The request from Professor Jörg Klekamp for me to write the foreword for this monograph was an appealing challenge. Prior to the era of microneu- surgery, I was firmly involved in the surgery of spinal lesions, and achieved surgical removal of spinal arteriovenous malformations (AVMs) on 12 - tients in the years between 1960 and 1965. Microneurosurgical techniques were introduced in Zurich in 1962, and since then I have applied these techniques to the exploration of the various spinal lesions: 182 herniated discs, 78 spinal cord AVMs, and 263 spinal tumors (46 epidural, 94 ext- medullary, and 123 intramedullary tumors). These have been published in a preliminary paper only, for I was unable to accomplish completion of the planned Volume V in my Microneurosurgery series within an adequate time frame. I therefore admire the achievement of Klekamp and Samii, who present to us a most comprehensive work. This monograph is outstanding in many aspects, providing an overview of the clinical experiences gained in a single neurological institution over a period of 25 years between 1978 and 2003, consisting of 1081 spinal tumors treated in 868 patients, with 973 operations (intramedullary tumors in 198 patients, extramedullary tumors in 446 patients, and epidural tumors in 329 patients). The entire cohort of patients was explored surgically by app- ing microsurgical techniques.