ICD-9-CM diagnosis code (retired)
235.8 — Neoplasm of uncertain behavior of pleura, thymus, and mediastinum
ICD-9-CM was replaced by ICD-10 on October 1, 2015. These are the ICD-10-CM equivalents from the CMS General Equivalence Mappings.
About ICD-9-CM 235.8
235.8 is an ICD-9-CM diagnosis code for neoplasm of uncertain behavior of pleura, thymus, and mediastinum. ICD-9-CM was retired for U.S. claims on October 1, 2015, when ICD-10-CM took over.
The CMS General Equivalence Mappings translate it to 3 ICD-10-CM codes, such as D38.2 (Neoplasm of uncertain behavior of pleura), D38.3 (Neoplasm of uncertain behavior of mediastinum) and D38.4 (Neoplasm of uncertain behavior of thymus). All of these are approximate matches, so review the record to pick the right one.
ICD-10-CM equivalents
Common questions about 235.8
GEMs are a translation aid, not a substitute for coding from the record. The 2027 ICD-10 code set has changed since the last GEMs release in 2018. Page updated September 29, 2026.