%0 Journal Article %J Polish Journal of Pathology %@ 1233-9687 %V 68 %N 4 %D 2017 %F Benej2017 %T Soft tissue metastasis of mediastinal non-functioning paraganglioma with unusual TTF-1 expression: a potential diagnostic pitfall %X Metastatic extra-adrenal paragangliomas are very rare and can represent diagnostic challenges. We report a case of 69-year-old man with a tumor of the right shoulder. Histologic and immunohistochemical examinations confirmed the diagnosis of paraganglioma. Surprisingly, tumor cells were diffusely thyroid transcription factor 1 (TTF-1) positive. Succinate dehydrogenase complex subunit B (SDHB) deficiency has not been detected. Inherited syndromes associated with paragangliomas were ruled out. The primary tumor was identified in the mediastinum. This is the first report of TTF-1 expression in paraganglioma. To avoid misdiagnosis, careful clinical and pathological examination of any tumor with organoid growths pattern is necessary. %A Benej, Michal %A Zambo, Iva %A BĂ­lek, Ondrej %A Capov, Ivan %P 354-358 %9 journal article %R 10.5114/pjp.2017.73931 %U http://dx.doi.org/10.5114/pjp.2017.73931