Paraneoplastic Syndromes Flashcards
What is a Paraneoplastic Syndrome?
Tumor secretes substances or evokes other factors
Tumor secretes substances of evokes other factors
Paraneoplastic Syndrome
Levels of calcium and PTH with Humoral Hypercalcemia of Malignancy
Calcium = HIGH PTH = LOW
What will be INCREASED that mediates Humoral Hypercalcemia of Malignancy?
PTH-rp
PTH - related protein
Symptoms of Humoral Hypercalcemia of Malignancy?
Mental status changes
With Humoral Hypercalcemia of Malignancy, cancers will release PTH-rp, what does this cause?
Bone resorption and renal distal tubule calcium reabsorption
Humoral Hypercalcemia of Malignancy does NOT affect?
Vitamin D pathway and intestinal calcium absorption
Symptoms of Humoral Hypercalcemia of Malignancy?
Mental status changes due to increased calcium
SIADH
Syndrome of Inappropriate ADH Secretion
With SIADH, what are the levels of plasma sodium and serum osmolality?
LOW
With SIADH, what is the level of urine osmolality?
ELEVATED
Symptoms of SIADH?
Drowsy and irritable
What mediates SIADH?
ADH (anti-diuretic hormone) and
AVP (arginine vasopressin)
What mediates SIADH?
ADH and AVP
What carcinoma usually causes SIADH?
Small cell neuroendocrine carcinoma
Describe how SIADH arises?
- Small cell neuroendocrine carcinoma secretes ADH and AVP
- ADH and AVP cause renal receptors to retain free water
- Thus, the water is not excreted in the urine = high osmolality
- Thus, the water dilutes the serum
Describe how SIADH arises?
- Small cell neuroendocrine carcinoma secretes ADH and AVP
- ADH and AVP cause renal receptors to retain free water
- Thus, the water is not excreted in the urine = high osmolality
- Thus, the water dilutes the serum
With SIADH, levels of plasma sodium, serum osmolality and urine osmolality
Plasma sodium - LOW
Serum osmolality - LOW
Urine osmolality - HIGH
What is the most common paraneoplastic syndrome caused by small cell neuroendocrine carcinoma?
SIADH
What is the 2nd most common paraneoplastic syndrome caused by small cell neuroendocrine carcinoma?
Cushing Syndrome
Level of serum potassium with Cushing Syndrome?
LOW
Symptoms of Cushing Syndrome?
Weight loss, muscle weakness, and new-onset hypertension
Weight loss, muscle weakness, new onset hypertension?
Cushing Syndrome
What will BOTH be elevated with Cushing Syndrome?
ACTH
CORTISOL
What will be absent from Cushing syndrome if it is a paraneoplastic syndrome?
Central obesity and moon facies
Describe how Cushing Syndrome arises?
- Small cell neuroendocrine carcinoma secretes ACTH
- ACTH causes adrenal gland to secrete Cortisol
= Hypertension, muscle weakness, weight loss
Describe how Cushing Syndrome arises?
- Small cell neuroendocrine carcinoma secretes ACTH
- ACTH causes adrenal gland to secrete Cortisol
= Hypertension, muscle weakness, weight loss
Serum potassium level with Cushing syndrome?
LOW
What is Lambert-Eaton Myasthenic Syndrome?
Auto-antibodies against voltage gated calcium channels
“anti-VGCC antibodies”
Anti-voltage gated calcium channel antibodies are seen with?
Lambert-Eaton Myasthenic Syndrome
The autoantibodies against voltage gated calcium channels with Lambert-Eaton Myasthenic Syndrome target?
NMJ
What cancer commonly causes Lambert-Eaton Myasthenic Syndrome?
Small cell
Symptoms of Lambert-Eaton Myasthenic Syndrome?
Proximal muscle weakness that improves with repetitive motion/stimulation
Proximal muscle weakness that improves with repetitive motion/stimulation
Lambert-Eaton Myasthenic Syndrome
How do you diagnose Lambert-Eaton Myasthenic Syndrome?
Antibodies and nerve stimulation testing
