Sec and unsp malig neoplasm of nodes of multiple regions

This code signifies the presence of metastatic cancer affecting lymph nodes in more than one distinct anatomical region. It indicates that the primary site of the malignancy is unknown or has been previously treated, and the current focus is on the widespread lymphatic involvement.

Apply this code when documentation clearly states metastatic carcinoma to lymph nodes in multiple, non-contiguous regions, and the primary site is either not identified or is no longer active. Supporting documentation would include pathology reports confirming malignancy in multiple lymph node biopsies, imaging studies showing widespread lymphadenopathy, and physician notes indicating secondary involvement.

• Do not use this code if a specific primary site is identified and still active; instead, code the primary malignancy and the specific secondary lymph node sites.
• Distinguish from localized lymph node metastasis (e.g., C77.0-C77.5) which specifies a single regional lymph node group.
• Ensure documentation explicitly states "multiple regions" or lists distinct, non-adjacent lymph node groups involved.