15Diseases of the musculoskeletal system or connective tissue
Soft tissue disorders
Miscellaneous specified soft tissue disorders
FB51Fibroblastic disorders
FB51.4Retroperitoneal fibrosis
FB51.40
category
Primary retroperitoneal fibrosis
Definition This is the commonest form of retroperitoneal fibrosis. By definition, no associated trigger (e.g. drugs or malignancy) can be determined, although atherosclerosis of the abdominal aorta is often associated. It has been postulated that such atherosclerosis may be of aetiological significance in some cases.
Also indexed as
Chronic periaortitis Primary retroperitoneal fibrosis idiopathic retroperitoneal fibrosis
Nearby in Retroperitoneal fibrosis
International Classification of Diseases, Eleventh Revision (ICD-11), World Health Organization (WHO) 2019/2021, https://icd.who.int/browse11. Licensed under Creative Commons Attribution-NoDerivatives 3.0 IGO (CC BY-ND 3.0 IGO).
Release 2026-01.
View this entity in the official WHO ICD-11 browser .
This page reproduces WHO classification content for reference. It is not
medical advice and must not be used to diagnose or treat. For coding
decisions, consult the official release and your national coding guidelines.
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