Neuroblastoma of unknown primary site with periorbital bone metastasis in a child.

Neuroblastoma is the second most common solid tumor in children. Most tumors arise in the adrenal glands or paravertebral region. Rarely, patients present with metastatic disease but no primary site can be found despite extensive imaging. We report here a patient with a large periorbital bone metastasis and bone marrow involvement but with no known primary site. (c) 2010 Wiley-Liss, Inc.