MEDIASTINAL MASS AS A MELANOMA METASTASIS, AN UNUSUAL PRESENTATION

Aims We present a case of diagnosis of metastatic melanoma in the form of mediastinal mass, which debuts clinically with an Guillain Barré paraneoplastic syndrome.

Methods A 66-year-old male admitted in the Neurology department because of weakness and strength loss clinic, diagnosed with Guillain-Barré syndrome (GBS). CT scan was performed as part of the etiological study and a 53 x 37mm, well-delimited, right paraesophageal lesion was found incidentally.

Results Endosonography (EUS) showed a heteroechogenic mass with cystic areas, located adjacent to the aorta and extrinsic to the thoracic esophagus. Fine needle aspiration (22G) of the mass revealed a melanoma metastases (immunohistochemistry with diffuse and intense positivity for S-100, SOX-10 and HMB45).

Conclusions A mediastinal mass such as metastasis of a melanoma is an extraordinary form of presentation, with less than 20 cases described in the literature. However, the potential therapeutic possibility, thanks to the new treatment targets, makes the diagnosis of these lesions even more important.

Regarding the diagnosis of mediastinal lesions, the aspiration puncture guided by echoendoscopy is positioned as the test with better diagnostic performance compared to other, being also a safe technique.