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Case report: Chronic recurrent multifocal osteomyelitis with magnetic resonance imaging
ClinicalRadiology (1994) 49, 133-136
Case Report: Chronic Recurrent Multifocal Osteomyelitis With Magnetic Resonance Imaging J. S. D A W S O N , J. K. WEBB* a n d B. J. P R E S T O N
Departments of Radiology and *Orthopaedic Surgery, University Hospital, Queen's Medical Centre, Nottingham A case of chronic recurrent multifocal osteomyelitis (CRMO) with spinal involvement is described. Diagnosis and monitoring of the disease process was considerably aided by magnetic resonance (MR) imaging. The M R appearances in chronic recurrent multifocal osteomyelitis have been rarely reported. D a w s o n , J . S , Webb, J.K. & Preston, B.J. (1994). Clinical
Radiology 49, 133-136. Case Report: C h r o n i c R e c u r r e n t Multifocal Osteomyelitis W i t h Magnetic R e s o n a n c e I m a g i n g
CASE REPORT A normally fit 13-year-oldgirl presented with a 3 month history of lumbar back pain. The back pain had been spontaneous in onset and was aggravated by exercise. There were no systemicsymptoms. Physical examination was unhelpful. Lumbar spine radiographs showed no convincing abnormality and whole body bone scintigraphy (99 m TcMDP) revealedno abnormal uptake. The ESR was 4 and the white cell count (WCC) 7.0. The patient continued to experience intermittent lumbar back pain although regular analgesics were unnecessary. Four months after the patient presented, a magnetic resonance (MR) study of the lumbar spine was performed. Tl-weighted (T1W) gradient-echo images and T2W spin-echoimageswere obtained using a 0.5 T MR Max unit (Fig. 1). The MR findings were in keeping with osteomyelitisaffecting the vertebral body of L2 with involvement of the LI/2 disc space. Bone scintigraphy was repeated but again failed to show any abnormal uptake in the lumbar spine. A needle biopsy of L2 was performed under fluoroscopic guidance and two good specimen cores were obtained. Culture gave no growth and histopathology revealed a non-specificlow grade osteomyelitiswith marrow spaces containing a scattered infiltrate of plasma cells, lymphocytes and polymorphs. No specific treatment was instituted but the patient remained under review. Initially her lumbar back pain was much improved but subsequently worsened. Repeat ESR and WCC were l0 and 5.8 respectively. The MR images of the lumbar spine were repeated 7 months after the patient initially presented (Fig. 2), and again at 13 months (Fig. 3). These showed additional foci of osteomyelitisin L I and TI2 as well as the L2 changes. The intervening disc spaces were also affected. The patient subsequently developed neck pain. Cervical spine radiographs showed some equivocal erosion of the inferior end-plate of C6. Concurrent MR images of the cervical spine showed changes compatible with osteomyelitisaffecting the C5 and C6 vertebral bodies with involvement of the C6/7 disc space (Fig. 4). Due to the increasingspinal involvementit was decided to perform an open biopsy. The C6/7 disc was excised together with part of the vertebral body of C6 and a one-segment fusion was performed taking bone graft from the iliac crest. The specimenswere cultured for aerobic and anaerobic bacteria, mycobacteria and fungi but all cultures were negative. Histopathology showed fibrosis and a non-specific chronic inflammation. Two years after the clinicalonset of her illness, the patient continues under review. She remains systemicallywelland is obtaining symptomatic relief of her bone pain with non-steroidal anti-inflammatory drugs. On account of the clinicalpicture and various investigationsa diagnosis of chronic recurrent multifocal osteomyelitishas been made.
DISCUSSION C h r o n i c recurrent multifocal osteomyelitis ( C R M O ) is an u n u s u a l form of chronic osteomyelitis which was first Correspondence to: Dr J. S. Dawson, Department of Radiology, University Hospital, Queen's Medical Centre, Nottingham NG7 2UH.
described by G i e d i o n et al. in 1972 [1] u n d e r the n a m e of 'subacute a n d chronic symmetrical osteomyelitis'. The term C R M O was first suggested by Bj6rkst6n et al. in 1978 [2] a n d is n o w widely accepted. The aetiology is obscure b u t C R M O is increasingly recognized as a well defined clinico-pathological entity. C R M O is a disease of children a n d adolescents, Females are twice as often affected as males [3], There is insidious onset of pain, tenderness a n d swelling at multiple bone sites. Most patients with C R M O have 5-10 skeletal lesions [4]. Fever, malaise a n d other systemic s y m p t o m s are usually absent or mild. The disease is characterized by i n t e r m i t t e n t periods of exacerbation a n d i m p r o v e m e n t . S y m p t o m s m a y persist for as long as 15 years [3]. C R M O generally has a self-limited course causing significant s y m p t o m s while it lasts b u t leaving few if a n y p e r m a n e n t sequelae in most cases. Bone lesions frequently affect the metaphyses of long bones but C R M O has been reported at virtually all sites in the axial a n d a p p e n d i c u l a r skeleton, The lesions are p r e d o m i n a n t l y lytic on plain radiographs b u t varying degrees of sclerosis m a y also be evident. Bone scintigraphy m a y show increased activity in affected areas. The E S R a n d W C C are usually n o r m a l or slightly elevated. Cultures of specimens from b o n e lesions are u n r e w a r d i n g a n d histopathology shows a non-specific subacute or chronic osteomyelitis with varying n u m b e r s o f lymphocytes, plasma cells a n d polymorphs. R e c o g n i t i o n of C R M O is i m p o r t a n t . It allows appropriate counselling a n d avoids unnecessary investigations a n d prolonged antibiotic therapy. The diagnosis of C R M O is based on clinical, radiological, histological a n d microbiological features a n d is a diagnosis of exclusion. At least one biopsy specimen with culture is necessary to rule out bacterial osteomyelitis a n d to exclude other causes of multifocal b o n e lesions in childhood such as leukaemia, Ewing sarcoma, n e u r o b l a s t o m a a n d eosinophilic g r a n u l o m a . According to K i n g et al. [5], a diagnosis of C R M O requires: (i) multifocal (two or more) bone lesions, clinically or radiographically diagnosed; (ii) a prolonged course (over 6 m o n t h s ) characterized by varying activity of disease a n d with most patients being healthy between recurrent episodes of pain, swelling a n d tenderness; (iii) lack of response to a n t i m i c r o b i a l therapy given for at least 1 m o n t h . There is no specific therapy for C R M O . Antibiotics do not a p p e a r to affect the course o f the disease [3]. However, both steroids a n d non-steroidal a n t i - i n f l a m m a t o r y agents
134
CLINICAL RADIOLOGY
(a)
Fig. 2 Sagittal MR image of the lumbar spine. T2W spin-echo image (SE 2000/90) showing that the abnormal signal characteristics of the L2 vertebral body have now changed. In place of high signal there is predominantly low signal at the postero-superior corner of the L2 vertebral body (curved black arrow). There is LI/2 disc narrowing. The LI and TI2 vertebral bodies now show evidence of increased signal (open white arrows). have been effective in relieving s y m p t o m s in s o m e patients
is].
(b) Fig. 1 - Sagittal MR images of the lumbar spine. (a) TIW gradient-echo image (GE 300/14, flip angle 90~ showing reduced signal from the upper vertebral body of L2 (white arrow). There is also loss of definition of the L1/2 disc with disruption of the intervening superior end-plate band. (b) T2W spin-echo image (SE 2000/90) showing increased signal from the upper vertebral body of L2 (white arrow).
The literature c o n t a i n s little reference to the M R a p p e a r a n c e s in C R M O , b u t M R i m a g i n g has been shown to be m o r e sensitive a n d specific for the diagnosis o f c o n v e n t i o n a l vertebral osteomyelitis t h a n either r a d i o i s o t o p e b o n e scanning o r plain r a d i o g r a p h y [6]. In o u r p a t i e n t T l W images showed r e d u c e d signal in the vertebral bodies a n d discs. There was also discal n a r r o w i n g a n d d i s r u p t i o n o f the low signal e n d - p l a t e b a n d s separating m a r r o w cavity from the nucleus p u l p o s u s o f the discs. T 2 W images initially showed increased signal f r o m the vertebral bodies. These signal changes p r o b a b l y result f r o m an increased water c o n t e n t due to i n f l a m m a t o r y exudate. Such signal alterations are n o t specific for osteomyelitis a n d are also seen in the m a r r o w o f patients with p r i m a r y or s e c o n d a r y neoplasms. H o w e v e r , t u m o u r does n o t generally breach the e n d - p l a t e s a n d the disc spaces r e m a i n intact. A s the lesions o f C R M O progressed in o u r patient, T 2 W images showed a decreased signal f r o m the vertebral bodies. This signal c o n v e r s i o n o n T 2 W images m a y be a reflection o f healing resulting in a fibrous scar with some degree o f new b o n e f o r m a t i o n . Both fibrosis a n d new b o n e f o r m a t i o n are k n o w n to occur in l o n g - s t a n d i n g lesions o f C R M O [7]. C R M O is still a c o n d i t i o n t h a t is n o t readily recognized by m a n y radiologists a n d clinicians. T h e disease m a y well be m o r e c o m m o n t h a n is presently a p p r e c i a t e d [8] a n d the full s p e c t r u m o f C R M O is still being realized as m o r e cases are seen. The a e t i o l o g y r e m a i n s u n k n o w n b u t the
135
CHRONIC RECURRENT MULTIFOCAL OSTEOMYELITIS
(a)
(b)
Fig. 3 - Sagittal M R images of the lumbar spine. (a) T l W gradient-echo image (GE 380/14, flip angle 90 ~')showing well-defined areas of reduced signal at the upper aspects of the L2 and L1 vertebral bodies (white arrows). The T12 vertebral body also shows patchy reduced signal. There is disc space narrowing at the intervening levels with disruption of the adjacent end-plate bands. (b) T2W spin-echo image (SE 2000/100). The L2 vertebral body retains predominantly low signal at the postero-superior corner (curved black arrow). The L 1 vertebral body is beginning to show signal conversion with some loss of high signal and the appearance of areas of low signal (open white arrow). The T12 vertebral body continues to show mainly high signal.
(a)
(b)
Fig. 4 Sagittal MR images of the cervical spine. (a) T1W gradienl-echo image (GE 380/14, flip angle 90~ showing reduced signal from the C5 and C6 vertebral bodies (white arrows). There is also reduced signal from the C6/7 disc which herniates into the vertebral body of C6. (b) T2W spin-echo image (SE 1800/100) showing increased signal from the C5 and C6 vertebral bodies (white arrows).
136
CLINICALRADIOLOGY
chronic inflammation is consistent with an infective cause. The negative results of cultures rule out common pathogens but a fastidious organism of low virulence remains a possibility. M R imaging appears to be a very sensitive method of detecting lesions in CRMO. Furthermore, it does not have any inherent radiation hazard and would seem the ideal method of monitoring these multiple and chronic lesions which occur in childhood and adolescence.
REFERENCES
1 Giedion A, Holthusen W, Masel LF, Vischer D. Subacute and chronic symmetrical osteomyetitis. Annals of Radiology 1972; 15:329342.
2 Bj6rkstbn B, Gustavson KH, Eriksson B, Lindholm A, Nordstrom S. Chronic recurrent multifocal osteomyelitis and pustulosis palmoplantaris. Journal of Pediatrics 1978;93:227 231. 3 Cyrlak D, Pais MJ. Chronic recurrent multifocal osteomyelitis. Skeletal Radiology' 1986; 15:32-39. 4 Rahav G, Sacks TG, Bar-Ziv J. Chronic recurrent multifocal osteomyelitis: report of a case. Clinical Infectious Diseases 1992; 14:587-588. 5 King SM, Laxer RM, Manson D, Gold R. Chronic recurrent multifocal osteomyelitis: a non-infectious inflammatory process. Pediatric Infectious Disease Journal 1987;6:907 911. 6 Modic MT, Feiglin DH, Piraino DW, Boumphrey F, Weinstein MA, Duchesneau PM, Rehm S. Vertebral osteomyelitis: assessment using MR. Radiology 1985;157:157 166. 7 Bj6rkst~n B, Boquist L. Histopathological aspects of chronic recurrent multifocal osteomyelitis. Journal of Bone and Joint Surgery (British) 1980;62:376-380. 8 Rosenberg ZS, Shankman S, Klein M, Lechman W. Chronic recurrent multifocal osteomyelitis. Ameriean Journal of Roentgenology 1988;151:142-144.
Case Report: Chronic Recurrent Multifocal Osteomyelitis With Magnetic Resonance Imaging J. S. D A W S O N , J. K. WEBB* a n d B. J. P R E S T O N
Departments of Radiology and *Orthopaedic Surgery, University Hospital, Queen's Medical Centre, Nottingham A case of chronic recurrent multifocal osteomyelitis (CRMO) with spinal involvement is described. Diagnosis and monitoring of the disease process was considerably aided by magnetic resonance (MR) imaging. The M R appearances in chronic recurrent multifocal osteomyelitis have been rarely reported. D a w s o n , J . S , Webb, J.K. & Preston, B.J. (1994). Clinical
Radiology 49, 133-136. Case Report: C h r o n i c R e c u r r e n t Multifocal Osteomyelitis W i t h Magnetic R e s o n a n c e I m a g i n g
CASE REPORT A normally fit 13-year-oldgirl presented with a 3 month history of lumbar back pain. The back pain had been spontaneous in onset and was aggravated by exercise. There were no systemicsymptoms. Physical examination was unhelpful. Lumbar spine radiographs showed no convincing abnormality and whole body bone scintigraphy (99 m TcMDP) revealedno abnormal uptake. The ESR was 4 and the white cell count (WCC) 7.0. The patient continued to experience intermittent lumbar back pain although regular analgesics were unnecessary. Four months after the patient presented, a magnetic resonance (MR) study of the lumbar spine was performed. Tl-weighted (T1W) gradient-echo images and T2W spin-echoimageswere obtained using a 0.5 T MR Max unit (Fig. 1). The MR findings were in keeping with osteomyelitisaffecting the vertebral body of L2 with involvement of the LI/2 disc space. Bone scintigraphy was repeated but again failed to show any abnormal uptake in the lumbar spine. A needle biopsy of L2 was performed under fluoroscopic guidance and two good specimen cores were obtained. Culture gave no growth and histopathology revealed a non-specificlow grade osteomyelitiswith marrow spaces containing a scattered infiltrate of plasma cells, lymphocytes and polymorphs. No specific treatment was instituted but the patient remained under review. Initially her lumbar back pain was much improved but subsequently worsened. Repeat ESR and WCC were l0 and 5.8 respectively. The MR images of the lumbar spine were repeated 7 months after the patient initially presented (Fig. 2), and again at 13 months (Fig. 3). These showed additional foci of osteomyelitisin L I and TI2 as well as the L2 changes. The intervening disc spaces were also affected. The patient subsequently developed neck pain. Cervical spine radiographs showed some equivocal erosion of the inferior end-plate of C6. Concurrent MR images of the cervical spine showed changes compatible with osteomyelitisaffecting the C5 and C6 vertebral bodies with involvement of the C6/7 disc space (Fig. 4). Due to the increasingspinal involvementit was decided to perform an open biopsy. The C6/7 disc was excised together with part of the vertebral body of C6 and a one-segment fusion was performed taking bone graft from the iliac crest. The specimenswere cultured for aerobic and anaerobic bacteria, mycobacteria and fungi but all cultures were negative. Histopathology showed fibrosis and a non-specific chronic inflammation. Two years after the clinicalonset of her illness, the patient continues under review. She remains systemicallywelland is obtaining symptomatic relief of her bone pain with non-steroidal anti-inflammatory drugs. On account of the clinicalpicture and various investigationsa diagnosis of chronic recurrent multifocal osteomyelitishas been made.
DISCUSSION C h r o n i c recurrent multifocal osteomyelitis ( C R M O ) is an u n u s u a l form of chronic osteomyelitis which was first Correspondence to: Dr J. S. Dawson, Department of Radiology, University Hospital, Queen's Medical Centre, Nottingham NG7 2UH.
described by G i e d i o n et al. in 1972 [1] u n d e r the n a m e of 'subacute a n d chronic symmetrical osteomyelitis'. The term C R M O was first suggested by Bj6rkst6n et al. in 1978 [2] a n d is n o w widely accepted. The aetiology is obscure b u t C R M O is increasingly recognized as a well defined clinico-pathological entity. C R M O is a disease of children a n d adolescents, Females are twice as often affected as males [3], There is insidious onset of pain, tenderness a n d swelling at multiple bone sites. Most patients with C R M O have 5-10 skeletal lesions [4]. Fever, malaise a n d other systemic s y m p t o m s are usually absent or mild. The disease is characterized by i n t e r m i t t e n t periods of exacerbation a n d i m p r o v e m e n t . S y m p t o m s m a y persist for as long as 15 years [3]. C R M O generally has a self-limited course causing significant s y m p t o m s while it lasts b u t leaving few if a n y p e r m a n e n t sequelae in most cases. Bone lesions frequently affect the metaphyses of long bones but C R M O has been reported at virtually all sites in the axial a n d a p p e n d i c u l a r skeleton, The lesions are p r e d o m i n a n t l y lytic on plain radiographs b u t varying degrees of sclerosis m a y also be evident. Bone scintigraphy m a y show increased activity in affected areas. The E S R a n d W C C are usually n o r m a l or slightly elevated. Cultures of specimens from b o n e lesions are u n r e w a r d i n g a n d histopathology shows a non-specific subacute or chronic osteomyelitis with varying n u m b e r s o f lymphocytes, plasma cells a n d polymorphs. R e c o g n i t i o n of C R M O is i m p o r t a n t . It allows appropriate counselling a n d avoids unnecessary investigations a n d prolonged antibiotic therapy. The diagnosis of C R M O is based on clinical, radiological, histological a n d microbiological features a n d is a diagnosis of exclusion. At least one biopsy specimen with culture is necessary to rule out bacterial osteomyelitis a n d to exclude other causes of multifocal b o n e lesions in childhood such as leukaemia, Ewing sarcoma, n e u r o b l a s t o m a a n d eosinophilic g r a n u l o m a . According to K i n g et al. [5], a diagnosis of C R M O requires: (i) multifocal (two or more) bone lesions, clinically or radiographically diagnosed; (ii) a prolonged course (over 6 m o n t h s ) characterized by varying activity of disease a n d with most patients being healthy between recurrent episodes of pain, swelling a n d tenderness; (iii) lack of response to a n t i m i c r o b i a l therapy given for at least 1 m o n t h . There is no specific therapy for C R M O . Antibiotics do not a p p e a r to affect the course o f the disease [3]. However, both steroids a n d non-steroidal a n t i - i n f l a m m a t o r y agents
134
CLINICAL RADIOLOGY
(a)
Fig. 2 Sagittal MR image of the lumbar spine. T2W spin-echo image (SE 2000/90) showing that the abnormal signal characteristics of the L2 vertebral body have now changed. In place of high signal there is predominantly low signal at the postero-superior corner of the L2 vertebral body (curved black arrow). There is LI/2 disc narrowing. The LI and TI2 vertebral bodies now show evidence of increased signal (open white arrows). have been effective in relieving s y m p t o m s in s o m e patients
is].
(b) Fig. 1 - Sagittal MR images of the lumbar spine. (a) TIW gradient-echo image (GE 300/14, flip angle 90~ showing reduced signal from the upper vertebral body of L2 (white arrow). There is also loss of definition of the L1/2 disc with disruption of the intervening superior end-plate band. (b) T2W spin-echo image (SE 2000/90) showing increased signal from the upper vertebral body of L2 (white arrow).
The literature c o n t a i n s little reference to the M R a p p e a r a n c e s in C R M O , b u t M R i m a g i n g has been shown to be m o r e sensitive a n d specific for the diagnosis o f c o n v e n t i o n a l vertebral osteomyelitis t h a n either r a d i o i s o t o p e b o n e scanning o r plain r a d i o g r a p h y [6]. In o u r p a t i e n t T l W images showed r e d u c e d signal in the vertebral bodies a n d discs. There was also discal n a r r o w i n g a n d d i s r u p t i o n o f the low signal e n d - p l a t e b a n d s separating m a r r o w cavity from the nucleus p u l p o s u s o f the discs. T 2 W images initially showed increased signal f r o m the vertebral bodies. These signal changes p r o b a b l y result f r o m an increased water c o n t e n t due to i n f l a m m a t o r y exudate. Such signal alterations are n o t specific for osteomyelitis a n d are also seen in the m a r r o w o f patients with p r i m a r y or s e c o n d a r y neoplasms. H o w e v e r , t u m o u r does n o t generally breach the e n d - p l a t e s a n d the disc spaces r e m a i n intact. A s the lesions o f C R M O progressed in o u r patient, T 2 W images showed a decreased signal f r o m the vertebral bodies. This signal c o n v e r s i o n o n T 2 W images m a y be a reflection o f healing resulting in a fibrous scar with some degree o f new b o n e f o r m a t i o n . Both fibrosis a n d new b o n e f o r m a t i o n are k n o w n to occur in l o n g - s t a n d i n g lesions o f C R M O [7]. C R M O is still a c o n d i t i o n t h a t is n o t readily recognized by m a n y radiologists a n d clinicians. T h e disease m a y well be m o r e c o m m o n t h a n is presently a p p r e c i a t e d [8] a n d the full s p e c t r u m o f C R M O is still being realized as m o r e cases are seen. The a e t i o l o g y r e m a i n s u n k n o w n b u t the
135
CHRONIC RECURRENT MULTIFOCAL OSTEOMYELITIS
(a)
(b)
Fig. 3 - Sagittal M R images of the lumbar spine. (a) T l W gradient-echo image (GE 380/14, flip angle 90 ~')showing well-defined areas of reduced signal at the upper aspects of the L2 and L1 vertebral bodies (white arrows). The T12 vertebral body also shows patchy reduced signal. There is disc space narrowing at the intervening levels with disruption of the adjacent end-plate bands. (b) T2W spin-echo image (SE 2000/100). The L2 vertebral body retains predominantly low signal at the postero-superior corner (curved black arrow). The L 1 vertebral body is beginning to show signal conversion with some loss of high signal and the appearance of areas of low signal (open white arrow). The T12 vertebral body continues to show mainly high signal.
(a)
(b)
Fig. 4 Sagittal MR images of the cervical spine. (a) T1W gradienl-echo image (GE 380/14, flip angle 90~ showing reduced signal from the C5 and C6 vertebral bodies (white arrows). There is also reduced signal from the C6/7 disc which herniates into the vertebral body of C6. (b) T2W spin-echo image (SE 1800/100) showing increased signal from the C5 and C6 vertebral bodies (white arrows).
136
CLINICALRADIOLOGY
chronic inflammation is consistent with an infective cause. The negative results of cultures rule out common pathogens but a fastidious organism of low virulence remains a possibility. M R imaging appears to be a very sensitive method of detecting lesions in CRMO. Furthermore, it does not have any inherent radiation hazard and would seem the ideal method of monitoring these multiple and chronic lesions which occur in childhood and adolescence.
REFERENCES
1 Giedion A, Holthusen W, Masel LF, Vischer D. Subacute and chronic symmetrical osteomyetitis. Annals of Radiology 1972; 15:329342.
2 Bj6rkstbn B, Gustavson KH, Eriksson B, Lindholm A, Nordstrom S. Chronic recurrent multifocal osteomyelitis and pustulosis palmoplantaris. Journal of Pediatrics 1978;93:227 231. 3 Cyrlak D, Pais MJ. Chronic recurrent multifocal osteomyelitis. Skeletal Radiology' 1986; 15:32-39. 4 Rahav G, Sacks TG, Bar-Ziv J. Chronic recurrent multifocal osteomyelitis: report of a case. Clinical Infectious Diseases 1992; 14:587-588. 5 King SM, Laxer RM, Manson D, Gold R. Chronic recurrent multifocal osteomyelitis: a non-infectious inflammatory process. Pediatric Infectious Disease Journal 1987;6:907 911. 6 Modic MT, Feiglin DH, Piraino DW, Boumphrey F, Weinstein MA, Duchesneau PM, Rehm S. Vertebral osteomyelitis: assessment using MR. Radiology 1985;157:157 166. 7 Bj6rkst~n B, Boquist L. Histopathological aspects of chronic recurrent multifocal osteomyelitis. Journal of Bone and Joint Surgery (British) 1980;62:376-380. 8 Rosenberg ZS, Shankman S, Klein M, Lechman W. Chronic recurrent multifocal osteomyelitis. Ameriean Journal of Roentgenology 1988;151:142-144.