|Ahead of print publication
Chronic recurrent multifocal osteomyelitis on magnetic resonance imaging
Sonia Sandip1, SH Chandarashekhara2
1 Department of Radio-diagnosis, ABVIMS and Dr RML Hospital, New Delhi, India
2 Department of Radio-diagnosis IRCH, All India Institute of Medical Sciences, New Delhi, India
|Date of Submission||25-Oct-2021|
|Date of Acceptance||02-Jun-2022|
|Date of Web Publication||01-Jul-2022|
Department of Radio-diagnosis, IRCH, All India Institute of Medical Sciences, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
Chronic recurrent multifocal osteomyelitis (CRMO) is a noninfective auto-inflammatory bone disease; characterized by multifocal involvement of bone. This condition is primarily seen in children and adolescents though sometimes can be found in adults. It is primarily diagnosis of exclusion which is made in conjunction with radiological finding with clinical details with/or histopathology and at present no single test or modality is available to make the diagnosis. Magnetic resonance (MR) imaging can give clue to the diagnosis by demonstration of the involvement of bone in a specific distribution pattern. We report a case of an 11-year-old girl with MR features of CRMO.
Keywords: Magnetic resonance imaging, osteomyelitis, radiograph
| Case Report|| |
An 11-year-old girl presented to our institute with vague pain in her right knee of 6 months duration. There was no history of associated fever and weight loss. She gave the previous history of similar pain in the left ankle. No history of trauma was present. On clinical examination, there was no soft tissue swelling or tenderness. Her X-rays of knee and ankle joints were within normal limits. Blood investigations were unremarkable except for mild elevation of alkaline phosphatase. Given the clinical history and blood investigation picture, the possibility of indolent infection was considered. As magnetic resonance imaging (MRI) is the sensitive modality to pick up early changes of marrow signal abnormality and soft tissue changes as well as the benefit of radiation free, particularly in pediatric population, same was advised. Her MRI of the right knee revealed focal tiny T2 hyperintense lesions in the meta-epiphysis of distal femur and proximal tibia with marrow edema. Similar lesions were also noted in the contralateral knee. Post-contrast imaging revealed mild inhomogeneous enhancement in the corresponding areas [Figure 1]. In view of previous history of the left ankle pain, whole-body STIR screening was done to rule out any other area of similar marrow abnormality. STIR images revealed similar changes around bilateral ankle joint involving meta-epiphysis of distal tibia and tarsal bones [Figure 2]. Based on long duration of off and on waxing–waning clinical symptoms which was not responding to antibiotics, normal blood complete blood count picture, and typical radiological findings involving Metaphysis of multiple long bones in symmetrical distribution, diagnosis of chronic recurrent multifocal osteomyelitis was made. The patient was treated with anti-inflammatory drugs, which improved the symptoms.
|Figure 1: Knee MRI in CROM. Coronal STIR image of the right knee reveals focal tiny T2 hyperintense lesions (white arrow in a) with surrounding edema in meta-epiphysis of the distal femur and proximal metaphysis of tibia. Similar lesions can be appreciated in the distal meta-epiphysis of femur in the contralateral knee as well (white arrow in a). These areas are hypointense on T1WI (white arrow in b). Post gadolinium contrast-enhanced image reveals heterogeneous enhancement of corresponding areas (white arrow in [Figure 2]c). MRI: Magnetic resonance imaging|
Click here to view
|Figure 2: X-ray and whole-body MRI in CROM. X-ray of bilateral ankles (AP and lateral views) were normal (a and b). No lytic or sclerotic lesion seen. Whole-body STIR screening reveals similar T2 hyperintense lesions and marrow edema (white arrows). Involving distal meta-epiphyses of bilateral tibia and tarsal bones (c and d). MRI: Magnetic resonance imaging|
Click here to view
| Introduction|| |
Chronic recurrent multifocal osteomyelitis (CRMO) is a noninfective auto-inflammatory bone disease; characterized by multifocal involvement of bone, primarily affecting the children and adolescents though sometimes can be seen in adults.,, This entity was first described by Giedion et al., in 1972. It is a non-bacterial osteomyelitis which results from sterile osseous inflammation, and this disease has a relapsing and remitting course.
| Discussion|| |
The exact cause of CRMO is still not clear, although several studies suggest a genetic component. The association of CRMO with skin disorders (e.g., psoriasis) and inflammatory bowel disease have been found which suggests toward autoimmune origin., Clinical presentation is nonspecific and patient often present with pain, swelling and tenderness of the site involved. Systemic symptoms such as fever, lethargy are usually absent, although at times may be seen. Majority of the patients with this entity present with single symptomatic site, however, occult lesions may be found at imaging or may be seen during follow-up. The characteristic feature of disease is relapsing–remitting course. Laboratory tests at initial presentation are usually normal, though mild elevation in erythrocyte sedimentation rate can be seen. Histology reveals sterile nonspecific inflammatory changes with granulocytic infiltration. The radiographic appearance of CRMO varies, ranging from normal radiograph at presentation to the presence of lytic or sclerotic lesion depending on the course and duration of disease. Our patient presented with history of pain in the right knee of 6 month's duration and previous history of left ankle pain was also present. Blood investigations were within normal limits except for mild elevation of alkaline phosphatase and X-ray imaging was unremarkable. When clinical suspicion is high, MRI plays an important role and is especially helpful in detecting early disease and occult lesions before radiographic findings become overt. Though not pathognomonic, typical MR findings can suggest this diagnosis. The characteristic pattern of CRMO includes multifocal, bilateral symmetrical lesions, and marrow edema involving the metaphysis of long bones along the growth plates. The most common involved sites of skeletal system are long tubular bones and clavicle, however, lesions can be seen involving other bones as well including spine, ribs, pelvis, sacroiliac joint, sternum, scapula, mandible, and hands and feet. Among long tubular bones involvement of tibia is most common. In a coherent study by von Kalle et al., MRI of 75% of patients showed multifocal bilateral symmetrical geographical metaphyseal lesions adjacent to growth plates in long bones of lower extremities or presence of lesions in clavicle, sternum, spine, and pelvis. MRI not only determines the extent of disease but also useful for surveillance. MR can also demonstrate additional findings including soft tissue inflammation, periostitis, and transphyseal involvement (which is underestimated on radiographs). The demonstration of transphyseal involvement helps to predict prognosis by allowing high-risk patient identification for growth deformities due to the formation of physeal bars. MRI in our patient revealed involvement of distal meta-epiphysis of bilateral femur, proximal, and distal meta-epiphysis of bilateral tibia and bilateral tarsal bones [Figure 1] and [Figure 2]. The differential diagnosis of CRMO not only includes infectious but also a malignant process. Non-Hodgkin's lymphoma can resemble the same, however, cortical destruction and involvement of additional sites (e.g., lymph nodes/parenchymal organs) helps to differentiate. In conjunction with clinical findings, symmetrical and multifocal involvement of meta-epiphysis without any cortical erosion helps differentiate CRMO from other malignant conditions such as leukemia, early stage of Ewing's sarcoma, and metastases. Differentiating CRMO from bacterial osteomyelitis may be difficult at times, particularly with single-site involvement. In uncertain cases, biopsy is mandatory. CRMO is the diagnosis of exclusion based on combination with clinical, radiological, and/or histological criteria and there is no single test or examination to confirm the diagnosis.,,, Very often a long period of diagnostic uncertainty remains and delay in appropriate treatment follows the diagnosis of CRMO.
| Conclusion|| |
Although CRMO is diagnosis of exclusion, clinical course of remitting–relapsing disease, characteristic MRI findings and distribution of lesions with the absence of positive microbiologic result suggest the diagnosis. Knowledge of characteristic radiographic and MR appearance of CRMO is important for every radiologist as at times radiologist can be the first to suggest the diagnosis and thus can help to prevent aggressive medical and surgical evaluation and treatment.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Jansson AF, Grote V, ESPED Study Group. Nonbacterial osteitis in children: Data of a German Incidence Surveillance Study. Acta Paediatr 2011;100:1150-7.
Hospach T, Langendoerfer M, von Kalle T, Maier J, Dannecker GE. Spinal involvement in chronic recurrent multifocal osteomyelitis (CRMO) in childhood and effect of pamidronate. Eur J Pediatr 2010;169:1105-11.
Bjorkstén B, Boquist L. Histopathological aspects of chronic recurrent multifocal osteomyelitis. J Bone Joint Surg Br 1980;62:376-80.
Giedion A, Holthusen W, Masel LF, Vischer D. Subacute and chronic “symmetrical” osteomyelitis. Ann Radiol (Paris) 1972;15:329-42.
Khanna G, Sato TS, Ferguson P. Imaging of chronic recurrent multifocal osteomyelitis. Radiographics 2009;29:1159-77.
Laxer RM, Shore AD, Manson D, King S, Silverman ED, Wilmot DM. Chronic recurrent multifocal osteomyelitis and psoriasis – A report of a new association and review of related disorders. Semin Arthritis Rheum 1988;17:260-70.
Dagan O, Barak Y, Metzker A. Pyoderma gangrenosum and sterile multifocal osteomyelitis preceding the appearance of Takayasu arteritis. Pediatr Dermatol 1995;12:39-42.
El-Shanti HI, Ferguson PJ. Chronic recurrent multifocal osteomyelitis: A concise review and genetic update. Clin Orthop Relat Res 2007;462:11-9.
von Kalle T, Heim N, Hospach T, Langendörfer M, Winkler P, Stuber T. Typical patterns of bone involvement in whole-body MRI of patients with chronic recurrent multifocal osteomyelitis (CRMO). Rofo 2013;185:655-61.
Jurik AG, Egund N. MRI in chronic recurrent multifocal osteomyelitis. Skeletal Radiol 1997;26:230-8.
Sato TS, Ferguson PJ, Khanna G. Primary multifocal osseous lymphoma in a child. Pediatr Radiol 2008;38:1338-41.
Jansson A, Renner ED, Ramser J, Mayer A, Haban M, Meindl A, et al.
Classification of non-bacterial osteitis: Retrospective study of clinical, immunological and genetic aspects in 89 patients. Rheumatology (Oxford) 2007;46:154-60.
Kellenberger CJ, Miller SF, Khan M, Gilday DL, Weitzman S, Babyn PS. Initial experience with FSE STIR whole-body MR imaging for staging lymphoma in children. Eur Radiol 2004;14:1829-41.
Moreno-Mateo F, Perea SH, Onel KB. Chronic recurrent multifocal osteomyelitis: Diagnosis and treatment. Curr Opin Pediatr 2021;33:90-6.
Girschick HJ, Raab P, Surbaum S, Trusen A, Kirschner S, Schneider P, et al
. Chronic non-bacterial osteomyelitis in children. Ann Rheum Dis 2005;64:279-85.
[Figure 1], [Figure 2]