Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Six patients with malignant head and neck tumors are shown to have required electron microscopy for accurate diagnosis. In all of these tumors, there were ultrastructural features of cytodifferentiation that were not discernible by light microscopy, such as neurosecretory granules, desmosomes, cytoplasmic processes, tonofibrils, and myofilaments. Electron microscopy is helpful in the differential diagnosis of tumors in general, but its effectiveness is particularly apparent in small-cell "undifferentiated" tumors such as neuroblastoma, rhabdomyosarcoma, Ewing's sarcoma, undifferentiated squamous-cell carcinoma of the lymphoepithelioma type, and malignant lymphoma. It has also been helpful in the identification of amelanotic melanoma and spindle-cell carcinoma.
 ...
PMID:Electron microscopy in the diagnosis of head and neck tumors. 50 Mar 59

Primitive malignant melanoma of the nasal fossae is rare and amelanotic melanoma of the same site is highly unusual. The present work reports a case where positive diagnosis was only possible by means of ultrastructural study. Giving evidence of the premelanosomes, this technique made it possible to differentiate from other types of cancers (in particular from olfactory neuroblastoma, non differentiated small cell carcinomas and lymphoma). Although in all cases we are dealing with malignancies, the need for a precise histological diagnosis is fundamental to work up an adequate therapeutic protocol. Given the difficulties in getting an electronic microscope in any hospital, the method used in the present case is quite significant since it made precise diagnosis possible even on bioptic fragments fixed in non buffered formalin. Finally some problems regarding diagnosis and treatment linked to diagnosis by means of electronic microscopy are discussed.
 ...
PMID:[Primary amelanotic melanoma of the nasal fossa. Importance of ultrastructural study for diagnosis]. 281 54

We have isolated a pigment cell-specific cDNA clone from a B16 mouse melanoma cDNA library by differential hybridization. The mRNA of isolated cDNA is highly expressed in B16 melanoma cells and in black mouse (C57BL/6) skin, but is not detectable in mouse neuroblastoma cells nor in K1735 mouse amelanotic melanoma cells. The protein sequence deduced from the nucleotide sequence of the cloned cDNA shows significant similarity to the entire region of Neurospora tyrosinase. To know the identity of cDNA, we transfected K1735 amelanotic melanoma and COS-7 cells with the cDNA carried in a simian virus 40 vector (pKCRH2). We confirmed that the isolated cDNA encodes mouse tyrosinase by immunofluorescence staining of transfected cells using two different anti-T4-tyrosinase monoclonal antibodies. Tyrosinase is composed of 513 amino acids with a molecular weight of 57,872 excluding a hydrophobic signal peptide of 24 amino acids.
 ...
PMID:Cloning and expression of cDNA encoding mouse tyrosinase. 300 90

In the majority of cases the histogenesis and classification of tumours can be unequivocally established by light microscopy, but in some instances the diagnosis remains ambiguous even after special staining techniques have been employed. So wide and varied are the situations in which the electron microscope can help establish a diagnosis that it is impossible to even mention them all in the brief time available. I will therefore present only a brief description of the manner in which one can resolve with the electron microscopy some well known diagnostic problems. This includes distinguishing: (1) an anaplastic carcinoma from a sarcoma; (2) an amelanotic melanoma from other tumours; (3) APUDomas from other tumors; (4) myosarcomas from other tumours; and (5) Ewing's tumour, neuroblastoma and lymphoma from each other.
 ...
PMID:The role of electron microscopy in the determination of tumour histogenesis. 727 95