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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies of the genetics of melanoma have focused on the dysplastic nevus syndrome (DNS). The variability in clinical and histopathological expression of affected individuals, however, has made definition and diagnosis of the syndrome difficult and subjective. Independent of the DNS, case-control studies have demonstrated the total number of nevi to be a significant risk factor for melanoma. In this article, we report results of genetic analyses of two quantitative nevus phenotypes that can be measured objectively in all subjects: the total number of nevi on an individual (TNN) and total nevus density (TND), a derived phenotype which incorporates both number and size of nevi. Ten kindreds ascertained for multiple cases of DNS-melanoma (multiplex ascertainment) and 16 kindreds and 19 solitary cases ascertained from a sequential list of melanoma cases without regard for family history (simplex ascertainment) were studied. Both phenotypes exhibited increased levels in relatives of probands compared with those in spouse controls. While neither TNN nor TND exhibited evidence for a major factor in the simplex pedigrees, a major factor was strongly indicated in the multiplex kindreds for TND. When both phenotypes were examined in more detail in the multiplex kindreds, the phenotype incorporating nevus size, TND, fit a mendelian pattern of inheritance better than the TNN. Significant residual familial correlations were found for both phenotypes. Parameter estimates from the best fitting genetic model indicated that a major gene may be responsible for 55% of the phenotypic variability of TND in the multiplex kindreds.
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PMID:Inheritance of nevus number and size in melanoma and dysplastic nevus syndrome kindreds. 177 May 51

The authors reviewed the clinical and histopathologic features of 32 patients with cutaneous malignant melanoma of the eyelid. The lower eyelid was more frequently the site of origin than the upper eyelid (21 patients, 66% of cases). A clinical diagnosis of melanoma was made in only 2 of 13 patients (15%) for whom the clinical diagnosis was listed. Clinical findings of pigmentation, ulceration/hemorrhage, or growth were documented in 25 (78%) patients. The histopathologic classification of the melanomas included nodular (19 patients, 59%), superficial spreading (7 patients, 22%), and lentigo maligna (6 patients, 19%). Associated histopathologic findings included solar elastosis (13 patients, 41%), nevus (12 patients, 38%), and basal cell carcinoma (4 patients, 13%). One of eighteen patients with follow-up data available died of metastatic melanoma.
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PMID:Cutaneous melanoma of the eyelid. Clinicopathologic features. 177 23

The authors analyse the results of echobiometry carried out in 21 patients with choroid nevi and in 8 patients with primary melanomas of the choroid, administered no treatment for this or that reason. Nevi with a prominence of less than 1 mm were found to be the most incident, and their elevation did not increase over the course of the follow-up. Only in two patients with nevi these formations were found elevating, this corresponding with the manifestation of clinical signs of primary melanoma. The tumor progress was clearly seen in the patients with primary melanoma of the choroid, it was permanently elevating.
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PMID:[Possibilities of ultrasound biometry in the differential diagnosis of early melanomas and nevi of the choroid]. 178 Nov 24

The purpose of this study was to assess the sensitivity of clinical diagnosis of cutaneous malignant melanoma and to evaluate histologic characteristics of lesions not clinically diagnosed as such. Of 1,784 cases of histologically proven cutaneous malignant melanoma submitted routinely to a university dermatopathology laboratory between 1985 and 1990, 583 (33%) were not clinically suspected. The overall sensitivity in clinical diagnosis was 67%. Histologic features evaluated included presence of melanin, pagetoid spread of melanocytes, degree of inflammation, regression, presence and degree of sun damage as evidenced by solar elastosis, presence of melanin in the cornified layer, and coexisting nevus cells. Melanomas clinically thought to be nevi had less solar elastosis and most frequently had associated nevus cells. Those thought to be basal cell carcinomas had less melanin in lesions and less melanin in the cornified layer, and most often had foci of regression. Lesions thought to be keratoses showed melanin in the cornified layer 70% of the time, more often than any other type of lesion. Melanoma may be unsuspected clinically in a significant number of cases and can be mistaken for less serious cutaneous neoplasms. Histologic features of these lesions correlated well with original clinical diagnoses.
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PMID:Histologic features and sensitivity of diagnosis of clinically unsuspected cutaneous melanoma. 180 50

Nucleolar organizer regions (NORs) are loops of ribosomal DNA seen in nuclei, which are demonstrable as black dots (AgNOR) in tissue sections by silver (Ag) colloid staining. The number of such AgNORs is correlated with cellular activity and is an indicator of the degree of malignancy. In this study, 76 melanocytic lesions were analyzed by AgNOR staining, and the clinical and histopathological characteristics of malignant melanoma and melanocytic nevi were considered. Although the AgNOR counts for melanocytic nevi were significantly different from those in malignant melanoma, an obvious overlap between them was detected. The number of AgNORs in melanocytic nevi per cell was usually 1 or 2. On the other hand, the number of AgNORs per malignant melanoma cell was variable. Morphologically, malignant melanoma cells often showed dispersal of AgNORs throughout the nucleus as well as multiple nucleoli containing clustered AgNORs, whereas melanocytic nevus cells tended to have a regular nucleolus with tightly clustered AgNORs. The correlation between AgNOR count and pathological staging was uncertain, but a slight correlation between AgNOR count and thickness of the primary lesion was obtained. However, the AgNOR count in malignant melanoma was not a prognostic factor for the disease. Therefore, the AgNOR method is difficult to use for differential diagnosis between benign pigmented lesions and malignant melanoma. Nonetheless, an AgNOR count of more than two per cell favors a diagnosis of malignant melanoma.
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PMID:AgNOR (nucleolar organizer regions) staining in malignant melanoma. 180 4

A silver colloidal technique to demonstrate argyrophilic proteins of the nucleolar organizer regions (AgNORs) was performed on sections of 20 cases of malignant melanoma (MM) associated with underlying benign nevus (BN). In these cases, significant different AgNOR counts were found for MM and BN. In addition, this technique permitted the identification of melanocytic cells located between malignant and benign cells showing AgNOR scores intermediate (5.51) between BN (2.6) and MM (7.71) with a more complex and bizarre morphology than that observed in BN. The AgNOR technique can be suitable in the identification of residual nevus cells in MM, especially when their number is minimal and the common histologic criteria are unsatisfactory; it can also increase the understanding of the natural history of MM.
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PMID:Argyrophilic nucleolar organizer region counts in malignant melanoma associated with benign intradermal nevus. 180 85

To investigate the UV effect on epidermal melanocytes, 21 volunteers and 11 patients with dysplastic nevus syndrome (DNS) received UVB irradiation three times weekly during 17 days. Skin biopsies were taken before and three weeks after the last irradiation (on day 37) from exposed and covered buttock skin. The epidermal melanocyte population density was estimated in dopa-stained split skin preparations. The biopsies taken on day 37 revealed that repeated UVB irradiation induces an increase in the number of melanocytes not only in exposed but also in covered skin. This increased mitotic activity might be a link between sun exposure and melanoma development in covered skin. The size of the proliferative response was inversely correlated to the basal melanocyte number. The larger population increase in skin with few melanocytes might amplify the propagation of DNA damage and increase the likelihood of tumor development. The pigment metabolite 5-S-cysteinyldopa (5-S-CD) was measured in urine before the irradiation and twice weekly until day 38. No correlation was found between the basal 5-S-CD excretion and the size or activity of the melanocyte organ, suggesting that the basal 5-S-CD excretion is mainly of non-melanocytic origin. Despite numerous nevi, DNS-patients did not differ from controls in their 5-S-CD excretion. The normal upper range for the tumor maker 5-S-CD is therefore valid in these melanoma-prone subjects. During the irradiation, subjects with a low tanning ability developed a more pronounced erythema and excreted more 5-S-CD than those with a good tanning ability. This suggests that the UVB-induced 5-S-CD excretion is rather due to melanocyte damage than to an increased melanin synthesis. To investigate the influence of sun exposure on the development of nevi and melanoma (CMM), the distribution over the body surface of CMM, common nevi (CN) greater than or equal to 2 mm and dysplastic nevi (DN) was registered in 121 melanoma patients and 310 controls. Four times as many nevi were found in a sun-exposed area than in a comparable sun-protected area, demonstrating that sun exposure plays an important role in nevus development. Subjects with DNA had a larger difference in nevus counts between the two areas than subjects without DN, indicating a different UV-dose and/or a higher sensitivity to the "nevogenic" effect of UV-light than subjects without DN.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Melanocytes, moles and melanoma--a study on UV effects. 181 38

A series of 233 consecutive primary cutaneous melanomas was histologically and clinically studied. Histologically, 53 melanomas (22.7%) were associated with naevus cells. Such a high degree of association suggests that melanocytic naevus may be a precursor of a large number of melanomas. Analysing the cases according to Clark's levels and Breslow's index, a decrease in the naevus-melanoma association was seen with tumour progression, suggesting that advanced tumours may overgrow pre-existing nevus cells, appearing as de novo melanomas. The comparison between histological and clinical data suggest some interpretations of the natural history of melanoma.
Melanoma Res
PMID:Spatial association of melanocytic naevus and melanoma. 182 33

Experienced ophthalmologists who appropriately employ ancillary diagnostic testing, including fluorescein angiography, ocular ultrasonography, MRI, and fine needle aspiration biopsy, are remarkably accurate in the diagnosis of intraocular neoplasms. Recognizing the classic clinical features of the more commonly encountered lesions, such as choroidal melanoma, choroidal nevus, metastatic carcinoma to choroid, lymphoid tumors, and circumscribed choroidal hemangioma, and understanding the applicability and limitations of the various diagnostic tests are the keys to accurate detection.
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PMID:Differential diagnosis of choroidal neoplasms. 182 11

Nerve growth factor (NGF) stimulates growth and differentiation of sensory and sympathetic neurons. It is not known what role NGF plays in melanoma development, but nevus and malignant melanoma cells express NGF-receptor (NGF-R). We counted nerve fibers within melanocytic nevi, primary cutaneous melanomas, and cutaneous melanoma metastases using a monoclonal antibody (MoAb) as marker against a 200-kD glycoprotein that is expressed on human nerves. The expression of NGF-R was studied in serial cryostat sections using a MoAb against the NGF-R. Compared to normal skin, increased numbers of nerve fibers were found in 72 melanocytic nevi. In congenital nevi their number significantly increased with age. In 47 primary cutaneous melanomas the number of nerve fibers decreased in proportion to tumor thickness. In 33 cutaneous melanoma metastases no accumulation of nerve fibers was found. NGF-R was not expressed in normal skin melanocytes and in the majority of nevus cells in melanocytic nevi. Considerable numbers of NGF-R-positive nervus cells were found only in some congenital nevi and few acquired nevi with dysplastic features. By contrast, in primary and metastatic melanomas higher expression of NGF-R was observed. The increased number of nerve fibers in melanocytic nevi suggests that neurite-promoting factors are produced in situ. Production of such factors appears to be lost in malignant melanoma cells. The finding of an inverse correlation between an abundance of nerve fibers in NGF-R-poor nevi and a high expression of NGF-R in melanomas that show no evidence of nerve growth suggest a role of NGF and its receptor in malignant melanocytic tumors.
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PMID:Nerve growth and expression of receptors for nerve growth factor in tumors of melanocyte origin. 185 Jul 72


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