KEY POINTS
- The report describes a 77-year-old woman with intravascular papillary endothelial hyperplasia, or Masson’s tumor, of the left supraorbital neurocranium. The benign vascular lesion grew rapidly after local trauma, causing major skull deformation, orbital involvement and severe functional impairment of the left eye.
- MRI demonstrated a large hypervascular and centrally necrotic mass with bony destruction, extension into the anterior and middle cranial fossae, ventricular compression, midline shift and orbital involvement. Initial surgery was abandoned because of extensive intraoperative bleeding risk, leaving the lesion functionally inoperable.
- The tumor continued to enlarge from approximately 11.5 × 6.8 × 8.1 cm on initial MRI to 12.2 × 8.0 × 8.5 cm at planning CT. The patient therefore received 54 Gy in 27 fractions using 6-MV FFF IMRT with a six-field sliding-window technique.
- Interim MRI after 44 Gy showed only minimal further progression but increasing consolidation of the vascular component. Because puncture produced little reduction and embolization was not feasible, RT was completed to the planned 54 Gy.
- After RT stabilized the lesion, local necrosectomy became feasible. Subsequent imaging demonstrated progressive tumor shrinkage, while eye mobility and subjective vision improved; the patient was again able to wear glasses and reported improved quality of life. Follow-up extended to 3 years.
- Toxicity was limited in this case to grade 1 fatigue, transient subjective short-term memory impairment and low-grade skin hyperpigmentation. No additional treatment-related toxicity was reported during follow-up.
- The accompanying literature review identified 22 relevant publications, predominantly case reports. Surgery remained the most common primary treatment (16 reports), while therapeutic RT generally used conventionally fractionated doses of 40–54 Gy; paradoxically, previous SRS or fractionated RT has also been reported as a potential antecedent to IPEH development.
CLINICAL TAKEAWAY
For a rare benign vascular tumor that could not initially be resected because of bleeding risk, conventionally fractionated RT achieved sufficient growth control to permit later surgery and functional recovery. The result is compelling at a case level, but Masson’s tumor is exceptionally rare and the literature remains too sparse—and biologically contradictory regarding prior radiation exposure—to define RT as a standard treatment.