2007 ICD-9-CM Procedure 86.21 Excision of pilonidal cyst or sinus 86.21 is a specific code that can be used to specify a procedure 86.21 contains 5 index entries View the full Volume 3 86.* hierarchy 86.21 also known as: Marsupialization of cyst 86.21 excludes: incision of pilonidal cyst or sinus (86.03) Index entries containing 86.21: Excision pilonidal cyst or sinus (open) (with partial closure) 86.21 sinus -- see also Excision, lesion, by site pilonidal 86.21 Exteriorization pilonidal cyst or sinus (open excision) (with partial closure) 86.21 Marsupialization -- see also Destruction, lesion, by site cyst pilonidal (open excision) (with partial closure) 86.21 pilonidal cyst or sinus (open excision) (with partial closure) 86.21