摘要:

Epidermodysplasia verruciformis (EV) is a rare disease characterized by a generalized cutaneous infection with human papillomaviruses (HPVs) and a propensity for transformation of the lesions to squamous cell carcinomas on sun-exposed areas of the skin. Black-skinned patients with EV have a much lower incidence of skin cancer. Nine of 32 black African patients with EV presented deeply pigmented, flat or slightly raised lesions, located mostly in sun-exposed areas, that clinically had been diagnosed as seborrheic keratoses. Seborrheic keratoses are otherwise very rare in black Africans. Histology of these lesions disclosed seborrheic keratoses, lesions with seborrheic keratosis, and EV changes in the same biopsy specimens and seborrheic keratoses with features of bowenoid dysplasia. Reverse blot hybridization indicated the presence of DNA related to the HPV-5 group of papillomaviruses in seborrheic keratoses in three patients. Subsequent Southern blot analysis revealed a DNA that was related but not identical to any of the papillomaviruses in this HPV-5 group. The fourth lesion studied a few years earlier contained HPV-5c. The question arises whether a different type of HPV is responsible for development of these tumors in black patients with EV.

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Cutaneous neuroblastoma (CN) is a rare tumor in adults. Histologically CN can be confused with other small, round cell tumors, especially with Merkel cell tumor. This is the second case that we have encountered in a 6-year period. A 46-year-old man with severe adult respiratory distress syndrome had a 2.5 × 2.0 × 2.0-cm, rapidly growing, fleshy nodule over his nose. The clinical impression was pyogenic granuloma (PG) or keratoacanthoma (KA). Histologically, the tumor showed undifferentiated cells with frequent Homer Wright rosettes and mitoses. Conventional special stains and a broad panel of immunohistochemical markers were applied that were positive only for neuron-specific enolase. Ultrastructurally the cells contained dense-core granules and immature desmosomes. The diagnosis of CN was made and an extensive radiologic and laboratory workup was initiated, but the results were negative for another primary tumor. The patient subsequently died and a thorough postmortem examination revealed multiple visceral metastatic lesions but no primary tumors in the adrenal glands, the sympathetic chain, or the central nervous system. Conclusions: (a) CN does occur in adults and can mimic other fast-growing tumors of the skin, for example, PG or KA; (b) the diagnosis of CN requires the combined use of immunohistochemistry and electron microscopy; and (c) the dermatologist should be aware of this rare, but important, tumor because its primary cutaneous manifestation may enable early recognition.

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We describe two cases of malignant schwannoma in the skin that did not originate from a nerve trunk and was not associated with neurofibromatosis. Light microscopy showed that both tumors were composed predominantly of atypical spindle-shaped cells. Immunohistochemical analysis was performed with various monoclonal antibodies against mesenchymal determinants. In both patients, tumor cells were positive for S-100α and S-100β, neuron-specific enolase, vimentin, neurofilament protein, and myelin basic protein, and negative for HMB-45, glial fibrillary acidic protein, epithelial membrane antigen, and desmin. Electron microscopy revealed that the tumor cells possessed indented nuclei with an electron-lucent cytoplasm. Immunoelectron microscopy showed diffuse fine granular staining for S-100α, not detectable in normal Schwann cells, in the cytoplasm of the tumor cells.

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Loricrin is a glycine-, serine-, and cysteine-rich protein expressed very late in epidermal differentiation in the granular layers of normal human epidermis. Subsequently, loricrin becomes cross-linked by the activity of transglutaminases TGK/E as a major component of the cornified cell envelope by N-(γ-glutamyl)lysine isopeptide bonds. In this study, 115 biopsy specimens from patients with various cutaneous diseases with a morphologically altered epidermal differentiation were analyzed with use of immunohistology with antibodies to loricrin and to involucrin. In addition, antibodies to filaggrin were used for ichthyotic lesions. In contrast to involucrin, loricrin expression was consistently down-regulated in agranulotic, parakeratotic keratinization as observed in psoriasis, dermatitis, pityriasis lichenoides, porokeratosis, or precancerous and malignant squamous lesions. High levels of loricrin were found in hypergranulotic and hyperorthokeratotic epidermis as observed in lichen planus, benign papillomas, and pseudocarcinomatous hyperplasia. Eleven biopsy specimens from patients with ichthyosis vulgaris showed a normal staining in the granular layers. Our results demonstrate that loricrin expression is closely linked to an orthokeratotic phenotype of human epidermal keratinization. The different expression patterns of loricrin and involucrin provide further evidence that these proteins are regulated by different mechanisms and serve different functions during terminal epidermal differentiation.

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Pyoderma gangrenosum is a well-known clinical cutaneous condition, that has had a variety of conflicting microscopic descriptions. In an attempt to further our understanding of this condition, we obtained nine skin biopsy specimens of evolving, fully developed, regressing, and resolved lesions from six patients with pyoderma gangrenosum. We found that histopathologically, pyoderma gangrenosum evolves from folliculitis and abscess formation; it may also show leukocytoclastic vasculitis. The lesions then evolve to suppurative granulomatous dermatitis and finally regress with prominent fibroplasia. We illustrate the clinical and microscopic features herein and compare them to previous descriptions.

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0193-1091    

出版商:OVID    

年代:1993

数据来源: OVID