Updated reference intervals for urine normetanephrine have no effect on test sensitivity but fewer false positives.

OBJECTIVE: We previously highlighted the problem of frequent false positives in 24 h urine normetanephrine(UNM) measurements owing to reference intervals that are inappropriately low for the population being screened for pheochromocytoma. Using a large population database, we devised new age-stratified reference intervals for the 24 h UNM test that were higher compared to previous. However, it was uncertain as to whether this would compromise test sensitivity for true pheochromocytoma cases. DESIGN AND METHODS: Retrospective analysis of all pheochromocytoma cases from a recently constructed provincial registry. All confirmed cases had their diagnostic UNM results retrospectively re-analysed according to the newly proposed UNM reference intervals to determine the percentage and phenotype of cases that might have been theoretically missed with the new reference range. RESULTS: After excluding pediatric and non-secretory head and neck paragangliomas, there were 60 confirmed pheochromocytoma cases. Using prior reference intervals, 51/60 (85%) had an abnormally high UNM. Of the 9 with normal UNM, 4 had a high urine metanephrine(UMN), 5 had normal levels of both UNM and UMN such that 55/60 had abnormal test results, representing the historical combined test sensitivity of 92%. Using the proposed reference interval, 43/60 (72%) had high UNM results. Of the 17 with normal UNM, 12 had high UMN, 5 had normal levels of both UNM and UMN. Therefore, 55/60 patients had had elevations in either UNM or UMN, corresponding to an identical combined test sensitivity of 92%. CONCLUSIONS: Reference intervals for UNM derived from actual clinical population screening data are higher than in traditional healthy volunteers. Use of these more appropriate reference intervals can significantly reduce the false positive rate without compromising test sensitivity for true pheochromocytoma.

Gynecomastia in Infants, Children, and Adolescents.

BACKGROUND: Gynecomastia may occur physiologically in the neonatal period, during puberty, and in old age. It may also develop in association with various pathologic states. The challenge for the physician is to distinguish physiological gynecomastia from those with an underlying pathology. OBJECTIVE: To review in depth the pathophysiology, clinical manifestations, and treatment of gynecomastia. METHOD: A PubMed search was completed in Clinical Queries using the key term "gynecomastia". Patents were searched using the key term "gynecomastia" from www.google.com/patents, www.uspto.gov, and www.freepatentsonline.com. RESULTS: Gynecomastia is caused by an imbalance between the stimulatory effect of estrogen and the inhibitory effect of androgen at the breast tissue level. Clinically, gynecomastia is characterized by the presence of a firm or rubbery, discrete, subareolar ridge of glandular tissue that is symmetrical in shape, freely movable, and nonadherent to skin or underlying tissue. Since most cases of physiological gynecomastia regress spontaneously with time, reassurance is all that is necessary. For pathological gynecomastia, treatment should be directed at the underlying cause, if possible. If gynecomastia persists in spite of the above measures, pharmacologic therapy and reduction mammoplasty may be considered. Recent patents related to the management of gynecomastia are discussed. CONCLUSION: The majority of cases are physiological and do not require treatment other than reassurance. For pathological cases, the underlying cause should be treated if possible. If gynecomastia persists in spite of the above measures and treatment becomes necessary, tamoxifen is the treatment of choice. Reduction mammoplasty may be considered for resistant cases.

Evaluation and Management of Children with Thyrotoxicosis.

BACKGROUND: Uncontrolled thyrotoxicosis, especially in early infancy, may cause irreversible damage to the central nervous system as well as profound effects on the function of many organs. Thyrotoxicosis has multiple etiologies and treatment depends on the underlying etiology. An accurate diagnosis is essential so that appropriate treatment can be initiated without undue delay. OBJECTIVE: To review in depth the evaluation, diagnosis, and treatment of children with thyrotoxicosis. METHODS: A PubMed search was completed in Clinical Queries using the key terms "thyrotoxicosis" and "hyperthyroidism". The search strategy included meta-analysis, randomized controlled trials, clinical trials, observational studies, and reviews. Patents were searched using the key terms "thyrotoxicosis" and "hyperthyroidism" from www.freepatentsonline.com and www.google.com/patents. RESULTS: Graves' disease accounts for approximately 96% of pediatric cases of thyrotoxicosis. Other causes include Hashitoxicosis, toxic adenoma, toxic multinodular goiter, subacute granulomatous thyroiditis, acute suppurative thyroiditis, pituitary thyroid-stimulating hormone-secreting adenoma, pituitary thyroid hormone resistance, iodine-induced thyrotoxicosis, and drug-induced thyrotoxicosis. Familiarity of the clinical features would allow prompt diagnosis and institution of treatment. The underlying cause of thyrotoxicosis should be treated if possible. Treatment options for Graves' disease include antithyroid medications, radioiodine therapy, and surgery. Recent patents related to the management of thyrotoxicosis are discussed. CONCLUSION: Currently, antithyroid medications are considered to be the initial treatment of choice for Graves' disease in the pediatric age group. Radioactive iodine treatment is generally used for children with poor compliance with antithyroid medications, children not in remission after 1 to 2 years of antithyroid medications, and children with a major adverse effect while receiving an antithyroid medication. Total or near-total thyroidectomy should be considered in children younger than 5 years of age who do not respond to or experience a major adverse effect to antithyroid medications. Surgery should also be considered in those with very large goiter, severe ophthalmopathy, pregnancy, persistent hyperthyroidism in spite of treatment with antithyroid medications and radioactive iodine, and personal preference.

Persistent Mongolian spots in Chinese adults.

Four Chinese females aged 21-35 years with Mongolian spots are reported. Two patients had the spots on their arms while the other two had the spots on their shoulders. The persistence of Mongolian spots in Chinese adults has not been previously reported.