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Philip E LeBoit

Publications and source records attributed to Philip E LeBoit.

At least 19 recordsLinked to original sources
PubMed2006

Cutaneous malignancy and human immunodeficiency virus disease.

UNLABELLED: Certain skin cancers occur with increased frequency or altered course in patients infected with HIV. Malignant melanoma and squamous cell carcinoma are examples of cutaneous malignancies that have a more aggressive course in patients with HIV. Others, such as basal cell carcinoma, appear more frequently in this population but do not appear to be more aggressive. The incidence of HIV-associated Kapsosi's sarcoma has markedly decreased since the advent of HIV antiretroviral therapy. Our understanding of the pathogenesis of this malignancy and its unique management issues are fully reviewed. Cutaneous T-cell lymphoma (CTCL) is rare in this population. Other types of cutaneous lymphoma and HIV-associated pseudo-CTCL are discussed. This article addresses prevention, treatment, and follow-up strategies for this at-risk population. LEARNING OBJECTIVE: At the completion of this learning activity, participants should be familiar with the unique epidemiology, clinical course, and management of cutaneous malignancy in patients infected with HIV.

Algorithms↗
PubMed2006

Seborrheic keratosis with basal clear cells: a distinctive microscopic mimic of melanoma in situ.

BACKGROUND: We observed seborrheic keratoses with many basilar clear cells, creating a microscopic pattern that mimicked a seborrheic keratosis involved by melanoma in situ. OBJECTIVE: We sought to report a series of these seborrheic keratoses and the immunohistochemical stains used to reach a proper diagnosis. METHODS: We reviewed 9 cases of seborrheic keratosis that had a distinctive pattern of basal clear cells with ample cytoplasm. All cases were evaluated by conventional microscopy, and Melan-A, S-100, and high molecular weight keratin 903 immunostains. RESULTS: The basal clear cells failed to react with Melan-A and S-100 protein antisera. In contrast, these cells labeled with an antikeratin antibody in all cases. In all, 7/9 (78%) showed immunopositivity only at the peripheries of cells, creating a pattern that could be mistaken for a negative stain if not examined at high magnification. LIMITATIONS: This is a retrospective review of cases limited to a large referral dermatopathology service. CONCLUSIONS: We describe a previously uncharacterized pattern of seborrheic keratosis that can microscopically mimic melanoma in situ. Careful conventional microscopy coupled with a panel of immunostains can allow the proper diagnosis to be reached.

Aged↗
PubMed2005

Distinct sets of genetic alterations in melanoma.

BACKGROUND: Exposure to ultraviolet light is a major causative factor in melanoma, although the relationship between risk and exposure is complex. We hypothesized that the clinical heterogeneity is explained by genetically distinct types of melanoma with different susceptibility to ultraviolet light. METHODS: We compared genome-wide alterations in the number of copies of DNA and mutational status of BRAF and N-RAS in 126 melanomas from four groups in which the degree of exposure to ultraviolet light differs: 30 melanomas from skin with chronic sun-induced damage and 40 melanomas from skin without such damage; 36 melanomas from palms, soles, and subungual (acral) sites; and 20 mucosal melanomas. RESULTS: We found significant differences in the frequencies of regional changes in the number of copies of DNA and mutation frequencies in BRAF among the four groups of melanomas. Samples could be correctly classified into the four groups with 70 percent accuracy on the basis of the changes in the number of copies of genomic DNA. In two-way comparisons, melanomas arising on skin with signs of chronic sun-induced damage and skin without such signs could be correctly classified with 84 percent accuracy. Acral melanoma could be distinguished from mucosal melanoma with 89 percent accuracy. Eighty-one percent of melanomas on skin without chronic sun-induced damage had mutations in BRAF or N-RAS; the majority of melanomas in the other groups had mutations in neither gene. Melanomas with wild-type BRAF or N-RAS frequently had increases in the number of copies of the genes for cyclin-dependent kinase 4 (CDK4) and cyclin D1 (CCND1), downstream components of the RAS-BRAF pathway. CONCLUSIONS: The genetic alterations identified in melanomas at different sites and with different levels of sun exposure indicate that there are distinct genetic pathways in the development of melanoma and implicate CDK4 and CCND1 as independent oncogenes in melanomas without mutations in BRAF or N-RAS.

Adult↗
PubMed2005

Dust to dust.

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Adolescent↗
PubMed2005

Fibroepithelioma of pinkus is a fenestrated trichoblastoma.

Pinkus described "pre-malignant fibroepithelioma" as a proliferation that gave rise to many tiny basal cell carcinomas within each lesion. Later authors have generally considered it to be an unusual variant of basal cell carcinoma (BCC). The delineation of trichoblastoma as the general term for the benign counterpart of BCC raises the possibility that the fibroepithelioma of Pinkus (FEP) would be better classified under that rubric. To address this subject, we examined the records of 114 patients with FEP for body site, age and sex distribution, and sections from 75 lesions. All FEP examined show a blunt interface with the underlying dermis (where one could be seen), differentiation toward follicular bulbs and papillae, and large areas of cellular stroma. FEP has a slight female preponderance in contrast to BCC, which is more common in males. Unlike the common types of BCC, FEP has an overwhelming predilection for the trunk and extremities, and only 5% of tumors are set in a dermis with significant amounts of solar elastosis. Next, FEP, BCC, and FEP with BCC-like areas were stained with MIB-1 (to assess proliferation), p53 (an oncogene product), and CK20 (a Merkel cell marker) antisera. FEP shows a low level of staining for p53 and MIB-1, in contrast to conventional BCCs that over-express these markers. FEP also shows retention of Merkel cells, a characteristic of benign neoplasms with follicular germinative differentiation but not in general of BCC. The BCC-like areas in some FEP tumors reflect these staining tendencies with less striking differences. Given the contrast between FEP and BCC with respect to site of occurrence, relationship to sun damage, histopathologic features, and immunohistochemical studies, it appears that FEP more closely resembles trichoblastoma than BCC.

Adolescent↗
PubMed2005

Mucinous carcinoma of the skin, primary, and secondary: a clinicopathologic study of 63 cases with emphasis on the morphologic spectrum of primary cutaneous forms: homologies with mucinous lesions in the breast.

We present the largest series of mucinous carcinoma involving the skin, describing the histopathologic, immunohistochemical, electron microscopic, and cytogenetic findings. Our aim was fully to characterize the clinicopathologic spectrum and compare it with that seen in the breast. In addition, we wished to reevaluate the differential diagnostic criteria for distinguishing primary mucinous carcinomas from histologically similar neoplasms involving the skin secondarily, and study some aspects of their pathogenesis. We demonstrate that primary cutaneous mucinous carcinomas span a morphologic spectrum compatible to their mammary counterparts. Both pure and mixed types can be delineated morphologically, and some lesions have mucocele-like configurations. Most lesions seem to originate from in situ lesions that may represent, using mammary pathology terminology, ductal hyperplasia, atypical ductal hyperplasia, or ductal carcinoma in situ or a combination of the three. Inverse cell polarity appears to facilitate the progression of the changes similar to lesions in the breast. The presence of an in situ component defines the neoplasm as primary cutaneous, but its absence does not exclude the diagnosis; although for such neoplasms, full clinical assessment is essential. Mammary mucinous carcinoma involving the skin: all patients presented with lesions on chest wall, breast, axilla, and these locations can serve as clue to the breast origin. Microscopically, cutaneous lesions were of both pure and mixed type, and this correlated with the primary in the breast. Dirty necrosis was a constant histologic finding in intestine mucinous carcinomas involving the skin, and this feature may serve as a clue to an intestinal origin.

Adenocarcinoma, Mucinous↗
PubMed2004

Etiology of pruritic papular eruption with HIV infection in Uganda.

CONTEXT: A frequent cause of human immunodeficiency virus (HIV)-related morbidity in sub-Saharan Africa is a commonly occurring, intensely pruritic skin rash. The resulting scars are disfiguring and stigmatizing. Despite the substantial prevalence of pruritic papular eruption (PPE) among HIV-infected Africans, the cause has been elusive. OBJECTIVE: To determine the etiology of PPE occurring in HIV-infected individuals. DESIGN, SETTING, AND PATIENTS: Cross-sectional study of HIV-infected patients with active PPE from clinics in Uganda conducted from May 19 through June 6, 2003. Enrollment occurred in the month preceding May 19. Each participant was clinically examined by 2 dermatologists, had laboratory studies performed, was administered an epidemiologic questionnaire, and had a skin biopsy of a new lesion evaluated by a dermatopathologist. MAIN OUTCOME MEASURES: Histological characteristics of new pruritic lesions. Other assessments included CD4 cell count, eosinophil count, and physician-assessed rash severity. RESULTS: Of 109 patients meeting inclusion criteria, 102 (93.6%) completed the study. The CD4 cell counts in this study population were generally low (median, 46/microL) and inversely related to increasing rash severity (median CD4 cell counts: 122 for mild, 41 for moderate, and 9 for severe; P<.001 for trend). Eighty-six patients (84%; 95% confidence interval, 77%-91%) had biopsy findings characteristic of arthropod bites. Patients with arthropod bites on biopsy had significantly higher peripheral eosinophil counts (median, 330 vs 180/microL; P = .02) and had a trend toward lower CD4 cell counts (median, 40 vs 99/microL; P = .07) than those without histological evidence of arthropod bites. CONCLUSIONS: Pruritic papular eruption occurring in HIV-infected individuals may be a reaction to arthropod bites. We hypothesize that this condition reflects an altered and exaggerated immune response to arthropod antigens in a subset of susceptible HIV-infected patients.

Adult↗
PubMed2004

Margin call.

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Aged↗