Synovitis, acne, pustulosis, hyperostosis and osteitis syndrome with trigeminal brainstem involvement

The synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome is defined as the association of characteristic osteoarticular and dermatological manifestations. The diagnosis is based on clinical and radiological aspects, but in the recent years it has been described as an extension of other systems different from the skin and the bones. We report the first case of parenchymal brainstem trigeminal involvement in the context of clinically-active SAPHO syndrome. We review the literature and discuss the underlying mechanism of this multi-organ presentation.