ICD-11 classes
15 Diseases of the musculoskeletal system or connective...
Soft tissue disorders
Miscellaneous specified soft tissue disorders
FB51 — Fibroblastic disorders
FB51.4 — Retroperitoneal fibrosis
FB51.40 — Primary retroperitoneal fibrosis

ICD-11 FB51.40 — Primary retroperitoneal fibrosis

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.

The diagnosis includes nothing.

The diagnosis excludes nothing.

It has no clarifying diagnoses.