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SEER Inquiry System - Report
Produced: 09/17/2026 7:05 AM
Question 20170014
Inquiry Details
References:
Heme & Lymph Manual & DB
Question:
Reportability/Histology--Heme & Lymphoid Neoplasms: Is a physician statement that a patient has a malignant histiocytic disorder best described as Erdheim-Chester disease reportable? If reportable, should histology be coded to 9751/3? See Discussion.
Discussion:
The patient had a mediastinal mass biopsy showing fibrosclerotic tissue with patchy lymphohistiocytic foci and scattered plasma cells, followed by a retroperitoneal mass biopsy showing fibrohistiocytic infiltrate. Erdheim-Chester disease is not reportable per the Heme Database. However, the physician specifically states this is a malignant disorder.
Answer:
Updated May 2026
For years prior to 2021, Erdheim-Chester disease is not reportable.
Starting in 2021, Erdheim-Chester disease is reportable and coded 9749/3. See the Hematopoietic database.
