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 location of genes involved in tumor evolution has been inferred from experiments in which loss of constitutional heterozygosity has been detected in tumor DNA at high frequency in specific chromosome regions. For example, cytogenetic and molecular abnormalities on chromosome 1p have been reported in tumors such as malignant melanoma and neuroblastoma which arise in cells derived from embryonic neural crest tissue. To extend these observations, we have examined tumor DNA from three cases of Merkel cell carcinoma for evidence of loss of constitutional heterozygosity on the short arm of chromosome 1. In all three cases, heterozygous allelic deletions of varying extent on distal chromosome 1p were detected in tumor DNA. Comparisons with neural crest tumors suggest that loss of heterozygosity on distal chromosome 1p in Merkel cell tumors may be a marker of neural crest origin.
 ...
PMID:Loss of allelic heterozygosity on distal chromosome 1p in Merkel cell carcinoma. A marker of neural crest origins? 167 9

The gene for the human p58 protein kinase, a cell division control-related gene, has been mapped by somatic cell hybrid analyses, in situ localization with the chromosomal gene, and nested polymerase chain reaction amplification of microdissected chromosomes. These studies indicate that the expressed p58 chromosomal gene maps to 1p36, while a highly related p58 sequence of unknown nature maps to chromosome 15. Assignment of a p34cdc2-related gene to 1p36 may have implications for numerous tumors that involve deletion of this region, including neuroblastoma, ductal carcinoma of the breast, malignant melanoma, Merkel cell carcinoma, and endocrine neoplasia.
 ...
PMID:Localization of the expressed human p58 protein kinase chromosomal gene to chromosome 1p36 and a highly related sequence to chromosome 15. 177 66

A mouse monoclonal antibody, FKH1, was produced to detect cytoplasmic melanoma-associated antigen. FKH1 was raised using cultured human melanoma cell line KHm-6 as immunogen. Reactivity of this antibody was assessed by immunohistochemical techniques. Positive reactions were seen against 5 human melanoma cell lines and cultured human epidermal melanocyte. It stained cytoplasm of melanoma cells in a diffuse and granular pattern with indirect immunofluorescence. Immunoelectron microscopy showed diffuse distribution of immuno-reactant in the cytoplasm of KHm-1 cells excluding melanosomes and other subcellular organelles. In immunoblotting, FKH1 bound with proteins having molecular weight of 71 kd and 55 kd extracted from KHm-6 cells. Reactivity against frozen and alcohol-fixed paraffin-embedded melanocytic tumors was also tested with indirect immunofluorescence or ABC (avidin biotin peroxidase complex) techniques. All cases of frozen sections from benign and malignant melanocytic tumors including 2 cases of amelanotic melanoma showed positive staining with FKH1. In fixed tissues, reactivity was 16/19 (84.2%) in malignant melanoma and 30/44 (68.2%) in other melanocytic tumors. FKH1 did not react against normal melanocytes, C-type nevus cell, intradermal nevus pigmentosus with neuroid structure and neurofibroma. It was demonstrated that FKH1 recognized proliferative melanocytes originated from melanoblast or melanoblastic nevoblast. FKH1 failed to stain normal human peripheral nerves and nonmelanocytic tumors except APUDoma and malignant Merkel cell tumor. In halo nevus, nevus cells were clearly distinguished from intermingling inflammatory cell infiltrate. It was suggested that FKH1 is a useful monoclonal antibody in diagnosing human malignant melanoma, particularly in evaluating tumor thickness of Breslow more precisely.
 ...
PMID:[Mouse monoclonal antibody (FKH1) detecting human melanoma-associated antigens: production, partial characterization and immunohistochemical analysis]. 188 56

All the consultants agree that, given this patient's history, a common skin tumor like squamous cell or basal cell carcinoma is unlikely. Melanoma or Merkel cell carcinoma belong in the differential. Interestingly, the consultants all suggest a biopsy of the lesion prior to other testing, and because this tumor is so accessible, a biopsy should not interfere with further testing or treatment. Drs. Weymuller and Marks would then proceed with a CT scan; Dr. Ridge favors an MRI scan. While a chest-ray is in order to rule out metastases, Dr. Weymuller also suggests immunocytochemistry. All the experts agree that the primary tumor should be excised. Dr. Weymuller would perform a total parotidectomy with facial nerve preservation, while Drs. Marks and Ridge suggest a superficial parotidectomy with facial nerve preservation. Drs. Weymuller and Ridge would also perform a modified radical neck dissection. In the absence of cervical disease, Dr. Marks would treat the neck primarily with radiotherapy. Only Dr. Weymuller favors immediate reconstruction and would use a lower trapezius island flap or a large rotational flap. Drs. Marks and Ridge prefer primary closure or skin graft. Drs. Weymuller and Ridge would treat this patient with combined therapy, giving radiotherapy to the primary area and the neck postoperatively at a dose of 55-60 Gy. However, Dr. Marks would treat the primary site postoperatively and the neck primarily with radiotherapy. He would treat the primary site with 59.40 Gy and the neck with 50.40 Gy.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Merkel cell carcinoma of the ear. 198 33

We have reviewed 30 reports of Merkel cell tumour and described a further five cases in order to establish a database and from this more clearly define the biology of this tumour, prognostic factors that govern outcome, and optimal management. After excision alone of the primary lesion, local recurrence occurred in 39 per cent of patients and regional failure occurred in 46 per cent. In contrast, in patients treated by excision plus prophylactic treatment (adjuvant node dissection and/or adjuvant radiation), local recurrence occurred in 26 per cent and regional failure in 22 per cent. Locoregional recurrence carried an ominous significance with 67 per cent of patients subsequently dying of the disease. For patients who either presented with regional disease or later developed regional disease, the best outcome (44 per cent survival with mean follow-up of 40 months) was obtained following treatment by therapeutic node dissection with or without radiation. In contrast, treatment of regional disease with radiation alone was associated with only a 20 per cent survival rate. Unfavourable prognostic factors included young age, lesions sited in the head and neck or trunk, male sex, and the presence of locoregional failure and/or systemic disease. We conclude that Merkel cell tumours behave in a similar manner to the aggressive variants of melanoma and that minimal treatment consists of wide surgical resection of the primary lesion (with a margin of 2.5-3 cm) coupled with resection and probably also radiation of regional disease if present. In addition, consideration should be given to prophylactic node dissection in node negative patients, especially in those patients with unfavourable prognostic factors.
 ...
PMID:Merkel cell tumour: clinical behaviour and treatment. 201 60

Molecular characterization of neuroendocrine (Merkel cell) carcinoma of the skin. Review of the literature and report of three cases. Although neuroendocrine carcinoma of the skin (NECS) is comparatively a rare clinical-histological entity, numerous morphological and ultrastructural studies have been carried out since the tumor was identificated by Toker (1972). Recently immunocytochemistry has allowed a better molecular characterization (immunophenotype) of this tumor and a more exact diagnosis. The main problem for the pathologist is the differential diagnosis between NECS and skin neoplasms--both primitive and metastatic--which require a more aggressive treatment. Often the classical morphological criteria do not distinguish NECS from non-Hodgkin's lymphoma, amelanotic melanomas, cutaneous metastases of lung small cell carcinoma or of neuroblastoma. The co-expression of cytokeratins and neurofilaments constantly found in NECS, is surely the best differential criterion from non-neuroendocrine carcinomas. Furthermore, the typical paranuclear location of both the intermediate filaments in NECS is a distinctive peculiarity as opposed to lung microcytoma, where cytokeratins and neurofilaments, when present, show widespread perinuclear positivity. Chromogranin A is found only in a small percentage of tumor cells, whilst synthesis of calcitonin, somatostatin, gastrin, ACTH, is very rare. Finally, the lack of common leukocyte antigen (CLA), S-100 protein and vimentin in NECS rules out the diagnoses of lymphoma, melanoma and sarcoma respectively.
 ...
PMID:[Molecular characterization of cutaneous neuroendocrine (Merkel cell) carcinoma. Review of the literature and presentation of a caseload]. 209 Oct 10

Merkel cell carcinoma of the skin has only recently been described. From the literature 115 cases are analysed. This carcinoma is most probably far more common than would be assumed from the few publications presently available. Between 40 to 50% of tumours are found in the head and neck area. Clinically the tumour presents as a typical bluish red firm intracutaneous nodule with the overlying skin intact, and sometimes malignant melanoma-like intracutaneous satellites. Regional lymph node metastasis is frequent and the five year survival rate, although not yet available, may well be about 50% or less. Clinical diagnosis is of paramount importance, as final diagnosis is only confirmed by electron microscopy and routine light microscopy leaves a wide range of differential diagnoses. In our case all typical characteristics are present. A cervicofacial flap which utilizes the abundant cervical skin for direct closure of the secondary defect in a U-Y manner was used to cover the primary defect. The flap is based on the preauricular area. Advantages and indications for the cervicofacial as opposed to Esser's cheek rotation flap are discussed.
 ...
PMID:Merkel cell carcinoma of the face. Case report and review of the literature. 385 24

We describe a patient with malignant melanoma that resembled a Merkel cell carcinoma both clinically and histologically. Immunohistochemical studies showed focally positive staining with S-100 protein and strongly positive staining with HMB-45. Ultrastructural study confirmed the diagnosis by demonstrating premelanosomes and melanosomes. Although the tumor appeared to be clinically unimpressive, it was a deep melanoma with a Breslow level of 3.8 mm that necessitated aggressive treatment. Small cell melanoma must be considered in the differential diagnosis of small cell tumors, which also includes lymphoma, eccrine carcinoma, squamous cell carcinoma, and Merkel cell carcinoma. The diagnosis of amelanotic melanoma, including the small cell variant, may require electron microscopic studies.
 ...
PMID:Malignant melanoma with clinical and histologic features of Merkel cell carcinoma. 752 66

The alpha subunit of guanine nucleotide-binding protein Go (Go alpha), which was initially isolated from bovine brain, interacts with muscarinic cholinergic receptors and regulates neuronal calcium channels. Go alpha is known to be localized in neural tissues, some endocrine cells, and neuroendocrine tumors. We have immunohistochemically investigated the expression of Go alpha in 4 cases of Merkel cell carcinoma using the method of microwave treatment. In all cases of Merkel cell carcinoma, Go alpha was consistently detected on the plasma membrane and cytoplasm of the tumor cells. Nerve fibers in the skin were also positive for Go alpha, but other epidermal or dermal components such as keratinocytes, melanocytes, fibroblasts, or lymphoid cells were negative. Tumor cells of squamous cell carcinoma, cutaneous lymphoma, sweat gland carcinoma, and malignant melanoma were negative for Go alpha. The present study indicates that Go alpha may be a useful immunohistochemical marker of Merkel cell carcinoma.
 ...
PMID:Expression of alpha subunit of guanine nucleotide-binding protein Go in Merkel cell carcinoma. 756 Mar 47

A case of Merkel cell tumour that developed on the left upper lid of a 76-year-old white man is reported. The diagnosis was ultrastructurally made by demonstrating characteristic light microscopic features of Merkel cell carcinoma; such as large, round nuclei and frequent mitoses. Immunohistochemically, the tumour cells were shown to possess simple epithelia-type keratin intermediate filaments. Merkel cell tumour probably develops from precursor cells which give rise to keratinocytes and Merkel cells, and nearly one out of 10 Merkel cell tumours occur in the eyelid and periocular region. They tend to be bulging lesions near the lid margin of elderly patients. The condition can be misdiagnosed as lymphoma, oat cell carcinoma, malignant melanoma, sweat gland tumours, neuroblastoma and Ewing's sarcoma, and frequently invades lymphatic vessels. Nearly one out of three Merkel cell tumours recur and two thirds cause regional lymph node metastases. Wide surgical resection and reconstructive procedures, should be followed by routine postoperative irradiation. This patient was treated with wide resection and the Cutler-Beard technique, then scheduled for radiotherapy.
 ...
PMID:Merkel cell tumour of the eyelid and reconstruction with the Cutler-Beard technique: a clinicopathologic case report. 792 66


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