Radiological Findings, Disease course, and Management
Radiograph Of the Right Thigh
03 January 2015
AP Lateral
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A Solitary mildly expansile geographic lytic lesion involving the diaphysis of femur with wide zone of transition
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Focal endosteal scalloping seen along the anterior cortex
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Solid periosteal reaction present
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No cortical break
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No associated soft tissue component
MRI OF Right Thigh
T2W
T1W
T1W FS Gd
Findings
Lesion
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appears heterogeneously hyperintense on T2W
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appears isointense on T1W images
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shows strong heterogeneous enhancement in post contrast study
Surrounding soft tissues
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Abnormal contrast enhancement
Provisional Diagnosis:
Ewing’s sarcoma on imaging findings.
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Initial biopsy report:
Ewing’s sarcoma
Course
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Patient underwent repeat biopsy at CMC hospital, Vellore
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Reported as Eosinophilic granuloma
Treatment
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Patient underwent surgery
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Lesion curettage+ bone graft substitute +local pamidronate and rush rodding on 21/01/2015
Follow up Radiograph
18 January 2016
Follow-up after 1 year
Patient well and asymptomatic
Discussion
Also called Langerhans cell histiocytosis.
Etiology: Unknown
? an inflammatory reaction to some agent of infection
Age: Children and young adults
Site: Any bone proximal to wrist and ankle
Most common: Skull, ribs, femur, vertebrae, pelvis, mandible, humerus, and clavicles
In long bones: Lesion is usually situated in the shaft.
Subperiosteal new bone formation as seen in this case is an unusual finding resembling the classical description of Ewing’s tumor
Radiologic Findings
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Affects the skeleton in a monostotic or polyostotic fashion
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Presents as a well-defined osteolytic lesion with a benign periosteal reaction or
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as an aggressive lesion with ill-defined margins and an aggressive type of periostitis mimicking Ewing sarcoma or osteomyelitis.
Sites involved with monostotic eosinophilic granuloma include
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calvarium
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mandible
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ribs
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long bones: usually shaft
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pelvis and
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vertebrae
Tubular bone involvement
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diaphyseal and metaphyseal localization more frequent than epiphyseal localization
Long bones below knees and distal to the elbows rarely involved.
Lesions are
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lytic
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round or oval
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expansile with ill-defined or sclerotic margins
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medullary cavity may be expanded
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may be associated with cortical thinning, intracortical tunneling, and erosion of the cortex or an adjacent soft-tissue mass
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Laminated periosteal new bone formation is common around the involved segment of bone
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May appear rapidly over 3 weeks
MRI: Common findings
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Focal lesion surrounded by extensive ill-defined bone marrow and soft tissue reaction
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Low signal intensity on T1-weighted images
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High signal intensity on T2-weighted images
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Considered to represent bone marrow and soft tissue edema (the flare phenomenon)
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Early stages MRI findings nonspecific
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May simulate an aggressive lesion like osteomyelitis or Ewing's sarcoma or benign bone tumors like osteoid osteoma or chondroblastoma
Differential Diagnosis
In case of long bones differential diagnosis includes
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Ewing sarcoma
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chronic osteomyelitis
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Brodie abscess and
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chondroblastoma should be considered.
As seen in this case it is difficult to radiologically exclude Ewing's sarcoma which usually shows an irregular and interrupted periosteal reaction.
References
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Beltran, J., Aparisi, F., Bonmati, L. M., Rosenberg, Z. S., Present, D., & Steiner, G. (1993, January). Eosinophilic granuloma: MRI manifestations. Retrieved March 1, 2016, from https://www. research gate.net/publication/14719515_ Eosinophilic_granuloma_MRI _ manifestations
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Bone tumor A-G. (n.d.). Retrieved February 20, 2016, from http://www.radiologyassistant.nl/en/p4bc9b15f76a78/bone-tumor-a-g.html#i4bc9b40259019
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Hunter, T., & Romford. (n.d.). SOLITARY EOSINOPHILIC GRANULOMA OF BONE. Retrieved February 20, 2016, from http://www.boneandjoint.org.uk/content/jbjsbr/38-B/2/545.full.pdf
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Imaging in Eosinophilic Granuloma of the Skeleton. (n.d.). Retrieved February 20, 2016, from http://emedicine.medscape. com/article/ 389350-overview
Case 4
Contributor
Prof.Dr. S.K. Joshi
Diagnosis
Eosinophilic Granuloma