An 18-year-old female presented with pain in the left clavicle. She was known with intermittent pain and swelling on the medial clavicle and right ribs in the last four years, nonresponsive to local corticoid. The histology and culture of two previous percutaneous biopsies were inconclusive. The laboratory tests were unremarkable.
Radiographs (anteroposterior clavicle and posteroanterior chest) revealed predominantly sclerotic lesions with a minor lytic component, and marked expansion and solid periosteal reaction on the medial two-thirds of the left clavicle and anterior aspect of the 6th right rib (Fig. 1-3).
Tc-99m methylene diphosphonate bone scintigraphy (anterior projection) demonstrated increased uptake in the locations previously described as well as in the 5th right rib, the latter being radiographically occult (Fig. 4).
Magnetic resonance imaging (MRI) of the left clavicle depicted a medullary lesion with sclerosis and multiple patchy and coalescent areas isointense in T1-weighted images (WI), hyperintense in T2-WI, and strongly enhancing after gadolinium on the medial two-thirds of the clavicle. The solid periosteal reaction is also appreciated as well as soft tissue edematous changes (Fig. 5-8).
Chronic recurrent multifocal osteomyelitis (CRMO) is a rare, autoinflammatory disorder typically affecting children and adolescents. CRMO belongs to the spectrum of aseptic osteomyelitis-like conditions in which SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis) syndrome is included. Its cause remains unknown though recently a genetic component has been suggested. Its incidence is estimated to be 2–5% of all osteomyelitis cases [1, 2]. CRMO is twice as common in females and the age of onset is usually 4–14 years although it has been reported in adulthood [1, 2, 3]. The main complaints are localized pain and variable swelling, possibly associated with mild malaise and dermatologic affections as palmoplantar pustulosis [2, 3].
Lesions are typically bilateral and multifocal at presentation and involve the metaphyses of tubular bones and medial clavicle, and also commonly the spine, ribs, mandible and pelvis [1, 2, 4]. CRMO has a prolonged course with relapses and remissions, involving the same or a different location. Histopathology is that of a non-specific inflammation, with fibrosis and/or hyperostotic regeneration [5].
The mainstays of imaging diagnosis are radiography and bone scintigraphy. Initially, the lesions are purely osteolytic developing variable sclerosis and periosteal reaction over time. After clinical resolution, radiographic appearance can normalize in 0,5-5 years or maintain remnants of the bony alteration. Complete healing of the clavicular lesions is rare [2, 3, 4]. MRI is highly sensitive for diagnosing occult lesions and whole body MRI is increasingly used for evaluation of multifocal bone lesions. MRI is extremely accurate to evaluate disease activity and local extent, being helpful for biopsy guidance and evaluation of long-standing disease. Active disease manifests as areas of high signal on T2-WI and enhancement. Quiescent disease correlates with low signal on T1- and T2-WI corresponding to sclerosis, possibly with scattered areas of high signal related to fatty marrow [1, 2].
Owing to the lack of specific tests the diagnosis of CRMO is one of exclusion. Although CRMO can be self-limited, it can have a protracted course and result in significant morbidity. The multifocal involvement of typical sites particularly the anterior thoracic wall, as in the case in appreciation, is crucial to accurate diagnosis.
Radiologists can be the first to suggest CRMO diagnosis given its characteristic radiographic appearance and distribution, thus preventing unnecessary multiple biopsies and long-term antibiotic treatment.
Chronic Recurrent Multifocal Osteomyelitis
The patient’s imaging (including routine chest radiograph, localized clavicle X-ray, and MRI, etc.) shows:
These imaging findings suggest multifocal, nonspecific bone destruction accompanied by recurrent inflammation or bone hyperplasia, mainly affecting the medial segment of the clavicle, the anterior chest wall, and ribs. The lesions show intermittent onset, recurrence, and periods of remission.
Based on the above imaging findings, the patient’s history, and clinical symptoms, the following possibilities are considered:
Considering the following factors:
These findings strongly suggest “Chronic Recurrent Multifocal Osteomyelitis (CRMO)” as the most likely final diagnosis.
If uncertainty remains, combined immunological and genetic testing, along with additional targeted biopsy and pathological evaluation, can help confirm the diagnosis.
For patients diagnosed with or highly suspected of CRMO, the following treatment and rehabilitation options can be considered:
Throughout the rehabilitation process, regular imaging studies and inflammatory markers should be monitored to assess disease progression, appropriately adjust exercise intensity, and prevent relapses or severe complications.
Disclaimer:
This report is based on the available case data for analysis and serves only as a clinical reference. It does not replace an in-person consultation or professional medical advice. If you have any concerns or if symptoms worsen, please seek medical attention promptly.
Chronic Recurrent Multifocal Osteomyelitis
