laboratory and radiological findings in hyperparathyroidism

1. LABORATORY AND RADIOLOGICAL
FINDINGS IN HYPERPARATHYROIDISM

2. Hyperparathyroidism
• Hyperparathyroidism is a common cause of
hypercalcemia
• Prevalence of 1-4 cases per 1000 persons
• Most common in 7th decade and women(74%)
• Caused by hypersecretion of PTH usually by:
1. Single parathyroid adenoma(80%)
2. Hyperplasia of 2 or more parathyroid
glands(20%)
3. Carcinoma(≤1)

3. • Familial in 10% of cases
• Hyperplasia may arise in MEN types 1, 2A, 2B
• MEN1 has multiglandular hyperparathyroidism
as initial manifestation and ultimately occurs in
90%od affected individuals
• MEN2 has less frequent occurrence and is
milder
• Familial hyperparathyroidism can also occur in
hyperparathroidism-jaw tumor syndrome
• Rare autosomal dominant trait in which there is
association with ossifying fibromas of mandible,
maxilla and renal lesions

4. • Hyperparathyroidism results in excessive
excretion of calcium and phosphate by
kidneys
• PTH stimulates renal tubular reabsorption of
calcium; however in hyperparathyroidism causes
hypercalcemia and an increase in calcium in the
glomerular filtrate that overwhelms tubular
reabsorption capacity, resulting in hypercalciuria
• 5% of renal calculi are associated with this
• Excessive PTH can cause cortical
demineralization that is evident at wrist and
pelvis
• Chronic state can cause diffuse demineraliztion,
pathological fractures and cystic bone lesions;
osteitis fibrosa cystica

5. • In chronic renal disease hyperphosphatemia
and decreased renal production of 1,25-
dihydroxycholecalciferol initially produce a
decrease in ionized calcium
• Parathyroid glands are stimulated(secondary)
and may enlarge becoming
autonomous(tertiary)
• Renal disease here is called renal
osteodystrophy
• Parathyroid hyperplasia in uremia can result in
high serum PTH that lead to uremic vascular
calcification
• Hypercalcemia often occurs after kidney
transplant

6. • Parathyroid carcinoma is rare cause
• More common in patients with serum calcium
≥14mcg/dL
• 50% of parathyroid carcinoma are palpable

7. Clinical findings
• Mostly asymptomatic or mild symptoms
• Adenomas are small and deeply located, almost
never palpable
• Symptomatic patients have problems:
“Bones, stones, abdominal groans, psychic moans
with fatigue overtones”

8. Skeletal manifestations
• Loss of cortical bone
• Gain of trabecular bone
• Low bone density; particularly in wrist
• Asymptomatic vertebral fractures; post
menopausal women more prone
• Bone pain
• Arthralgia
• Brown tumors
• Cysts of jaw

9. Hypercalcemia manifestations
CNS
• Depression
• Constipation
• Bone and joint pain
• Paresthesia
• Muscular weakness
• Diminished deep tendon reflexes
• Malaise
• Fatigue
• Intellectual weariness
• Disorientation

10. Hypercalcemia manifestations
CVS
• Prolonged P-R interval
• Shortened Q-T interval
• Sensitivity to arrhythmic effects of digitalis
• Bradyarrhythmias
• Heart block
• Asystole

11. Hypercalcemia manifestations
Renal
• Polyuria
• Polydipsia
• Nephrogenic diabetes insipidus
• Calcium nephrolithiasis

12. Hypercalcemia manifestations
GI
• Anorexia
• Abdominal pain
• Weight loss
• Constipation
• Constipation
• Pancreatitis
MISC
• Pruritis
• Precipitation of Ca in cornea; band keratopathy
• Precipitation in extravascular tissue and arteries
causing small vessel thrombosis and skin necrosis

13. Laboratory findings
• Hypercalcemia with serum adjusted total
calcium ≥10.5 mg/dL
Adjusted total calcium=measured serum
calcium in mg/dL +[0.8x(4-patient’s serum
albumin in g/dL)]
• Serum ionized calcium in hyperproteinemic
states and hyperparathyroidism is >5.4mg/dL

14. • Low serum phosphate <2.5mg/dL due to loss in
urine
• In secondary renal disease serum phosphate is high
• Alkaline phosphatase is elevated if bone
disease present
• Plasma chloride and uric acid levels elevated
• Vitamin D deficiency
• Low serum 25-OH vitamin D levels <20mcg/L
aggravate bone manifestation
• Elevated serum level of intact PTH confirm
diagnosis (normal 10-65ng/L)
• 24hour urine for calcium and creatinine done to
screen for familial benign hypocalciuric
hypercalcemia; Ca <50mg/24hours

15. • Patients with low bone density and elevated PTH
but normal serum Ca must be evaluated for
causes of secondary hyperparathyroidism
• In absence of secondary hyperparthyroisim but
raised PTH and normal serum Ca patients are
said to have normocalcemic
hyperparathyroidism

16. Imaging
• Preoperative sestamibi-iodine subtraction scanning
• Involve injecting a small amount of special radioactive
material into a vein and taking an X-ray image of the
chest, neck, and head
• Accuracy rate of about 80 to 95%
• Neck ultrasound can locate parathyroid adenoma
• Adenomas appear as well-defined hypoechoic lesions
with potential cystic or necrotic areas.
• Ultrasonography offers the advantage of depicting
potential concomitant thyroid disease, present in 40%
of patients
• Helps in limiting the invasiveness in surgery

17. • CT and MRI of neck are helpful for ectopic
parathyroid glands
• CT scanning of kidneys to determine calcium
containing stones
• Bone density measurement by dual energy x-
ray absorptiometry(DXA) to see the bone loss
• DXA of lumbar spine, pelvis and distal radius

18. • X-rays to show bone demineralization;
subperiosteal resorption; radial aspects of fingers
• About 30-50% of the bone density must be lost to
show changes on radiographs.
• Loss of lamina dura of teeth
• Mottling of skull; salt and pepper appearance
• Pathological fractures
• Articular cartilage calcification
• In patients with renal osteodystrophy ectopic
calcifications around joints or soft tissue
• Radiographic changes show osteopenia, osteitis
fibrosa, osteosclerosis
• Osteosclerosis of vertebral bodies; rugger jersey
spine

23. Brown tumors
• Brown tumors are well-circumscribed lytic
lesions of bone that represent the osteoclastic
resorption of a confluent area of bone with
fibrous replacement.
• The lesions may be single or multiple, with
expansion of overlying bone, usually occur in
cortical bone.
• Common sites include the mandible, clavicle,
ribs, pelvis, and femur.

28. Distal femur shows scalloped defects along
the inner margin of the cortex, which
denote endosteal resorption.

29. Humerus- osseous expansion and
lucency of the proximal humerus.
Radiograph of the mid femoral diaphysis -
eccentric (arrowheads) and central
positions (arrow) of the lesions.

31. Management
• IV fluids
• Bisphosphonates; pamidronate, zoledronic acid
• Vitamin D and vitamin D analogs; calcitriol,
paricalcitrol, doxercalciferol
• Cinacalcet; calcimimetic agent

32. THANK YOU