C84.4Peripheral T-cell lymphoma, not elsewhere classified

C84.4 is the ICD-10-CM diagnosis code for peripheral T-cell lymphoma, not elsewhere classified. It belongs to category C84 (mature T/NK-cell lymphomas), 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 11 subcodes must be used instead.

Within C84 (mature T/NK-cell lymphomas), C84.4 is specifically for peripheral T-cell lymphoma, not elsewhere classified. Related codes cover mycosis fungoides (C84.0), Sezary disease (C84.1), Anaplastic large cell lymphoma, ALK-positive (C84.6), Anaplastic large cell lymphoma, ALK-negative (C84.7), unspecified (C84.9), cutaneous T-cell lymphoma, unspecified (C84.A) and other mature T/NK-cell lymphomas (C84.Z).

To report this condition, pick the subcode that matches the documentation: C84.40 (unspecified site), C84.41 (lymph nodes of head, face, and neck), C84.42 (intrathoracic lymph nodes), C84.43 (intra-abdominal lymph nodes), C84.44 (lymph nodes of axilla and upper limb), C84.45 (lymph nodes of inguinal region and lower limb), C84.46 (intrapelvic lymph nodes), C84.47 (spleen) and 3 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2023 (title revised).