A Rare Case of Mediastinal NUT (Nuclear Protein in Testis) Carcinoma Presenting with Acute Respiratory Failure: A Case Report

Background: NUT (nuclear protein in testis) carcinoma is a rare but aggressive cancer, which was first described in 1991. Given the rarity of this enigmatic entity, risk factors are unknown, treatment options are limited, and the prognosis is dismal. We present the case of a 30-year-old male who presented with acute respiratory failure secondary to a rapidly enlarging mediastinal mass and was subsequently diagnosed with NUT carcinoma. Case Report: A 30-year-old male presented with symptoms of rapidly progressive shortness of breath and chest pain. CT chest revealed mediastinal lymphadenopathy with extrinsic compression of the left lower lobe bronchus leading to lobar atelectasis. Bronchoscopy with endobronchial ultrasonography was performed to obtain a fine-needle aspirate of the subcarinal lymph node, which was consistent with poorly differentiated carcinoma. An ultrasound-guided percutaneous right supraclavicular core-needle biopsy confirmed NUT carcinoma. Despite prompt initiation of mechanical ventilation as well as chemotherapy, the patient’s condition continued to deteriorate and he passed away after being hospitalized for 127 days. Conclusion: Mediastinal NUT carcinoma is a rare cause of acute respiratory failure. Despite the rarity of this cancer, its aggressive and serious nature necessitates all physicians to be aware of this clinical entity and maintain a high index of suspicion. Prompt diagnosis and initiation of chemotherapy is essential. The prognosis remains dismal given that the cancer is resistant to known antineoplastic therapies. Further research should focus on new treatment paradigms for this rare cancer and patients should be encouraged to participate in clinical trials.