Well-differentiated Liposarcoma of the Esophagus with an Extramural Growth—Report of a Resected Case—

Abstract

We report a case of an esophageal liposarcoma growing extramurally to the mediastinum which is rare. A 54-year-old man was referred to our hospital for detailed examinations of an abnormality in the right lower lung field on a routine chest X-ray. The patient was asymptomatic and could take a regular diet. Computed tomography (CT) of the chest showed a 14-cm tumor adjacent to the esophagus and extending from the posterior mediastinum into the right thoracic cavity. Although histopathological malignancy was not proven by a CT-guided percutaneous needle biopsy, a transthoracic tumor excision was performed. Esophagectomy was avoidable, because the tumor was only partially connected to the outer muscle layer of the middle esophagus. The excised specimen involved an 18×10×7 cm yellowish solid tumor. The histopathological examination revealed the tumor to be composed of relatively mature but irregular adipose tissue with a fibrous component. Adipocytes in the tumor had nuclear atypia, and the cells were positive for S100, CDK4, MDM2 (in part), and Ki-67 immunostaining. The tumor was finally diagnosed as well-differentiated liposarcoma. The patient's postoperative course was uneventful and no recurrence has occurred as of 5 months after the operation. Because well-differentiated liposarcomas occurring at deep anatomical sites have a high incidence of local recurrence, long-term surveillance examination is necessary in this case.