Paraneoplastic syndrome classification

Overview
A paraneoplastic syndrome is a disease or symptom that is the consequence of the presence of cancer in the body, but is not due to the local presence of cancer cells. These phenomena are mediated by humoral factors (by hormones or cytokines) excreted by tumor cells or by an immune response against the tumor. Sometimes the symptoms of paraneoplastic syndromes show even before the diagnosis of a malignancy.

Classification
Paraneoplastic syndromes can be divided into 4 main categories:


 * Mucocutaneous paraneoplastic syndromes
 * Dermatomyositis (25-50% of adult patients have an underlying malignancy)
 * Leser-Trélat sign, a sudden onset of many pigmented skin lesions
 * Acanthosis nigricans
 * Necrolytic migratory erythema
 * Sweet's syndrome
 * Pyoderma gangrenosum


 * Neurological paraneoplastic syndromes
 * Paraneoplastic cerebellar degeneration associated with lung, ovarian, breast, lymphatic, and other cancers
 * Encephalomyelitis (inflammation of the brain and spinal cord)
 * Limbic encephalitis
 * Brainstem encephalitis
 * Opsoclonus (involving eye movement)
 * Encephalitis triggered by a teratoma
 * Polymyositis
 * Lambert-Eaton myasthenic syndrome (LEMS) in small-cell lung cancer


 * Hematological paraneoplastic syndromes
 * Granulocytosis (increased granulocytes) due to the production of G-CSF


 * Endocrine metabolic syndromes
 * Hypercalcemia in breast cancer and lung cancer (typically squamous cell) due to the production of PTHrP (Parathyroid hormone-related protein)
 * SIADH associated w/ lung and CNS malignancies, typically small cell.
 * Ectopic ACTH secretion associated with small-cell lung cancer, carcinoid tumor, thymoma and other cancers
 * Tumor induced osteomalacia


 * Others that may not fit into any of the above categories include:
 * Membranous glomerulonephritis