摘要:

Squamous metaplasia of the upper portion of the sweat ducts has been observed in four patients who received chemotherapy; two patients with acute myelogenous leukemia, one patient with testicular carcinoma, and one patient with anaplastic carcinoma of the lung. This change is different (but perhaps related) from what is described in neutrophilic eccrine hidradenitis in patients with acute myelogenous leukemia and other tumors after chemotherapy. Syringosquamous metaplasia may be confused with well differentiated squamous cell carcinoma histologically.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

We report 18 cases of primary cutaneous neuroendocrine carcinoma (CNEC, Merkel cell tumor) that occurred mainly in the sun-exposed skin of elderly patients as dermal and subcutaneous masses of generally monomorphic cells with foci of pronounced pleomorphism. All 18 cases showed immunoreactivity for neuron-specific enolase (NSE), whereas 16 of them showed immunoreactivity for another neuroendocrine marker, protein gene product 9.5 (PGP 9.5). Positivity for PGP 9.5 was more intense and more sharply localized to tumor cells than the staining for NSE. Immunoreactivity for keratins detected by AE1/AE3 and CAM 5.2 monoclonal antibodies was found in 16 and 15 cases, respectively, with prominent paranuclear globular staining. One case stained positively for S-100 protein; all were negative for leukocyte common antigen (LCA). Typical ultrastructural features of neuroendocrine differentiation were noted in all of 14 tumors examined. Morphological and immunohistochemical similarities between these neoplasms and pulmonary small-cell anaplastic carcinoma, now thought to be of bronchial basal cell origin, suggest that CNEC are also derived from epithelium. In addition, their dermal location suggests that this epithelium is likely to be adnexal rather than epidermal.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The microtubulus system as a part of the cellular cytoskeleton contributes to cell movement. Microtubulus assembly and disassembly is considered to be essential for tumor invasion and serves as a target for tumor chemotherapy. Using immunohistochemical methods, we investigated the distribution of tubulin in normal skin and 34 melanocytic skin tumors. In normal skin, tubulin was strongly expressed in dermal nerves, melanocytes, fibroblasts within the papillary dermis and in myoepithelial cells. In melanocytic skin tumors, nevus cells and melanoma cells stained positive, particularly at the periphery of the lesions, where there were single cells and small nests. The main difference between benign and malignant melanocytic tumors was found in the stromal cells: In melanocytic nevi, the stromal fibroblasts were entirely tubulin negative; whereas, adjacent to the invasive edge in primary and metastatic malignant melanoma, the stroma fibroblasts were strongly positive. Our results show that tubulin is regularly expressed in melanocytic skin tumors and may serve as a prerequisite for cell movement. The pronounced expression of tubulin in fibroblasts surrounding malignant melanocytic skin lesions reflects a stromal alteration that might contribute to tumor invasion.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Paraffin-embedded material from 26 cases of dermatofibrosarcoma protuberans (DFSP) was investigated by the peroxidase-antiperoxidase technique. Antibodies to S-100 protein, Leu-7 antigen, and neuron-specific enolase (neural markers); to lysozyme, $aP-1-antitrypsin, and $aP-1-antichymotrypsin (histiocytic markers); and to cytokeratin, desmin, vimentin, and factor VIII were used. The tumor cells reacted only for vimentin. In addition, 12 cases showed positive reactions with histiocytic markers (1–3% of the cells; in two cases, up to 10%). These results support a fibroblastic and contradict a neural or histiocytic histogenesis of DFSP.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Lectins are glycoproteins that bind to specific carbohydrate groups on cell surfaces. Peanut lectin (PNA) binds to carbohydrates on the membranes of normal keratinocytes. Recently, some authors have proposed that PNA may be a useful marker to help differentiate keratoacanthomas from well-differentiated squamous cell carcinomas of the skin. We studied a total of 34 skin biopsy specimens, including 11 keratoacanthomas, 15 well-differentiated squamous cell carcinomas, and 8 poorly differentiated squamous cell carcinomas, using peanut lectin with the avidin-biotin complex (ABC) peroxidase technique. All keratoacanthomas demonstrated uniform positive membrane staining of keratinocytes, which was identical to PNA staining in normal skin. Keratinocytes in 80% of the well-differentiated squamous cell carcinomas and keratinocytes in all the poorly differentiated squamous cell carcinomas did not stain. With prior digestion by neuraminidase, however, positive membrane staining for PNA was demonstrated in the squamous cells of all well-differentiated squamous cell carcinomas and all but one case of the poorly differentiated squamous cell carcinomas. Our results support the efficacy of PNA in most cases as a marker to aid in the often difficult histologic differentiation of keratoacanthoma from well-differentiated squamous cell carcinoma. Our findings also support those of previous authors who suggested that the negative PNA stain of malignant squamous cells is not the result of a lack of PNA receptors, but is due instead to a masking of receptor sites by terminal sialic acid residues.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Residual groups of hair follicles and unusual “tufts” of multiple hairs emerging from single follicular openings have been described in scarring alopecia associated with staphylococcal infection. Various mechanisms have been proposed to explain these findings. Histological study of four cases suggests that retention of telogen hairs through several hair cycles may be responsible for this phenomenon.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

We quantified the histologic features of 100 consecutive dysplastic nevi. Although there is heterogeneity in the microscopic attributes of dysplastic nevi, certain features that are seen repeatedly should enable the histologic identification of these melanocytic neoplasms. These features include a central dermal nevocytic component with a peripheral extension of a junctional component, elongated epidermal rete ridges, bridging of nests of melanocytes at the dermo-epidermal junction, nests of melanocytes at the sides of rete ridges as well as at their bases, and concentric eosinophilic fibrosis. Cytologic features of melanocytes were not as valuable as architectural features of individual nevi in classifying these lesions. We also provide an atlas of selected histologic features that depicts some aspects of this heterogeneity.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The fine structure of healthy and of psoriatic skin was studied after dithranol irritation. Following a minimum erythematogenic or a moderate-to-considerable irritant reaction of healthy skin with dithranol, all epidermal cell types were focally affected. The Langerhans' cells (LC) were most sensitive, reacting with strongly swollen mitochondria with broken cristae, and sometimes by forming branched and circular Birbeck granules. More often than is normal, the Birbeck granules showed continuity with the LC cytomembrane. Also, melanocytes were more sensitive than keratinocytes. Most of the more strongly affected keratinocytes became cytolytic with edemic cytoplasm, but scattered cells underwent dyskeratosis (apoptosis) resulting in colloid bodies in the upper dermis. High amounts of lipid droplets developed in the basal keratinocytes, LCs, melanocytes, and dermal cells. Lipid droplets also developed in the keratinocytes at the stratum granulosum/stratum corneum interface concomitantly with a decrease in keratohyalin. Ten days after challenge, keratohyalin granules were normal again, but otherwise many changes in epidermis persisted, with increased numbers of exocytic cells and LC-mononuclear cell contacts in the epidermis and immunocompetent cells crossing the dermal-epidermal junction. These findings indicate that an irritant reaction could predispose to sensitization via nonspecifically activated immunocompetent cells. A single half-hour contact treatment with dithranol caused negligible changes in the psoriatic skin, while 24 hours' occlusion caused moderate-to-massive changes in mitochondria of keratinocytes, resulting in giant perinuclear mitochondria with broken cristae. Dithranol affects all cell types in the skin and morphologically it cannot be concluded which effect is the important one in clearing the psoriatic lesions.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

We report a new case of mixed infection occurring at the same site of the skin in a human immune deficiency virus-positive patient. Hyperkeratotic and crusted erosions contained fusospirochetal organisms,Cryptococcus neoformans, and another unidentified fungus.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A case of follicular lymphomatoid papulosis was studied by light- and electron-microscopic methods. The nature of atypical cells was analyzed with monoclonal antibodies. This case proved to be mainly a type B lymphomatoid papulosis with a predominance of T-helper markers in atypical lymphoid cells. All previously reported cases of this rare variant corresponded to type A lymphomatoid papulosis. Therefore we believe this to be the first case report of type B follicular lymphomatoid papulosis.

ISSN:0193-1091    

出版商:OVID    

年代:1990

数据来源: OVID