Bladder Anatomy and ICD-O-3

Anatomy of the Bladder. Source: TNM Atlas, 3rd edition, 2nd revision.

The bladder is divided into eight subsites (see table below). The location of the bladder tumor is not commonly recorded on the pathology report.

For Primary Sites, use ICD-O-3 (Topography section): ICD-O-3.1 or the Solid Tumor Rules

Priority order for coding primary site

NAACCR Item # 400: Primary Site (NAACCR Item #2580 Text-Primary Site Title)

ICD-O-3 Codes	ICD-O-3 Preferred Term	Synonyms
C670	Trigone of bladder	Base of bladder Below interureteric crest Below interureteric field Below interureteric ridge Floor of bladder
C671	Dome of bladder	Roof Vault Vertex
C672	Lateral wall of bladder	Lateral to ureteral orifice Left wall Right wall Sidewall
C673	Anterior wall of bladder
C674	Posterior wall of bladder
C675	Bladder neck	Internal urethral orifice Vesical neck
C676	Ureteric orifice	Just above ureteric orifice
C677	Urachus	Mid umbilical ligament Urachal remnant
C678	Overlapping lesion of bladder	Lateral-posterior wall (hyphen)
C679	Bladder, NOS	Lateral posterior wall (no hyphen)

See the current version of the SEER Program Coding Manual, Section IV: Description of this Neoplasm and Appendix C for complete coding instructions for primary site.

Updated: April 22, 2025