giovedì 13 aprile 2006
Vertebral plana due to Langerhan's cell histiocystosis
Figure 1: Reconstructed sagittal CT scan through the thoracic spine demonstrates a flattened vertebral body. The disk spaces are maintained. The remaining vertebral bodies are unremarkable.
Figure 2: Sagittal T2-weighted MRI demonstrates a focal kyphosis at the level of the flattened vertebral body, with a ventral epidural soft tissue component resulting in thoracic spinal cord compression.
Figure 3: Sagittal T1 post-contrast MRI with fat saturation again demonstrates a focal kyphosis at the level of the flattened vertebral body. The ventral epidural soft tissue component is better demonstrated than on the T2 series
Differential diagnosis for vertebral plana = “MELTS”
- M: Metastasis, myeloma
- E: Ewing’s sarcoma
- L: Langerhan’s cell histiocystosis, leukemia, lymphoma
- T: Trauma, tuberculous osteomyelitis
- S: Steroids
Diagnosis: Vertebral plana due to Langerhan's cell histiocystosis
LCH predominantly affects children and is comprised of three conditions: eosinophilic granuloma, Hand-Schuller-Christian disease, and Letterer-Siwe disease. All three conditions are characterized by the presence of abnormal histiocytes called Langerhan’s cells. Eosinophilic granuloma is the mildest form and is the most common, comprising approximately 70% of the disease. It consists of single or multiple bony lytic lesions, and most commonly involves the skull, mandible, spine, ribs, and long bones. Hand-Schuller-Christian disease (20% of LCH) is a multisystem disease comprised of diabetes insipidus, exopthalmos, and one or multiple bony lesions. It is fatal in approximately 30% of patients. Letterer-Siwe disease (10% of LCH) is the most severe form and it affects children less than three years old with liver, spleen, skin, and bony involvement. It is usually fatal within two years of diagnosis.
Eosinophilic granuloma is a benign condition that has a variable prognosis. Specifically, the prognosis for vertebral plana is favorable. The lesions may regress spontaneously, taking up to two years. The treatment is often conservative, but surgery, radiation, chemotherapy, and steroids may be used if conservative treatment fails.