Neurosurgery Coding Alert

Question: What is the difference between a schwannoma and neurofibroma?

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Answer: Both terms refer to benign nerve sheath tumors that originate within a nerve, although some pathologists differentiate between the two based on the degree of nerve involvement.

Neurofibromas are often associated with neurofibromatosis (237.7x), but the tumors also occur in patients without the condition. It's difficult to distinguish these tumors on pre-operative MRI, so your neurosurgeon probably won't know what he's dealing with until the procedure begins.

Schwannomas usually originate from a single, small, nonfunctional nerve fascicle; neurofibromas tend to be more extensive and often involve two or more functional nerve fascicles. Because of this, schwannomas are usually easier for the surgeon to remove.

Pinpoint diagnosis: ICD-9 includes a comprehensive list of potential diagnosis codes for schwannomas and neurofibromas. When choosing your diagnosis, rely on the "connective tissue" choices in the Neoplasm Index. Code according to the tumor's location and status (malignant, benign, etc.). For sites that do not appear on the list, guidelines direct you to code to the neoplasm of that site (such as reporting 215.4, [Other benign neoplasm of connective and other soft tissue; thorax] for a neurofibroma of the chest wall).

-- Technical and coding guidance for You Be the Coder and Reader Questions provided by Gregory Przybylski, MD, director of neurosurgery at the New Jersey Neuroscience Institute, JFK Medical Center in Edison.