C-cell hyperplasia (CCH) and medullary thyroid carcinoma (MTC) in patients affected by germline mutations of the RET oncogene represent an exceptional opportunity to study the regulation of proliferation and apoptosis during tumour initiation and progression.
Among RET mutation-positive patients, thyroidectomy performed for clinical or biochemical indication disclosed medullary thyroid carcinoma in 44 (98%) of 45 patients and precursor C-cell hyperplasia in only 1 (2%) patient.
Recently, a somatic mutation at codon 918 of RET was reported in medullary thyroid carcinoma (MTC) and C-cell hyperplasia in patients with MEN 2A or familial MTC (FMTC), suggesting its possible contribution to tumorigenesis.
Histologic examination of the thyroid glands in the two RET mutation negative individuals who had thyroidectomy demonstrated C-cell hyperplasia in one but not in the other.
The noncarriers included seven persons who had previously undergone thyroidectomies for suspected C-cell hyperplasia but were negative for the RET mutation present in affected members of their families.
Thyroidectomy is recommended within the first year of life, preferably as soon as possible, due to the very early transformation of C cell hyperplasia to more aggressive tumours.Calcitonin levels may be less helpful.
Since calcitonin stimulation test indicated positive result, total thyroidectomy was performed 1 year after the bilateral adrenalectomy, and C-cell hyperplasia was diagnosed by histopathological examination.
GLP-1 receptor agonists stimulated calcitonin release, up-regulation of calcitonin gene expression, and subsequently C-cell hyperplasia in rats and, to a lesser extent, in mice.
Following total thyroidectomy, one gene carrier had a histologically normal thyroid at age 46, following a mildly elevated calcitonin, one had C-cell hyperplasia at the age of 39, and one had a frank focus of carcinoma in the left thyroid lobe at the age of 45.
Although one child had a high stimulated calcitonin level, the histopathologic findings were normal; another child with high stimulated calcitonin levels showed C-cell hyperplasia on histopathologic examination.
We report a 48-year-old woman suffering from primary hyperparathyroidism (parathormone 121-166 pg/ml, normal <72), bilateral diffuse and nodular C-cell hyperplasia (calcitonin after pentagastrin administration 156 pg/ml, normal <4.6), and papillary thyroid carcinoma.
We investigated prevalence and interrelationship of C-cell hyperplasia (CCH) and medullary thyroid carcinoma (MTC) in patients with thyroid and parathyroid disorders that showed increased calcitonin serum levels detected by routine screening.
Screening of 11 family members spanning 4 generations revealed 7 subjects with corneal nerve thickening; of these subjects, 3 had abnormal pentagastrin-stimulated calcitonin studies, and these 3 subjects were each found to have C-cell hyperplasia or medullary thyroid carcinoma at surgery.
None of these 68 subjects had medullary thyroid carcinoma or pheochromocytoma; 6 had elevated plasma calcitonin concentrations and underwent thyroidectomy but had only C-cell hyperplasia.
In the authors' Medullary Screening Clinic, medullary thyroid cancer (MTC) or C-cell hyperplasia (CCH) has been identified in 26 relatives of 12 apparently "sporadic" patients from 56 families in which calcitonin (CT) testing has been performed.
Basal immunoreactive calcitonin level was increased in 3 of 7 patients with C-cell hyperplasia alone, in 10 of 18 patients with nonmetastatic MCT, and in all 5 patients with metastatic MCT.
Laboratory markers can also identify a precursor state for cancer, eg, elevated calcitonin levels in patients with familial medullary thyroid carcinoma and premalignant thyroid C-cell hyperplasia.
In 5 siblings of medullary thyroid carcinoma patients, PDN-21 and calcitonin were increased in response to iv pentagastrin, and we suspect C-cell hyperplasia or medullary thyroid carcinoma.
Abnormal calcitonin secretion provides a reliable marker for the presence of medullary carcinoma of the thyroid (MCT) and its precursor form, C-cell hyperplasia (CCH).
Electron microscopy was used to confirm the presence of C cell hyperplasia afte demonstration of elevated serum calcitonin values in three asymptomatic young women from two affected kindreds.