Primary vascular bone tumors in the spine: a challenge for pathologists and spine oncology surgeons.

PURPOSE: Primary vascular bone tumors of the spine represent a challenge for oncology surgeons, due to the need of planning a surgical strategy appropriate to the tumor behavior. But these tumors represent a challenge also for pathologists, as immunohistochemical and molecular analyses have recently refined the terminology.
METHODS: A cohort of 81 cases was retrospectively reviewed, targeting the evolution of diagnoses and the treatment-related outcome. Sixty-six cases (including one case originally diagnosed as chordoma) were diagnosed before 2011, and 15 were diagnosed and treated in the period 2011-2017. Fully documented outcome studies are available for 46 patients whose immunohistochemical and molecular analyses were available. The follow-up ranges from 6 months of the early patient death to 300 months of the longest disease-free survival.
RESULTS: The outcome was related not only to the treatment performed, but also to the evolution of diagnoses. The term Hemangioendothelioma that defined a benign aggressive (Enneking stage 3) tumor is now obsolete and replaced by the diagnosis of Epithelioid Hemangioma for benign aggressive tumor and Epithelioid Hemangioendothelioma for low-grade malignant tumor. En bloc resection was appropriate for local control, but 2 out of 7 cases of epithelioid Hemangioendotheliomas died due to the spread of the disease None of the Hemangiomas recurred after intralesional excision with or without radiotherapy, or after vertebroplasty. Both cases of Angiosarcoma had a fast and lethal evolution.
CONCLUSIONS: Surgeons must be aware of the evolution of terminology to decide the most appropriate treatment options. These slides can be retrieved from Electronic Supplementary Material.