452 Section II / General Surgery
What is Riedel’s thyroiditis?	Benign inflammatory thyroid
	enlargement with fibrosis of thyroid
	Patients present with painless, large thyroid
	Fibrosis may involve surrounding tissues

What is the treatment for Riedel’s thyroiditis?

Surgical tracheal decompression, thyroid hormone replacement as needed— possibly steroids/tamoxifen if refractory

C h a p t e r 59

Parathyroid

ANATOMY

How many parathyroids are	Usually four (two superior and two
there?	inferior)
What percentage of patients	5% (Think: 5 5)
have five parathyroid glands?
What percentage of patients	10%
have three parathyroid
glands?

What is the usual position of the inferior parathyroid glands?

What is the most common site of an “extra” gland?

What percentage of patients have a parathyroid gland in the mediastinum?

Posterior and lateral behind the thyroid and below the inferior thyroid artery

Thymus gland

1%

If only three parathyroid	Thyroid gland
glands are found at surgery,	Thymus/mediastinum
where can the fourth one	Carotid sheath
be hiding?	Tracheoesophageal groove
	Behind the esophagus

	Chapter 59 / Parathyroid 453
What is the embryologic
origin of the following
structures:
Superior parathyroid	Fourth pharyngeal pouch
glands?
Inferior parathyroid	Third pharyngeal pouch
glands?	(counterintuitive)
What supplies blood to the	Inferior thyroid artery
parathyroid glands?
What percentage of patients	80%
have all four parathyroid
glands supplied by the
inferior thyroid arteries
exclusively?
What is DiGeorge’s	Congenital absence of the parathyroid
syndrome?	glands and the thymus
What is the most common	Cancer
cause of hypercalcemia in
hospitalized patients?
What is the most common	Hyperparathyroidism
cause of hypercalcemia in
outpatients?
PHYSIOLOGY
What cell type produces	Chief cells produce ParaThyroid
PTH?	Hormone (PTH)
What are the major actions	Increases blood calcium levels (takes
of PTH?	from bone breakdown, GI absorption,
	increased resorption from kidney,
	excretion of phosphate by kidney),
	decreases serum phosphate

How does vitamin D work?

Increases intestinal absorption of calcium and phosphate

Where is calcium absorbed? Duodenum and proximal jejunum

454 Section II / General Surgery

HYPERPARATHYROIDISM (HPTH)

Define primary HPTH.

Define secondary HPTH.

Define tertiary HPTH.

What are the methods of imaging the parathyroids?

What are the indications for a localizing preoperative study?

What is the most common cause of primary HPTH?

What are the etiologies of primary HPTH and percentages?

What is the incidence of primary HPTH in the United States?

Increased secretion of PTH by parathyroid gland(s); marked by elevated calcium, low phosphorus

Increased serum PTH resulting from calcium wasting caused by renal failure or decreased GI calcium absorption, rickets or osteomalacia; calcium levels are usually low

Persistent HPTH after correction of secondary hyperparathyroidism; results from autonomous PTH secretion not responsive to the normal negative feedback due to elevated Ca levels

Surgical operation Ultrasound

Sestamibi scan

201TI (technetium)–thallium subtraction scan

CT/MRI A-gram (rare)

Venous sampling for PTH (rare)

Reoperation for recurrent hyperparathyroidism

Adenoma ( 85%)

Adenoma ( 85%)

Hyperplasia ( 10%)

Carcinoma ( 1%)

1/1000–4000

What are the risk factors for primary HPTH?

Family history, MEN-I and MEN-IIa, irradiation

	Chapter 59 / Parathyroid 455
What are the signs/	“Stones, bones, groans, and
symptoms of primary HPTH	psychiatric overtones”:
hypercalcemia?	Stones: Kidney stones
	Bones: Bone pain, pathologic
	fractures, subperiosteal resorption
	Groans: Muscle pain and weakness,
	pancreatitis, gout, constipation
	Psychiatric overtones: Depression,
	anorexia, anxiety
	Other symptoms: Polydipsia, weight
	loss, HTN (10%), polyuria, lethargy
What is the “33 to 1” rule?	Most patients with primary HPTH have a
	ratio of serum (Cl ) to phosphate 33
What plain x-ray findings are	Subperiosteal bone resorption (usually in
classic for HPTH?	hand digits; said to be “pathognomonic”
	for HPTH!)
How is primary HPTH	Labs—elevated PTH (hypercalcemia,
diagnosed?	T phosphorus, c chloride); urine calcium
	should be checked for familial
	hypocalciuric hypercalcemia

What is familial hypocalciuric hypercalcemia?

How many of the glands are USUALLY affected by the following conditions:

Hyperplasia?

Adenoma?

Carcinoma?

What percentage of adenomas are not single but found in more than one gland?

Familial (autosomal-dominant) inheritance of a condition of asymptomatic hypercalcemia and low urine calcium, with or without elevated PTH; in contrast,

hypercalcemia from HPTH results in high levels of urine calcium

Note: Surgery to remove parathyroid glands is not indicated for this diagnosis

4

1

1

5%

456 Section II / General Surgery

What is the differential diagnosis of hypercalcemia?

What is the initial medical treatment of hypercalcemia (1 HPTH)?

What is the definitive treatment of HPTH in the following cases:

Primary HPTH resulting from HYPERPLASIA?

Primary HPTH resulting from parathyroid ADENOMA?

Primary HPTH resulting from parathyroid CARCINOMA?

Secondary HPTH?

“CHIMPANZEES”: Calcium overdose

Hyperparathyroidism (1 /2 /3 ), Hyperthyroidism, Hypocalciuric Hypercalcemia (familial) Immobility/Iatrogenic (thiazide

diuretics)

Metastasis/Milk alkali syndrome (rare) Paget’s disease (bone)

Addison’s disease/acromegaly Neoplasm (colon, lung, breast,

prostate, multiple myeloma) Zollinger-Ellison syndrome Excessive vitamin D

Excessive vitamin A Sarcoid

Medical—IV fluids, furosemide—NOT thiazide diuretics

Neck exploration removing all parathyroid glands and leaving at least 30 mg of parathyroid tissue placed in the forearm muscles (nondominant arm, of course!)

Surgically remove adenoma (send for frozen section) and biopsy all abnormally enlarged parathyroid glands (some experts biopsy all glands)

Remove carcinoma, ipsilateral thyroid lobe, and all enlarged lymph nodes (modified radical neck dissection for LN metastases)

Correct calcium and phosphate; perform renal transplantation (no role for parathyroid surgery)