photothermolysis, absorption of laser energy by the target chromophore melanin. It is claimed that larger spot sizes may be more effective for hair removal at identical fluences. OBJECTIVE: To compare the efficacy of 18- vs. 12-mm spot size in hair removal using a Gentlelase Alexandrite laser from Candela Corporation (Boston, MA). METHODS: In this double-blind, randomized control trial, patients underwent laser-assisted hair removal on the axillary region. Regions were randomly selected and treated with either an 18- or a 12-mm spot size. Three treatments at 6-week intervals with a 755-nm Gentlelase Alexandrite laser (Candela Corp., Canton, MA) at a fluence of 16 J/cm(2) with cooling and delay times of 60 ms. Hair counts were taken before each treatment session and compared. The mean percentage hair reduction and student's paired t-test were used to compare 18 versus 12 mm versus control sites at each visit and compared it with the baseline hair count. RESULTS: There was a 10.3% difference in mean reduction favoring the 18-mm spot size treated area at the 6-month follow-up. CONCLUSION: Our results indicate that a larger spot size appears to be more effective for laser assisted hair removal.

Determination of the area of skin capable of being covered by the application of 250 mg of 5% imiquimod cream.

BACKGROUND: Five percent imiquimod cream is FDA-approved for the treatment of genital and perianal warts and actinic Keratosis. The manufacturer recommends that a single sachet containing 250 mg of 5% imiquimod cream (12.5 mg of imiquimod) is adequate for a single use and is sufficient to cover a wart area of up to 20 cm(2). OBJECTIVE: To determine the maximal area of skin that can be evenly covered by 250 mg of 5% imiquimod cream that is contained in one single-use sachet. METHODS: The contents of one 250-mg single-use sachet of 5% imiquimod cream were mixed with less than 1 mg of fluorescein sodium. The cream was applied evenly onto the abdomen of two Yorkshire female pigs and onto the medial and lateral aspects of the upper left arm of a human subject. The area of application was then measured. RESULTS: The average area obtained on the pig skin was 196 cm(2). The area covered on the human subject was 386 cm(2). CONCLUSION: We have found that one sachet of 250 mg of 5% imiquimod cream can be applied to an area of skin up to 386 cm(2). In light of the increasing use of 5% imiquimod cream in the treatment of cutaneous diseases, such as actinic keratoses, which affect larger areas of skin than genital warts, a more efficient use of 5% imiquimod cream may make this medication a more cost-effective treatment modality.