Brodie’s abscess (cystic osteomyelitis)

Toddler with
a limp. AP radiograph of the knee at presentation (upper left) shows lucent lesions of the metaphysis and epiphysis which show some interval healing on a followup AP radiograph of the knee taken 2 months later (upper right). The patient was lost to followup and did not complete antibiotic therapy and returned to clinic 2 years later and the AP radiograph at that time (lower left) shows a lucent sinus tract extending from the epiphysis to the metaphysis that persists on the next AP radiograph of the knee obtained 1 year later (lower right).The diagnosis was beyond neonatal to 18 months osteomyelitis with a Brodie’s abscess.
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AP radiograph
of the distal tibia showing a lytic lesion proved to be a subacute staphlococcal osteomyelitis.
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MRI
characteristics of cysts and “cyst-like” lesions in and around the knee: what the radiologist needs to know. Brodie’s abscess and lymph nodes in a patient with ACL reconstruction. (a) Axial and (b) sagittal fat saturated proton density weighted, (c) sagittal T1-weighted, (d) sagittal fat saturated contrast-enhanced T1-weighted and (e, f) sequential axial fat saturated contrast-enhanced T1-weighted images. A small cystic lesion (white arrow) at the anterior aspect of the tibia in contact with the ACL graft (black arrow) with marked peripheral enhancement (grey arrows) and a central non-enhancing portion is depicted. The abscess was draining via a sinus tract along the ACL graft to the anterior surface of the tibia. Three small cystic-like lesions (grey arrowheads) in the popliteal fossa, represent enlarged lymph nodes
insightsimaging.springeropen.com • Open Access
School ager
with knee pain for several months. Sagittal T1 MRI without contrast of the knee (left) shows a small round low signal intensity lesion in the middle of the proximal tibia that is surrounded by low signal intensity peri-lesional marrow edema. Sagittal T1 MRI with contrast (center) better demonstrates the small round low signal intensity lesion and coronal T1 MRI with contrast (right) shows a faint enhancing ring (penumbra) around the lesion.The diagnosis was subacute osteomyelitis with Brodie abscess.
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Brodie abscess is an intraosseous abscess related to a focus of subacute or chronic pyogenic osteomyelitis. Unfortunately, there is no reliable way to radiographically exclude a focus of osteomyelitis. It has a protean radiographic appearance and can occur at any location and in a patient of any age. It might or might not be expansile, have a sclerotic or nonsclerotic border, or have associated periostitis.

Epidemiology

Typically these present in children with unfused epiphyseal plates, more frequently in boys.

Pathology

Etiology 
  • S. aureus (most common); cultures often negative
Location

It has a predilection for ends (metaphysis) of tubular bones:

  • proximal/distal tibial metaphysis (most common)
  • femur
  • carpal and tarsal bones

Rarely traversing the open growth plate; epiphysis (in children and infants).

Markers
  • inflammatory markers (e.g. CRP, ESR) are often normal

Radiographic features

Plain radiograph 
  • lytic lesion often in an oval configuration that is oriented along the long axis of the bone
  • surrounded by a thick dense rim of reactive sclerosis that fades imperceptibly into surrounding bone
  • lucent tortuous channel extending toward growth plate prior to physeal closure (pathognomonic)
  • periosteal new-bone formation +/- adjacent soft-tissue swelling
  • may persist for many months
CT
  • central intramedullary hypodense cystic lesion with thick rim ossification
  • extensive thick well-circumscribed periosteal reaction and bone sclerosis around the lesion could be seen
MRI

The “penumbra sign” on magnetic resonance (MR) imaging is useful for discriminating subacute osteomyelitis from other bone lesions. The penumbra sign is a rim lining of an abscess cavity with higher signal intensity than that of the main abscess on T1-weighted images with strongly and rapidly enhance after contrast.

Differential diagnosis

History and etymology

The lesion is named after Sir Benjamin Collins Brodie (1783-1862), who initially described a chronic inflammatory process affecting the tibia without acute precipitating factors in the 1830s.

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Brodie-Abszess:
Osteoid-Osteom
 
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Abszess
 
Wikipedia • CC BY-SA 4.0
skeletale
Manifestationen bei Syphilis
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