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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a 37-year-old man with neurothekeoma that developed on the tip of the nose. Histopathological examination revealed a lobulated myxoid dermal tumour. The tumour cells were spindle-shaped or bizarre configuration. In the lower part of the dermis the lesion contained abundant cells simulating glomus tumour or melanocytic naevus. Staining with S-100 protein, epithelial membrane antigen (EMA), neuron-specific enolase (NSE) and desmin were negative. The matrix of the tumour was positive for Alcian blue and periodic acid-Schiff (PAS). Electron microscopic examination showed that the lesion was composed of dendritic cells separated by abundant glassy matrix and varying amounts of collagen fibres. Some of the cells looked like fibroblasts, and others like perineurial cells. The histogenesis of the tumour is discussed with particular attention to histochemical, immunohistochemical, light and electron microscopic findings.
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PMID:[Neurothekeoma. A light and electron microscopy, histochemical and immunohistochemical study]. 147 72

Human Merkel cell regeneration in epidermis derived from cultured keratinocyte autografts was studied from 6 days to 6 years after transplantation. Cultured keratinocyte sheets derived from skin of the sole, axilla, groin, or scalp were transplanted to full-thickness wounds in 20 pediatric patients treated for massive burns or giant congenital nevi. Normal age- and site-matched skin as well as meshed split-thickness autografts from the same patients served as controls. Merkel cells were identified by immunohistochemistry using antibodies to cytokeratins #8 and #18. Cultured keratinocytes in vitro expressed no neuroendocrine markers, but nonspecific, simple-epithelial cytokeratin expression was observed in about 20% of cells. After transplantation, Merkel cells were identified only in cultured grafts derived from sole skin and appeared in the epidermis as early as 21 days postgrafting. Dermal Merkel cells were rarely observed, but their appearance invariably succeeded that of intraepidermal Merkel cells. Regenerated Merkel cells were never innervated, and their emergence was unrelated either spatially or temporally to epidermal reinnervation. In skin bridges of meshed split-thickness grafts, Merkel cells survived after degeneration of associated neurites, but no Merkel cells appeared within re-epithelialized interstices. Among the neuroendocrine markers tested, Merkel cells in cultured grafts, meshed skin grafts or normal pediatric skin expressed only neuron-specific enolase. They failed to stain for calcitonin, chromogranin A, Leu-7, synaptophysin, bombesin, or vasoactive intestinal polypeptide by immunohistochemistry. These findings suggest that: (a) Merkel cells derive from keratinocyte precursors which undergo neuroendocrine differentiation in the epidermis; (b) that keratinocyte stem cells are capable of undergoing Merkel cell differentiation postnatally; (c) that postnatal Merkel cell differentiation may be body-site dependent; and (d) that Merkel cell development and maintenance is independent of neural induction.
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PMID:Human Merkel cell regeneration in skin derived from cultured keratinocyte grafts. 169 32

The authors compared the immunohistochemical reactivity of 13 uveal nevi and 20 uveal melanomas for HMB-45, S-100 protein, and neuron-specific enolase (NSE) in formalin-fixed, paraffin-embedded sections. All 33 of the lesions were positive for HMB-45. The false-negative rates for S-100 protein and NSE were 21% and 18%, respectively. If only strongly positive reactions were considered, more than 50% of the tumors would be interpreted as negative for S-100 protein and NSE. Nevi stained with less intensity than melanomas using all three antibodies. The expression of HMB-45 appeared to be greater in active nevi than in inactive nevi. There was a weak association between S-100 protein reactivity and the ability of the uveal melanomas to metastasize (P = 0.1); however, the standard deviation of nucleolar area was a much better predictor (P = 0.02). These results indicate that pathologists will find HMB-45 to be a useful tool in differentiating uveal melanoma from nonmelanocytic tumors.
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PMID:Immunohistochemical evaluation of uveal melanocytic tumors. Expression of HMB-45, S-100 protein, and neuron-specific enolase. 185 81

The author has performed study on the histogenesis of the nevus cells in the nevocellular nevi. In the study, specimens of the intradermal nevi in 124 cases were evaluated histologically and immunohistochemically and the following results were obtained: 1) Findings of hematoxylin eosin staining It was observed that three types of cells, including type A cells (epidermoid type cells), type B cells (lymphoid type cells), type C cells (neuroid type cells) were found to run through an intermediate stage from the upper part to the lower part of the nevocellular structure, although they disclosed different histological structures. In 39 (31.5%) of the 124 cases, Meissner's corpuscle-like cells were confirmed. 2) Findings of immunohistochemical staining i. Of the type A, type B and type C cells, the S-100 alpha protein stain was essentially negative. Meissner's corpuscle-like cells were selectively positive by this stain. ii. Although no particular difference was noted in the staining of S-100 protein between the type A and type B cells, a somewhat greater proportion of positive cells was noted in type C cells. In the Meissner's corpuscle-like cells, a notably higher positive conversion of cells was observed as compared to those of the three other types of cells. iii. Type A, type B and type C cells compared more or less similarly for the positive ratio of neuron-specific enolase but the ratio was unusually high in the Meissner's corpuscle-like cells. 3) Findings from routine electron microscopic staining i. Similar to the light microscopic findings, the nevus cells were found to change in shape uninterruptedly from the upper layer to the lower layer of the dermis. Unusually marked changes were noted both in the number and shape of the melanosome and premelanosome in the cytoplasm. ii. In the Meissner's corpuscle-like cells both melanosomes and premelanosomes were missing but a finding suggestive of a neuroid structure was affirmed. As noted above, the results of the histological, immunohistological and electron microscopic studies were in support of the general findings suggestive of a gradual shift of the nevus cells from the upper layer to the lower layer in the dermis, which prompted the author to support the so-called "neural crest origin hypothesis".
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PMID:[Histological and immunohistochemical studies on nevocellular nevi in the dermis. With special reference to the histogenesis of nevus cells]. 232 79

A 4-year-old Japanese girl with a nonpigmented nodule on the anterior portion of the palate since birth is described. The overall microscopic appearance of the lesion was very similar to that of Spitz nevus of the skin. Diagnosis of Spitz nevus (mixed epithelioid cell and spindle cell nevus) was made on the basis of the clinical and histologic criteria for differentiating this lesion from malignant melanomas and common compound nevi. Positive immunostaining of epithelioid and spindle cells for S-100 protein and neuron-specific enolase was also indicative of their nevocellular nature. Review of the cases of Spitz nevus from the literature revealed that the present case most probably represents the first reported instance of this type of nevus in the oral cavity.
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PMID:Spitz nevus of the palate. Report of a case. 233 13

The malignant transformation of congenital nevocellular nevi, both large and small, is controversial and presents problems in management. The size of the lesion is taken to indicate potential malignant transformation, but this is an arbitrary scale. A more reliable biological indicator is needed to help predict the lesions at risk. Following the localization of neuron-specific enolase to most cells of the diffuse neuroendocrine system and their neoplasms (including benign and malignant melanocytic lesions), it has been suggested that its level is related to tumor activity. In a prospective trial, the presence of neuron-specific enolase immunoreactivity, its concentration, and gene expression in nevus cells were studied in 31 congenital melanocytic nevi of various sizes (1.5 cm to bathing trunk) using immunocytochemistry, biochemical assay, and in situ hybridization. Twenty-five of the 31 congenital nevi were immunoreeactive to neuron-specific enolase antiserum, with stronger immunostaining in the larger lesions. There is an apparent linear relationship between the size of the nevi and the level of neuron-specific enolase (expressed as nanograms per milligram protein). Neuron-specific enolase mRNA was highly expressed in most of the large congenital nevi (greater than 15 cm in diameter), as revealed by autoradiography following in situ hybridization. Our results show that neuron-specific enolase and its mRNA are expressed to a greater extent in large congenital nevi compared with the smaller lesions. This might prove to be a useful indicator of those lesions at risk of malignant transformation.
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PMID:Neuron-specific enolase and its mRNA are highly expressed in large congenital nevi: a study using immunocytochemistry, biochemical assay, and in situ hybridization. 264 Dec 80

Immunohistochemical analyses were performed on 64 nevocellular nevi (12 compound nevi and 52 intradermal nevi). S-100 protein and its alpha- and beta-subunits were almost always demonstrated in type A, B and C cells, and the staining intensity tended to increase in the type C cells. Neuron-specific enolase was detected in each type of cell; however, the population of positive cells was smaller among type C cells. Beta 2-microglobulin was occasionally demonstrated, but only in type A cells. Vimentin was frequently revealed in every type of cell. Neither myelin basic protein nor glial fibrillary acidic protein was observed in any type of cell. In contrast, normal epidermal melanocytes were positive for vimentin, but negative for S-100 protein and its subunits and neuron-specific enolase. Schwann cells were positive for S-100 protein and its beta-subunit, but negative for the alpha-subunit. Thus, the nevus cells shared a common nature with epidermal melanocytes and Schwann cells which originate from the neural crest; however, the former cells were somewhat different from the latter two kinds and from benign and malignant tumors derived from these cells in the expression of these antigenic substances. Such differences in the expression of antigenic substances may be due to dysontogenic manifestations in nevus cells.
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PMID:[Immunohistochemical study of nevocellular nevi]. 268 14

Nevus cell components have been observed in up to 40% of melanomas, but little is known of the pathobiology of these components in relation to their malignant potential. We studied 44 nevi of the typical, dysplastic, congenital, and Spitz types with a battery of monoclonal and polyclonal antibodies that react on formalin-fixed, paraffin-embedded tissues (HMB.45, S-100 protein, RAP-5, epithelial membrane antigen [EMA], and neuron-specific enolase [NSE]) by avidin-biotin immunohistochemical methods. EMA and RAP-5 (which detects the ras oncogene-associated P21 protein) were negative in all cases. Melanoma-specific HMB.45 was strongly reactive with the epidermal component and had a weak to negative reaction with the dermal component in the typical nevi. However, the reaction seen with HMB.45 in the junctional component of dysplastic nevi, congenital nevi, and some Spitz nevi was heterogeneous. One Spitz nevi showed HMB.45 staining in a pattern near to that of melanoma. In contrast to HMB.45, S-100 protein labeled nevomelanocytes, regardless of whether they were within the epidermis or dermis, although, in half of the dysplastic nevi, the reaction was heterogeneous, with some atypical cells failing to stain. But, with cytologically atypical junctional component (dysplastic-appearing), congenital nevi also stained heterogeneously for S-100 protein compared with the dermal component. NSE stained the central component of some Spitz nevi more intensely than the lateral component. Junctional nevomelanocytic subsets of some congenital nevi revealed HMB.45 and S-100 reactivity similar to dysplastic nevi.
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PMID:Typical, dysplastic, congenital, and Spitz nevi: a comparative immunohistochemical study. 229 3

A primary cellular blue nevus (melanocytoma) of the spinal canal in a 21-year-old woman is reported. Light microscopic examination revealed a melanotic neoplasm with histological patterns resembling schwannoma, dermal nevi, and neuroblastic-like tumor. The ultrastructural features of the neoplastic cells were similar to those in dermal blue nevi and melanomas. There was no evidence of arachnoidal cell differentiation. Immunohistochemistry revealed positive reactions for S-100 protein and neuron-specific enolase in many cells and no reactions for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, 70-kD neurofilament protein, or Leu-7. Vimentin was strongly positive in the melanocytic cells as well as in the arachnoidal cells of involved meninges. The ultrastructural and immunohistochemical features support the nevoid nature of this tumor, which is frequently mislabeled as "melanotic meningioma."
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PMID:Cellular blue nevus ("melanocytoma") of the spinal meninges: electron microscopic and immunohistochemical features. 337 92

Agminated, or grouped Spitz nevi are a curious expression of nevomelanocytic growth; and represent an uncommon manifestation of these nevi. We encountered an example of agminated Spitz nevi present at birth, which showed progression and rapid growth over months. All showed histologic Spitz nevus features. Avidin-biotin immunohistochemical techniques using anti S-100 protein, neuron-specific enolase (NSE), and melanoma-specific monoclonal antibody, HMB-45 labelled the nevi as follows: diffuse S-100 and NSE staining in most and HMB-45 positivity in sporadic cells deep in the dermis. HMB-45 reactivity occurred in both spindle cells and epithelioid forms.
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PMID:Congenital agminated Spitz nevi: immunoreactivity with a melanoma-associated monoclonal antibody. 339 10


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