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Basal cell carcinoma (BCC) of the skin is a locally invasive, rarely metastasizing epithelial tumor. In the current study, the expression of E-cadherin, alpha- and beta-catenin and CD44V6 in normal epidermis and on BCC cells were investigated. A significantly reduced expression of alpha-catenin and CD44V6 and a slightly reduced expression of E-cadherin on BCC cells were observed compared with the overlying epidermis. Immunoelectron microscopy was used to investigate whether the decreased expression of E-cadherin and CD44V6 was due to either an absence or downregulation of specific membrane structures or due to an overall downregulation of these adhesion molecules in all membrane structures in BCC. E-cadherin and CD44V6 were expressed in adherens junctions, desmosomes, and complex interdigitating membrane structures both in normal epidermis and in BCC. A quantitative analysis showed that only a percentage of desmosomes was stained. In addition, the effect of pro-inflammatory cytokines, such as interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), was investigated in biopsy specimens of normal skin and BCC, using a biopsy culture system and immunohistochemistry. The expression of E-cadherin and CD44V6 was not significantly decreased after culturing BCC or normal skin biopsy specimens for 48 hours with or without recombinant human (rHu)IFN-gamma or rHuTNF-alpha. It may be concluded that the decreased expression of both E-cadherin and CD44V6, observed in light microscopy, was not attributable to the absence of specific specialized structures in BCC and most likely also not caused by downregulation by local cytokines, but rather by generic downregulation of both of these adhesion molecules during malignant transformation.

Objective: To study the localisation of treponemes and to analyse the inflammatory infiltrate in biopsy specimens from patients with primary or secondary syphilis, or early infectious yaws., Materials and Methods: Skin biopsies originating from human lesions of primary (29x) or secondary (15x) syphilis (Rotterdam), or early yaws (18x) (West Sumatra) were studied. Different histochemical and immunohistochemical detection methods were used in this study., Results and Conclusion: The histochemical silver staining method according to Steiner revealed the presence of T. pallidum in all cases of primary syphilis studied. In 10 out of 14 cases of secondary syphilis, treponemes were demonstrated. With an immunofluorescence staining technique (IF) using anti-T. pallidum antiserum raised in rabbits (a-Tp), T. pallidum was demonstrated in 28 out of 29 cases of primary syphilis, and in 14 out of 14 studied cases of secondary syphilis. The silver staining method and IF showed identical localisations of T. pallidum (mainly in the dermal-epidermal junction zone or throughout the dermis). Using a-Tp antiserum in the indirect immunofluorescence technique, T. pertenue could be demonstrated in the dermis more often than with Steiner silver staining. However, epidermotropism of T. pertenue in yaws specimens was remarkable, compared with more mesodermotropism of T. pallidum; numbers of T. pertenue in the dermis were limited in all specimens. The dermal inflammatory infiltrate in primary and secondary syphilis was composed mainly of lymphocytes and plasma cells. In most cases more T (CD3 positive) cells than B (CD22 positive) cells were present. Regarding T cell subpopulations, in primary syphilis, T helper/inducer (CD4 positive) cells predominated in 86% of cases. In secondary syphilitic lesions, numbers of T helper/inducer cells were less frequent than or equal to T-suppressor/cytotoxic (CD8 positive) cells in 60% of cases. Remarkably, in yaws specimens the inflammatory infiltrate consisted mainly of IgG, but also IgA and IgM producing plasma cells. T or B lymphocytes were scarce, which is in sharp contrast with findings in syphilitic lesions.

Objective: To study ultrastructural aspects of infection with Treponema pertenue (Pariaman strain), originating from West Sumatra, Indonesia., Materials and Methods: Biopsy material originating from skin lesions in ten young children suffering from early infectious yaws in Indonesia, and rabbit testicular tissue inoculated with T pertenue. Human skin as well as rabbit testicular tissue was examined by means of conventional electron microscopy., Results: In human skin, treponemes were found in interepidermal spaces in 5 out of 10 specimens. In two of five positive specimens, treponemes were also seen in the dermis. In one out of five specimens from rabbit testicular tissue a profusion of treponemes was found lying in the interstitial myxomatous tissue. Microorganisms showed no adhesion to fibroblasts., Conclusion: This ultrastructural study of T pertenue demonstrated the scarcity and focal distribution of treponemes in tissue and did not reveal any morphological differences from the Gauthier strain of T pertenue. No differences from the ultrastructure of T pallidum were observed either.

We report a case of a 35-year-old female with a persistent pruritic acantholytic and dyskeratotic eruption on the chest and vulva. The light and electron microscopic studies showed suprabasal epidermal clefting with acantholysis and dyskeratotic cells. We suggest that the most appropriate term for this case is that of benign persistent papular acantholytic and dyskeratotic eruption.

This paper presents the light microscopic findings in biopsies of skin lesions from 45 patients, in whom a diagnosis of early yaws was suspected. In 27 cases typical light-microscopic features of yaws were observed, consisting of parakeratosis or crust containing exudate, marked acanthosis with widening and elongation of the rete ridges or pseudo-carcinomatous hyperplasia and spongiosis. Intraepidermal microabscesses consisting of polymorphonuclear leucocytes were frequently encountered. In a large majority a moderate to dense infiltrate was present, composed mainly of lymphocytes and plasma cells. Vascular changes consisted of only slight endothelial cell proliferation and thickening of vessel walls. Steiner staining revealed the presence of treponemes in the epidermis in 23 of 27 cases. Remarkably, clusters of treponemes were also seen in the papillary dermis in three out of 23 cases. Seven other cases were strongly suggestive of yaws. Other histopathological diagnoses were made in 6 patients, due to the simultaneous occurrence of other skin diseases. The remaining five specimens did not contain enough tissue to allow conclusions to be made.

The pathologic findings in the skin in a new case of toxic shock syndrome (TSS) are detailed and are discussed in view of previously reported data on TSS in the literature. Necrolysis of keratinocytes at different levels of the epidermis in combination with a predominantly perivascular lymphocytic infiltrate were characteristic features in lesional skin biopsy specimens obtained 5 days after the onset of acute illness and during the development of erythroderma with purpura and diffuse intravasal coagulation. Prominent vascular changes in the skin, which have not been reported before in TSS, were excited endothelial cells in combination with the presence of thrombi in the superficial capillaries. Histopathologic investigations of the dermatitis in TSS can be helpful in differentiating this syndrome from other acute toxic skin eruptions.