Osteohydatidosis

“Hydatid cyst” of the bone is, therefore, a misnomer, not in accord with the facts, and should be replaced by the term osteohydatidosis.

In some cases, there is a so-called "ossifluent abscess," considered pathognomonic of vertebral osteohydatidosis, especially when noted with three other radiologic features.

Osteohydatidosis is uncommon and comprises but 1 per cent of all cases.

Invasion of the paravertebral or intraspinal spaces takes place late, that is, in the ossifluent stage of osteohydatidosis.