Progressive multifocal leukoencephalopathy

This diagnosis code signifies a rare, demyelinating disease of the central nervous system caused by the JC virus. It primarily affects individuals with compromised immune systems, leading to progressive damage to the white matter of the brain. The condition results in a variety of neurological deficits, often with a fatal outcome.

Apply this code for patients diagnosed with progressive multifocal leukoencephalopathy, typically confirmed through brain imaging (MRI) showing characteristic white matter lesions and detection of JC virus DNA in cerebrospinal fluid or brain biopsy. This code is appropriate when the patient's medical record clearly documents the clinical presentation, diagnostic findings, and a definitive diagnosis of PML.

• Always ensure documentation specifies "progressive multifocal leukoencephalopathy" to support this specific code.
• Consider co-reporting underlying immunocompromising conditions (e.g., HIV, malignancy, immunosuppressive therapy) as primary or secondary diagnoses, as they are often causative factors.
• Do not confuse with other demyelinating diseases like multiple sclerosis; PML has distinct etiology and pathology.