malignant mediastinum hemangiopericytoma (MONDO_0003809) is a malignant hemangiopericytoma arising in the mediastinum. Also known as: malignant hemangiopericytoma of mediastinum, malignant hemangiopericytoma of the mediastinum, malignant mediastinal hemangiopericytoma, mediastinum hemangiopericytoma, mediastinum spindle cell tumor, mediastinum spindle cell tumour.