Findings:

Plain radiograph shows a geographic
osteolytic lesion with ill-defined margin in vertebral body and pedicle of L4

Axial CT images and sagittal and coronal
reconstruction views show geographic osteolytic lesion with wide transitional
zone at L4 vertebral body. And this lesion extends into right pedicle and
anterior epidural fat through posterior cortical destruction and focal cortical
destruction in endplate. There is no detection of tumor matrix calcification.  

Sagittal T1, T2-weighted and fat saturation
sagittal T2-weighted MR images show a well-defined bone tumor with low signal
intense rim at L4 vertebral body. This tumor is hypoSI with low SI portion on
T1WI and hypoSI with focal hyperSI on T2WI and fat saturation T2WI and it shows
peritumoral edema in surrounding bone marrow, right paravertebral soft tissue and
anterior epidural fat. This tumor focally extends into anterior epidural fat.  Axial T1, T2WI and fat saturation T2WI show
this tumor extending to right pedicle. Gadolinium enhance image show
heterogeneous enhancement with focal non-enhanced portion.

Differential diagnosis:

Ewing sarcoma or Giant cell tumor

Diagnosis

Langerhans cell histiocytosis (LCH)  -  surgically confirmed.

Discussion

Although LCH is mainly seen in children and
adolescents, it may occur in any age group, and occasionally occurs in adults.
With regard to gender, it is most commonly found in male patients; with a ratio
of 2.5:1 (M:F). The common clinical manifestation includes pain, restricted
motion of spine, neurologic symptom, and deformity. Neurologic symptoms were
more common in adult patients.

Radiographic findings

Plain radiographs show lytic lesions of
vertebral body, which usually led to vertebral collapse, suggesting vertebra
plana. However, this typical sign is seldom seen in the adult group. CT scans
show expansive and lytic bone destruction of the involved vertebra. The lesions
can extend to the pedicle. transverse process, lamina, and spinous process. On
MRI, most lesions show a low to intermediate signal on T1-weighted imaging and
show intermediate to hyperintense on T2-weighted imaging. All lesions show
homogeneous enhancement. MRI is more sensitive to identifying paravertebral
soft-tissue mass, peridural compression, or edema zone around the lesions.