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Age / Sex : 15 / M
15/M
C.C.: Pain on anterior aspect of Rt. Leg, 2 months ago, without trauma Hx (Click to enlarge)
1) What is your impression?
2) A first impression and three or less differential diagnoses are acceptable.
Courtesy : Soon Tae Kwon,MD
Chungnam National University Hospital
Diagnosis: LCH (Langerhans cell histiocytosis)
Discussion
Findings:
Plane radiographs show osteolytic bone destruction with endosteal scalloping including cortex in medial aspect of the right proximal tibia and formation of multilayered periosteal reaction. There shows increased uptake on WBBS and bone marrow edema adjacent the lesion on MRI. Mutilayered periosteal reactions are also well visualized on MRI (T1WI). The margin of the lesion is ill-defined, but shows partially sclerotic low signal intensity on MRI
Differential Diagnosis:
- Langerhans' Cell Histiocystosis, Osteomyelitis (Cortical abscess), Osteoid osteoma (Osteoblastoma, Stress fracture (in plane radiographs), Ewing's sarcoma
Diagnosis: Langerhans' Cell Histiocystosis
Discussion:
The primary proliferative element in this disease is the Langerhans’ cell, a mononuclear cell of the dendritic line which is found in the epidermis but is derived from precursors in the bone marrow. Histologically early lesions may contain large amounts of Langerhans’ cells and eosinophils. Older lesions contain fewer Langerhans’ cells and dominated by fibrous tissue. Therefore they may be mistaken for chronic osteomyelitis. In the long bones, lesions usually arise in the diaphysis or metaphysis. Lesions usually centered in the medullary cavity and cause endosteal scalloping and eventual cortical penetration. Margings initially are poorly defined but may later become sharply defined or sclerotic. Lamellated or solid thick periosteal reaction is typical. Bone scintigraphy is of limited usefulness in the evaluation of LCH. MR appearance varies and seems to correlate with the radiographic appearance, clinical symptoms, and perhaps the age of the lesion. In this case, extensive edema represents relatively early stage. As differentiated diagnosis in the long bone, the frequently aggressive appearance of LCH may evoked consideration of the round cell lesions, Ewing’s sarcoma, osteosarcoma, leukemia, neuroblastoma, or acute osteomyelitis. In less aggressive appearing lesions, simple bone cysts, fibrous dysplasia, or chronic osteomyelitis must be considered.
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