Chronic recurrent multifocal osteomyelitis (CRMO): a longitudinal case series review

Abstract

Background: Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory disorder that is currently diagnosed based on clinical, radiologic, pathological and longitudinal findings.

Objective: To provide detailed descriptions of CRMO lesion patterns seen on radiographs and MRI and to suggest clinical use of whole-body MRI and propose noninvasive diagnostic strategy.

Materials and methods: Retrospective longitudinal study (1989-2010) of 31 children (22 girls, 9 boys) diagnosed with CRMO. Imaging data were evaluated by two pediatric radiologists.

Results: Mean age at diagnosis was 11 years (3-17). A total of 108 lesions were investigated. The most common sites were the long bone metaphyses (56 lesions in 24 children) especially femoral and tibial (20/24); pelvis (10/31); spine (9/31); clavicle (6/31) and mandible (3/31). In long bones, the radiologic appearance was normal (22/56), mixed lytic and sclerotic (20/56), sclerotic (8/56) or lytic (6/56) often juxtaphyseal (36/56), with hyperostosis or periosteal thickening (10/56). Vertebral involvement was often multifocal (6/9). Medullary edema was seen on MRI (42) with epiphyseal (23/42) or soft-tissue (22/42) inflammation and juxtaphyseal nodule-like appearance (7/42). Whole-body MRI (15/31) was key in detecting subclinical lesions.

Conclusion: CRMO is a polymorphous disorder in which whole-body MRI is extremely useful for showing subclinical edema. Vertebral collapse requires long-term monitoring.