Nuclear Protein in Testis Midline Carcinoma Simulating Germ Cell Tumor of the Mediastinum

摘要

Nuclear protein in testis (NUT) midline carcinoma (NMC) is a very rare and aggressive human cancer characterized by overexpression of the nuclear protein in testis (NUT) most commonly due to a chromosomal translocation that fuses the NUT gene on chromosome 15 with the BRD4 gene on chromosome19. It has been described mainly in younger individuals in the mediastinum and head and neck regions and known to be highly aggressive with poor outcomes. We report the case of 23 years old male, diagnosed with locally advanced mediastinal malignancy metastatic to the lung with elevated serum alpha-fetoprotein (AFP) suggestive of germ cell tumor. However, pathology with immunohistochemistry excluded the dignosis of germ cell tumor and confirmed the diagnosis of poorly differentiated carcinoma. Despite aggressive treatment, evolution was marked by rapid clinical deterioration leading to death within 1 month of initial diagnosis. We report this case to underline the rarity of this disease, clinico-radiological and pathologic features, especially misleading presentation with germ cell tumors, treatment management and prognosis.