Transcript E - Texas Tech University Health Sciences Center

Board Pearls
in Endocrinology
Part 2
Rey Vivo, MD
Assistant Professor of Medicine
Texas Tech University Health Sciences Center
Objectives
• Discuss frequently tested Endocrine cases in the
IM Boards
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Pituitary
Cushing’s, Adrenal Incidentaloma
Amenorrhea, Hirsutism, Anorexia vs. Bulimia
Calcium homeostasis, Parathyroid, Bone disorders
Hemochromatosis, Wilson’s disease
Diabetes insipidus
• Examine practice questions from MKSAP and
other sources
Calcium homeostasis:
Parathyroid, Vit. D, Bone diseases
Hypercalcemia Causes
Increased bone resorption
Primary and secondary hyperparthyroidism (usually 10.5 – 11.0 mg/dL)
Malignancy (usually >13 mg/dL)
Others: hyperthyroid, Paget’s, etc.
Increased intestinal calcium absorption
Increased calcium intake (renal disease)
Hypervitaminosis D (e.g. sarcoidosis)
Miscellaneous
Thiazides, lithium, rhabdomyolysis, theophylline toxicity, etc.
PTH homeostasis
plasma Ca
PTH
Bone
Resorption
Release of
Ca, PO4
Kidney
PO4
excretion
Ca
reabsorption
Calcitriol
formation
Intestinal
CaHPO4
absorption
Hypercalcemia
• PEARLS:
– Indications for surgery in hyperparathyroidism:
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1.
2.
3.
4.
Calcium >11.5 mg/dL
24-hour urinary calcium >400 mg
Age <50
Symtomatic: kidney stones, osteoporosis,
dehydration
MKSAP Q #10
• 48F is seen for serum calcium of 11.4 mg/dL. DEXA scan showed T
scores at the lumbar spine and L femoral neck of -0.88 and -0.55
respectively. There is no history of renal stones, bone fractures,
cognitive impairment or fatigue. Intact PTH is 115 pg/mL, creatinine
0.9 mg/dL. The urine calcium/creatinine clearance ratio is >0.01 but
the 24-hr. urine calcium excretion is 250 mg. What is the best next
step in management?
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A. Observation
B. IV pamidronate
C. Mammography
D. Parathyroidectomy
E. Low calcium diet
MKSAP Q #118
• A 30F is found to have asymptomatic hypercalcemia. She notes
occasional milky discharge from her breasts. Her menses have been
irregular for the past year. Both her mother and her sister have been
diagnosed with pituitary tumors and hypercalcemia. Her estimated
oral calcium intake is 600 mg/d. On PE, she has expressible
galactorrhea. Funduscopic examination and visual field testing are
normal. Labs: calcium 11.2 mg/dL, phosphorus 2.5 mg/dL, chloride
109 meq/L, albumin 4.8 g/dL, intact PTH 55 pg/mL, prolactin 142
ng/mL. Which therapy is most likely to correct the patient's
hypercalcemia?
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A. An oral bisphosphonate
B. Surgery to remove a parathyroid adenoma
C. Surgery to remove a pheochromocytoma
D. Surgery to remove 3½ parathyroid glands
E. Surgery to remove a pituitary tumor
MEN syndromes
• PEARLS:
MEN-I
Parathyroid + pituitary + pancreatic
MEN-IIa Parathyroid + pheochromocytoma + medullary thyroid CA
MEN-IIb Pheochromocytoma + medullary thyroid CA + neuroganglioma
MKSAP Q #41
• A 42M is evaluated for an anterior neck mass. He has a family
history of thyroid CA and hyperparathyroidism. On PE, BP is 147/85
and pulse rate is 88/min; he has a 3-cm right thyroid nodule and
bilateral anterior cervical lymphadenopathy. Lungs are clear and
cardiac examination reveals a 2/6 systolic ejection murmur; there is
no pedal edema. Labs: TSH 1.4 µU/mL, calcium 10.6 mg/dL, and
microscopic hematuria. Fine-needle aspiration biopsy of the nodule
suggests medullary thyroid cancer. What is the most appropriate
next step?
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A. Serum calcitonin level
B. Repeat biopsy with immunostaining for calcitonin
C. Serum PTH level
D. Urine metanephrines
E. Urine calcium, phosphate, and citrate
Bone disorders
Condition
Calcium
Phosphorus
Alk. Phos.
PTH
Osteoporosis
N
N
N
N
Osteomalacia
N/Low
Low
High
High
N
N/Sl. High
Very High
N
Low
High
N/High
High
Paget’s
CKD
MKSAP Q #36
• A 60M is evaluated for increasing fatigue, malaise, and bone pain
over the past 2 years. He has chronic alcoholism, HTN, and gout.
He was started on pancreatic enzymes 8 years ago when he
developed steatorrhea and weight loss. He stopped drinking then.
He suffered a Colles wrist fracture 18 months ago. A recent digital
rectal examination showed a normal prostate gland, and his PSA
level is 2.0 ng/mL. He does not have fevers, chills, or night sweats.
On PE, there is generalized tenderness of the bones. Proximal
muscle weakness is noted along with a waddling gait. Labs:
hematocrit 34%, calcium 7.2 mg/dL, phosphorus 2.2 mg/dL, albumin
3.5 g/dL, alkaline phosphatase 290 U/L. Xrays of the long bones
reveal bilateral radiolucent bands on the femur. Next best step?
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A. Osteoporosis
B. Osteomalacia
C. Paget's disease of bone
D. Metastatic prostate cancer
E. Paraneoplastic syndrome
Board Q
• 82F with osteoporosis and severe kyphosis has been
taking alendronate and calcium + Vitamin D supplements
with good adherence. However, she still complains of
bone pains. What is the best step in management?
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A.
B.
C.
D.
Start Fentanyl patch
Add calcitonin
Add estrogen
Refer to pain clinic
MKSAP Q #14
• A 78F is evaluated for fatigue, irritability, and depression. She is a
resident of a nursing home and her ambulation is limited by rightsided hemiparesis following a stroke 3 years ago. She has type 2
DM, HTN and hyperlipidemia. Medications include glipizide,
simvastatin, aspirin, lisinopril, furosemide and amlodipine. PE
reveals a positive Chvostek's sign on the right side, dry skin, brittle
nails, and coarse hair. Labs: BUN18 mg/dL, creatinine 1.2 mg/dL,
albumin 3.5 g/dL, calcium 7.2 mg/dL, alkaline phosphatase 260 U/L.
What is the most approprioate next step?
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A. Parathyroid sestamibi scan
B. 25-hydroxyvitamin D
C. 1,25-dihydroxyvitamin D3
D. Calcitonin
MKSAP Q #133
• A 75F is seen after a recent fractured hip. She has HTN and
hypothyroidism but has not been on any medications for the past
year. She lives alone and seldom leaves her house. She has a
scanty diet and does not consume dairy products. She does not
smoke cigarettes or drink alcohol. On PE, she has moderate dorsal
kyphosis, a small firm goiter, and diffuse muscle weakness. Bone
densitometry confirms low bone mass in her spine (T-score −2.9)
and the unaffected hip (T-score −3.4). Labs: CBC normal, calcium
8.6 mg/dL, phosphorus 2.4 mg/dL, alkaline phosphatase165 U/L,
TSH 21 µU/mL. Which serum tests would be most helpful in
determining the cause of this patient's skeletal disease?
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A. Parathyroid hormone
B. 25-dihydroxyvitamin D
C. 1,25-dihydroxyvitamin D3
D. Osteocalcin
E. Protein electrophoresis
Hemochromatosis,
Wilson’s disease
PEARLS
Hemochromatosis
Presentation Hypogonadism, DM, liver
dysfunction, large joint arthritis,
skin hyperpigmentation,
cardiomyopathy/arrhythmias
Wilson’s
Hepatic – hepatitis, cirrhosis
Extrahepatic – neuropsych
(movement, cognitive disorder),
kidney, blood
Kayser Fleischer ring
Defect
Abnormal iron accumulation
HFE gene
Increased copper deposition
Diagnosis
High ferritin, iron, transferrin
Low serum ceruloplasmin
Treatment
Phlebotomy, Iron chelation
Dietary restriction
Penicillamine
MKSAP Q #63
• 42M presents with decreased libido, erectile dysfunction and
general fatigue. He does not take any medications. He also
mentions that he has to shave only every other day and that he has
nocturia. On PE, he is well developed but mildly overweight (BMI
26). BP is 126/80, pulse rate is 70/min. He has normal fundi and
visual fields; decreased body hair and slightly soft testes; skin is
somewhat tan, but he has recently been on a tropical vacation. His
family history is significant for type 2 DM. Labs: CBC normal, fasting
glucose160 mg/dL, ALT 55 U/L, AST 68 U/L, urinalysis shows mild
glucosuria. Repeat fasting glucose is 135 mg/dL. Which test will
confirm the most likely diagnosis?
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A. Serum FSH, LH, and iron studies
B. Liver biopsy
C. Hepatitis serologies
D. Liver ultrasound
E. Inferior petrosal sinus sampling for ACTH and cortisol levels
MKSAP Q #72
• 42M is evaluated for poor libido, fatigue, and progressive skin
darkening. He underwent a normal puberty and has two children 8
and 10 years old. He denies vision loss, gynecomastia, or cold
intolerance. His only other medical problem is arthritis in the hands.
Family history is negative for calcium or pituitary tumors, and a
maternal uncle had cryptogenic cirrhosis. PE: full visual fields, soft
12-mL testes, and bilateral swollen metacarpophalangeal joints. The
skin is dark. Labs: hematocrit 50%, LH 0.2 mU/mL, FSH 0.2 mU/mL,
prolactin 4 ng/mL, testosterone 128 ng/dL, PSA 0.2 ng/mL. Best
next step?
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A. Gonadotropin-releasing hormone stimulation test
B. Karyotype
C. MRI of the head
D. Measurement of serum transferrin saturation and ferritin
E. Therapeutic trial of testosterone
Diabetes Insipidus
PEARLS
Normal
Central
DI
Nephrogenic
DI
Primary
Polydipsia
Urine osm
after
dehydration
Increased
No increase
No increase
Partial
increase
Urine osm
after
vasopressin
< 5%
increase
> 50%
increase
No increase
< 9%
increase
MKSAP Q #49
• A 34F is seen for polyuria and polydipsia. She has depression, is
overweight and has a family history of DM. She is taking no meds.
Fasting glucose is 100 mg/dL and there is no glucosuria. However,
her urine SG is <1.005. Her measured 24-hour urine output is 7 to 8
L/d. Serum Na is 140 meq/L; electrolytes are otherwise normal. A
water deprivation test is performed: serum Na rises to 148 meq/L,
the urine osmolality remains <300 mosm/kg H2O and the plasma
osmolality increases to 299 mosm/kg H2O. Despite no oral intake
during the test, her urine output remains on average 275 mL/h. At
this time, blood is collected for measurement of ADH, and 1 µg of
vasopressin is administered subcutaneously. One hour later, the
urine osmolality increases to 600 mosm/kg H2O and the urine
output decreases to less than 100 mL/h. The blood ADH level is
pending. Most likely diagnosis?
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A. Normal, no evidence of pathology
B. Nephrogenic diabetes insipidus
C. Central diabetes insipidus
D. Primary polydipsia
Thank you