摘要:

A causative role of UV light in the development of melanocytic neoplasms has often been suggested. In order to investigate the short-term effects of UV light on melanocytic nevi. the morphological and immunohistochemical changes in nevi after a single UV irradiation are studied in 12 nevi from 10 patients and compared with the nonirradiated part of the same nevus. After irradiation more melanocytes above the dermal-epidermal junction are observed in seven nevi. simulating a melanoma in situ in three nevi. Moreover, a marked increase in the expression of HMB-45 is found after irradiation in all investigated nevi, indicating an activation of the melanocytes and active melanosome formation. The metabolic activity correlates with the ultrastructural findings, which show a large cytoplasm, hypertrophic Golgi apparatus, abundant mitochondria, and an increased number of mclanosomes of different stages. One week after irradiation, no increase in the proliferative activity of the melanocytes is found. The morphological and immunohistochemical changes after one low dose of UV irradiation should be considered in the differential diagnosis of pigmented skin lesions. The UV-irradiated nevus should be added to the list of so-called simulators of malignant melanoma.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

bcl-2 is a proto-oncogene belonging to a new category of oncogenes that are not involved in the mechanisms of cell proliferation but instead influence tissue homeostasis regulating cell death. The gene encodes for a protein that preserves cells from death by apoptosis, allowing them to survive in Gophase even in the absence of essential growth factors. The expression ofbcl-2protein has been observed in most follicular lymphomas and in ∼25% of high-grade non-Hodgkin's lymphomas. as well as in solid tumors such as carcinomas of the lung, prostate, and nasopharynx. In this study, we analyzedbcl-2protein expression in cutaneous malignant melanoma (MM) (29 cases) and benign melanocytic nevi (BMN) (35 cases) using a highly specific anti-bcl-2monoclonal antibody with a standard three-step immunoperoxidase technique on formalin-fixed, paraffin-embedded tissue sections. High levels ofbcl-2protein were observed in 27 of 29 MM (93.1%) and 33 of 35 BMN (94.3%). Our results indicate thatbcl-2protein expression is a common finding in cutaneous melanocytic lesions regardless of their biologic behavior. Expression of the protein in the great majority of MM seems to exclude a prognostic significance ofbcl-2in MM of the skin.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

A stepwise schema for the developmental biology of malignant melanomas has been proposed. In this study, two properties associated with malignant transformation— AgNOR production and Ki-67 immunoreactivity—were tested on a series of lesions representative of this model. Fourteen ordinary nevi (N). seven dysplastic nevi (DN), 12 radial growth phase melanomas (RGPM). and eight vertical growth phase melanomas (VGPM) were stained for AgNORs; Ki-67 immunoreactivity was determined in paraffin sections after antigen retrieval. AgNORs averaged 2.1 in N. 3.8 in DN. 5.4 in RGPM. and 7.3 in VGPM (p < 0.001 between all groups). Ki-67 immunoreactivity averaged

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Annular lesions with histological changes that include a sarcoidal granulomatous reaction have been observed within hydroquinone-induced ochronotic changes in some patients. The clinical and histological similarity of these lesions to actinic granuloma has been reported previously. We describe six patients with annular granulomatous lesions located within the ochronotic areas. Three of them had evidence of systemic sarcoidosis. A comparison of the histological features of the annular lesions of this group with those of the three patients with only cutaneous sarcoidal changes showed only insignificant quantitative differences. We conclude that annular granulomatous lesions in patients with exogenous ochronosis is a form of sarcoidosis.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Epidermolytic hyperkeratosis is the distinctive histopathologic change that has been described as the main feature of bullous congenital ichthyosiform erythroderma and as an incidental finding in other cutaneous disorders. We retrospectively evaluated our cases of incidental epidermolytic hyperkeratosis over a 5-year period and reviewed the conditions that have been associated with incidental epidermolytic hyperkeratosis. We identified 21 individuals (14 men and seven women), ranging in age from 3 to 87 years, in whom incidental epidermolytic hyperkeratosis was found. Lesions in which the pathologic changes of incidental epidermolytic hyperkeratosis have been reported include dermal fibrohistiocytic lesions, epithelial neoplasms, hereditary disorders, inflammatory conditions, and melanocytic neoplasms. The histogenesis of incidental epidermolytic hyperkeratosis remains to be determined.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Cutaneous patch and plaque lesions, and erythroderma may suggest mycosis fungoides both clinically and histopathologically in HIV+ patients. However, in some cases, this diagnosis is questionable. Five such cases are presented. When we compared these cases with cases of mycosis fungoides unassociated with HIV infection, we found less concordance among dermatopathologists in making a histopathological diagnosis, a greater proportion of CD8 than CD4 T cells in the cutaneous infiltrates, and no instances of demonstrated clonality of the cutaneous T-cell infiltrates in the HIV + group. We conclude that CD8 T-cell predominant dermatoses may simulate mycosis fungoides in HIV + patients.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Mixed tumors of the skin are characterized by a proliferation of epithelial cells embedded in a mesenchymal matrix with a wide spectrum of histologic appearances. The characterization of the extracellular matrix components of mixed tumors of the skin has so far received little attention. We performed an immunohistochemical study of type IV collagen, laminin. fibronectin. and tenascin distribution in a series of 10 mixed tumors of the skin. Laminin localized at the basement membrane around solid epithelial nests and tubulo-alveolar structures, whereas type IV collagen, fibronectin, and tenascin were also expressed in the myxoid stroma. Tenascin and fibronectin localized in the chondroid matrix. The extracellular matrix components were prominently expressed in mixed tumors of the skin. suggesting that they could play an important role in the formation and organization of myxoid and chondroid matrices and in the epithelialmesenchymal interactions of these tumors.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

We studied 11 cases of mixed tumor of the skin with a polyclonal antibody against human type II collagen. Two of the cases were of the eccrine type, six were apocine, and three were malignant. In all of the benign cases of mixed tumor and in some of the malignant type, “chondroid” and mucinous portions stained. The clearly epithelial portions of the tumor stained as well, and staining was most intense in the eccrine types and least intense in the malignant types. The positive staining in mixed tumors may help elucidate the histogenesis of these unusual tumors as well as help differentiate among the various subtypes.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Dermatitis herpetiformis has a characteristic histologic pattern consisting of subepidermal blisters often containing fibrin, infiltrates of neutrophils and nuclear dust at tips of dermal papillae, and papillary dermal edema. These are features of early and evolving lesions. We present two cases of clinically typical dermatitis herpetiformis with previously unreported histologic features that may provide a significant diagnostic clue. In each of these cases there were focal collections of nuclear dust in the cornified layer of the epidermis, a finding that may represent a resolving phase of dermatitis herpetiformis. beyond the usual papillary dermal neutrophilic microabscesses seen in early lesions. Biopsy material was available for immunofluorescent studies in one of the cases presented. In addition to the granular pattern of IgA positivity at the dermal-epidermal junction, which is diagnostic of dermatitis herpetiformis. this biopsy also showed similar IgA positivity in the intracorneal nuclear dust aggregates. In the second case, initial sections showed only intracorneal nuclear dust, but at deeper levels there were more typical diagnostic microabscesses at the tips of dermal papillae.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

A 78-year-old man had a I-cm cutaneous nodule on his shoulder; subsequent excisional biopsy showed osteosurcoma. There was no connection to deeper structures, and no primary bone lesion was found. The tumor recurred at the same site 9 months after diagnosis and was reexcised. We believe this to be the first well-illustrated case of primary cutaneous osteosarcoma, which should now be included on the list of sarcomas that may occur in the skin.

ISSN:0193-1091    

出版商:OVID    

年代:1995

数据来源: OVID