Multiple intercostal nerve sheath cysts located at costovertebral angle in bilateral hemithorax

Neurogenic tumors arising from nerve tissues may be located on the posterior mediastinum.[1,2] This study presents the case of an asymptomatic male patient who presented with multiple bilateral mediastinal lesions of different sizes that were radiologically similar to neurogenic tumors. After a histopathological examination, the lesions were identified as "edematous nerve tissue".

A 41-year-old asymptomatic male patient was evaluated by computed tomography prior to an appendectomy, revealing multiple bilateral, paravertebral, and uniformly limited lesions (Figure 1-d). The largest lesion was 3.4¥2.2 cm and all lesions were found to have a cystic structure in magnetic resonance imaging (Figure 1e) and to be non-metabolic in positron emission tomography. Multiple cystic lesions, ranging in size from 1 cm to 4 cm and located at the 3-7 costal vertebral angles were detected on video-assisted thoracoscopic exploration of the right hemithorax (Figure 1f). Cyst fluid was aspirated and lesions with diameters of 3-cm and 4-cm were fully excised. Thoracic drainage was terminated on the third day and the patient was discharged. A histopathological examination revealed the cyst fluid to be benign, and the cysts, which were fully excised, were composed of edematous nerve tissue.

Figure 1. (a-d) Different computed tomographic images of the lesions. (e) Magnetic resonance imaging section. (f) Peroperative view.