Pediatric head and neck manifestations associated with multiple endocrine neoplasia syndromes.

INTRODUCTION: Multiple endocrine neoplasia (MEN) syndromes are a group of hereditary cancer syndromes that can predispose children to endocrine neoplasms developing within the head and neck. OBJECTIVE: To examine the neoplastic manifestations of MEN type 1 (MEN1) and MEN type 2 (MEN2) in the pediatric head and neck. METHODS: Single-institution, retrospective review of pediatric MEN between 2005 and 2022. RESULTS: Fifty-three children were genetically confirmed with MEN (15 MEN1, 34 MEN2A, and 4 MEN2B), while three patients received clinical diagnoses of MEN1. The male to female ratio was essentially equal (1.15:1), and a documented family history of cancer was present in 89% (50/56). After multidisciplinary evaluation, a familial MEN diagnosis was confirmed in 91% (51/56). The mean ages of initial presentation and surgical intervention were 8.9 years (SD 5) and 9.8 years (SD 4.8), respectively. Although patients with MEN2 received surgery earlier than patients with MEN1 (8.7 vs 12.7 years), surgical patients with MEN2 in this cohort were older relative to current American Thyroid Association (ATA) guidelines primarily due to late presentation. Thyroid malignancies were identified in 36% (9/25) of thyroidectomy specimens (21 MEN2A, 4 MEN2B), with medullary thyroid carcinoma (MTC) present in five MEN2A patients and three MEN2B patients (89%), and papillary thyroid carcinoma (PTC) present in one MEN2A patient (11%). Nearly 90% (8/9) of thyroid malignancies were occult, with some occurring earlier than predicted by current guidelines (ATA-MOD and ATA-H). Central neck dissections were performed in 24% (2 MEN1, 2 MEN2A, and 4 MEN2B), with two MEN2B (50%) demonstrating cervical lymph node (LN) metastases. Additional histopathologic findings included C-cell hyperplasia in 57% (12/21) of MEN2A thyroidectomy patients. Of the eight MEN1 parathyroidectomy patients, four demonstrated parathyroid hyperplasia and four presented with parathyroid adenoma. CONCLUSION: Nearly 60% required head and neck procedures. While MEN1 guidelines were appropriate for our cohort, we identified patients with MEN2 that developed MTC earlier than expected based on current ATA guidelines, including children in categories considered lower risk. In conjunction with a multidisciplinary approach, pediatric head and neck surgeons should be aware of the potential need for earlier surgical intervention in the pediatric MEN2 population.

Lipofibromatosis presenting as a pediatric neck mass.

Lipofibromatosis is a recently described, benign neoplasm that presents in the pediatric population [J.F. Fetsch, M. Miettinen, W.B. Laskin, M. Michal, F.M. Enzinger, A clinicopathologic study of 45 pediatric soft tissue tumors with an admixture of adipose tissue and fibroblastic elements, and a proposal for classification as lipofibromatosis, Am. J. Surg. Pathol. 24 (2000) 1491-1500]. It is a rare soft tissue tumor histologically distinct from other fibromatoses such as juvenile fibromatosis, fibrous hamartoma of infancy, calcifying aponeurotic fibroma, and lipoblastoma. Distinguishing histopathologic features of lipofibromatosis include abundant and disorganized adipose lobules traversed by bundles of spindled fibroblast-like cells. It most commonly presents in the extremities. We present a case involving a young girl, which we believe represents the first report of lipofibromatosis involving the neck.

The effect of peroxynitrite on sphincter of Oddi motility.

BACKGROUND: Nitric oxide (NO*) is an inhibitory neurotransmitter that induces sphincter of Oddi relaxation. Superoxide (O*-2)-scavenging enzymes are present in enteric plexuses of the sphincter of Oddi and O*-2 alters sphincter of Oddi motor function. O*-2 rapidly oxidizes nitric oxide (NO*) to form peroxynitrite (ONOO-), thus terminating the biological activity of NO*. The aim of our study was to determine the effects of ONOO- on sphincter of Oddi motility in vitro. MATERIALS AND METHODS: Adult opossums were sacrificed and the sphincter of Oddi was removed and placed in a tissue bath containing oxygenated Krebs solution at 37 degreesC. In the first series of experiments, force transducers recorded tension in a transverse orientation at two sites along the spontaneously contracting sphincter of Oddi. In a second series of experiments, circular muscle strips were precontracted with carbachol and stimulated by an electrical field. RESULTS: ONOO-, superoxide dismutase (SOD), Nomega-nitro-l-arginine (l-NNA), or oxyhemoglobin were added to the tissue baths. ONOO- decreased the frequency of contractions in the spontaneously contracting sphincter of Oddi. Adding hemoglobin increased the frequency of contractions. ONOO- also increased the stimulation-induced relaxation compared to controls. The increase in relaxation induced by ONOO- was inhibited by oxyhemoglobin and l-NNA but not SOD. Pretreatment with oxyhemoglobin prevented the increase in the stimulation-induced relaxation caused by ONOO-. CONCLUSION: These results suggest that hemoglobin binds ONOO- or that ONOO- generates NO.