Mediastinal tumour with rare histology: case report

Solitary fibrous tumour (SFT) of the pleura is a rare mesenchymal neoplasm usually originating from the parietal pleura or from the visceral pleura close to the fissures, but seldom can affect any anatomic site. Nowadays this kind of tumour is classificated, under a histological point of view, together with the hemangiopericytoma. Herein we report a case of a rare form of a bulky mediastinal SFT/ hemangiopericytoma (size 15 cm × 12 cm × 9 cm), localized in the anterior mediastinum, dislocating the heart and major mediastinal vessels, in a 67 years old female patient with a synchronous papillary thyroid carcinoma. The patient presented respiratory and cardiac symptoms due to the mass effect. Median sternotomy was mandatory because of the size and because of the suspected involvement of the inferior part of sternum body, as the CT images suggested. During surgery the mass result easily resectable from mediastinal structures with a confined, highly vascularized, implant base at the posterior wall of the sternal body. Final pathological report confirmed the presence of STF/hemangiopericytoma on the bone. During the immediate postoperative period were verified two episodes of atrial fibrillation, totally asymptomatic, converted with intravenous drug amiodarone with subsequent maintenance of sinus rhythm. In consideration of the location, the intraoperative features and the apparent origin from the capillary pericytic cell of the sternal periosteum, this tumour seems closer to a hemangiopericytoma histology than to a SFT, representing a rare localization for this kind of neoplasm. As well as for the SFT, also the histological features of this Hemangiopericytoma, direct to a “low malignant potential” and for this reason, a multidisciplinary group have decided for a radiological Follow up.