Diagnosis, Differential; Diagnostic Errors; Neoplasms/diagnosis; Nervous System Diseases/diagnosis; Paraneoplastic Syndromes, Nervous System/diagnosis; Adenoma/diagnosis; Adolescent; Adult; Anti-N-Methyl-D-Aspartate Receptor Encephalitis/diagnosis; Ataxia/diagnosis; Carcinoma/diagnosis; Child; Dementia/diagnosis; Female; Ganglioneuroma/diagnosis; Humans; Hypokalemic Periodic Paralysis/diagnosis; Lipoma/diagnosis; Lymphoma, Non-Hodgkin/diagnosis; MERRF Syndrome/diagnosis; Male; Middle Aged; Myoclonic Epilepsy, Juvenile/diagnosis; Neuroblastoma/diagnosis; Opsoclonus-Myoclonus Syndrome/diagnosis; Ovarian Neoplasms/diagnosis; POEMS Syndrome/diagnosis; Pancreatic Neoplasms/diagnosis; Parathyroid Neoplasms/diagnosis; Parkinsonian Disorders/diagnosis; Plasmacytoma/diagnosis; Polymyositis/diagnosis; Stomach Neoplasms/diagnosis; Subacute Combined Degeneration/diagnosis; Teratoma/diagnosis; Thymus Neoplasms/diagnosis; Young Adult

Mass lesions; TRIAD; prognostic and therapeutic relevance; treatment-resistant neurology