Guillain-Barré syndrome involving reproductive system revealed on 18F-FDG PET/CT: a case report.

Guillain-Barré syndrome (GBS) is an immune-mediated acute inflammatory peripheral neuropathy. While it is well-established that its typical manifestations involve the peripheral nerves, it is noteworthy that involvement of the central nervous system and the reproductive system is exceedingly rare. Here we report the case of a 67-year-old man with GBS in whom the 18F-FDG PET/CT demonstrated systemic inflammatory hypermetabolism. The imaging revealed multifocal, heterogeneous high-activity along the nerve roots, cerebral cortex, hypothalamus, and medulla oblongata. Crucially, it also identified significant involvement of the right testis and the transition zone of the right prostate, suggesting direct inflammatory engagement of the reproductive system. This case underscores the potential of 18F-FDG PET/CT as a comprehensive imaging tool for assessing the extent of systemic disease and inflammatory activity in complex GBS presentations.