Oth mature T/NK-cell lymphomas, intra-abdominal lymph nodes

This code signifies a diagnosis of a mature T-cell or natural killer (NK)-cell lymphoma that is not otherwise specified or classifiable within more specific categories, and is primarily located within the intra-abdominal lymph nodes. These are aggressive non-Hodgkin lymphomas originating from mature T-lymphocytes or NK-cells.

Use this code when documentation specifies a mature T-cell or NK-cell lymphoma affecting lymph nodes within the abdominal cavity (e.g., mesenteric, retroperitoneal, celiac) and the specific subtype is not detailed enough for a more precise C84.x code. This applies when the pathology report confirms a T/NK-cell lineage but lacks further subtyping, or when the subtype falls under "other" mature T/NK-cell lymphomas.

• Ensure the documentation explicitly states "intra-abdominal lymph nodes" as the primary site of involvement.
• Differentiate from lymphomas of other sites (e.g., cutaneous, nodal outside abdomen) or other cell lineages (e.g., B-cell).
• Always seek more specific subtyping (e.g., C84.4- Peripheral T-cell lymphoma, not otherwise specified) if available in the pathology report.