Unsp B-cell lymphoma, extranodal and solid organ sites

This code signifies a malignant neoplasm originating from B-lymphocytes, where the specific subtype of B-cell lymphoma has not been determined. It specifically indicates that the lymphoma is located outside of the lymphatic system (extranodal) or within a solid organ, rather than in lymph nodes, spleen, or bone marrow.

Assign this code when a definitive diagnosis of B-cell lymphoma is established, but the pathologist has not specified the exact B-cell subtype (e.g., diffuse large B-cell, follicular, mantle cell). Documentation must clearly state "unspecified B-cell lymphoma" and indicate an extranodal or solid organ site involvement. This code is appropriate when further pathological characterization is pending or unobtainable.

• Avoid using this code if a more specific B-cell lymphoma subtype (e.g., C83.3- for diffuse large B-cell lymphoma) is documented.
• Ensure the documentation explicitly states "extranodal" or identifies a specific solid organ site (e.g., stomach, lung, skin) to support the "extranodal and solid organ sites" specificity.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, followed by codes for any associated symptoms or complications.