Clinical Summary

A 26-year-old male presented in January 2020 with a 5-day history of nausea, vomiting, and photophobia, who was found to have cranial lesions demonstrating contrast enhancement. Thirty-one months later (August 2022), he presented with a viral illness and anemia, and was found to have innumerable enhancing bony lesions throughout the entire visible axial and appendicular skeleton. Past medical history is significant for a remote resection of a pilocytic astrocytoma of the thoracic spine in Brazil (age 12), and a T2-T12 fusion for scoliosis in Brazil (age 14). A bone marrow biopsy was performed.

Discussion points

1. What are the major histological findings?
2. What is the differential diagnosis?
3. What further investigations are warranted?