Cervical presentations of thymic anomalies in children

Abstract

Objective: To better define the clinical manifestations, radiologic imaging and the surgical management of cervical thymic lesions in children. Study design: Multi-center retrospective case review. Methods: The charts of all children with pathologically confirmed thymic lesions at six children’s hospitals (1990–2002) were reviewed for demographics, physical findings, X-ray findings, operative outcomes and pathology. Results: There were a total of 15 children, 2 of whom had ectopic cervical thymus and 13 who had thymic cysts. They ranged in age from 1 month to 18 years. Thymic lesions were more common in males. Ectopic cervical thymus was best defined by MRI whereas thymic cyst had a more consistent appearance on CT. All children had successful surgical resection with no recorded complications or recurrences. Conclusions: Cervical thymic lesions are rare. Ectopic cervical thymus tends to be found primarily in infants whereas thymic cysts occur in a wider age range. Radiologic imaging is important but is not histologically specific. Definitive diagnosis and cure requires complete surgical excision.

Introduction

The thymus is the central organ of the lymphoid system in infancy. Although thymic tissue is an uncommon source of pediatric neck masses, cervical thymic anomalies must be kept in the differential diagnosis for children presenting with neck masses. The three entities which have been described are thymic cyst, ectopic cervical thymus and cervical thymoma. Approximately 150 cases of thymic cyst have been reported, while less than 100 cases of ectopic thymus have been reported. Cervical thymoma is extremely rare with only 20 documented cases.

In this study, we review several cases of thymic anomalies presenting in the neck along with the associated radiographic and pathologic findings. In doing so, we hope to consolidate data regarding these entities as most of the prior work in this area has been in the form of case reports.