C86.4Blastic NK-cell lymphoma

C86.4 is the ICD-10-CM diagnosis code for Blastic NK-cell lymphoma. It belongs to category C86 (other specified types of T/NK-cell lymphoma), block C81-C96 (malignant neoplasms of lymphoid, hematopoietic and related tissue) and chapter 2 (neoplasms). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within C86 (other specified types of T/NK-cell lymphoma), C86.4 is specifically for Blastic NK-cell lymphoma. Related codes cover extranodal NK/T-cell lymphoma, nasal type (C86.0), Hepatosplenic T-cell lymphoma (C86.1), Enteropathy-type (intestinal) T-cell lymphoma (C86.2), subcutaneous panniculitis-like T-cell lymphoma (C86.3), Angioimmunoblastic T-cell lymphoma (C86.5) and primary cutaneous CD30-positive T-cell proliferations (C86.6).

To report this condition, pick the subcode that matches the documentation: C86.40 (not having achieved remission) and C86.41 (in remission).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2025 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 202.80 (other malignant lymphomas, unspecified site, extranodal and solid organ sites).