Paraneoplastic syndromes

Paraneoplastic syndromes are a group of metabolic and neurologic disorders resulting from remote neoplasms, but are not themselves cancers. They appear to be caused by cytokines release either from the tumors themselves, or from T-lymphocytes, or by antibodies characteristic of autoimmune disease.

Laboratory diagnosis

A paraneoplastic antibody screen panel, for example, can consist of:

• Neuronal Nuclear Antibody (Hu) Screen, Serum
• Neuronal Nuclear Antibody Screen, Ri
• Neuronal Nuclear Antibody Titer, Serum
• Neuronal Nuclear Antibody, Ri, Titer
• Neuronal Nuclear Antibody, Ri, Western Blot
• Neuronal Nuclear Antibody, Western Blot, Serum
• Purkinje Cell (Yo) Antibody Screen, IFA, Serum
• Purkinje Cell Antibody Titer, IFA, Serum

Metabolic

Fever is the most common manifestation. Cachexia, with or without loss of appetite, is common.

Rheumatologic

An assortment of rheumatologic disorders may precede or accompany the neoplasm:

• Scleroderma often precedes a cancer diagnosis.
  • Its widespread form is typical of malignancies of the breast, uterus, and lung (both alveolar and bronchial forms).
  • The localized form is characteristic of carcinoids and of lung tumors (bronchoalveolar forms).
• arthropathies arise as rheumatic polyarthritis or polymyalgia, particularly in patients with myelomas; lymphomas; acute leukemia; malignant histiocytosis; and tumors of the colon, pancreas, prostate, and CNS
• Hypertrophic osteoarthropathy may be observed in patients with lung cancers, pleural mesothelioma, or phrenic neurilemmoma.
• Systemic lupus erythematosus (SLE) may develop in patients with lymphomas or cancers of the lung, breast, or gonads.
• Secondary amyloidosis of the connective tissues is a rare presentation in patients with myeloma, renal carcinoma, and lymphomas.

Neurologic

The linkage between cancer and neurologic disorder was first reported in 1890 "Neurologic symptoms generally develop over a period of days to weeks and usually occur prior to the tumor being discovered. These symptoms may include difficulty in walking or swallowing, loss of muscle tone, loss of fine motor coordination, slurred speech, memory loss, vision problems, sleep disturbances, dementia, seizures, sensory loss in the limbs, and vertigo or dizziness. Paraneoplastic syndromes include Lambert-Eaton myasthenic syndrome, stiff-person syndrome, encephalomyelitis, myasthenia gravis, cerebellar degeneration, limbic or brainstem encephalitis, neuromyotonia, opsoclonus, and sensory neuropathy."