Paraneoplastic Syndromes¶
Bailey DeCoursey, Justin Lo
Hypercalcemia of Malignancy¶
Background¶
- Caused by PTHrP production, osteolytic lesions, and/or rarely exogenous Vit D
- PTHrP: breast cancer, NSCLC (squamous)
- Osteolysis: multiple myeloma, Breast Cancer;
- Exogenous vit D: lymphoma
Evaluation¶
- Correct [Ca2+] for hypoalbuminemia: [Ca2+] + 0.8 x (4.0 – albumin)
- Send basic hyperCa+2 work-up: PTH, vit D, etc (see “Hypercalcemia” section)
- PTHrP is called “Parathyroid Hormone-related Peptide-ARUP” in Epic
Management¶
- First line: IVF without calcium such as Normosol; goal urinary output of 150-200 mL/hr
- Strict I/Os: cautious IV fluids in pts with cardiac or renal dysfunction
- Add Furosemide if hypervolemic (do not empirically start)
- Second line: zoledronic acid 4mg IV (takes 24-48 hours to see effect)
- AMS or severe hypercalcemia (>14mg/dL): calcitonin 4 IU/kg (requires attending approval)
SIADH¶
Background¶
- Euvolemic hypotonic hyponatremia with urine sodium >20 and typically urine Osm >100
- Associated with: SCLC (most common), head/neck cancers, breast cancer
- See "Hyponatremia” section for additional information
Management¶
- Free water restriction to 800mL/day
- Refractory: salt supplementation (e.g. salt tabs) ± loop diuretic
Carcinoid Syndrome¶
Background¶
- Episodic flushing, diarrhea, wheezing/SOB due to secretion of histamine & serotonin
- Most common: Neuroendocrine tumors, GI (often with mets to liver and lung)
Evaluation¶
- Urine: UR 5-HIAA (ARUP)
- Imaging to identify tumor(s): CT C/A/P
Management¶
- Short-term treatment: subQ or IV octreotide (see UpToDate for dosing)
- Antidiarrheals (Imodium, Lomotil) to slow transit
- Long-term treatment: depot (IM) forms of octreotide and lanreotide
Autoimmune Encephalitis, Encephalomyelitis, and Myelitis¶
Background¶
- Encephalopathy (limbic or brainstem) ± myelitis (limb ataxia, sensory deficits)
- Associated with small cell lung cancer and checkpoint inhibitor therapy
Evaluation¶
- LP: make sure to order CSF oligoclonal bands and CSF IgG index
- “Paraneoplastic AutoAb Eval-MAYO” (add "CSF" to the front of the order name if for LP)
- NMDA-R can be ordered as a standalone test
- CT head
- EEG if concern for subclinical seizures
Management¶
- Consult Neurology for possible immunosuppressive therapy (steroids, IVIG)
Lambert-Eaton Myasthenic Syndrome (LEMS)¶
Background¶
- Muscle weakness due to autoantibody against calcium channels resulting in ↓ ACh release
- Associated with SCLC (most common) & lymphoma
- See “Myasthenia Gravis (MG) and Lambert-Eaton Myasthenic Syndrome (LEMS)” section in Neurology