|IMAGES IN RHEUMATOLOGY
|Ahead of print publication
Chronic regional multifocal osteomyelitis: A diagnosis of exclusion
Abhijeet Taori1, Divya Malpani2
1 Department of Radiology, Suyash Hospital, Indore, Madhya Pradesh, India
2 Apollo Hospital, Indore, Madhya Pradesh, India
|Date of Submission||05-May-2020|
|Date of Acceptance||11-May-2020|
Suyash Hospital, Indore, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
Keywords: CRMO, Pediatrics, SAPHO
A 10-year-old boy presented to us with on-and-off pain in the right knee for 4 months with new-onset swelling and exacerbation. He played basketball and football for his school team, but increasing pain was impairing his movement on the playing field. There was no history of known trauma. On clinical examination, there was slight swelling along the knee with redness and significant tenderness on touch. The remainder of the clinical examination was normal. The initial laboratory nonsignificantly elevated white blood cell count and erythrocyte sedimentation rate.
The radiograph [Figure 1] of the right knee showed an aggressive permeative lesion with an ill-defined margin and wide zone of transition involving the distal metadiaphyseal region of the femur with “Codman's triangle” appearance of periosteal reaction. In view of the clinical course and imaging findings, possible differentials included osteosarcoma, Ewing's sarcoma, or unlikely osteomyelitis.
|Figure 1: Anteroposterior radiograph of the right knee. There is an aggressive permeative lesion with wide zone of transition involving the distal metadiaphyseal region of the femur (asterix) with “Codman's triangle” type of periosteal reaction (arrowhead)|
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Surprisingly, when chest X-ray [Figure 2] on admission was reviewed, we saw sclerosis and cortical thickening along the posterior aspects of left ribs (6th–8th). This changed our differential to possible multifocal osseous lymphoma versus unlikely widespread Langerhans cell histiocytosis.
|Figure 2: Chest X-ray. There is a sclerosis and cortical thickening reaction (arrowheads) along the posterior aspects of the left ribs (6th–8th)|
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A minimally invasive open approach biopsy of the femoral lesion showed no evidence of tumor or infection. Serology for typical and atypical infections was also negative. At this point, the diagnosis of chronic recurrent multifocal osteomyelitis (CRMO) was suspected, and a whole-body scintigram was obtained [Figure 3], with scan showing uptake along the posterior aspects of the lower left ribs and right lower end of the femur confirming our suspicion.
|Figure 3: Technetium-99m bone scan anterior and posterior projections show increased uptake in the lower end of the right femur (arrowhead) and along the posterior end of the left ribs (arrow)|
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CRMO is thus an extremely rare presentation with unknown pathogenesis. It is largely believed to be slow response to an undetected infection versus a sequela to autoimmune condition. The disease being a diagnosis of exclusion is a significant challenge with multiple aforementioned differential diagnoses. A combination of imaging, clinical input, and adherence to proposed diagnostic criteria improves confidence in cases. Treatment involves a combination of anti-inflammatory medication with bisphosphonates. A timely diagnosis of CRMO presents us with an opportunity to spare a pediatric patient from significant number of unnecessary investigations, antibiotics, and repeated biopsies.
It would also be pertinent to mention SAPHO, i.e., a spectrum of synovitis, acne, palmoplantar pustulosis, hyperostosis, and osteitis or as it is the colloquially called “adult equivalent of CRMO.” Comparative features include presentation of SAPHO syndrome in middle ages, predilection for lesions along the chest wall, and increased prevalence of skin lesions.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Khanna G, Sato TS, Ferguson P. Imaging of chronic recurrent multifocal osteomyelitis. Radio Graphics 2009;29:1159-77.
Fritz J, Tzaribatchev N, Claussen CD, Carrino JA, Horger MS. Chronic recurrent multifocal osteomyelitis: Comparison of whole-body MR imaging with radiography and correlation with clinical and laboratory data. Radiology 2009;252:842-51.
Roderick MR, Shah R, Rogers V, Finn A, Ramanan AV. Chronic recurrent multifocal osteomyelitis (CRMO) – Advancing the diagnosis. Pediatr Rheumatol Online J 2016;14:47.
Cotten A, Flipo RM, Mentre A, Delaporte E, Duquesnoy B, Chastanet P. SAPHO syndrome. Radiographics 1995;15:1147-54.
[Figure 1], [Figure 2], [Figure 3]