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Biomedical subjects

A Claudy

Publications and source records attributed to A Claudy.

223 records · Page 13Linked to original sources
PubMedDate not supplied

[Epidermotropic eccrine carcinoma. Apropos of a case with ultrastructural examination].

Pinkus and Mehregan's epidermotropic eccrine carcinoma shows particular clinico-pathological characteristics which makes it different from the other cutaneous epitheliomas. A case observed on a 81 year old woman is reported. The initial lesion consisted of an ulcerating tumor on the calf, then followed by multiple verrucous papules eruption around it. Within a few weeks, many other verrucous tumors occurred on the upper part of the leg while a lymphedema was developing. One year after the initial lesion has been noticed, the patient died of metastases in distant organs. From a histological point of view, the tumor corresponded to a squamous cell carcinoma that was slightly keratinizing, Bowenoïd epidermotropic, with dermal involvement too. Features of duct formation were identified within solid nests of neoplastic cells, tumor emboli were seen in the lymphatics. The ultra-structural study made it evident that the tonofilaments were precarious in neoplastic cells; the cytoplasm contained glycogen. The inter-cellular bridges and desmosomes were scanty and micro-villi were noted. The latter confirm the sudoral nature of these cells. For Pinkus and Mehregan, this type of tumor originates in the acrosyringium, but we think that a contiguous segment of the sudoral duct must also be probably concerned. The spreading of the epidermotropic eccrine carcinoma occurs in the teguments themselves in a uncommon way. The tumor re-appears from the dermal lymphatic channels. The lymphatic involvement is the main characteristic of this cutaneous carcinoma, verified by metastases existing in distant organs.

Aged↗
PubMedDate not supplied

Expression of adhesion receptors in epidermal tumors: correlation with TNF alpha expressing cells.

The expression of intercellular adhesion molecule-1 (ICAM-1), endothelial leukocyte adhesion molecule-1 (E-selectin) and vascular cell adhesion molecule-1 (VCAM-1) was investigated in a series of basal cell carcinomas and squamous cell carcinomas in comparison to benign viral-induced lesions (cutaneous warts, condyloma) and was correlated to the infiltration density and the presence of TNF alpha expressing cells. Tumor cells expressing ICAM-1 were frequently detected in squamous cell carcinoma and condyloma and were correlated with a dense infiltration of HLA-DR and LFA-1 positive cells. Tumor cells were devoid of ICAM-1 in other lesions. Tumor microvessels detected by Von Willebrand factor were consistently present but vessels expressing adhesion receptors were less frequent. E-selectin was usually intense and frequent, whereas VCAM-1 was rare except in dense infiltrated zones and in viral-induced lesions. In all samples, tumor cells strongly expressed TNF alpha. Though the cytotoxin has been reported to be an inducer of adhesion receptors, its expression in epidermal tumors did not correlate with a concomitant up-regulation of epithelial ICAM-1 or endothelial VCAM-1. This may contribute to a reduced influx of T cells into the tumors.

Adolescent↗
PubMedDate not supplied

TNF alpha expressing cells in epidermal tumors: correlation with ICAM-1 induction on keratinocytes and Langerhans cell distribution.

TNF alpha may be a locally expressed immunomediator of cutaneous diseases. An immunohistochemical technique was used to study the expression of the cytotoxin in correlation with the intercellular adhesion molecule-1 (ICAM-1) and Langerhans cell (LC) distribution in viral-induced lesions, epidermal tumors and normal skin. In most cutaneous tumors, TNF alpha immunoreactivity localized to tumor cells and some cells of the histiocytic macrophage lineage including LC. In normal human skin only rare epidermal dendritic cells were found positive. TNF alpha expression by tumor cells did not correlate with a corresponding ICAM-1 induction but coincided with drastic LC depletion in the lesions except in condyloma acuminata. These results suggest that TNF alpha expression by keratinocytes under viral infection or transformation process may contribute to the self-limiting evolution of the lesions and to the modulation of the local immune reaction. Though the cytokine is not involved in the ICAM-1 induction on keratinocytes it may influence the LC depletion observed in these lesions.

Adolescent↗
PubMedDate not supplied

p53 protein expression in mammary and extramammary Paget's disease.

p53 is a tumour-suppressor gene, mutations of which are found in malignant skin lesions. We studied the immunohistochemical expression of the (mutated) p53 protein in 17 cases of Paget's disease (12 mammary and 5 extramammary). Four of the mammary specimens (33.3%) expressed p53 within Paget's cells; in one of these an underlying ductal adenocarcinoma was present and this was also p53-positive. All extramammary cases proved p53-negative. These results underline the differences that exist between mammary and extramammary Paget's disease and favour the origin of the former from the underlying adenocarcinoma rather than the surface epithelium.

Cell Nucleus↗
PubMedDate not supplied

CD40 expression in epidermal tumors.

CD40 antigen, expressed on many cell types is involved in cell-cell interactions, with activated T cells expressing the CD40 ligand. In the skin, keratinocytes express CD40 which may play a role in amplifying inflammatory responses. We investigated the expression of this antigen in a series of epidermal tumors in correlation with T cell infiltrates. Our results indicate a-down-regulation or a drastic loss of CD40 antigen by tumor cells from basal cell carcinoma and squamous cell carcinoma and a moderate to discrete CD40 reactivity of keratinocyte from proliferative layers of benign viral-induced lesions. Endothelial cells, most infiltrating cells and a subpopulation of intraepidermal dendritic cells strongly expressed CD40, mainly in benign lesions, in which T cell-keratinocyte interactions may be observed, and were restricted to epithelial cells expressing CD40. The lack of CD40 expression by tumor cells might account for tumor escape mechanism from activated T cells expressing the CD40 ligand.

Antigens, Neoplasm↗
PubMedDate not supplied

Expression of the intermediate filament peripherin in skin tumors.

Peripherin is a neuronal intermediate filament reportedly expressed in neuroendocrine skin carcinomas and some melanocytic tumors. In order to assess the diagnostic usefulness of antibodies to peripherin in dermatopathology, we studied its expression in 68 skin tumors mostly of neural origin, and compared this expression with that of neurofilaments, a well-established neuronal marker. Antibodies to peripherin and neurofilaments both labeled dermal neurons present in normal skin and within the tumors. Specific labeling of tumor cells for peripherin was seen in only 2/5 neuroendocrine skin carcinomas, 3/18 benign nevi and 7/19 melanomas; even in these cases the percentage of tumor cells did not exceed 20%. We conclude that antibodies to peripherin may be used for the demonstration of cutaneous neurons in normal and diseased skin; however their diagnostic usefulness appears limited, less than that of antibodies to neurofilaments.

Humans↗