Multiple endocrine neoplasia

Clinical experience with pheochromocytoma in a single centre over 16 years

BACKGROUND

Pheochromocytoma and paraganglioma are rare tumours of neuroectodermal origin. Pheochromocytoma occurs in 0.1-2% of people with hypertension, while the incidence rises to 4-5% in patients with incidental adrenal mass.

AIM

To analyse the presentation, diagnosis and localization, pathology, molecular genetic aspects, surgical management and long-term outcome of a large series of patients with pheochromocytoma referred to a single centre.

METHODS

From 1992 to 2008, we observed 91 patients with pheochromocytoma, 70 (77%) with the sporadic form and 21 (23%) with the hereditary form. In the group with the hereditary form, the mean age at diagnosis was significantly lower than the mean age of the group with the sporadic form (38 vs 48 years; p < 0.001).

RESULTS

Eighty (88%) patients with pheochromocytoma were symptomatic and the classical triad of palpitations, headache and diaphoresis was present in 30% of patients. In 12% of patients, the pheochromocytoma was discovered during radiological images (adrenal incidentaloma). The unilateral adrenal localization was observed in 78% of patients, bilateral in 15% and extra-adrenal in 7% of patients. All pheochromocytoma patients underwent surgical procedure and the laparotomic approach was used in 49 (53%) patients, while the laparoscopic approach was performed in 42 (47%) patients. Pheochromocytoma was benign in 86 patients (93%) [mean size was 4.3 cm] and the malignant form was found in five patients (7%) [mean size was 10 cm].

CONCLUSIONS

These data from a large cohort of patients are consistent with those reported in the literature and show that pheochromocytoma is an in important challenge for clinicians.

Clinical testing for multiple endocrine neoplasia type 1 in a DNA diagnostic laboratory

PURPOSE

Based on results of diagnostic MEN1 testing, we have attempted to further define the mutational spectrum of the MEN1 gene and the clinical features most frequently associated with MEN1 mutations.

METHODS

Mutation testing was performed on blood samples by PCR amplification and sequencing of exons 2 to 10 of the MEN1 gene and the corresponding intron-exon junctions. Pedigree phenotypic information was obtained by written questionnaire.

RESULTS

Among 288 presumably unrelated pedigrees, 73 independent mutations were found in 89 families. Five mutations were found in 2 pedigrees, and 4 mutations were seen in more than 2 pedigrees. There were 17 nonsense mutations (23.3%), 2 in-frame deletions (2.7%), 18 frameshift-deletion mutations (24.7%), 10 frameshift-insertion or -duplication mutations (13.7%), 13 splice-site mutations (17.8%), and 13 presumptive missense mutations (17.8%). Thirty-nine of 56 pedigrees with parathyroid and pancreatic islet neoplasia tested positive, compared with 4/24 and 8/32 pedigrees affected with hyperparathyroidism or hyperparathyroidism and pituitary tumors. MEN1 mutations were found in 6/20 sporadic patients, all of whom had both parathyroid and pancreatic neoplasms. Of 14 mutation-negative sporadic patients, 10 exhibited hyperparathyroidism and pituitary tumors without islet cell neoplasia. Somatic mosaicism was detected in 1 sporadic patient.

CONCLUSION

Patients from pedigrees with hyperparathyroidism and pancreatic islet tumors are most likely to test positive for MEN1 mutations. Mutations are less often detected in patients from pedigrees with hyperparathyroidism alone or in combination with pituitary tumors without pancreatic islet neoplasia. Sporadic cases are less likely to test positive than familial cases, in part due to somatic mosaicism.