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

The cellular proto-oncogene, ras, is known to play an important role in the regulation of cell growth and proliferation in normal and malignant conditions. The present study was undertaken to immunohistochemically examine the expression of ras protooncogene product p21 in normal human skin and some cutaneous tumours. In normal skin, the expression of p21 was found in sweat glands, sebaceous glands, capillary endothelium, and smooth muscles, while epidermis was devoid of reaction product. Keratoacanthoma and the granular cells of verruca vulgaris were immunoreactive to the antibody for p21. Bowen's disease and squamous cell carcinoma were positive for p21, but basal cell carcinoma and seborrheic keratosis were negative. In mammary and extramammary Paget's diseases, the immunoreactivity was inconsistent. The expression of p21 in malignant melanoma cells was intense, whereas normal melanocytes and nevus cells were devoid of the expression. These results suggest that the expression of p21 does not correlate with nuclear anaplasia and malignant behaviour of cutaneous tumours.
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PMID:Expression of ras proto-oncogene related protein p21 in normal human skin and cutaneous tumours. 132 35

A 7-month-old boy had a giant pigmented lesion involving the trunk and thighs that exhibited many hyperpigmented hairy and verrucous nevi. One of the nevi ulcerated and on histological examination consisted of pleomorphic rhabdomyosarcoma cells that stained for muscle-specific actin (HHF-35), desmin, and myoglobin. Around the tumor, in the dermis, benign pigmented nevus cells were observed. The occurrence of malignant tumors, other than malignant melanoma, in pigmented nevi is rarely described.
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PMID:Rhabdomyosarcoma in a congenital pigmented nevus. 137 40

This report describes 41 patients with lesions similar to those previously termed "deep penetrating" or "plexiform spindle cell" nevus (DPN). DPN occurs primarily during the first four decades, is somewhat more common in females, and has a predilection for the face, trunk, and proximal extremities. It is usually less than 1 cm in diameter and often shows variegation in color, including shades of brown, blue, and black, that create clinical concern regarding malignant melanoma. None of the present tumors nor those from the literature recurred following excision. Microscopically, DPN usually has a wedge shape, invariably involves reticular dermis, and may penetrate subcutis. Involvement of neurovascular structures and adnexae and spread between fibers of the reticular dermis create a fascicular-plexiform architecture. The melanocytes are fusiform or epithelioid, lightly to moderately pigmented, and exhibit mild to focally prominent nuclear atypia. Sparse to abundant melanophages are characteristic. Mitotic figures are few and present in only a small minority of lesions. The present study of a consecutive series also indicates that DPN is a frequent participant in combined nevus, as it was associated with ordinary nevus in two-thirds of the lesions.
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PMID:Deep penetrating (plexiform spindle cell) nevus. A frequent participant in combined nevus. 140 42

Although sun exposure is believed to be associated causally with cutaneous melanoma, the high incidence on less sun-exposed areas such as the back, as well as on chronically exposed sites such as the face, suggests that the association with sunlight is less straightforward than for other skin cancers. To explain this enigmatic site distribution, a theory of site-dependent susceptibility of melanocytes to malignant transformation is proposed. As possible evidence, all melanomas diagnosed in the state of Queensland, Australia, over a one-year period were surveyed for histologic evidence of benign melanocytic nevus cells adjacent to the melanoma, and analyzed according to anatomic distribution. Results showed a regional variation in the proportion of melanomas with adjacent nevi not explicable by regional variation in nevus density, which suggests that there is a varying susceptibility of nevi to malignant change. Given that nevus cells are equivalent to melanocytes, this finding would support the hypothesis that melanocytes at-large have a differential response to the mitogenic stimulus of sunlight according to anatomic site.
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PMID:A theory of site distribution of melanomas: Queensland, Australia. 142 Aug 53

Nevus of Ota is uncommon in the non-Oriental population. We report a case of malignant melanoma with metastasis to the genitourinary tract in a Hispanic male with nevus of Ota. Thirty-six prior cases of nevus of Ota with malignant melanoma reported in the English language are reviewed. Sixty-eight percent were women; 76% were Caucasians. Metastatic disease was reported in 16%. Three patients had liver metastases. Our case was the first involving the genitourinary tract. All but one patient with metastatic disease died within 1 month of presentation. Despite the increased frequency of nevus of Ota in the Japanese, only 4 cases of malignant melanoma have been reported. Nevus of Ota would appear to be a risk factor for developing malignant melanoma in the Caucasian population.
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PMID:Malignant melanoma in a Hispanic male with nevus of Ota. 142 29

Melanoma cells have surface markers that are expressed differently than in normal melanocytes and nevus cells. Monoclonal antibodies may define a phenotypic map of the various melanocytic lesions and can be used in immunohistopathology and immunoscintigraphy. Monoclonal antibodies directed against melanoma-associated glycoproteins and glycolipids are being tested for therapy. Rearrangements or deletions on chromosome 1, 6, and 7 are the most frequently observed cytogenetic abnormalities. Molecular studies have not given a clear picture. A subset of HRAS alleles has been reported to be associated with melanoma. NRAS activation by point mutation has been found in one fourth of the cases. Allele losses at different loci have been reported. Genetic linkage studies have given conflicting results on the presence of a gene for the melanoma-dysplastic nevus syndrome on the short arm of chromosome 1.
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PMID:Cellular and molecular biology of melanoma. 143 44

Based on the clinicopathological classification of distinct stages of tumor progression in the melanocytic system, we have investigated the in vitro growth patterns and requirements of normal melanocytes and melanocytes isolated from different lesions of melanoma progression. Normal melanocytes depend on a combination of insulin-like growth factor (IGF-I) or insulin, 12-O-tetradecanoyl phorbol-13-acetate (TPA), alpha-melanocyte stimulating hormone (alpha-MSH), and basic fibroblast growth factor (bFGF) for in vitro proliferation. Nevus cells display a reduced need for TPA and are largely independent of bFGF. Both melanocytes and nevus cells have a finite lifespan in vitro and show no spontaneous transformation, whereas melanoma cells can be grown indefinitely in vitro. Cells from primary melanomas require only IGF-I or insulin for continuous growth, and metastatic melanoma cells can proliferate in base medium without addition of any growth factors or proteins. This progressive growth autonomy is paralleled by an increased competence for endogenous growth factor production. Among these growth factors, bFGF and melanoma growth-stimulatory activity (MGSA) act in an autocrine fashion. Melanoma-derived growth factors without apparent autocrine function, such as platelet-derived growth factor A and B (PDGF-A and PDGF-B) and transforming growth factor-alpha (TGF-alpha), might still be important for melanoma growth by stimulating surrounding normal fibroblasts, endothelial cells, or keratinocytes to secrete growth-promoting factors. The significance of growth factors such as transforming growth factor-beta (TGF-beta) and melanoma-inhibiting activity II (MIA II), which have a potentially negative autocrine function, remains unknown. The successful propagation of melanocytic cells of all stages of melanoma progression has yielded valuable insight into the mechanisms of growth regulation and malignant transformation.
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PMID:In vitro growth patterns of normal human melanocytes and melanocytes from different stages of melanoma progression. 144 12

A retrospective review of 891 patients with newly diagnosed primary cutaneous malignant melanoma (CMM) registered at the British Columbia Cancer Agency from 1972 to 1981 is presented. Age-standardized incidence rates in British Columbia have increased markedly over that time. The female-to-male ratio was 1.13:1 and the median age overall was 47 years. A change in the size of a mole was the most common presenting sign (in 43% of patients) and the median duration of signs was 5.9 months. Predominant tumour sites were the trunk for males and the lower limbs for females. Dominant growth patterns were superficial spreading melanoma (65%), nodular melanoma (25%), lentigo maligna melanoma (5%) and acral lentiginous melanoma (2%). On staging of the primary tumour, 90% of patients had local disease, 9% of patients had regional disease and 1% of patients had distant disease at presentation. Median depths of tumours were 1.45 mm for males and 1.10 mm for females; no T1 tumours (tumours 0.75 mm or less in depth [TNM classification]) were staged beyond the local area. Disease recurred in 44% of males and 32% of females. The 15-year survival rate was 55.5% for males and 70.3% for females. These findings are compared with those of recent international series. It is apparent that earlier diagnosis improves survival and that more education is needed in view of the increasing incidence and death from CMM.
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PMID:Primary cutaneous malignant melanoma: experience of the British Columbia Cancer Agency from 1972 to 1981. 145 84

B cells derived from peripheral-blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) from a patient with a high serum antibody titer to autologous melanoma were transformed with Epstein-Barr virus (EBV) and evaluated for reactivity against autologous tumor. B cells producing antibody reactive with autologous tumor and unreactive with normal fibroblasts were detected both in TIL and in PBL. One cell line derived from PBL and another derived from TIL sustained production of tumor-reactive antibody for 10 weeks and over 15 months respectively. The cell line derived from PBL, 2D11, produced an antibody reactive with a trypsin-resistant antigen expressed on the cell membrane of autologous and allogeneic melanoma cell lines. The cell line derived from TIL, 1F6, produced an antibody reactive with a cell-surface glycoprotein expressed by 5 autologous melanoma cell lines derived from 5 different metastases and 16/19 allogeneic melanoma cell lines. 1F6 also showed reactivity with cell lines derived from a blue nevus, a congenital nevus, an astrocytoma, and 1/4 renal-cell carcinomas; but it was not reactive with 5 foreskin melanocyte cell lines, 2 normal fibroblast lines, 5 leukemia/lymphoma lines, 8 lung-cancer lines, 8 glioblastoma lines, or lines derived from 1 ovarian carcinoma, 1 colon carcinoma, 1 vulvar carcinoma, 1 fibrosarcoma, 1 murine melanoma, or 4 murine leukemia/lymphomas. We describe here an antibody that detects a new melanoma specificity obtained by EBV transformation of tumor-infiltrating B cells.
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PMID:Analysis of two human monoclonal antibodies against melanoma. 145 38

The expression of gangliosides in non-malignant tissues (epidermis and pigmented nevus) and neoplastic lesions (melanoma, squamous cell carcinoma [SCC] and basal cell carcinoma [BCS]) of the human skin was analyzed immunohistochemically and biochemically to characterize the features associated with malignancy. Immunohistochemical staining with an anti-II3NeuAc-LacCer (GM3) monoclonal antibody (M2590 mAb) and an anti-II3(NeuAc)2-LacCer (GD3) mAb (R24) showed the expression of the gangliosides GM3 and GD3 to vary among the different tissues. M2590 clearly stained epidermal keratinocytes and the tumor cells of BCC and SCC, and strongly stained melanocytes and melanoma cells. In contrast, R24 did not stain epidermal keratinocytes and only faintly stained SCC cells, while it clearly stained BCC cells, and intensely stained melanocytes and melanoma cells. GM3 showed a similar level of staining among the tissue specimens, while the level of GD3 staining was quite variable among the tumor specimens. Biochemical analysis by thin-layer chromatography (TLC) with resorcinol staining and TLC immunostaining with either M2590 or R24 showed both GM3 and GD3 to be commonly expressed by both the normal and malignant skin tissues, including SCC. There was no close correlation between the intensity of immunohistochemical staining and the biochemically detected amounts of these gangliosides. This may have been partly due to the so-called cryptic expression of cell membrane gangliosides. Our results thus suggest that analysis of the tumor-associated expression of gangliosides requires several methods, since the sensitivity of the methods used may have a considerable effect on the diagnostic value of gangliosides as skin cancer markers.
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PMID:Common phenotypic expression of gangliosides GM3 and GD3 in normal human tissues and neoplastic skin lesions. 146 93


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