Paraneoplasic Syndrome

Question 1

Paraneoplastic syndrome definition, pathophysiology and common presentations

Answer 1

• clinical syndromes involving non-metastatic systemic effects that accompany malignant disease
• triggered by antibodies against neoplasm cross-reacting with normal tissue or by production of a physiologically active substance by the neoplasm
• commonly present with cancers of lung, breast, ovaries, or lymphatic system

Question 2

Cushing’s syndrome Paraneoplastic syndrome associated malignancies

Answer 2

Small-cell lung cancer

Pancreatic carcinoma

Neural tumours

Thymoma

Question 3

Cushing’s syndrome Paraneoplastic syndrome mechanism

Answer 3

Ectopic ACTH and ACTH-like substance secretion

Question 4

SIADH Paraneoplastic syndrome associated malignancies and mechanism

Answer 4

Small-cell lung cancer
CNS malignancies

Antidiuretic hormone secretion

Question 5

Hypercalcemia Paraneoplastic syndrome associated malignancies and mechanism

Answer 5

Lung cancer Breast carcinoma Renal cell carcinoma Multiple myeloma Ovarian carcinoma

PTH-related protein, TGF-α, TNF secretion

Question 6

Hypoglycemia Paraneoplastic syndrome associated malignancies and mechanism

Answer 6

Hepatocellular carcinoma Fibrosarcoma

Insulin or insulin-like substance secretion

Question 7

Carcinoid Paraneoplastic syndrome associated malignancies and mechanism

Answer 7

Pancreatic carcinoma
Gastric carcinoma

Serotonin, bradykinin secretion

Question 8

Lambert-Eaton myasthenic syndrome (LEMS) Paraneoplastic syndrome presentation, associated malignancies and mechanism

Answer 8

Muscle weakness in limbs

Small-cell lung cancer

Ab interferes with ACh release

Question 9

Myasthenia gravis Paraneoplastic syndrome presentation, associated malignancies and mechanism

Answer 9

Fluctuating muscle weakness and fatiguability

Thymoma

Ab interferes with ACh release

Question 10

Paraneoplastic limbic encephalitis Paraneoplastic syndrome presentation, associated malignancies and mechanism

Answer 10

Depression, seizures, shortterm memory loss

Small-cell lung cancer

Unknown

Question 11

Hypokalemic nephropathy Paraneoplastic syndrome associated malignancies and mechanism

Answer 11

Small-cell lung cancer

Ectopic ACTH and ACTH-like substance secretion

Question 12

Nephrotic syndrome Paraneoplastic syndrome associated malignancies and mechanism

Answer 12

Lymphoma Melanomas

Immunocomplex sedimentation in nephrons

Question 13

Watery diarrhea Paraneoplastic syndrome associated malignancies and mechanism

Answer 13

Medullary thyroid carcinomas

Prostaglandin secretion

Question 14

Erythrocytosis Paraneoplastic syndrome associated malignancies and mechanism

Answer 14

Renal cell carcinoma Hepatocellular carcinoma

EPO production

Question 15

SLE Paraneoplastic syndrome associated malignancies and mechanism

Answer 15

Lymphomas Lung cancer Breast carcinoma Gonadal carcinoma

Anti-nuclear Ab production

Question 16

Scleroderma Paraneoplastic syndrome associated malignancies and mechanism

Answer 16

Breast carcinoma Lung cancer Uterine cancer

Anti-nuclear Ab produ tion

Question 17

Paraneoplastic syndrome investigations

Answer 17

• CBC, electrolytes, creatinine, LFTs, ALP, ESR, CRP, serum/urine electrophoresis
• serum autoantibodies, lumbar puncture
• imaging: skeletal survey, CT, MRI, PET scan
• ± endoscopy

Question 18

Paraneoplastic syndrome treatment

Answer 18

• treat underlying tumour: surgery, radiation, chemotherapy
• treat immune-mediated disorder: IVIg, steroids, immunosuppressive drugs, plasmapheresis (reserved for patients with identifiable antibodies in serum)