1. Department of Neurosurgery, Red Cross Hospital, Athens, Greece
Langerhans cell histiocytosis presenting as an atypical extradural thoracic spine mass in a young adult. Diagnostic and therapeutic approach.
Markogiannakis G, Zisakis A, Hadjigeorgiou GF, Petrosyan T, Psilovassilopoulos G, Karakalos S, Panteli A, Varsos V
Department of Neurosurgery, Red Cross Hospital, Athens, Greece
Keywords: Langerhans cell histiocytosis, thoracic spine

2. Introduction
Langerhans cell histiocytosis is a rare reticuloendothelial system disease occurring as an isolated lesion or as a multisystemic disease, that affects primarily children and young adults. Primary lesion is mostly found in bone and the incidence of spinal involvement is 7-15%.

3. Aim
We report the case of an adult male with Langerhans cell histiocytosis of thoracic spine who presented with atypical clinical symptoms and radiological findings, emphasizing on the diagnostic and therapeutic approach.

4. Material and Methods
A 20 year-old male was admitted to our clinic complaining of arm and shoulder pain for two months.

5. Material and Methods
Neurological examination revealed no weakness, paresthesias or numbness. MRI of the spine showed an extra-dural mass involving the body and pedicle of T1 vertebra extending into the spinal canal and the right C7-T1 foramen, without compression of the spinal cord. A full diagnostic approach with a skeletal survey and abdominal ultrasonography revealed no other lesions.

6. Material and Methods
MRI thoracic spine

7. Results
Due to the atypical manifestations of the lesion, the patient underwent a computed tomography-guided percutaneous needle biopsy. Histopathology showed fibrocollagenous tissue infiltration by a dense collection of characteristic histiocytes expressing positivity for S-100 protein. These findings were consistent with the diagnosis of Langerhans cell histiocytosis.

8. Results
The patient was subjected to immobilization with a spinal brace. Amelioration of symptoms without radiological worsening was seen in the 6-months follow-up.

9. Discussion
The presentation of Langerhans cell histiocytosis as a focal vertebral lesion should be carefully differentiated from other disease processes, especially when atypical characteristics as involvement of the posterior elements and soft tissue mass extension are present. Langerhans cell histiocytosis involving bone at a single site tends to be self-limiting and conservative treatment with biopsy and immobilization is suggested in the absence of significant spinal instability and neurological deficit.