Glioblastoma Multiforme: Clinical Insights, ICD-10 Coding, and Streamlined Documentation

Updated on: August 1, 2025

Glioblastoma multiforme (GBM) is one of the most aggressive and common primary brain tumors in adults. With its rapid growth, poor prognosis, and resistance to treatment, GBM poses significant challenges to both diagnosis and management. For clinicians, documenting this condition accurately and comprehensively is essential for ensuring the best possible care, as well as proper reimbursement.

In this article, we’ll explore:

• What glioblastoma multiforme is and how it presents

• Key diagnostic and treatment strategies

• ICD-10 codes for glioblastoma and related conditions

• How to document GBM effectively

• How DocScrib can streamline clinical documentation for brain tumor cases

What is Glioblastoma Multiforme?

Glioblastoma multiforme (GBM) is a malignant brain tumor that originates in the glial cells, specifically the astrocytes—cells that provide support and nourishment to neurons. Known for its aggressiveness and poor prognosis, GBM typically affects older adults, though it can occur at any age.

Key Characteristics of GBM:

• Rapid growth: The tumor can double in size within weeks.

• Infiltrative nature: GBM cells spread into surrounding brain tissue, making complete surgical removal difficult.

• Resistance to therapy: Despite treatments like surgery, radiation, and chemotherapy, GBM often recurs.

• Poor prognosis: Median survival post-diagnosis is typically 12–18 months, even with aggressive treatment.

💡 Glioblastoma is classified as a grade IV astrocytoma by the World Health Organization due to its high malignancy.

Symptoms of Glioblastoma Multiforme

GBM symptoms vary depending on the tumor’s location but often include:

• Headaches (usually worse in the morning or upon waking)

• Seizures

• Cognitive dysfunction (memory loss, confusion, personality changes)

• Focal neurological deficits (weakness, speech difficulty, visual disturbances)

• Nausea and vomiting (often due to increased intracranial pressure)

• Motor or sensory disturbances depending on the tumor location

Red Flags:

• Rapid progression of symptoms

• New-onset seizures in an older adult

• Sudden cognitive or personality changes

ICD-10 Coding for Glioblastoma Multiforme

Primary ICD-10 Code

✅ C71.9 is the most commonly used code for glioblastoma multiforme, but be specific if the tumor’s location is known (e.g., C71.0 for the frontal lobe).

Diagnosis of Glioblastoma Multiforme

Diagnostic Workup

1. MRI of the brain – Gold standard imaging tool to identify tumor location, size, and involvement of surrounding structures.

2. CT scan – May be used for initial assessment or when MRI is contraindicated.

3. Histopathology – A biopsy is required for definitive diagnosis, often through surgery.

4. Genetic testing – To assess IDH mutations or MGMT methylation, which may impact treatment and prognosis.

5. PET scan – Sometimes used to evaluate tumor activity and spread.

Glioblastomas often show contrast enhancement on MRI and may have areas of necrosis or cystic degeneration within the tumor.

Treatment Options for Glioblastoma Multiforme

1. Surgical Resection

While complete resection is rarely possible due to the infiltrative nature of the tumor, surgery can help reduce tumor mass, improve symptoms, and provide tissue for diagnosis.

2. Radiotherapy

• Postoperative radiation therapy (with or without concurrent chemotherapy) is a standard treatment.

• Fractionated external beam radiation is commonly used.

3. Chemotherapy

• Temozolomide (TMZ) is the standard chemotherapy for GBM, often used concurrently with radiation.

• Newer treatments like Bevacizumab (anti-VEGF therapy) may be used for recurrent GBM.

4. Tumor Treating Fields (TTF)

A newer, FDA-approved treatment using electrical fields to disrupt tumor cell division.

5. Experimental Therapies

Clinical trials are exploring immunotherapy, gene therapy, and other treatments in an attempt to address GBM’s resistance to traditional therapies.

Management and Prognosis

• Survival: Median survival is generally around 14–16 months with treatment. Patients who undergo gross total resection and follow up with radiotherapy and chemotherapy tend to have better outcomes.

• Recurrent GBM: When GBM recurs, treatment options are limited, and survival significantly shortens. Clinical trials are an option for many patients.

🔍 Prognostic factors include age, functional status, MGMT methylation status, and extent of tumor resection.

Documentation Tips for Glioblastoma Multiforme

✅ Document neurological exam findings in detail (focal deficits, cognitive changes)
✅ Note imaging findings clearly (location, size, features of malignancy)
✅ Record treatment regimens—chemotherapy, radiation, and surgery
✅ Track symptom progression and treatment responses regularly
✅ Use Z85.3 for post-treatment documentation (especially for follow-up visits)

Common Documentation Pitfalls

🚫 Vague terms like “brain tumor” without specifying glioblastoma
🚫 Failing to document the complications of GBM (e.g., increased intracranial pressure, seizures)
🚫 Missing ICD-10 updates for recurrent GBM (e.g., C71.9 to Z85.3)
🚫 Not including treatment details and expected prognosis

How DocScrib Can Streamline Glioblastoma Documentation

Accurate and thorough documentation of glioblastoma cases is critical for managing treatment, monitoring progression, and ensuring reimbursement. DocScrib helps by:

✅ Auto-suggesting ICD-10 codes like C71.9, G93.1, and Z85.3 based on dictated notes
✅ Structuring SOAP notes with detailed neurological and imaging findings
✅ Automating treatment documentation (e.g., surgery, radiation, chemotherapy)
✅ Flagging follow-up requirements and next steps for ongoing management

Enhance your glioblastoma care documentation with DocScrib—automatically!
👉 Book your free DocScrib demo today

ICD-10 Coding Quick Reference for Glioblastoma Multiforme

FAQs

Q1: Can glioblastoma be detected early?
Unfortunately, early detection is difficult due to its nonspecific symptoms. However, patients with unexplained neurological changes or focal deficits should be promptly evaluated with imaging.

Q2: How often should I monitor glioblastoma patients after treatment?
Frequent imaging and clinical evaluations are essential, typically every 3–6 months post-treatment, and more often if recurrence is suspected.

Q3: What is the role of immunotherapy in GBM?
While still investigational, immunotherapy shows promise in clinical trials. Patients may be referred to clinical studies for novel therapies.

Q4: How does DocScrib help with glioblastoma documentation?
DocScrib streamlines the process by suggesting relevant ICD-10 codes, structuring neurological findings, and providing templates for tracking patient progress through treatment stages.

Final Thoughts

Glioblastoma multiforme is one of the most challenging and aggressive brain tumors to manage. Timely diagnosis, clear documentation, and proper coding are essential for providing optimal care and ensuring appropriate treatment. With DocScrib, you can improve efficiency, accuracy, and overall quality of care for patients with GBM.

👉 Book your free demo today and start documenting smarter!