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Biomedical subjects

H Skelton

Publications and source records attributed to H Skelton.

42 records · Page 3Linked to original sources
PubMed1998

Cutaneous fibrous perineurioma.

Tumors of perineurial origin are rare. Three variants of perineuriomas have been described, a storiform perineurial fibroma, an intraneural perineurioma, and a recently described sclerosing perineurioma. We present two patients with cutaneous fibrous perineurioma located in acral areas. Both tumors had a deep circumscribed margin with a prominent vascular component. They contained small round cells and spindle cells that express EMA and show membrane staining for type IV collagen. Cutaneous fibrous perineuriomas fit within the spectrum of neurocristicly derived cellular proliferations.

Adult↗
PubMed1998

Neurocristic cutaneous hamartoma: a distinctive dermal melanocytosis with an unknown malignant potential.

Neurocristic hamartomas (NCHs) result from aberrant development of the neuromesenchyme. In addition to a dermal melanocytic component, these tumors can contain neurosustentacular and fibrogenic components and can undergo malignant transformation. Although NCHs have many features in common with other dermal melanocytic neoplasms, including cellular blue nevi and some congenital nevi, they have distinctive clinical and histologic features. We present a case report of a 27-year-old white woman with an NCH of the scalp. The clinical, histologic, and immunohistochemical features are compared with those of other dermal melanocytic neoplasms. The NCH contained epithelioid pigmented melanocytes positive for S-100 and HMB45, within which there were well-circumscribed nodules of S-100+/Leu 7+/HMB45- cells surrounded by a capsule composed of spindle cells positive for epithelial membrane antigen. The stromal cells throughout the tumor were diffusely CD34 positive, and hair follicles were decreased and dystrophic within the tumor. NCHs represent neoplastic dysplasia that involves not only melanocytic cells but also neurosustentacular and fibrocytic effector cells. The histologic and immunohistochemical features, along with the decreased and dystrophic hair follicles, suggest that the abnormalities in the mesenchyme are significant and result from the contribution of neural crest cells to the cellular and matrix components of the mesenchyme.

Adult↗
PubMed1997

Pityriasis lichenoides et varioliformis acuta in HIV-1+ patients: a marker of early stage disease. The Military Medical Consortium for the Advancement of Retroviral Research (MMCARR).

BACKGROUND: The high incidence of cutaneous disease in HIV-1+ patients may be a marker of the chronic state of immune activation. In addition, specific cutaneous diseases may be related to the pattern and degree of immune dysregulation present in the patients at the time of the eruption. We have observed that HIV-1+ patients with pityriasis lichenoides et varioliformis acuta (PLEVA) were in the early to midstage of HIV-1 disease. MATERIALS AND METHODS: To determine if there was a correlation between the phenotype of the lymphoid infiltrate and surface markers of the epidermis and the known changes in early or late-stage HIV-1 disease, we studied five HIV-1+ patients with PLEVA. Cutaneous biopsy specimens were obtained and immunohistochemical stains were used to determine the expression of ELAM-1, ICAM-1, and HLA-DR and the phenotype of the lymphoid infiltrate. RESULTS: The HIV-1+ patients showed increased expression of HLA-DR on keratinocytes as well as on the mononuclear and dendritic cell populations in the epidermis and dermis. The majority of T cells were activated CD8+ cells. CONCLUSIONS: Immunophenotyping of the inflammatory infiltrate in these patients is consistent with a pattern of immune dysregulation seen only in earlier stages of HIV-1 disease. Thus, PLEVA may be useful as a marker of early to midstages of HIV-1 disease.

Adult↗
PubMed1995

Histopathologic features seen in sulfur mustard induced cutaneous lesions in hairless guinea pigs.

Sulfur mustard (SM), a chemical warfare agent first used early in the 20th century, has re-emerged in the past decade as a major threat around the world. At present, there are no effective therapeutic measures for SM exposure. Because the skin as well as other interface epithelial surfaces are the first tissues effected as this agent is absorbed, reactions within the skin are an area of active research into the mechanism of action of this alkylating agent. The euthymic hairless guinea pig has been used as the animal model for the study of SM induced injuries because of morphologic similarity of its skin to human skin, with a multiple layer epidermis, and because this animal has a normal immune system. We reviewed 102 biopsy specimens from 51 animals exposed to three different dose times of saturated SM vapor. Histopathologic evidence exists for increased programmed cell death as well as cellular necrosis, subepidermal blister formation, and delayed re-epithelialization secondary to problems with adhesion. Information obtained from this study adds to the body of information important in the investigation of the mechanisms of action of SM.

Animals↗
PubMedDate not supplied

Are cutaneous reactions to fly larvae mediated by CD4+, TIA+ NK1.1 T Cells?

BACKGROUND: Although there have been reports of fly larvae in wounds and as isolated primary infestations, there have been only rare reports documenting reactions to the larvae within the skin in humans and animals. There have been no reports documenting the histopathologic and immunohistochemical characteristics of the inflammatory infiltrate. OBJECTIVE: We present a patient who developed local pruritus, erythema, and swelling approximately three weeks after infestation by a fly larva within the scalp. Histopathologically the biopsy site showed a mixed infiltrate containing lymphoid cells and numerous eosinophils. Immunohistochemical stains showed predominantly CD4+ T cells expressing an ab T-cell receptor (TCR) of which approximately 30% coexpressed T-cell intracellular antigen (TIA) and CD56. In addition, there were approximately 5% of these CD4+ T cells which coexpressed CD30. CONCLUSIONS: Histopathologic and immunohistochemical findings are consistent with an effector cell population of cytotoxic CD4+ T cells that produce a T-helper 2 cytokine pattern. The phenotype of this subset of T cells is unique and among its characteristics is that antigens--usually nonprotein antigens--are presented to these CD4+,TIA+ natural killer (NK)1.1T cells by CD1d molecules.

Antigen Presentation↗