Carcinoma of Unknown Primary in the Middle Mediastinum: Three Case Reports

Abstract

Carcinoma of unknown primary rarely occurs in the middle mediastinum. Here, we present three cases of carcinoma of unknown primary in the middle mediastinum, which were treated with surgical resection and adjuvant therapy. Positron emission tomography/computed tomography demonstrated high uptake of 18F-fluorodeoxyglucose in the tumors. Regarding the surgical procedure, dissection of the azygos vein was useful to obtain not only a good exposure of the surgical field but also mobilization of the superior vena cava, which led to safe separation of the tumors from the major mediastinal structures. The dissection and reconstruction of the superior vena cava was required due to extranodal invasion of the tumor in one case. Since the middle mediastinal carcinoma of unknown primary may be T0N2M0 NSCLC, the surgery alone seems to be insufficient treatment for this type of tumors. To evaluate whether the adjuvant therapy is associated with an improved prognosis for the patients with middle mediastinal carcinoma of unknown primary, a further accumulation of cases is required.