Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The epidermal melanin unit (EMU) denotes the symbiotic relationship between a melanocyte and a pool of associated keratinocytes. We propose to show that alterations in the biology of the EMU are the main determinant of the different patterns of intraepidermal growth of melanocytes in lentigo maligna melanoma (LMM) and superficial spreading melanoma (SSM). They also appear to affect the biosynthesis of melanin and melanosomes during malignant transformation. Findings in histochemical studies with monoclonal antibodies generated against melanosomal proteins to produce different stains of melanocytes of normal skin, dysplastic melanocytic nevi (DMN), common melanocytic nevi (CMN), LMM, and SSM have led to the suggestion that the altered melanosome synthesis is a main phenotype in the pathophysiology in neoplastic transformation of melanocytes. Altered melanin synthesis may also affect the carcinogenesis in malignant melanoma: pheomelanin is increased in malignant melanoma and DMN, but not in normal skin and CMN. Pheomelanin and its precursors could aid the malignant transformation of melanocytes through the generation of mutagenic ultraviolet photoproducts in familial DMN syndrome.
 ...
PMID:The epidermal melanin unit in the pathophysiology of malignant melanoma. 202 92

This essay places the concept of "primary acquired melanosis" of the conjunctiva in historical perspective and shows that it and its analogs, namely, lentigo-melanosis (Hutchinson), melanotic freckle (Hutchinson), melanose circonscrite precancereuse (Dubrueilh), melanotische precancerose (Miescher), lentigo maligna (Clark), precancerous melanosis (Reese), benign, precancerous, and cancerous melanosis (Zimmerman), atypical melanocytic hyperplasia (Silver et al.), and benign acquired melanosis (Zimmerman), are synonyms for melanoma in situ. The issue is not merely semantic or philosophical; it is urgently practical. If a clinician takes literally the meaning of a lesion designated "benign melanosis" and considers it to be benign, rather than the malignant melanoma that it actually is, a patient who bears that flat pigmented lesion may one day die of metastasis from an elevated sequella of it. The same is true of "primary acquired melanosis," which is not simply a condition of blackening by melanin, but a flat melanoma that, if not removed completely, may give rise one day to metastases that cause death. To avoid such misconstructions, we advocate naming melanomas in all organs "melanoma" and those that are confined to epithelial structures "melanoma in situ." Euphemisms like lentigo maligna and primary acquired melanosis are evasions of the diagnosis of melanoma, and use of them may be harmful. For that reason, they should be eschewed.
 ...
PMID:Primary acquired melanosis of the conjunctiva is melanoma in situ. 149 53

A patient with an amelanotic lentigo malignant melanoma is presented which manifested itself initially as an erythematous flare with the subsequent development of nodules. The diagnosis was only made histologically. A computer search of the literature revealed 6 previous cases, and a review of these rare tumours is presented.
 ...
PMID:Amelanotic lentigo malignant melanoma: a case report and review of the literature. 205 92

An epidemiological study of malignant melanoma in Puerto Rico was done by reviewing the Puerto Rico Cancer Registry for all melanoma cases reported between the years 1981 to 1987. A total of 367 new cases were documented with the annual incidence ranging from 1.20 to 2.12 per 100,000 inhabitants with a mean of 1.59. Most of the patients were between 40 and 80 years of age with a peak in the sixties. Nearly one half of the tumors were located on the extremities, most notably on the feet, sharing this predilection with Blacks and Japanese. The most frequently recognized clinico-histologic type was the superficial spreading melanoma followed by the acral lentiginous, the nodular and the lentigo maligna melanoma. Nearly one third of the total cases were not classified according to the histologic type, while Clark's levels and Breslow's thickness were not reported in 44 and 84% of the cases, respectively. When compared to a previous study during 1977 to 1980, the average annual incidence of new cases increased from 0.92 to 1.59 per 100,000 documenting an increased incidence of the condition in our population, but not as significant as that registered in the United States.
 ...
PMID:[Malignant melanoma in Puerto Rico]. 208 Sep 58

Progressive cranial nerve palsies and painful ophthalmoplegia developed in a 76-year-old man with lentigo maligna of the forehead 18 months after the excision of a spindle cell tumour of the forehead that proved on immunohistochemical study to be a malignant melanoma. The signs and symptoms were caused by neurotropic spread of the malignant melanoma into the cavernous sinus and subsequent neurosarcomatous transformation of the orbital metastasis.
 ...
PMID:Painful ophthalmoplegia caused by neurotropic malignant melanoma. 215 83

Using immunocytochemical techniques on fresh surgical samples, a series of 16 cases of cutaneous malignant melanoma (CMM) were examined to characterize further the host inflammatory response. Antibodies to the following cluster of differentiation (CD) antigens were used: CD-3, CD-4, CD-8 (T-cell markers), CD-11b, CD-14 (macrophage marker), CD-16 [an antigen expressed by natural killer (NK) cells and granulocytes], and CD-25. Also examined were a small number of other melanocytic lesions [two cases of lentigo maligna (Hutchinson's melanotic freckle) and five of intradermal naevi]. The results of the study document a population of cells with the morphological and immunophenotypic characteristics of NK cells in association with 10 of the 16 cases of CMM. These cells were consistently absent from the other melanocytic lesions studied. The presence of NK cells in association with some cases of CMM bears no clear relationship to the Breslow thickness, Clark level, tumour ulceration, or the presence of activated T cells as determined by expression of the CD-25 antigen. Whilst an explanation for the significant numbers of NK cells in some CMM lesions in unclear, their presence in intimate association with tumour cells does prompt speculation regarding a possible role in determining the biological behaviour of the tumour. Additionally, the study has confirmed and extended previous findings with respect to the broad characterization of mononuclear cells present in the host infiltrate associated with CMM.
 ...
PMID:Natural killer cells in cutaneous malignant melanoma. 219 50

Immunohistochemical localization of S-100 protein alpha and beta subunits in the cells of melanocytic nevi and malignant melanomas was studied by using monoclonal antibodies directed against each subunit. Although polyclonal anti-S-100 reactivities have been demonstrated uniformly in all nevus cells and melanoma cells, monoclonal anti-S-100 alpha and anti-S-100 beta reactivities were either absent or rarely found in ordinary junctional nevi or junctional nests of ordinary compound nevi. However, in the junctional nests of dysplastic junctional nevi and junctional components of dysplastic compound nevi, monoclonal anti-S-100 alpha reactivity become more frequent, whereas monoclonal anti-S-100 beta reactivity remains negative. In the superficial variety of melanomas such as superficial spreading melanoma and lentigo maligna melanoma, monoclonal anti-S-100 beta is nonreactive until vertical growth or invasiveness begins. Most nodular melanomas are positively stained with both monoclonal anti-S-100 alpha and anti-S-100 beta. It is suggested that monoclonal anti-S-100 alpha can be an indicator of active junctional nevus of melanocytic nevi and the reactivity with monoclonal anti-S-100 beta may be related to vertical progression of superficial spreading melanomas and lentigo maligna melanomas.
 ...
PMID:Immunohistochemical study of melanocytic nevus and malignant melanoma with monoclonal antibodies against S-100 subunits. 220 26

A 40-year-old male with early 'invasive' malignant melanoma of the glans penis and meatus urethrae externus is presented. Early stages of primary melanoma of the glans penis and the male urethra are distinctly rare and are often clinically indistinguishable from penile lentigo, melanosis and melanocytic nevus on the genitalia. In order to avoid large and useless surgery on such a delicate location we propose a punch biopsy with subsequent histological examination prior to definitive surgical procedure. Whereas malignant melanoma of the penis with a thick Breslow index is treated with extended surgical management, only local excision of the tumor without groin dissection was performed in our patient.
 ...
PMID:Early 'invasive' malignant melanoma of the glans penis and the male urethra. Report of a case and review of the literature. 222 87

For clinical dermatologists, proliferations of melanocytes confined to the epidermis (and epithelial structures of adnexa) are either flattish melanocytic nevi (junctional type) or flat lesions (macules and patches) of malignant melanoma (malignant melanoma in situ). The same should be true for histopathologists. During the past 30 years, however, histopathologists have avoided making specific diagnoses of malignant melanoma in situ by utilizing a variety of nondiagnostic, euphemistic descriptions for it such as melanotic freckle of Hutchinson, melanosis circumscripta precancerosa of Dubreuilh, active junctional nevus, lentigo maligna, atypical melanocytic hyperplasia, melanocytic dysplasia, and melanocytic intraepithelial neoplasia. Each of these terms evades a specific diagnosis of malignant melanoma in situ, a diagnosis than can, and should, be made clinically and histopathologically if reliable criteria are used. The legitimacy of a concept of malignant melanoma in situ in the context of historical perspective and the importance of that concept for management of patients are the themes of this essay.
 ...
PMID:Ideas in pathology. Malignant melanoma in situ: the evolution of a concept. 226 99

Neither the involvement of hairfollicles nor of the ducts of the sweat glands by melanoma cells nor the thickness of the epidermis are helpful in differential diagnosis of lentigo maligna melanoma and superficial spreading melanoma in situ. The epidermis was thinner in LMM, however, LLM is mostly localized in the face where the epidermis is thinner than in other areas of the integument.
 ...
PMID:[Is involvement of skin appendages or thickness of the epidermis an aid in differential diagnosis between lentigo maligna melanoma and superficially spreading melanoma in situ?]. 229 Dec 95


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>