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Epidermal Tumor (epidermal + tumor)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Is there a special relationship between CD30-positive lymphoproliferative disorders and epidermal proliferation?

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2000
Yvana P. Cespedes
The relationship between CD30+ lymphoma and epithelial proliferations is not well defined. CD30+ lymphoma and lymphomatoid papulos (LyP) share immunohistochemical epitopes and some other features. A single case of LyP associated with multiple keratoacanthomas (KAs) was recently reported. We report two cases of atypical lymphocytic proliferation with features of CD30+ lymphoma and LyP intimately associated to KA and squamous cell carcinoma (SCC), KA type. This similar combination of an epidermal tumor and apparent involvement with atypical lymphocytic infiltrates raises the possibility of an association between the two entities. We speculate that the association may be more than expected to occur by chance and suggest several mechanisms by which the association may evolve. [source]

Down-Regulated PAR-2 is Associated in Part with Interrupted Melanosome Transfer in Pigmented Basal Cell Epithelioma

PIGMENT CELL & MELANOMA RESEARCH, Issue 4 2004
Kazuko Sakuraba
In pigmented basal cell epithelioma (BCE), there seems to be an abnormal transfer of melanized melanosomes from proliferating melanocytes to basaloid tumor cells. In this study, the interruption of that melanosome transfer was studied with special respect to the altered function of a phagocytic receptor, protease-activated receptor (PAR)-2 in the basaloid tumor cells. We used electron microscopy to clarify the disrupted transfer at the ultrastructural level and then performed immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to examine the regulation of a phagocytic receptor, PAR-2, expressed on basaloid tumor cells. Electron microscopic analysis revealed that basaloid tumor cells of pigmented BCE have a significantly lower population of melanosomes (,16.4%) than do normal keratinocytes located in the perilesional normal epidermis (,91.0%). In contrast, in pigmented seborrheic keratosis (SK), a similarly pigmented epidermal tumor, the distribution of melanin granules does not differ between the lesional (,93.9%) and the perilesional normal epidermis (,92.2 %), indicating that interrupted melanosome transfer occurs in BCE but not in all pigmented epithelial tumors. RT-PCR analysis demonstrated that the expression of PAR-2 mRNA transcripts in basaloid cells is significantly decreased in pigmented BCE compared with the perilesional normal epidermis. In contrast, in pigmented SK, where melanosome transfer to basaloid tumor cells is not interrupted, the expression of PAR-2 mRNA transcripts is comparable between the basaloid tumor cells and the perilesional normal epidermis. Immunohistochemistry demonstrated that basaloid cells in pigmented BCE have less immunostaining for PAR-2 than do keratinocytes in the perilesional normal epidermis whereas in pigmented SK, there is no difference in immunostaining for PAR-2 between the basaloid tumor and the perilesional normal epidermis. These findings suggest that the decreased expression of PAR-2 in the basaloid cells is associated in part with the observed interruption of melanosome transfer in pigmented BCE. [source]

Immunohistochemical comparison of ,-catenin expression by human normal epidermis and epidermal tumors

THE JOURNAL OF DERMATOLOGY, Issue 11 2007
Keiko FUKUMARU
ABSTRACT ,-Catenin, a cytoplasmic protein that binds directly to the intracellular domain of cadherin, controls various functions such as cell adhesion. In many human carcinomas, E-cadherin-mediated cell,cell adhesion is lost or disturbed and related to metastasis. The purpose of this study was to compare the expression of ,-catenin in the normal epidermal keratinocytes and samples from cutaneous benign and malignant epidermal tumors in 140 patients. Our study population consisted of 140 patients with benign or malignant epidermal tumors. Using immunohistochemical methods, we compared the expression of ,-catenin in their normal epidermal keratinocytes, and in samples from 61 benign (seborrheic keratosis, n = 33; verruca vulgaris, n = 14; keratoacanthoma, n = 14), and 79 malignant (Bowen's disease, n = 18; basal cell carcinoma, n = 33; squamous cell carcinoma, n = 28) epidermal tumors. ,-Catenin was found to be expressed in the cell membrane of normal keratinocytes. Compared to other cell components of the normal epidermis, basal cells showed the strongest ,-catenin expression in all 140 patients. While absent in three of 61 benign tumors, compared to normal basal cells, the expression of ,-catenin in the other 58 tumors was not significantly different; it was reduced in 71 of 79 malignant tumors (P < 0.0001). In Bowen's disease, the expression of ,-catenin on the tumor cell membrane was reduced, however, strong expression was seen in the nuclei and cytoplasm. Our results suggest that ,-catenin expression on the membrane of keratinocytes is associated with the differentiation of normal keratinocytes but not with their stage of differentiation, nor with the proliferation ability of epidermal tumor cells. [source]