[Paraneoplastic optic neuritis in an unknown small cell lung carcinoma defined by CRMP-5-IgG].
METHODS
The case of a 64-year-old patient with bilateral, progressive and painless diminution of visual acuity is presented. Ophthalmologic evaluation revealed optic neuritis and vitreous cells in both eyes, at different stages. Suspecting a paraneoplastic optic neuritis, the study of antibodies was requested. This showed positivity to the marker CRMP-5-IgG. After mediastinoscopy, a small cell lung carcinoma was diagnosed.


CONCLUSIONS
Autoantibody CRMP-5-IgG defines a paraneoplastic entity of combined optic neuritis and vitreous inflammatory cells. The serological positivity avoids the vitreous biopsy and expedites the search for cancer. In our case, it allowed the diagnosis a previously unidentified tumor.
Toribio-García
J A
JA
Hospital de León, León, España. draltor@gmail.com
Franco-Benito
M
M
García-Ruiz-de-Morales
J M
JM
D001323:Autoantibodies / Q000032:analysis*; D018288:Carcinoma, Small Cell / Q000150:complications*; D006801:Humans; D006867:Hydrolases; D007074:Immunoglobulin G / Q000032:analysis*; D008175:Lung Neoplasms / Q000150:complications*; D008297:Male; D008869:Microtubule-Associated Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009902:Optic Neuritis / Q000175:diagnosis* / Q000209:etiology*; D010257:Paraneoplastic Syndromes / Q000175:diagnosis* / Q000209:etiology*
D001323:Autoantibodies; D007074:Immunoglobulin G; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; C415087:DPYSL5 protein, human; D006867:Hydrolases