摘要:

&NA;Nine cases of an unusual presentation of atypical fibroxanthoma that we previously termed pigmented atypical fibroxanthoma are reported. Pigmented atypical fibroxanthoma can be easily mistaken for malignant melanoma both clinically and histopathologically. The resemblance of pigmented atypical fibroxanthoma to melanoma is secondary to the ability of neoplastic cells to ingest and degrade erythrocytes following intratumoral hemorrhage and to accumulate hemosiderin in their cytoplasm. The histopathologic diagnosis of pigmented atypical fibroxanthoma can be easily confirmed by immunohistochemistry and iron stain.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;DNA microarrays, microscopic grids of DNA, can be used to assess gene expression within a particular cell or cell population. Since DNA from thousands of genes can be hybridized and analyzed in one experiment, researchers can globally characterize genes expressed in normal and various pathologic states. To accurately assess the differences between normal and pathologic states, one derives cDNA from control and diseased tissue specimens for genes expression profiling. For these reasons, microarray technology may be of particular interest to dermatopathologists and dermatologists interested in understanding cutaneous disease because these physicians have access to tissue specimens. In addition, microarray technology is an efficient way of identifying molecules expressed in a cell population; therefore, it can be used to search for unique immunohistologic markers. To this end, we have used microarray technology to define differences in the gene expression profile of nevi and melanomas. In this manuscript, we discuss the results of our study, which confirm previously known differences in gene expression between melanoma and nevi. While a few genes appear slightly overexpressed in nevi, a number of genes involved in regulating cell proliferation were upregulated in melanoma, such as cyclin D1, cdc2‐related protein kinase, c‐Myc binding protein, early growth response protein 1, and pleiotrophin. “Housekeeping” genes such as glyceraldehyde 3‐phosphate dehydrogenase were expressed at similar levels in melanoma and nevi. Surprisingly, a majority of genes were expressed at similar levels in both nevi and melanoma. Based on this study, DNA microarray technology appears to be a valuable tool for identifying genes that may be specifically expressed in cutaneous lesions.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Oral melanoacanthoma (MA) is rare reactive mucosal lesion that, like cutaneous MA, demonstrates hyperplasia of spinous keratinocytes and melanocytes. Unlike MA of the skin, oral MA is unrelated to seborrheic keratosis. This series adds 10 cases to the limited number of previous reports of oral MA. The clinicopathologic features of the cases in this series are generally consistent with those previously reported in the literature; that is, although documented in various intraoral locations in patients of differing ethnicity, oral melanoacanthoma most often presents as an enlarging flat or slightly raised area of hyperpigmentation on the buccal mucosa of adult black women. The current series provides evidence of occurrence over a wider age range (5–77 years) than previously reported. Additionally, the reactivity of oral melanoacanthoma to HMB‐45 was investigated. Strong HMB‐45 reactivity was present in all cases, thus demonstrating its limited utility in distinguishing oral MA from malignant melanoma.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Vitiligo is a disease of melanocytes characterized by achromic lesions in the skin, affecting the epidermis and the pilosebaceous follicle. We performed an ultrastructural analysis of biopsy specimens from four patients with noninflammatory, stable vitiligo of long duration (three had generalized vitiligo and one had segmental vitiligo). The samples were taken from the oldest achromic lesions, and the biopsy sites were far from normal skin. In all cases we noted alterations in keratinocytes, Langerhans cells, and melanocytes. We also found lymphocytes in the epidermis, and these cells and macrophages were noted in the dermis. The basal membrane disappeared at some points, and sometimes it was possible to see dermal cells with processes that engulfed either granular material or vesicles of epidermal origin in such areas. Our studies suggest that even in stable vitiligo, achromia implies intense cytologic activity, probably involving cell‐mediated cytotoxicity, and ultrastructural findings resemble those of a lichenoid reaction.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Malignant blue nevus is a rare melanocytic tumor that is described by some authors as a variant of malignant melanoma, whereas others regard it as a distinct entity. To our knowledge no molecular studies of this tumor have been performed, although the molecular pathogenesis of conventional melanomas has been extensively described. We present a case of malignant blue nevus that developed in a 15‐cm congenital blue nevus on the back of a 41‐year‐old man. Subsequent regional lymph node and lung metastases developed within 1 and 29 months, respectively. We performed a molecular analysis for loss of heterozygosity on microdissected samples from the spectrum of benign to malignant blue nevus, using a panel of eight genes (MTS1, MXI1, CMM1, p53, NF1, L‐myc,hOGG1, and MCC), many of which are commonly associated with conventional melanomas. No loss of heterozygosity was detected, despite informativeness in seven genes. We suggest that malignant blue nevus may represent a distinct entity with a different molecular pathway to tumorigenesis than that of conventional melanomas.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Kaposi's sarcoma is a neoplastic vascular lesion. Its form of onset is frequently disseminated, especially in HIV‐positive patients. Its association with the infection caused by a virus of the Epstein‐Barr family, human herpesvirus 8 (HHV‐8), has been recently demonstrated. In this article we discuss the unusual presentation of a solitary manifestation of Kaposi's sarcoma on the penis of a 53‐year‐old HIV‐negative patient. Polymerase chain reaction analysis of the tumor tissue was positive for HHV‐8 in the tumor cells but not in the reactive stroma cells surrounding the tumor. The case is interesting for its unusual site of presentation, the young age of onset, the association with HHV‐8 infection, the HIV‐negative serology, and the benign course of the disease.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;We report a case of schwannoma (neurilemmoma) predominantly composed of small cells arranged in rosettes around central collagenous cores and discuss the differential diagnosis of this unusual variant. Schwannoma with giant rosettes, previously designated as neuroblastoma‐like schwannoma by Goldblum et al., must be differentiated from neuroblastoma, peripheral neuroectodermal tumors, and malignant change in a schwannoma.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Rosette formation is a feature that has not been described as occurring in melanocytic neoplasms. We present such a unique case. A 59‐year‐old man presented with an asymptomatic, soft, hairy 3.0 × 2.0‐cm pigmented lesion that had been present for many years in the right external ear, extending from the conchal bowl onto the antitragus area. Examination of histologic sections showed a proliferation of nonatypical and heavily pigmented melanocytes in the superficial dermis and around deep adnexal structures, characteristic of a congenital nevus. In other areas, pigmented spindled and dendritic cells infiltrated thickened collagen bundles in a pattern of a blue nevus. A nodular proliferation of epithelioid melanocytes was seen within the deep dermis and subcutaneous tissue. The periphery of the nodule merged with the surrounding nevus cells. Neoplastic cells with nuclear atypia, melanin pigment, pseudonuclear inclusions, and balloon cell change were present. In addition, there was rosette formation by the tumor cells, with a central aggregate of coarse cell processes. Neuroid cords were also noted. No prominent mitotic figures, necrosis, or significant inflammatory infiltrate were noted. The neoplastic cells were positive for S‐100 protein, Mart‐1, tyrosinase, neuron‐specific enolase, and vimentin. HMB‐45 and Ki‐67 (MIB‐1) labeled only rare neoplastic cells within the proliferative nodule. The tumor cells were negative for synaptophysin, protein gene product 9.5, CD57, epithelial membrane antigen, CD31, and CD34. The central cell processes of the rosettes were negative for trichome, type IV collagen, neurofilament protein, glial fibrillary acidic protein, and tyrosine hydroxylase. We also retrospectively examined 78 congenital nevi of 65 pediatric patients at our institution. Rosette formation was not seen in any of these cases.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Ganglioneuroblastic differentiation in malignant melanomas is an exceedingly rare event. Although there has been a single report of this occurrence in a metastatic melanoma, divergent ganglioneuroblastic differentiation has not been documented previously in a primary cutaneous lesion of melanoma. The present report describes an unusual case of invasive melanoma arising on the lower leg of a 61‐year‐old woman. The 16.9‐mm thick tumor showed extensive ganglioneuroblastic differentiation, which was confirmed both immunohistochemically and ultrastructurally. Although the prognostic significance of this observation remains uncertain, the unique case reaffirms the potential morphologic diversity of melanomas and suggests a shared histogenetic origin from a common neural crest derivative.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

&NA;Embryonal rhabdomyosarcoma is the most common soft tissue sarcoma of childhood but is rarely seen in adults. We report an embryonal rhabdomyosarcoma of the cheek in a 21‐year‐old Filipino man presenting as a rapidly enlarging mass. An incisional biopsy was consistent with embryonal rhabdomyosarcoma. The patient failed to respond to one cycle of chemotherapy after initial diagnosis and workup for metastatic disease. Wide local excision of the tumor was then completed with the use of the Mohs technique to clear the glabrous cutaneous margins during surgery. A Mohs surgeon and dermatopathologist were involved in interpretation of the Mohs sections. Subsequent immunohistochemical staining revealed a poorly differentiated spindled and epithelioid cell tumor, which stained diffusely positive for vimentin, S‐100, and MyoD1. Rare rhabdomyoblasts were present and stained positively for desmin, musclespecific actin, and phosphotungstic acid hematoxylin. The patient subsequently underwent radiation therapy for a total of 6,000 cGy, followed by two cycles of chemotherapy. The patient continues to be disease‐free at 22 months after his wide local excision.

ISSN:0193-1091    

出版商:OVID    

年代:2003

数据来源: OVID