Thymic cyst: is a correct preoperative diagnosis possible? Report of a case and review of the literature

Abstract.

A case of a giant cervico-mediastinal cyst of thymic origin in an 8-year-old child is presented. The cyst was asymptomatic except for deformity due to its size. In spite of several diagnostic approaches like ultrasonography, computed tomography, cyst puncture with biochemical analysis of cyst content and direct contrast injection and radiography after emptying of the cyst, the ultimate diagnosis as to the origin of the cyst was not disclosed until after operation and histopathological examination of the operative specimen. On a more general basis the diagnostic possibilities and pitfalls are discussed. Conclusion: a correct preoperative diagnosis of a thymus cyst is difficult and in many instances impossible even when all diagnostic measures at hand are utilized, including radiographic methods, computed tomography, magnetic resonance imaging, ultrasonography and biochemical examination of cyst aspirate and estimation of tumour markers in cyst fluid and serum.