The clinical outcome of prospective screening for multiple endocrine neoplasia type 2a. An 18-year experience

High permanent plasma adrenaline levels: a marker of adrenal medullary disease in medullary thyroid carcinoma

Increases in urinary, plasma and tumour adrenaline have been previously observed in MEN II patients with phaeochromocytoma. However, the sensitivity of adrenaline for early detection of adrenal medullary disease has not been accurately evaluated. Twenty-five patients with medullary thyroid carcinoma (MTC) histologically confirmed but without clinical or biological evidence of phaeochromocytoma have been studied. Medullary adrenal status was evaluated by adrenal CT-scan. MIBG scintigraphy, determination of urinary VMA, metanephrines and total catecholamine levels, measurement of nyctohemeral plasma adrenaline or noradrenaline concentrations (every 2 h during 24 h) and clonidine suppression test. Four of the 25 patients had evidence of adrenal medullary disease in view of the coexistence of CT-scan, MIBG scintigraphy and plasma adrenaline abnormalities. Moderate adrenal enlargement (unilateral, n = 3; bilateral, n = 1) was observed on scans together with a high adrenal MIBG uptake (bilateral, n = 4). Among the urinary parameters studied, a minor MN increase was observed in only one of the four patients. Plasma adrenaline levels were significantly (P less than 0.01) different from those of the other 21 patients (mean + SD 115 + 110 pmol/l). This plasma adrenaline increase is reproducible and not suppressed by clonidine. Unilateral adrenalectomy performed in one patient confirmed a phaeochromocytoma and induced normalization of plasma adrenaline levels. In contrast, the plasma noradrenaline levels of the four patients were not statistically different from those of the other 21 patients. These data suggest that persistent high plasma adrenaline levels may be selectively increased in MTC patients together with a moderate adrenal CT-scan enlargement and a high adrenal MIBG uptake, despite a normal urinary excretion of total catecholamines and catecholamines metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)

Presymptomatic screening for multiple endocrine neoplasia type 2A with linked DNA markers. The MEN 2A International Collaborative Group

Seven DNA markers from the pericentromeric region of chromosome 10 were tested for linkage to MEN 2A in a panel of 17 families. Four of the markers proved to be tightly linked and therefore suitable for predictive testing. The markers were used to estimate carrier risks for individuals who had a negative biochemical screening test for thyroid C-cell hyperplasia. The analysis substantially altered the carrier risks of most of these individuals, which suggests that typing with DNA markers should be introduced into the screening programme of MEN 2A families. Accurate prenatal diagnosis for this disorder is also now possible.

The impact of gene mapping techniques on the management of multiple endocrine neoplasia type 2

There has been sustained progress toward the identification of the gene for multiple endocrine neoplasia type 2. Closely linked and flanking DNA markers have been identified, and it is now possible to assign gene carrier status in informative families at risk with a >90% certainty by the use of molecular genetic techniques. Application of-these techniques, however, requires an understanding of their current limitations and caution in their use of clinical decision making.

Long-term course of patients with persistent hypercalcitoninemia after apparent curative primary surgery for medullary thyroid carcinoma

Thirty-one patients with persistent hypercalcitoninemia after seemingly adequate primary operation for medullary thyroid carcinoma (MTC) were followed for a mean period of 11.9 years after operation. Ten patients had sporadic MTC and the remaining patients were members of families with multiple endocrine neoplasia (MEN)--either MEN 2A (15 patients) or MEN 2B (six patients). Overall 5- and 10-year survival rates were 90% and 86%, respectively. Only four patients died at the completion of the study: two of MTC and two of unrelated causes. Eleven patients (35.5%) underwent surgical re-exploration after demonstration of recurrent disease clinically or radiologically. In no patient did the calcitonin level return to normal after re-exploration. The presence of more than three metastatic nodes at the time of initial operation was a statistically significant (p = 0.003) predictor for disease recurrence. Factors approaching statistical significance were patients younger than age 35 (p = 0.06) and the percentage of cells in the S phase of cell division (0.07). This data supports a conservative surgical philosophy in the management of the patient with persistent hypercalcitoninemia after resection of MTC.

Multiple endocrine neoplasia type 2b: long-term follow-up of a case

Multiple endocrine neoplasia type 2b is a rare inherited syndrome which comprises the association of medullary thyroid carcinoma, phaeochromocytoma, widespread neuromatous proliferation and a characteristic body habitus. In this report we present the late clinical course and autopsy findings of the first patient with this syndrome described in Australia. At presentation she was found to have a right adrenal phaeochromocytoma and medullary thyroid carcinoma which were resected in separate operations. No clinical or biochemical evidence of residual medullary thyroid carcinoma was identified in life. However, in spite of serial vanillylmandelic acid estimations, which showed normal or only mildly elevated levels, and normal results of urinary catecholamine studies, a left adrenal phaeochromocytoma was identified in a metaiodobenzylguanidine (MIBG) study performed 14 years after presentation. Her late clinical course was dominated by progressive dysphagia, intestinal dysmotility and megacolon associated with unrelenting malnutrition. After her death due to an intracerebral haemorrhage, an autopsy confirmed the presence of a left adrenal phaeochromocytoma and revealed diffuse intestinal ganglioneuromatosis to be the cause of her intestinal dysmotility. No residual medullary thyroid carcinoma was found. This case emphasises the propensity for multiple endocrine tumours in these patients and highlights the potentially significant role of intestinal ganglioneuromatosis in the natural history of this condition.

The importance of multiple endocrine neoplasia syndromes in differential diagnosis

In the differential diagnosis of endocrine symptoms, the autosomal dominant multiple endocrine neoplasia (MEN) syndromes are rare but important. We found seven index cases of MEN-I in 176 patients with adenomas of the anterior pituitary and 26 patients with primary hyperparathyroidism. Of 23 cases of medullary thyroid carcinoma and eight cases of pheochromocytoma, 14 patients are classified as MEN-IIa and one as MEN-IIb. Family screening identified six MEN-I and seven MEN-II cases among 32 individuals examined. Because of autosomal dominant inheritance and sometimes-delayed manifestation of the complete syndrome, screening of healthy and affected family members should be repeated at least every other year.

Calcitonin secretion rate in elderly normal subjects

The aim of the study was to investigate the metabolic clearance rate (MCR) and the secretion rate (SR) of calcitonin (CT) in elderly men and women (mean age +/- SE: 75 +/- 3 and 78 +/- 3 yr, respectively). The basal levels of CT were higher in men than in women (9.6 +/- 3.2 vs 6.0 +/- 1.5 pg/ml; p less than 0.05). The MCR was not significantly different between sexes (905 +/- 54.2 vs 810 +/- 165.1 l/day). In contrast, CT SR was significantly higher in male subjects compared to women (8.7 +/- 3.1 vs 4.8 +/- 1.5 micrograms/day; p less than 0.05). These findings suggest that only a few units of CT are secreted daily by elderly subjects and that the lower basal values of the hormone in women are probably the result of a lower production rate.

The natural history of multiple endocrine neoplasia type 2A--a clinical analysis

The records of 18 patients with multiple endocrine neoplasia (MEN) type 2A in a family consisting of 87 members in 5 generations, were reviewed with respect to age at onset and length of survival in a study of the natural history of this syndrome. Of these 18 patients, 8 were alive following surgical treatment, while 10 had died without treatment. The clinical onset of medullary thyroid carcinoma was noticed as a nodule in the neck at between 17 and 34 years of age (mean 24 years); the onset of pheochromocytoma was characterized by palpitation, hypertensive attacks or recurrent headache at between 17 and 42 years of age (mean 27 years); and death occurred in 10 patients at between 23 and 67 years of age (mean 40.6 years). This information on the age at onset of individual clinical manifestations, and on the length of survival of gene carriers, may be useful for clinicians who are asked to assess the risk of the development of this syndrome in a genetically predisposed asymptomatic individual, because screening tests are often refused by members of Japanese families with MEN type 2A.

A comparison of calcium pentagastrin and TRH tests in screening for medullary carcinoma of the thyroid in MEN IIA

Intravenous injections of calcium gluconate and pentagastrin (CPG) or TRH were compared as secretagogues for calcitonin (CT) in screening for medullary thyroid carcinoma (MTC) in multiple endocrine neoplasia type IIA (MEN IIA). Administration of CPG resulted in a prompt increase in plasma CT in all five patients with MTC studied, one of whom had a normal baseline value (peak 412-371,000 ng/l, 636-4847% above basal). TRH produced a rise in plasma CT levels only in MTC patients with elevated basal values; the magnitude of increase was less than that observed with CPG (peak 168-17,200 ng/l, 113-180% above basal). CT levels did not rise above 300 ng/l with either test in four unaffected first-degree relatives of MEN IIA patients, three subjects with sporadic unilateral phaeochromocytomas and five controls with essential hypertension. CPG remains the CT secretagogue of choice in screening for MTC in MEN II A.

Screening for multiple endocrine neoplasia type 2a with DNA-polymorphism analysis

Multiple endocrine neoplasia type 2a has been shown to be genetically linked to a locus near the centromere of chromosome 10. The availability of polymorphic DNA probes for the region permits the use of restriction-fragment-length polymorphisms (RFLP) to identify carriers of the gene for this cancer syndrome. As part of a French national program, DNA probes were used in a genetic-linkage study of 130 members of 11 families of European and North African origin. In these families there was no recombination between the mutation causing multiple endocrine neoplasia type 2a and two of the three probes used. All 11 families were informative for at least one of the three markers, and linkage information was adequate to provide genetic counseling to 8 families. We found that RFLP analysis is much more useful in predicting the carrier state than conventional endocrine challenge, especially in younger people, but accuracy is maximal when both methods are employed. We conclude that genetic screening allows the identification of those who are at risk for multiple endocrine neoplasia type 2a at any age with a high level of certainty. After initial screening with DNA, tests for early neoplastic change may be directed toward those determined to be at high risk.

Early diagnosis of multiple endocrine neoplasia type IIa

We report on incidental findings during family screening of two kindreds with multiple endocrine neoplasia type IIa. Pheochromocytoma and medullary thyroid carcinoma of considerable size were detected. The results underline the importance of early diagnosis of the syndrome, since the afflicted may be almost or wholly asymptomatic. High resolution chromosome banding studies were carried out in both families, but no abnormality was found. Linkage analysis using DNA markers closely related to the chromosomal locus at chromosome 10 was carried out and was positive in two asymptomatic offspring of one family, whereas the markers were not informative in a second family. We recommend early linkage analysis for establishing the genetic status in offspring of multiple endocrine neoplasia type IIa families to identify for further screening those who are predicted to be gene carrier.

Meal-stimulated gastrin release and calcitonin secretion

In order to study the effects of a physiologic meal on calcitonin (CT) secretion we studied 6 normal male volunteers (aged 28-34 yr). Each subject was given, on two separate days, either a mixed meal or 200 ml of distilled water, in random order. Gastrin (G) was effectively stimulated by the meal (F = 8.82; p less than 0.001) and reached a peak (with an average 100% increase) 30 min after the end of the meal, slowly decreasing thereafter; no increase was seen after water ingestion. On the other hand, CT levels remained stable throughout the observation period on both occasions. Ionized and total calcium did not show significant variations either after the meal or after water ingestion. These findings suggest that G alone, at the concentrations usually reached after a physiologic meal, is unable to stimulate CT secretion, at least in the absence of calcium increases.

Phaeochromocytoma in pregnancy. Five cases and a review of the literature

We report five patients with phaeochromocytoma associated with pregnancy and review the 42 other cases reported in the literature from 1980 to 1987. The overall maternal mortality was 17% and the fetal loss 26%; antenatal diagnosis of phaeochromocytoma reduced the maternal mortality to zero and the fetal loss to 15%, but was made in only 53% of the patients. Although phaeochromocytoma is rare, a high index of clinical suspicion must be maintained and all those at risk investigated if earlier diagnosis and improved outcome are to be achieved. Once the diagnosis is confirmed, alpha-blockade is essential and beta-blockade may be required. CT scan or magnetic resonance imaging may be used to localize the tumour during the antenatal period. In the first and second trimesters, tumour resection has a good fetal outcome; in later pregnancy, delivery by elective caesarean section followed by tumour resection is recommended.

Pentagastrin stimulation of calcitonin in pheochromocytoma does not always indicate multiple endocrine neoplasia type II

The diagnosis of pheochromocytoma in a 48-year-old man was confirmed by elevated catecholamine secretion and a left adrenal mass on computerized tomography. Because of a plausible family history for Multiple Endocrine Neoplasia Type II, a calcitonin level was determined which was elevated, and pentagastrin stimulation caused a 235% increase. These findings normalized following surgical removal of the single adrenal tumor. It is concluded that pentagastrin stimulation of calcitonin is not necessarily diagnostic of medullary thyroid carcinoma, and such a response in a patient presenting with pheochromocytoma may not indicate underlying Multiple Endocrine Neoplasia Type II.