====== Axis tumor ======

Tumors are rare in this location.
Possibilities include those that involve the spine at any location. Some factors pertinent
to this location:

a) primary bone

● chondroma

● chondrosarcoma: rare in the craniovertebral junction. Lobulated tumors with calcified
areas

● chordoma: slow-growing radioresistant malignancy 

● osteochondroma (chondroma)

● osteoblastoma

● osteoid osteoma: more common in posterior elements than VB

● giant-cell tumors of bone: typically arise in adolescence. Lytic with bony collapse

b) metastatic: including

● typical metastases that spread hematogenously to bone, including: breast cancer, prostate
cancer, malignant melanoma, paraganglioma, renal cell carcinoma

● extension of regional tumors: nasopharyngeal tumors, craniopharyngioma

c) meningioma

d) neurofibroma

e) miscellaneous

● plasmacytoma

● multiple myeloma

● Langerhans cell histiocytosis: osteolytic defect with progressive vertebral collapse.

Occasionally occur in C2
● Ewing’s sarcoma: malignant. Peak incidence during 2nd decade of life

● aneurysmal bone cyst