The Approach External is identified by letter "X" and occupies the 5th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to 0WC1X
Extirpation of Matter from Cranial Cav, Perc Endo Approach
Extirpation of Matter from Cranial Cavity, Open Approach
Extirpation of Matter from Cranial Cavity, External Approach
Extirpation of Matter from Cranial Cavity, Perc Approach