Clinical significance of hyperparathyroidism in familial multiple endocrine adenomatosis type I (MEA I)

[Comparative analysis of bone complications/manifestations in sporadic and MEN1-related primary hyperparathyroidism]

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) - is a rare syndrome with an autosomal dominant inheritance pattern caused by a mutation in the tumor suppressor gene (MEN1). Parathyroid involvement is the most common MEN1 manifestation resulting in primary hyperparathyroidism (mPHPT). Data on the prevalence and structure of bone disease in mPHPT compared to sporadic one (sPHPT) are often incomplete and contradictory.

AIM

The purpose of this study was to compare the severity of bone involvement between mPHPT and sPHPT.

MATERIALS AND METHODS

A single-center retrospective study was conducted among young patients in the active phase of PHPT and without prior parathyroidectomy in anamnesis. The analysis included the main parameters of calcium-phosphorus metabolism, bone remodeling markers, as well as an assessment of disease complications. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA) at sites of lumbar spine, femur and radius. Trabecular bone score (TBS) was applied to estimate trabecular microarchitecture. All patients included in the study underwent genetic testing.

RESULTS

Group 1 (mPHPT) included 26 patients, and group 2 (sSHPT) included 30 age-matched patients: the median age in group 1 was 34.5 years [25; 39], in group 2 - 30.5 years [28; 36], (p=0.439, U-test). Within group 1, the subgroup 1A (n=21) was formed with patients without other hormone-produced neuroendocrine neoplasms (NEN) in the gastrointestinal tract (GI) and the anterior pituitary gland. The duration of PHPT was comparable in both groups: mPHPT - 1 year [0; 3] versus sPHPT - 1 year [0; 1], (p=0.533, U-test). There were no differences in the main parameters of calcium-phosphorus metabolism, as well as in the prevalence of kidney complications. In the mPHPT group, bone abnormalities were observed significantly more often compared to sPHPT: 54 vs 10% (p=<0.001; F-test). Statistically significant differences were revealed both in BMD and in Z-score values of the femoral neck and total hip, which were lower in the mPHPT group. These differences remained significant when comparing subgroup 1A with sPHPT.

CONCLUSION

MEN1-associated PHPT may be accompanied by a more severe decrease in BMD in the femoral neck and total hip compared to sPHPT regardless of the other hormone-producing NEN. Clarifying the role of mutation in the MEN1 gene in these processes requires further study.

Occult insulinoma with treatment refractory, severe hypoglycaemia in multiple endocrine neoplasia type 1 syndrome; difficulties faced during diagnosis, localization and management; a case report

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN 1) syndrome is a rare, complex genetic disorder characterized by increased predisposition to tumorigenesis in multiple endocrine and non-endocrine tissues. Diagnosis and management of MEN 1 syndrome is challenging due to its vast heterogeneity in clinical presentation.

CASE PRESENTATION

A 23-year-old female, previously diagnosed with Polycystic Ovarian Syndrome (PCOS) and pituitary microprolactinoma presented with drowsiness,confusion and profuse sweating developing over a period of one day. It was preceded by fluctuating, hallucinatory behavior for two weeks duration. There was recent increase in appetite with significant weight gain. There was no fever, seizures or symptoms suggestive of meningism. Her Body mass index(BMI) was 32 kg/m².She had signs of hyperandrogenism. Multiple cutaneous collagenomas were noted on anterior chest and abdominal wall. Her Glasgow Coma Scale was 9/15. Pupils were sluggishly reactive to light. Tendon reflexes were exaggerated with up going planter reflexes. Moderate hepatomegaly was present. Rest of the clinical examination was normal. Laboratory evaluation confirmed endogenous hyperinsulinaemic hypoglycaemia suggestive of an insulinoma. Hypercalcemia with elevated parathyroid hormone level suggested a parathyroid adenoma. Presence of insulinoma, primary hyperparathyroidism and pituitary microadenoma, in 3^rd decade of life with characteristic cutaneous tumours was suggestive of a clinical diagnosis of MEN 1 syndrome. Recurrent, severe hypoglycaemia complicated with hypoglycaemic encephalopathy refractory to continuous, parenteral glucose supplementation and optimal pharmacotherapy complicated the clinical course. Insulinoma was localized with selective arterial calcium stimulation test. Distal pancreatectomy and four gland parathyroidectomy was performed leading to resolution of symptoms.

CONCLUSIONS

Renal calculi or characteristic cutaneous lesions might be the only forewarning clinical manifestations of an undiagnosed MEN 1 syndrome impending a life-threatening presentation. Comprehensive management of MEN 1 syndrome requires multi-disciplinary approach with advanced imaging modalities, advanced surgical procedures and long-term follow up due to its heterogeneous presentation and the varying severity depending on the disease phenotype.

Genetics of multiple endocrine neoplasia type 1 syndrome: what's new and what's old

Despite its identification in 1997, the functions of the MEN1 gene-the main gene underlying multiple endocrine neoplasia type 1 syndrome-are not yet fully understood. In addition, unlike the RET-MEN2 causative gene-no hot-spot mutational areas or genotype-phenotype correlations have been identified. More than 1,300 MEN1 gene mutations have been reported and are mostly "private" (family specific). Even when mutations are shared at an intra- or inter-familial level, the spectrum of clinical presentation is highly variable, even in identical twins. Despite these inherent limitations for genetic counseling, identifying MEN1 mutations in individual carriers offers them the opportunity to have lifelong clinical surveillance schemes aimed at revealing MEN1-associated tumors and lesions, dictates the timing and scope of surgical procedures, and facilitates specific mutation analysis of relatives to define presymptomatic carriers.

Clinical and Genetic Analysis of Multiple Endocrine Neoplasia Type 1-Related Primary Hyperparathyroidism in Chinese

Objective

Multiple endocrine neoplasia type 1-related primary hyperparathyroidism (MHPT) differs in many aspects from sporadic PHPT (SHPT). The aims of this study were to summarize the clinical features and genetic background of Chinese MHPT patients and compare the severity of the disease with those of SHPT.

Design and Methods

A total of 40 MHPT (27 sporadic, 7 families) and 169 SHPT cases of Chinese descent were retrospectively analyzed. X-rays and ultrasound were used to assess the bone and urinary system. Dual energy x-ray absorptiometry (DXA) were performed to measure bone mineral density (BMD). Besides direct sequencing of the MEN1 and CDKN1B genes, multiplex ligation-dependent probe amplification (MLPA) was used to screen gross deletion for the MEN1 gene.

Results

Compared with SHPT patients, MHPT patients showed lower prevalence of typical X-ray changes related to PHPT (26.3% vs. 55.7%, P = 0.001) but higher prevalence of urolithiasis/renal calcification (40.2% vs. 60.0%, P = 0.024). MHPT patients showed higher phosphate level (0.84 vs. 0.73mmol/L, P<0.05) but lower ALP (103.0 vs. 174.0U/L, P<0.001) and PTH (4.0 vs. 9.8×upper limit, P<0.001) levels than SHPT patients. There were no significant differences in BMD Z-scores at the lumbar spine and femoral neck between the two groups. Mutations in the MEN1 gene were detected in 27 MHPT cases. Among the nine novel mutations were novel, one of them involved the deletion of exon 5 and 6.

Conclusions

MHPT patients experienced more common kidney complications but less skeletal issues, and a milder biochemical manifestation compared with SHPT patients. MEN1 mutation detection rate was 79.4% and 9 of the identified mutations were novel.

Differences between sporadic and MEN related primary hyperparathyroidism; clinical expression, preoperative workup, operative strategy and follow-up

Background

Primary hyperparathyroidism (PHPT) is most commonly sporadic (sPHPT). However, sometimes PHPT develops as part of multiple endocrine neoplasia (MEN) type 1 or 2A. In all, parathyroidectomy is the only curative treatment. Nevertheless, there are important differences in clinical expression and treatment.

Methods

We analyzed a consecutive cohort of patients treated for sporadic, MEN1-related, and MEN2A-related PHPT and compared them regarding clinical and biochemical parameters, differences in preoperative workup, operative strategies, findings, and outcome.

Results

A total of 467 patients with sPHPT, 52 with MEN1- and 16 with MEN2A-related PHPT were analyzed. Patients with sPHPT were older, more often female and had higher preoperative calcium and parathyroid hormone levels, when compared with MEN1 and MEN2A patients. Minimally invasive parathyroidectomy (MIP) was performed in 367 of 467 sPHPT patients (79%). One abnormal parathyroid was found in 426 patients (91%). Two or more in 35 patients (7%). In six patients (1%) no abnormal parathyroid gland was retrieved. Of 52 MEN1 patients, eight (15%) underwent a MIP and 44 patients (85%) underwent conventional neck exploration (CNE); with resection of fewer than 3½ enlarged glands in 21 patients (40%), subtotal parathyroidectomy (SPTX, 3-3½ glands) in seventeen (33%) and total parathyroidectomy with autotransplantation (TPTX) in six (12%). Eleven patients (21%) had persistent disease, 29 (56%) recurrent PHPT and nine (17%) permanent hypoparathyroidism, mostly after TPTX. Of 16 MEN2A patients, six (38%) underwent MIP, four (25%) CNE and six (38%) selective resection of the enlarged gland(s) during total thyroidectomy. Three patients (19%) suffered from persistent PHPT and two (13%) developed recurrent disease.

Conclusions

Sporadic PHPT, MEN1- and MEN2A-related PHPT are three distinct entities as is reflected preoperatively by differences in gender, age at diagnosis and calcium and PTH levels.

MEN2A patients are very similar to sPHPT with respect to operative approach and findings. MIP is the treatment of choice for both. MIP has low rates of persistent and recurrent PHPT and a low complication rate. The percentage of multiglandular disease and recurrences are significantly higher in MEN1 patients, demonstrating the need for a different approach. We advocate treating these patients with CNE and SPTX.

Biochemical, bone and renal patterns in hyperparathyroidism associated with multiple endocrine neoplasia type 1

Primary hyperparathyroidism associated with multiple endocrine neoplasia type I (hyperparathyroidism/multiple endocrine neoplasia type 1) differs in many aspects from sporadic hyperparathyroidism, which is the most frequently occurring form of hyperparathyroidism. Bone mineral density has frequently been studied in sporadic hyperparathyroidism but it has very rarely been examined in cases of hyperparathyroidism/multiple endocrine neoplasia type 1. Cortical bone mineral density in hyperparathyroidism/multiple endocrine neoplasia type 1 cases has only recently been examined, and early, severe and frequent bone mineral losses have been documented at this site. Early bone mineral losses are highly prevalent in the trabecular bone of patients with hyperparathyroidism/multiple endocrine neoplasia type 1. In summary, bone mineral disease in multiple endocrine neoplasia type 1 related hyperparathyroidism is an early, frequent and severe disturbance, occurring in both the cortical and trabecular bones. In addition, renal complications secondary to sporadic hyperparathyroidism are often studied, but very little work has been done on this issue in hyperparathyroidism/multiple endocrine neoplasia type 1. It has been recently verified that early, frequent, and severe renal lesions occur in patients with hyperparathyroidism/multiple endocrine neoplasia type 1, which may lead to increased morbidity and mortality. In this article we review the few available studies on bone mineral and renal disturbances in the setting of hyperparathyroidism/multiple endocrine neoplasia type 1. We performed a meta-analysis of the available data on bone mineral and renal disease in cases of multiple endocrine neoplasia type 1-related hyperparathyroidism.

Early-onset, progressive, frequent, extensive, and severe bone mineral and renal complications in multiple endocrine neoplasia type 1-associated primary hyperparathyroidism

Differences in bone mineral density (BMD) patterns have been recently reported between multiple endocrine neoplasia type 1-related primary hyperparathyroidism (HPT/MEN1) and sporadic primary HPT. However, studies on the early and later outcomes of bone/renal complications in HPT/MEN1 are lacking. In this cross-sectional study, performed in a tertiary academic hospital, 36 patients cases with uncontrolled HPT from 8 unrelated MEN1 families underwent dual-energy X-ray absorptiometry (DXA) scanning of the proximal one-third of the distal radius (1/3DR), femoral neck, total hip, and lumbar spine (LS). The mean age of the patients was 38.9 ± 14.5 years. Parathyroid hormone (PTH)/calcium values were mildly elevated despite an overall high percentage of bone demineralization (77.8%). In the younger group (<50 years of age), demineralization in the 1/3DR was more frequent, more severe, and occurred earlier (40%; Z-score -1.81 ± 0.26). The older group (>50 years of age) had a higher frequency of bone demineralization at all sites (p < .005) and a larger number of affected bone sites (p < .0001), and BMD was more severely compromised in the 1/3DR (p = .007) and LS (p = .002). BMD values were lower in symptomatic (88.9%) than in asymptomatic HPT patients (p < .006). Patients with long-standing HPT (>10 years) and gastrinoma/HPT presented significantly lower 1/3DR BMD values. Urolithiasis occurred earlier (<30 years) and more frequently (75%) and was associated with related renal comorbidities (50%) and renal insufficiency in the older group (33%). Bone mineral- and urolithiasis-related renal complications in HPT/MEN1 are early-onset, frequent, extensive, severe, and progressive. These data should be considered in the individualized clinical/surgical management of patients with MEN1-associated HPT.

The MEN1 gene and pituitary tumours

Sporadic multiple endocrine neoplasia type 1 (MEN1) is defined as the occurrence of tumours in two of three main endocrine tissue types: parathyroid, pituitary and pancreaticoduodenal. A prolactinoma variant or Burin variant of MEN1 was found to occur in three large kindreds, with more prolactinomas and fewer gastrinomas than typical MEN1. MEN1 tumours differ from common tumours by showing features from the MEN1 gene (e.g. larger pituitary tumours). They also show various expressions of tumour multiplicity; however, pituitary tumour in MEN1 is usually solitary. Diagnosis in MEN1 carriers during childhood is not directed at cancers but at benign morbid tumours. Morbid prolactinoma occurred at the age of 5 years in one MEN1 individual; hence, this is the earliest age at which to recommend tumour surveillance in carriers. The MEN1 gene shows biallelic inactivation in 30% of some types of common variety endocrine tumours (e.g. parathyroid adenoma, gastrinoma, insulinoma and bronchial carcinoid), but in only 1-5% of common pituitary tumours. Heterozygous knockout of MEN1 in mice provides a robust model of MEN1 and has been found to support further research on anti-angiogenesis therapy for pituitary tumours. The rarity of MEN1 mutations in some MEN1-like states aids the identification of other mutated genes, such as AIP, HRPT2 and p27(Kip1). We present recent clinical and basic findings about the MEN1 gene, particularly concerning hereditary vs. common variety pituitary tumours.

Clinical genetics of multiple endocrine neoplasias, Carney complex and related syndromes

The list of multiple endocrine neoplasias (MENs) that have been molecularly elucidated is growing with the most recent addition of Carney complex. MEN type 1 (MEN 1), which affects primarily the pituitary, pancreas, and parathyroid glands, is caused by mutations in the menin gene. MEN type 2 (MEN 2) syndromes, MEN 2A and MEN 2B that affect mainly the thyroid and parathyroid glands and the adrenal medulla, and familial medullary thyroid carcinoma (FMTC), are caused by mutations in the REToncogene. Finally, Carney complex, which affects the adrenal cortex, the pituitary and thyroid glands, and the gonads, is caused by mutations in the gene that codes for regulatory subunit type 1A of protein kinase A (PKA) (PRKAR1A) in at least half of the known patients. Molecular defects have also been identified in syndromes related to the MENs, like Peutz-Jeghers syndrome (PJS) (the STK11/LKB1 gene), and Cowden (CD; the PTEN gene) and von Hippel-Lindau disease (VHLD; the VHL gene). Although recognition of these syndromes at a young age generally improves prognosis, the need for molecular testing in the diagnostic evaluation of the MENs is less clear. This review presents the newest information on the clinical and molecular genetics of the MENs (MEN 1, MEN 2, and Carney complex), including recommendations for genetic screening, and discusses briefly the related syndromes PJS, CD and VHLD.

Parathyroid glands and the multiple endocrine neoplasia syndromes and familial hypocalciuric hypercalcemia

Hypercalcemia is a variable feature of inherited endocrine disorders. In the multiple endocrine neoplasia (MEN) syndromes, generalized hyperparathyroidism is a common feature. It occurs much more frequently in patients with MEN type 1 as compared to patients with MEN type 2A. Unlike the MEN syndromes, patients with familial hypocalciuric hypercalcemia (FHH) have only hypercalcemia with no associated endocrinopathies. The hyperparathyroidism in patients with either of the MEN syndromes is managed by parathyroidectomy, whereas patients with FHH are managed nonoperatively. The specific genetic defects associated with MEN type 2 syndromes and FHH have been identified. They explain, in part, the clinical and pathophysiologic features of these diseases. The genetic defect causative of MEN type 1 will doubtless soon be found and thereby provide further insights into the molecular basis of calcium homeostasis. We will review the clinical presentation and the management of patients with these disorders. We will also review the recent molecular discoveries in MEN 2A, MEN 2B, and FHH, and define how they have altered the management of patients who have these syndromes.

Results of treatment of pituitary disease in multiple endocrine neoplasia, type I

OBJECTIVE

The aim of the present study was to examine the clinical and pathological features of pituitary disease in patients with multiple endocrine neoplasia, Type I (MEN I) and to assess the prognosis.

METHODS

Fifty-two patients with pituitary disease and MEN I were studied retrospectively. Medical records were reviewed, and all of the patients known to be alive were sent a questionnaire to ascertain current disease status.

RESULTS

In 12 patients, pituitary disease was the initial manifestation of MEN I. The most common lesion was prolactinoma, followed, in frequency, by acromegaly and nonsecretory adenoma. Thirty-four of the patients had surgical treatment at the Mayo Clinic, Rochester, MN, as primary treatment, 3 had radiotherapy, and 12 received no specific therapy. Twelve patients had adjunctive radiotherapy postoperatively. Of the 34 patients receiving surgical treatment, 33 had adenoma and 1 had adenoma and pituitary hyperplasia. Immunocytochemical examination demonstrated that many tumors showed reactivity for more than one pituitary hormone. On survival analysis, no excess pituitary-related mortality was found, either in the surgically treated group or in the group as a whole.

CONCLUSION

On the basis of this study, we conclude that pituitary disease is frequently the initial manifestation of MEN I; that adenomas, particularly prolactinomas, are the rule and hyperplasia is rare; that a significant proportion of tumors are plurihormonal; and that excess pituitary-related mortality is not a factor in patients with MEN I.

The surgical management of hyperparathyroidism and endocrine disease of the pancreas in the multiple endocrine neoplasia type 1 patient

The surgical management of multiple endocrine neoplasia type 1 (MEN1) parathyroid disease and involvement of the endocrine pancreas remains controversial. Hyperparathyroidism, usually the first clinical manifestation of the syndrome, requires surgical treatment in nearly all patients. We favour a subtotal parathyroidectomy and cervical thymectomy rather than a total parathyroidectomy and autotransplant because of good long-term results and the absence of permanent hypoparathyroidism. The results of treating 34 MEN1 patients during a 20-year period are reported. The most common functional pancreatic or duodenal tumours in MEN1 patients are gastrinomas and insulinomas. In addition to the management of functional syndromes, another major concern is the malignant potential of the neuroendocrine tumours that frequently develop. Our surgical management of gastrinomas and the ZES has evolved over a period of 15 years. We have found that distal pancreatectomy, enucleation of any neoplasms in the head, and duodenotomy and excision of any neuroendocrine tumours (gastrinomas) combined with a regional node dissection are effective in the majority of patients. The results of treating 21 MEN1 patients with ZES are reported.

Genetic screening to identify the gene carrier in Italian and German kindreds affected by multiple endocrine neoplasia type 1 (MEN 1) syndrome

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominantly inherited disorder characterized by parathyroid hyperplasia, anterior pituitary adenomas and neoplasms of the endocrine cells of the gastroenteric tract. It has been established that also other tissues exhibit excessive proliferation associated to the MEN 1 syndrome: carcinoids (bronchial and intestinal), lipomas (visceral and cutaneous), thyroid adenomas and goiter, and adrenal gland cortex adenomas. The men 1 gene has been mapped by genetic studies to the long arm of human chromosome 11, region q12-13. Genetic analysis of families and tumoral deletion mapping made possible to narrow the men 1 region to a 5 cM interval on chromosome 11q12-13. Thirteen marker complexes (17 DNA probes) were found to be linked to the men 1 gene and they span a 14% meiotic recombination with the men 1 locus in the middle. We report a genetic study on 103 subjects from 7 collected MEN 1-kindreds, six Italian and one German, including 30 affected individuals. By linkage analysis to 9 DNA markers (10 DNA probes) of the chromosome region where the men 1 gene maps (11q12-13), we identified 10 mutant gene carriers. The predicted MEN 1 diagnosis was clinically confirmed for 2 of these identified carriers. A predictive accuracy of this genetic test can reach up to 99.5% when it is possible to exclude meiotic crossing-over between the analyzed DNA markers and the disease locus.

Double parathyroid adenomas. Clinical and biochemical characteristics before and after parathyroidectomy

OBJECTIVE

There is considerable debate about whether double parathyroid adenomas are a discrete entity or represent hyperplasia with parathyroid glands of varying sizes. This distinction is important because it impacts on the extent of parathyroid resection and the success of the parathyroid operation.

SUMMARY BACKGROUND DATA

Double parathyroid adenomas have been reported to occur in 1.7% to 9% of patients with primary hyperparathyroidism (HPT). It is important for surgeons to differentiate between double adenoma and hyperplasia with glands of varying sizes using gross examination during the initial procedure because microscopic findings of a small biopsy specimen at frozen-section examination may not be diagnostic.

METHODS

From 1982 to 1992, 416 unselected patients (309 women and 107 men) with primary HPT without familial HPT or multiple endocrine neoplasia (MEN) were treated by one surgeon at the University of California at San Francisco. Double adenoma occurred in 49 patients, solitary adenoma in 309 patients, and hyperplasia in 58 patients. The authors analyzed the clinical manifestations, the preoperative and postoperative serum levels of calcium, phosphate, and parathyroid hormone (PTH), and the success rate and outcome after parathyroidectomy and compared their results in 49 patients with double adenomas to the results for patients with solitary adenomas or hyperplasia.

RESULTS

Ten of the patients with double adenomas (20.4%) were referred for persistent HPT after removal of one abnormal parathyroid gland. The ages of the patients with double adenoma, single adenoma, and hyperplasia were 61 +/- 14, 56 +/- 15, and 58 +/- 7 years, respectively. Fatigue, muscle weakness, and bone pain were common in patients with double adenomas, whereas nephrolithiasis occurred more frequently in patients with solitary adenoma (p = 0.0001). Serum calcium and PTH levels (per cent of upper limit of normal) fell from 11.5 +/- 1.2 mg/dL and 487% to 9.5 +/- 0.8 mg/dL and 61% for patients with double adenomas; from 11.9 +/- 0.9 mg/dL and 378% to 9.3 +/- 1.4 mg/dL and 101% for patients with single adenoma; and from 10.9 +/- 0.5 mg/dL and 418% to 9.1 +/- 0.7 mg/dL and 94% for patients with hyperplasia, respectively. There was no recurrence in the patients with double adenomas with a mean follow-up time of 5.8 years.

CONCLUSIONS

Double adenomas are a discrete entity and occur more often in older patients. Patients with double adenomas can be successfully treated by removal of the two abnormal glands.

Findings and long-term results of parathyroid surgery in multiple endocrine neoplasia type 1

Forty-two patients with primary hyperparathyroidism (HPT) of multiple endocrine neoplasia type 1 (MEN-1) were evaluated a mean of 8.9 years after subtotal parathyroid resection (SPX, n = 34) or total parathyroidectomy with autotransplantation to the forearm (TPX, n = 23). TPX as the primary operation revealed asymmetric and mainly nodular enlargement of the parathyroid glands with the presence of at least one normal-size gland in half of the individuals. TPX and SPX were accompanied by resolution of the hypercalcemia in 78% and 38% of the patients. Persistent and recurrent HPT occurred in 22% and 61% of the patients, while hypoparathyroidism requiring oral supplements occurred in 30% and 12% of the patients, respectively. Intact serum parathyroid hormone (PTH) in the arm of parathyroid autograft was high in the normocalcemic patients, somewhat lower in the patients with recurrent HPT, and normal to very low in the hypoparathyroid patients. Ratios of intact PTH between the grafted and non-grafted arms varied from 1 to 56.3, with average of 28.1 in the normocalcemic individuals, 8.2 in the patients with recurrent HPT, and 3.3 in those requiring supplements to maintain normocalcemia. These findings substantiate an 80% to 92% reversal of hypercalcemia during long-term follow-up of MEN-1 patients undergoing total parathyroidectomy or subtotal resection of 3-4 parathyroid glands as primary operative procedures and demonstrate the usefulness of intact serum PTH for functional evaluation of parathyroid autografts.

Single and multigland disease in primary hyperparathyroidism: clinical follow-up, histopathology, and flow cytometric DNA analysis

Two-hundred seventy-four patients with primary hyperparathyroidism had selective removal of enlarged parathyroid glands. Biopsies were taken from all parathyroid glands. Normal-size glands were not resected irrespective of their histological appearance. After a mean follow-up of 13.5 years the rates of persistent and recurrent hyperparathyroidism were, respectively, 3.6% and 0.7%. Transient and permanent hypoparathyroidism occurred in 24% and 2.5% of the patients. The microscopic appearance of enlarged glands and of biopsies taken from normal-size glands were reviewed by two pathologists. Normal parathyroid glands were distinguished from abnormal glands fairly accurately (sensitivity 93%, specificity 80%). Microscopic classification of abnormal parathyroid glands as adenomas or hyperplastic glands correlated poorly with the gross classification as single or multigland disease. Flow cytometric DNA analysis of paraffin embedded parathyroid tissue showed significant differences for DNA index, % S-phase and % G2M (p less than 0.001). Differentiating single from multigland disease by means of DNA analysis was not possible. In conclusion, removal of only enlarged parathyroid glands results in acceptable rates of persistent and recurrent hyperparathyroidism. Biopsies should only be taken sparingly to prevent transient and permanent hypoparathyroidism. Microscopic examination and flow cytometric DNA analysis can differentiate normal from abnormal parathyroid glands but are unable to differentiate abnormal glands into single or multigland disease.

Management of primary hyperparathyroidism caused by multiple gland disease

Multiple gland parathyroid disease is the pathological finding in primary hyperparathyroidism (HPT) in about 10% to 20% of all patients and in approximately a third of all patients with persistent or recurrent disease. The variability of multiple gland disease spans from 2 adenomas to diffuse hyperplasia in patients with multiple endocrine neoplasia type 1. This variability calls into question the proposed common pathophysiologic background in all of these cases. As primary treatment of multiple gland primary HPT, subtotal parathyroidectomy and thymectomy or total parathyroidectomy and heterotopic autotransplantation including thymectomy can be equally advocated. Recurrent hyperparathyroidism frequently occurs in cases of diffuse parathyroid hyperplasia. This must be considered especially in patient follow up and before each surgical procedure. Thus, a defined but adaptable therapeutic regimen might prevent permanent hypoparathyroidism and persistent hyperparathyroidism.

Multiple endocrine syndrome type I. Clinical, laboratory findings, and management in five families

The clinical features of 20 patients from five families with multiple endocrine neoplasia syndrome type I (MEN-I) were studied. Nineteen patients (95%) had hyperparathyroidism. Five patients who had a diagnosis during surgery of adenoma and who had fewer than 3.5 glands removed had recurrence of hypercalcemia after surgery. Fourteen patients (70%) had pancreatic islet cell tumors. All had one or more elevated serum polypeptide hormones, and six had symptoms related to the hormones produced. Multiple pancreatic tumors were identified in the nine patients who underwent surgery. Three patients who died had a mean survival of 6.3 +/- 2.9 years. Eight patients had pituitary tumors; seven had macroadenomas. Of the eight patients with pituitary tumors, seven had high serum prolactin and responded to bromocriptine therapy, whereas the eighth patient had acromegaly treated with radiotherapy. It was concluded that hypercalcemia due to hyperparathyroidism in MEN-I syndrome patients should be managed by a resection of four glands and transplantation of one half gland into the forearm because none of the patients has shown evidence of a recurrence, and serum calcium levels have been normal. Pancreatic tumors, which are usually multiple, may be asymptomatic. Patients with these tumors usually have long survival rates, even with distant metastasis. Total pancreatectomy may be the method of choice, especially in patients with gastrinoma caused by the diffuse nature of the disease. Long-term follow-up is needed, however, with more patients. Pituitary tumors are primarily prolactin-producing tumors, and medical treatment is the method of choice.

Giant gastrinoma in a patient with multiple endocrine adenopathy (type 1)

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Pediatric endocrine surgery

The pediatric surgeon is in a unique position to understand endocrine surgery and, therefore, is expected to develop considerable expertise in this area. In recent years numerous advances and changes have occurred in pediatric endocrine surgery that have led to greater understanding of the disease processes and syndromes and the development of new diagnostic techniques and surgical approaches.

Primary hyperparathyroidism in familial multiple endocrine neoplasia type I. Long-term follow-up of serum calcium levels after parathyroidectomy

Serum calcium levels were analyzed after one or more explorations for primary hyperparathyroidism in familial multiple endocrine neoplasia type I. These data covered all 85 operations (performed in many hospitals) on 61 of 62 members from 14 kindreds. After 61 initial operations, there were high rates of persistent or recurrent hypercalcemia (54 percent) and chronic hypocalcemia (10 percent). These rates contrast with lower postoperative rates of hypercalcemia (4 to 16 percent) or chronic hypocalcemia (1 to 8 percent) in large series of primary hyperparathyroidism. Persistent or recurrent hypercalcemia after initial exploration decreased only modestly in patients who underwent surgery after 1975 versus before 1975 (46 versus 63 percent). The rate for long-term remission of hypercalcemia after initial parathyroidectomy was higher after a diagnosis of parathyroid hyperplasia was made (as opposed to adenoma) (57 versus 30 percent, p less than 0.05) and after removal of three or more glands (as opposed to removal of two and a half or less) (70 versus 34 percent, p less than 0.01). Following 24 reoperations, there were also high rates of persistent or recurrent hypercalcemia (46 percent) and chronic hypocalcemia (25 percent). After surgery in unselected patients with primary hyperparathyroidism, recurrent hypercalcemia (as opposed to persistent hypercalcemia) is distinctly uncommon; however, it was frequent in familial multiple endocrine neoplasia type I, with total recurrences increasing from 21 percent at five years to 41 percent at 10 years in patients who showed a normocalcemic interval after surgery. The data indicate that the occurrence of persistent or recurrent hypercalcemia after parathyroidectomy in familial multiple endocrine neoplasia type I remains frequent. Although recurrent hypercalcemia may be characteristic of the response to any technique of parathyroidectomy in familial multiple endocrine neoplasia type I and not preventable, persistent hypercalcemia can be decreased by preoperative recognition of the specific familial cause, involvement of an experienced surgical team, and histologic confirmation of the identification of three or more parathyroid glands.

[Association of familial hyperparathyroidism and Cushing's disease]

Five members of one family had been operated on for primary hyperparathyroidism. One of them also had Cushing's disease (i.e. pituitary tumor). An association between familial hyperparathyroidism and Cushing's disease is quite unusual. Such a combination of rare diseases is not fortuitous though; it probably is but a special type of multiple endocrine neoplasia.

Screening for multiple endocrine neoplasia syndrome (type 1) in patients with primary hyperparathyroidism

In 63 consecutive patients with primary hyperparathyroidism (HPT) a prospective screening study was undertaken for coexistent multiple endocrine neoplasma-(MEN)-syndrome type 1. The screening consisted of a clinical examination, a radiological examination of the sella turcica with skeletal tomography (and in equivocal cases computed tomography), visual field examination by perimetry and a hormonal evaluation including measurements of the serum levels of prolactin, gastrin, pancreatic polypeptide (PP) and subunits of human chorionic gonadotrophin (HCG-alpha and -beta). Clinical examination did not reveal any signs of endocrine disease suggestive of a MEN-1 syndrome. In only one case there was a radiological abnormality of the sella turcica; this patient had an empty sella syndrome and a raised serum prolactin value. All other prolactin values were within the normal range. In 41% of the patients raised serum gastrin levels were found; these tended to normalize after parathyroidectomy. As a group, patients with raised gastrin values were older than the others and generally they had hypo- or achlorhydria. The serum PP levels were raised in 28% of the patients but there was no clinical evidence of a pancreatic tumour in any of these cases, and the serum HCG-alpha and -beta levels were within the normal range in all patients but two. We conclude that the incidence of MEN-1 syndrome in unselected patients with primary HPT must be low, and that investigations for this syndrome are justified only in HPT patients with specific symptoms or with a positive family history.

Multiple endocrine neoplasia syndromes

The multiple endocrine neoplasia (MEN) syndromes are characterized by autosomal dominant inheritance with a high degree of penetrance but varying expression. This review gives a classification of these syndromes and a short summary of the historical background. The pathogenesis of the disease and its possible origin in the APUD cell system are discussed together with the mechanisms underlying normal and ectopic hormone production by MEN tumors on the basis of recent findings in molecular endocrinology. The natural history and the clinical manifestations of the different syndromes are described. The sensitivity and discriminative capacity of the tests used to detect the syndromes in an early stage are compared. The choice of therapy and criteria for the timing and extensiveness of treatment are also considered. Lastly, problems associated with the ethical and legal aspects of screening, central registration, and monitoring of relatives at risk are described.

A case of multiple endocrine adenomatosis (Type 1) with nesidioblastosis, terminating with an exocrine pancreatic carcinoma

We describe a patient with multiple endocrine adenomatosis Type I, characterized by pituitary-dependent Cushing's Syndrome, marked hyperprolactinaemia, primary hyperparathyroidism and hyperinsulinism leading to hypoglycaemia. The patient subsequently developed an exocrine pancreatic carcinoma at the age of 32 years from which she died. An additional finding was the demonstration by immunocytochemistry of nesidioblastosis in the pancreas.

Peptide hormone markers in screening for endocrine tumors in multiple endocrine adenomatosis type I

In three families with the multiple endocrine adenomatosis type I (MEA I) trait, 51 members were investigated by measurement of circulating peptide hormones as tumor markers. Twenty-five of 51 members (49 percent) were considered to be affected by MEA I disorders. The incidence rose with age (75 percent in generation II). Both sexes were affected equally. Hyperparathyroidism was present in 20 of 25 affected members (80 percent), and pituitary tumors (prolactinomas) were found in four of 25 (16 percent). Endocrine pancreatic tumors were found in nine of 25 affected members (36 percent), but when "probable" tumors (seven) are included the frequency rises to 72 percent. Hyperparathyroidism was found in all except one member with proved lesions in other organs. Among patients with proved and possible endocrine pancreatic tumors, elevated serum levels of gastrin and pancreatic polypeptide were frequently found, 78 percent and 67 percent, respectively, and we suggest that serum gastrin and pancreatic polypeptide levels are the most useful screening markers at present for pancreatic lesions in MEA I.

Disorders of calcium and magnesium homeostasis

The components of calcium and magnesium balance and the factors responsible for the maintenance of the serum concentration of these cations are reviewed. Within this framework, the causes and treatment of disturbances of the serum concentration are discussed. Hypercalcemia is usually a reflection of increased bone resorption and/or gut absorption with the kidney playing a secondary role. Hypocalcemia is usually due to either a disturbance in the parathyroid hormone-adenylate cyclase system or a disturbance in vitamin D metabolism. As vitamin D is required for expression of the action of PTH at bone and as PTH is a prime regulator of vitamin D metabolism, the absence of either component results in important disturbances in calcium balance. In contrast to calcium homeostasis, the kidney plays a major role in the determination and regulation of serum magnesium. The major causes of hypermagnesemia therefore are associated with loss of renal function, and hypomagnesemia is frequently due to renal magnesium wasting.

Long-term evaluation of patients with primary parathyroid hyperplasia managed by total parathyroidectomy and heterotopic autotransplantation

Since 1973, we have performed total parathyroidectomy and forearm parathyroid autotransplantation in 36 patients with generalized (four gland) primary parathyroid hyperplasia. Twenty (56%) patients had nonfamilial parathyroid hyperplasia (NFPH) and 16 (44%) patients had familial parathyroid hyperplasia (FPH). Twenty-one patients (Group A) were undergoing operation for the first time and 15 (Group B) were having either second, third or fourth re-explorations for persistent hyperparathyroidism. All patients in Group A and nine patients in Group B had parathyroid resection and immediate autotransplantation as a single procedure. Six Group B patients had hyperfunctioning parathyroid tissue resected, cryopreserved, and subsequently grafted when it was evident that they had been rendered aparathyroid. A sustained differential elevation (13.7 fold +/- 2.7) of parathyroid hormone was detected in the antecubital vein of the grafted compared to the nongrafted arm in 35 (97%) patients. Two (5.6%) of the 36 patients (both with FPH; one Group A and one Group B) required permanent oral calcium and vitamin D replacement therapy and one (3%) patient (NFPH: Group A) had persistent hypercalcemia postoperatively, presumably due to a supernumerary gland. The remaining 33 (92%) patients became normocalcemia after surgery and 23 (70%) of them remained so. Ten (30%) of the 33 patients developed recurrent graft dependent hyperparathyroidism. Eight patients were from the group with FPH (8/14, 57%) and two were from the group with NFPH (2/19, 11%)(FPH vs. NFPH, p < 0.005). Because of symptoms of hypercalcemia or a serum calcium concentration exceeding 11 mg/dl, partial graft resection was performed in five patients and four became normocalcemic. Patients with generalized primary parathyroid hyperplasia may be difficult to cure, especially if the disease is familial. The technique of total parathyroidectomy and heterotopic autotransplantation of fresh or cryopreserved parathyroid tissue offers distinct advantages over alternative techniques.