Nuclear protein in testis carcinoma of the mediastinum: a case report

BACKGROUND Nuclear protein in testis carcinoma is a rare and very aggressive undifferentiated cancer which characteristically arises in the midline of the head, neck, and mediastinum. CASE PRESENTATION We describe the case of a 46-year-old white woman admitted for superior vena cava syndrome revealing a mediastinal tumor. Pathological examination of specimens obtained by mediastinoscopy revealed an undifferentiated tumor with solid growth and positive immunoreactivity for p40 and negative immunoreactivity for cytokeratin markers. Immunohistochemical staining was positive for nuclear protein in testis, allowing the diagnosis of nuclear protein in testis midline carcinoma of the mediastinum. CONCLUSIONS We present a rare case of mediastinal nuclear protein in testis carcinoma with diagnosis based on nuclear protein in testis protein positivity and atypical immunohistochemical features including p40 positivity and anti-cytokeratin negativity. Physicians must remain aware of the possibility of nuclear protein in testis carcinoma especially in young patients with thoracic symptoms and suspicion of neoplasm.