Other non-follicular lymphoma, intra-abdominal lymph nodes

This code signifies a malignant lymphoma that originates from lymphoid cells other than follicular center cells, specifically located within the abdominal cavity's lymph nodes. This includes various aggressive and indolent non-follicular subtypes, excluding those classified elsewhere.

Apply this code when documentation confirms a diagnosis of a non-follicular lymphoma affecting the intra-abdominal lymph nodes, such as diffuse large B-cell lymphoma, mantle cell lymphoma, or marginal zone lymphoma, when a more specific site or type code is not available. Supporting documentation would include pathology reports confirming the non-follicular nature and imaging or surgical reports identifying intra-abdominal lymph node involvement.

• Ensure the pathology report explicitly states "non-follicular" or identifies a specific non-follicular subtype.
• Do not use this code if the lymphoma is definitively identified as follicular (C82.-) or if a more specific anatomical site within the abdomen is documented (e.g., C83.80 for unspecified site).
• Always sequence this code after the primary malignancy if the lymphoma is a secondary or metastatic finding, though typically lymphomas are primary.