Oth systemic atrophy aff cnsl in neoplastic disease

This code signifies a neurological disorder characterized by widespread degeneration of the central nervous system (CNS) that is directly caused by or associated with a neoplastic disease. This atrophy is not due to direct tumor invasion or metastasis but rather a paraneoplastic effect, where the body's immune response to the cancer inadvertently attacks healthy CNS tissue.

Apply this code when documentation clearly indicates a systemic atrophy of the CNS, such as cerebellar degeneration, limbic encephalitis, or encephalomyelitis, identified as a paraneoplastic syndrome. The patient must have an underlying malignancy, and the neurological symptoms should be attributed to the neoplastic disease rather than other causes.

• Always sequence the underlying neoplastic disease code first, followed by this code.
• Distinguish from direct CNS involvement by tumor (e.g., metastatic brain tumor) or treatment-related neurotoxicity.
• Ensure documentation explicitly links the CNS atrophy to the neoplastic process as a paraneoplastic syndrome.