Paraneoplastic Syndrome - H/O

Question 1

Paraneoplastic Syndrome

Answer 1

• Definition :Heterogeneous group of disorders caused by mechanisms other than metastases, metabolic and nutritional deficits, infections, coagulopathy or side effects of cancer treatment.
• Studies of the prevalence of PNS indicate that they are more common than is generally appreciated
• Often signs, symptoms and metabolic alterations associated with PNS are overlooked in the context of a malignancy and its treatment
• Many patients with paraneoplastic disorders may have autoantibodies against several tissues of the body.
• Most known autoantibodies are directed against nervous system structures

Question 2

most common cancers associated with paraneoplastic syndromes

Answer 2

• Lung carcinoma (most common)
• Renal carcinoma
• Hepatocellular carcinoma
• Leukemias
• Lymphomas
• Breast tumors
• Ovarian tumors
• Neural cancers
• Gastric cancers
• Pancreatic cancers

Question 3

Epidemiology

Answer 3

Frequency :
-The reported frequency of paraneoplastic syndromes ranges from 10-15% to 2-20% of malignancies. However, these could be underestimates. Neurological paraneoplastic syndromes are estimated to occur in fewer than 1% of patients with cancer.

Mortality/Morbidity :
-The true incidence of deaths and complications related to paraneoplastic syndromes is unknown.

Race :
-No race predilection is reported.

Sex :
-No sex predilection is known.

Age :
-People of all ages may be affected by cancers and their related paraneoplastic syndromes.

Question 4

Pathophysiology

Answer 4

• The mechanisms of how cancers affect distant sites are not understood precisely
• Cross-reacting Abs (as in the case of neurologic paraneoplastic syndromes)
• Production of physiologically active substances such as hormones, hormone precursors, a variety of enzymes, or cytokines(as in the case of endocrine paraneoplastic syndromes)
• Interference with normal metabolic pathways or steroid pathways
• Idiopathic

Question 5

Clinical Presentation

Answer 5

• Complex and varied
• Can be divided into the following categories:

General paraneoplastic symptoms:

• Rheumatologic
• Renal
• Gastrointestinal
• Hematologic
• Cutaneous
• Endocrine, and
• Neuromuscular.
• Fever, night sweats, anorexia, and cachexia

Question 6

Rheumatologic paraneoplastic syndrome

Answer 6

• Arthropathies : Rheumatic polyarthritis or Polymyalgia (myelomas; lymphomas; leukemia)
• Hypertrophic osteoarthropathy (lung cancers, pleural mesothelioma,or phrenic neurilemmoma)
• SLE: (Patients with lymphomas or cancers of the lung, breast, or gonads)
• Secondary amyloidosis:(Patients with myeloma, RCC, and lymphomas)

Question 7

Renal paraneoplastic syndrome

Answer 7

-Membranous glomerulonephritis may occur in patients with colon cancer, ovarian cancer, and lymphoma as a result of circulating immune complexes

Question 8

Gastrointestinal paraneoplastic syndrome

Answer 8

• Watery diarrhea accompanied by an electrolyte imbalance leading to asthenia, confusion, and exhaustion
• Typically seen in patients with Medullary ca of thyroid, Proctosigmoid tumors
• Also observed in patients with melanomas, myelomas, ovarian tumors, pineal body tumors, and lung metastases.

Question 9

Cutaneous paraneoplastic syndromes

Answer 9

• Itching is the most frequent cutaneous manifestation in patients with cancer(may result from hypereosinophilia)
• Herpes zoster, ichthyosis, alopecia, or hypertrichosis also may be observed
• Pigmented skin lesions, or keratoses : Acanthosis nigricans and dermic melanosis usually occur in patients with metastatic melanomas or pancreatic tumors

Question 10

Diagnostic Evaluation

Answer 10

• Laboratory Studies
• Patients with a suspected paraneoplastic disorder should receive a complete panel of laboratory studies of blood, urine, and cerebrospinal fluid (CSF).
• CBC may demonstrate anemia.
• ESR is usually increased in patients with cancers
• Microscopic study of the WBCs is helpful for diagnosis of leukemia or lymphoma-related disorders.
• Hypereosinophilia is frequently observed in patients with Hodgkin lymphoma.
• Platelet count must be performed in any patient with symptoms of DIC.
• Blood enzymes may be altered
• Protein electrophoresis of serum and CSF may demonstrate alterations of albumin levels and increased beta-globulins and gamma-globulins. Gamma-globulins are always increased in patients with autoimmune disorders, whether neoplastic or not.