Paraneoplastic Syndromes¶
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 [Ca+2] for hypoalbuminemia: add 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 if pt w/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 (req. 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 "Nephrology" 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 chest/abdomen/pelvis)
Management¶
- Short-term treatment: subQ or IV octreotide (see UpToDate for dosing)
- Antidiarrheals (Imodium, Lomotil, etc.) 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 & 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
Presentation¶
- Proximal muscle weakness, diminished DTRs
Evaluation¶
- Nerve conduction studies: EMG w/ NCV
- Serum “Paraneoplastic AutoAb Eval-MAYO”
Management¶
- Consult Neurology
Last update:
2022-06-25 02:05:01