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Thyroid and Parathyroid Glands 267

Lobectomy with isthmus resection may be sufficient for tumours The management of primary hyperparathyroidism in children is
clearly isolated to one lobe. Because thyroid cancer has been documented surgical. All four parathyroid glands should be identified and biopsies
to be bilateral in as many as 66% of cases, with about 80% of these performed. An enlarged and adenomatous gland should be removed. If
exhibiting multifocality, most paediatric surgeons recommend either the other glands are normal, they should be marked with nonabsorbable
a total or near total thyroidectomy for a differentiated thyroid cancer. sutures and left in place.
Lymph node dissection is recommended if regional nodes are Secondary Hyperparathyroidism
suggestive of metastasis. Increased PTH is secondary or compensatory to conditions that cause
The parathyroid gland can be preserved by identifying and low plasma calcium level. Secondary hyperparathyroidism occurs in
autotransplanting one or two of the glands into the sternocleidomastoid children with renal insufficiency, malabsorption, or Ricketts. Affected
muscle or into the nondominant forearm. The recurrent laryngeal nerve patients typically respond to medical treatment designed to decrease
should also be identified and protected. intestinal phosphorus absorption, but, in rare cases, severe renal osteo-
It is generally recommended that exogenous thyroid hormones be dystrophy develops, manifested by skeletal fracture and metastatic
used to treat all endocrine thyroid cancer, to suppress TSH-mediated calcifications. Very severe cases can be candidates for total parathyroid-
stimulation of the gland. ectomy with autotransplantation.
Radioiodine ablative therapy is successful in eradicating residual Tertiary Hyperparathyroidism
tumours. It is more effective, however, after removal of the entire gland
because less functioning endocrine tissue takes up the radionuclide. Tertiary hyperparathyroidism occurs when persistent hyperfunction
Overall survival rate in nonmedulary thyroid carcinoma is 98%. of the parathyroid glands occurs, even after the inciting stimulus has
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A higher recurrence rate is seen in children who did not receive been removed. This is often seen in patients with chronic renal failure
postoperative radio iodine I. and secondary hyperparathyroidism who undergo renal transplanta-
131
tion. It is commonly due to hyperplasia of all four glands, and chil-
Medullary Thyroid Carcinoma dren with this condition are candidates for total parathyroidectomy
Medullary thyroid carcinoma (MTC) accounts for approximately 5% with autotransplantation. 18
of thyroid neoplasms in children. It arises from the parafollicular C
cells. MTC may occur sporadically or in association with multiple Evidence-Based Research
endocrine neoplasia IIA or IIB or the familial MTC syndrome. The Table 40.2 presents a study that compares the female-to-male preva-
neoplasm is particularly virulent in patients with MEN IIB, and may lence of thyroid disease. Table 40.3 presents a study to evaluate the
occur in infancy. effect of clinical and treatment factors on thyroid carcinoma control,
The clinical diagnosis of MTC is usually made only after metastatic complications, and recurrence.
spread to the adjacent cervical lymph node or to distant sites. Table 40.2: Evidence-based research.
It is recommended that early detection of MTC with RET (REarranged
during Transfection) proto-oncogen mutation may improve survival. Title Thyroid diseases in a school population with thyromegaly
Total thyroidectomy is the recommended surgical management Authors Jaksic J, Dumic M, Filipovic B, Ille J, Cvijetic M, Gjuric G
of MTC in children. Lymph nodes in the central compartment of the Institution Department of Pediatrics, University School of Medicine,
neck, medial to the carotid sheaths and between the hyoid bone and the Zagreb, Croatia; Department of Pediatrics, Medical Centre,
sternum, should be removed. Surgery is recommended at approximately Sibenik, Croatia
5 years of age, especially in children with MEN IIA, before the cancer Reference Arch Dis Childhood 1994; 70:103–106
spreads beyond the thyroid gland. Due to the high virulence of MTC Problem Goiter is common in childhood and adolescence despite
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in children with MEN IIB, prophylactic thyroidectomy is recommended the widespread practice of iodising table salt, which has
eliminated the dietary lack of iodine, This study concerns the
at approximately 1 year of age. prevalence and nature of diffuse and nodular goiters found
Parathyroid Glands: Hyperparathyroidism during a survey of 5,462 schoolchildren in Sibenik, Croatia, a
seaside region where iodised (0-01% potassium iodide) table
Hyperparathyroidism is associated with an increased secretion of para- salt is regularly available.
thormone (PTH). This can be primary, secondary, or tertiary. Comparison/ The study compared the prevalence of thyroid disease in
Primary Hyperparathyroidism control boys and girls.
Primary hyperparathyroidism is an unstimulated and inappropriately (quality of
evidence)
6
high parathormone secretion. In childhood, it usually results from a
12
solitary hyperfunctioning adenoma in about 70–90% of patients, and Outcome/ Thyroid enlargement was found in 152 children (2.8%).
The most common disorder was simple goiter, which was
12
more rarely (10–20%) diffuse hyperplasia of all the four glands. The effect established in 126 (2.3%) of these—12 (0.45%) boys and
hyperparathyroidism resulting from hyperfunctioning of all four glands 114 (4.07%) girls. Juvenile autoimmune thyroiditis was found
is a feature of MEN-I. Primary hyperparathyroidism of infancy is a rare, in 19 of the children (prevalence, 0.35%), with a female-to-
often fatal, condition that usually develops within the first 3 months of male sex ratio of 8:1.
life. Signs include hypotonicity, respiratory distress, failure to thrive, Historical This survey of large series of children shows that it is
necessary to conduct a thorough examination of the thyroid,
lethargy, and polyuria. The serum PTH is elevated. There is usually dif- significance/ even in apparently healthy children in regions where regular
fuse parathyroid gland hyperplasia. A familial component of the disease comments iodine intake is established.
is found in about half of the patients. Early recognition and treatment
are essential to allow normal growth and development of the baby. 18