title: NUT midline carcinoma mimicking a germ cell tumor: a case report.
abstract: NUT midline carcinoma (NMC) is a rare and highly aggressive malignancy. Although more information on NMC has been recently accumulating in the literature, most oncologists and pathologists remain unfamiliar with the clinical and pathologic features of this disease. The clinical features of NMC sometimes mimic those of other malignancies, and NMC can therefore be overlooked if the diagnosis is not suspected. We present the case of a young male with NMC arising in the mediastinum with elevated serum alpha-fetoprotein levels suggestive of an extragonadal nonseminomatous germ-cell tumor.
  
  
  
  A 28-year-old Japanese male presented with cough and left-sided chest pain for 6 weeks. The patient had a mediastinal tumor with metastases to the right lung, lymph nodes, and bones at initial presentation. Nonseminomatous germ cell tumor was suspected due to the young age, location of the tumors, and elevated serum alpha-fetoprotein. However, biopsy confirmed the diagnosis of NMC with immunohistochemistry. The tumor briefly responded to cytotoxic chemotherapy but subsequently progressed and became refractory to the chemotherapy regimen. External beam radiotherapy was administered with dramatic shrinkage of the tumor and a metabolic response on 18-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan. However, the patient died 4.5 months after the diagnosis of NMC.
  
  
  
  Serum levels of alpha-fetoprotein may be elevated in patients with NMC. Regardless of the level of tumor markers, immunohistochemistry for NUT should be performed in cases of poorly differentiated carcinomas without glandular differentiation arising in the midline structures.18F-FDG PET/CT is useful for staging and assessing responses to therapy.
authors.affiliation: Department of Medical Oncology, Kameda Medical Center, Kamogawa, Chiba, 296-8602, Japan. yharada@cc.saga-u.ac.jp.|Department of Internal Medicine, Division of Haematology, Respiratory Medicine and Oncology, Faculty of Medicine, Saga University, Saga, Japan. yharada@cc.saga-u.ac.jp.
authors.forename: Yohei
authors.identifier: 0000-0001-9371-0965
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Department of Medical Oncology, Kameda Medical Center, Kamogawa, Chiba, 296-8602, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Pathology Project for Molecular Targets, the Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.|Division of Pathology, the Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Takeuchi
authors.affiliation: Department of Radiation Therapy, Kameda Medical Center, Kamogawa, Chiba, 296-8602, Japan.
authors.forename: Kazufusa
authors.initials: K
authors.lastname: Shoji
authors.affiliation: Department of Diagnostic Pathology, Kameda Medical Center, Kamogawa, Chiba, 296-8602, Japan.
authors.forename: Kazuei
authors.initials: K
authors.lastname: Hoshi
authors.affiliation: Department of Medical Oncology, Kameda Medical Center, Kamogawa, Chiba, 296-8602, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy; D059248:Chemoradiotherapy; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D008297:Male; D008479:Mediastinal Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D013736:Testicular Neoplasms / Q000473:pathology*; D015854:Up-Regulation; D000509:alpha-Fetoproteins / Q000378:metabolism*
chemical_list: C000630260:NUTM1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D000509:alpha-Fetoproteins
keywords: Alpha-fetoprotein; Case report; NUT midline carcinoma; PET/CT; Radiotherapy; Tumor markers