title: Metastasis in the subcarinal lymph node with unknown primary tumor.
abstract: A 59-year-old man with previous anaplastic large cell T-cell lymphoma stage 3A was admitted with an isolated positron emission tomography(PET)-positive spot in a subcarinal lymph node. Diagnosis was achieved with endobronchial ultrasound-guided fine-needle aspiration demonstrating a well-differentiated squamous cell carcinoma but no primary tumor was visible on PET-computed tomography. Because of his previous lymphoma the patient was scheduled for mediastinoscopy where the diagnosis was confirmed. Subsequent gastroscopy was normal and a right-sided thoracotomy showed no evidence of cancer elsewhere, only an inoperable metastasis in a subcarinal lymph node which infiltrated the trachea, esophagus and aorta. Such isolated squamous cell carcinoma in a subcarinal lymph node without a primary tumor despite invasive work-up has not been reported before.
authors.affiliation: Department of Cardiothoracic Surgery, Odense University Hospital, Odense, Denmark Department of Pathology, Odense University Hospital, Odense, Denmark Department of Nuclear Medicine, Odense University Hospital, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Eckardt
authors.affiliation: Department of Cardiothoracic Surgery, Odense University Hospital, Odense, Denmark Department of Pathology, Odense University Hospital, Odense, Denmark Department of Nuclear Medicine, Odense University Hospital, Denmark.
authors.forename: Karen Ege
authors.initials: KE
authors.lastname: Olsen
authors.affiliation: Department of Cardiothoracic Surgery, Odense University Hospital, Odense, Denmark Department of Pathology, Odense University Hospital, Odense, Denmark Department of Nuclear Medicine, Odense University Hospital, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Petersen
keywords: lung cancer; lymph node; metastasis