Pembrolizumab, an immune checkpoint inhibitor targeting the programmed cell death 1 (PD-1) protein, is widely used for renal cell carcinoma but rarely causes central nervous system adverse events such as myelitis. A 58-year-old woman with stage IV renal clear cell carcinoma developed radiating hip pain, paresthesia, hypoesthesia (T10 and below), constipation, urinary retention, and sudden right-eye blurred vision one month after her sixth cycle of pembrolizumab and lenvatinib. Neurologic examination revealed asymmetrical inferior paraparesis, upper motor neuron signs, and right eye papilledema. MRI demonstrated patchy hyperintensity on C2-C6 and T2-T5, supportive of myelitis. Intravenous methylprednisolone was initiated, leading to pain relief and motor improvement. This is the first reported case of pembrolizumab-induced myelitis in Indonesia, emphasizing the importance of early recognition and corticosteroid therapy for optimal recovery.

Background: The sacroiliac joint (SIJ) plays a crucial role in transmitting axial loads and maintaining pelvic stability. Sacroiliac joint arthropathy (SIJA) accounts for 10%–30% of low back pain cases but remains underrecognized due to overlapping pain referral patterns and nonspecific imaging findings. Diagnosis relies primarily on characteristic pain distribution and provocative maneuvers, with image-guided intra-articular block serving as the diagnostic gold standard. This study aimed to characterize the clinical profile of block-confirmed SIJA, emphasizing referral pain distribution, triggering position, and provocative test responses. Methods: A cross-sectional study was conducted on 98 patients with diagnostic block–confirmed SIJA at Siloam Hospital Lippo Village, Indonesia. Demographic data, referral pain sites, sitting duration, and results of FABER, compression, and distraction tests were analyzed descriptively. Results: The mean age was 52.07 ± 14.17 years, with 72.4% females. Referral pain most frequently involved the lower back (28.6%) and thigh (28.6%), with occasional extension to the groin (8.2%) or calf (4.1%). Over half of patients (55.1%) reported sitting more than six hours daily. Pain was predominantly triggered during sit-to-stand transitions (85.7%) and while sitting (74.5%). SIJ tenderness (98.0%) and FABER positivity (75.5%) were most consistent. Conclusion: The dominant referral pain in SIJA involves the lower back and posterior thigh. Sit-to-stand transition is the most frequent triggering position, while FABER testing demonstrates the highest diagnostic yield among provocative maneuvers. These consistent patterns may serve as practical clinical indicators to improve diagnostic accuracy in suspected SIJ-related pain.