HEMANGIOBLASTOMA

Understanding Hemangioblastomas and Their WHO Classification

Hemangioblastomas are typically characterized by their benign nature. These vascular lesions are non-cancerous and do not evolve into malignant forms. In the latest classification by the World Health Organization, detailed in the 5th Edition (2021) of the CNS tumor classification, hemangioblastomas are categorized as grade 1 tumors. This classification indicates a favorable prognosis and a benign behavior within the central nervous system.

Pathological Features

When examined under a microscope, hemangioblastomas reveal a unique histological structure. They are composed of large, pale stromal cells that are interwoven with an extensive network of blood vessels. This distinct cellular architecture is crucial for their identification and differentiation from other types of lesions.

By understanding these aspects, healthcare professionals can effectively diagnose and manage hemangioblastomas, ensuring appropriate treatment and monitoring strategies are employed.

Hemangioblastoma Causes 

Hemangioblastomas typically develop for unknown reasons. They are therefore impossible to forecast. Moreover, hemangioblastomas that recur might indicate a hereditary disorder like von Hippel-Lindau (VHL) disease. VHL is the root cause of 20% to 25% of hemangioblastoma instances. Hemangioblastomas often only have one tumor, but patients with VHL may experience several. The VHL gene becomes mutated as a result of VHL. This causes benign tumors to spread to several locations throughout the body. VHL has neither a treatment nor a preventative measure. Surgery to remove tumors is the main course of treatment.

Symptoms of Hemangioblastoma

Depending on where the tumor develops, the symptoms of hemangioblastoma might vary somewhat. For example, small, asymptomatic hemangioblastomas may not require treatment because of their benign growth pattern and moderate rate of growth. Furthermore, these are frequently discovered by chance and are easily monitored with yearly imaging exams. As they push on the spinal cord, bigger hemangioblastomas might result in the following symptoms.

• Bowel and bladder dysfunction
• numbness or pins and needles in the arms or legs
• clumsiness in the hands; weakness in the arms or legs
• trouble walking
• and/or weakness in the hands

The location and size of the tumor will affect the specific symptoms. However, the following conditions might exist if you have a spinal cord hemangioblastoma:

• Constipation or fecal (bowel) incontinence.
• Urinary retention or incontinence.
• Numbness or tingling sensation.
• Muscle weakness.
• Headache
• Loss of coordination
• Imbalance
• Nausea
• Vomiting

How is Hemangioblastoma Diagnosed?

Your doctor at the Southwest Scoliosis and Spine Institute will interview you to learn your symptoms and medical background. Then your doctor will want to obtain imaging scans to identify any potential anomalies:

• The two imaging procedures that are most often employed are MRIs and CT scans. These non-invasive, painless examinations offer precise pictures of tumors and any swelling tissue nearby. Also, your doctor may use ultrasound, another noninvasive screening technique, to find a tumor.
• If an MRI or CT Scan fails to produce a diagnosis, a more comprehensive imaging test called a spinal angiography will take place.
• A catheter is placed during this test and advanced up to a vertebral artery through a blood vessel in the thigh. The catheter gently injects a particular dye into the artery that supplies blood to the Tumor. The dye makes it simpler to see the tumor and its size and form on an X-ray.
• It can take many dye injections to find the proper artery. However, your doctor can use angiography to assess how the tumor is influencing blood flow after the proper artery has been located.

The particular location and higher blood supply of hemangioblastomas set them apart from other frequently occurring tumors.

When diagnosing spinal hemangioblastomas, two primary categories of conditions are typically considered: neoplasms and vascular malformations in the spinal region. Here’s a breakdown of these categories and the specific conditions examined:

Neoplasms of the Spinal Canal

These involve enhancing components and include several specific tumor types:

Intradural Extramedullary Tumors:

• Spinal Meningioma: A typically benign tumor located within the spinal canal, but outside the spinal cord.
• Myxopapillary Ependymoma: Often found in the lower spine, this tumor originates from ependymal cells.
• Leptomeningeal Spinal Metastases: Cancer cells metastasize from other areas of the body to the spinal canal.

Neurogenic Tumors:

• Spinal Schwannoma: A tumor arising from Schwann cells in the spine.
• Spinal Neurofibroma: A benign nerve sheath tumor.
• Spinal Paraganglioma: Rare tumors that occur near the spine’s nerve tissue.

Intramedullary Spinal Cord Tumors:

• Spinal Cord Metastases: Secondary cancerous growths from primary tumors located elsewhere.
• Spinal Astrocytoma: A tumor arising from astrocytes within the spinal cord.
• Spinal Ependymoma: Originates from ependymal cells within the spinal cord.

Vascular Malformations of the Spinal Cord

These involve abnormal blood vessel formations and include:

• Other Hypervascular Cord Neoplasms: Tumors with an abundant blood supply.
• Spinal Arteriovenous Malformation (AVM): Abnormal tangle of arteries and veins within the spinal cord.
• Spinal Dural Arteriovenous Fistula (DAVF): An abnormal connection between a dural artery and a vein.
• Spinal Cavernous Malformations: Collections of dilated blood vessels within the spine.

Each of these conditions presents distinct characteristics that aid in differentiating them from spinal hemangioblastomas during diagnosis. Proper imaging and clinical evaluation are crucial for accurate diagnosis and treatment planning.

Characteristic Radiographic Features of Spinal Hemangioblastomas

CT Imaging: On non-contrast CT, hemangioblastomas may present as a soft tissue nodule with a prominent hypodense cyst-like component. When contrast is administered, there is vivid enhancement of the solid component, offering a clear distinction for diagnosis.

MRI Findings:

• T1: The signal may vary relative to the normal spinal cord. Most often, these lesions appear hypo- to isointense, making them challenging to identify, though they can be hyperintense in about 25% of cases.
• T2: Hemangioblastomas often show iso- to hyperintensity. Larger lesions may exhibit focal flow voids, with surrounding edema and an associated syrinx commonly observed. Hemosiderin capping might also be present.
• T1 C+ (Gd): The tumor nodule typically enhances vividly with contrast, aiding in detection.

Angiographic Features: Characterized by a densely enhancing nidus with associated dilated arteries and prominent draining veins, these features help differentiate hemangioblastomas from other spinal tumors.

Careful imaging of the entire neuraxis is crucial to ensure no other lesions are present, as this comprehensive approach is key to accurate diagnosis and treatment planning.

Common Imaging Characteristics of Spinal Hemangioblastomas on MRI

Spinal hemangioblastomas can present distinct imaging features, which are essential for proper diagnosis and treatment planning:

General Appearance

These tumors typically manifest as discrete nodules, although they can also lead to widespread enlargement of the spinal cord. Additionally, they frequently form tumor-associated cysts or syrinxes, appearing in 50% to 100% of cases. While uncommon, they can sometimes cause subarachnoid hemorrhage or bleeding within the spinal cord itself.

Signal Characteristics

T1-Weighted Images:

• The signal intensity compared to the normal spinal cord can vary.
• Often, these lesions exhibit hypo- to isointense signals, making them challenging to identify.
• In about 25% of cases, they may appear hyperintense.

T2-Weighted Images:

• The lesions generally range from iso- to hyperintense signals.
• Larger lesions may show areas with no signal flow due to rapid blood movement.
• Surrounding edema is typical, and an associated syrinx often accompanies the lesion.
• There may be the presence of hemosiderin, a blood product, at the ends of the tumor.

T1 with Contrast (Gadolinium):

• The tumor nodule tends to show strong enhancement with contrast medium, appearing vividly on the images.

These signal patterns play a crucial role in distinguishing spinal hemangioblastomas from other types of spinal lesions on MRI scans.

Types of Spinal Tumors to Consider in Differential Diagnosis

When evaluating spinal tumors, it’s crucial to distinguish between intradural extramedullary and intramedullary tumors. Each type presents unique characteristics that are important in determining an accurate diagnosis.

Intradural Extramedullary Tumors

These tumors are located within the dura but outside the spinal cord itself. Notable examples include:

• Spinal Meningioma: Usually benign and often found in middle-aged women.
• Myxopapillary Ependymoma: Commonly arises in the lower back region, particularly the sacrum.
• Leptomeningeal Spinal Metastases: Malignant tumors spread from another primary site.
• Spinal Paraganglioma: Rare tumors that can secrete hormones, found near nerve roots.
• Neurogenic Tumors: Includes types like:
  • Spinal Schwannoma: Generally benign and originates from the nerve sheath.
  • Spinal Neurofibroma: This can be part of neurofibromatosis or occur sporadically.

Intramedullary Spinal Cord Tumors

These tumors occur within the spinal cord and can significantly affect its function. Important forms to consider are:

• Spinal Cord Metastases: Secondary tumors that have spread from other body parts.
• Spinal Astrocytoma: Often found in the pediatric population and varies in aggressiveness.
• Spinal Ependymoma: Typically benign, slow-growing, and can be surgically removed.

Vascular Malformations

These malformations can mimic or accompany spinal tumors, and consideration should be given to:

• Hypervascular Cord Neoplasms: Highly vascular tumors that may appear explosive on imaging.
• Spinal Arteriovenous Malformation: Abnormal connections between arteries and veins that can cause bleeding or ischemia.
• Spinal Dural Arteriovenous Fistula: Abnormal connections usually outside the spinal cord but can drain into the cord’s venous system.
• Spinal Cavernous Malformations: Vascular lesions that may result in bleeding or neurological symptoms.

Understanding these distinct types of spinal tumors and malformations aids in forming a comprehensive differential diagnosis and guide further medical evaluation and management.

How is a Hemangioblastoma Treated?

Microsurgery, or removal with a surgical microscope and extremely fine operating instruments, is the therapeutic option for symptomatic spinal cord hemangioblastomas. Standard microsurgical procedures may generally remove most tumors while maintaining neurological functions. If the surgeon cannot remove the entire tumor, radiation may be the solution. There are two methods for treating hemangioblastomas. Both procedures include removing or eliminating the tumors. The removal of a hemangioblastoma is frequently advised by healthcare teams in our country. Depending on the circumstances, our team will use the following treatments.

Surgery 

To eliminate the tumor, surgery is frequently employed. The term “resection” refers to this kind of surgery, which involves the removal of tissue from an organ. Removal of the tumor will stop any symptoms.  You can still feel symptoms if a portion of the tumor is still there since it might develop again. If hemangioblastoma is present together with VHL disease, resection surgery might not provide the complete solution.

Stereotactic radiosurgery 

The use of stereotactic radiosurgery can replace surgical resection. It is a non-invasive therapy that targets the tumor with extremely concentrated radiation beams. The tumor may not disappear for several months even though the surgery only requires one session. There isn’t a chance of bleeding or other consequences, unlike surgical resection. This implies that as soon as the treatment is over, you should get back to your regular activities. If the hemangioblastoma is situated in a region of the spinal cord where typical surgical methods would be risky to use, radiosurgery may produce the desired results.

Radiation

This procedure employs precisely timed radiation beams to either reduce or eliminate the tumor. The tumor’s location and your medical history determine how long the radiation will last.

Medication

Drugs that can halt or reduce cancers are the subject of promising research.

Risk Factors

Hemangioblastoma cells develop into blood vessels at an early stage. They are most typical in the early and middle years of life and affect men and women equally. Patients often only have one hemangioblastoma. We refer to these as occasional instances. However, numerous hemangioblastomas and cysts are more likely to form in various areas of the body, including the kidneys and other organs, in people with the hereditary genetic disorder von Hippel-Lindau Disease.

Outlook

Long-term problems are rare following effective hemangioblastoma treatment. Upon successfully removing or eliminating the tumor, your symptoms should go away. However, long-term issues can arise if a hemangioblastoma has developed and injured nerves. You should discuss this with your Southwest Scoliosis and Spine Institute doctor to determine what it could signify for you and what you can do to lessen its effect on your quality of life. It’s crucial to get routine examinations after hemangioblastoma treatment. Your doctor can keep an eye out for the growth of fresh tumors or the return of a tumor that wasn’t entirely removed or eradicated. Talk to your doctor as soon as you start experiencing any strange symptoms. Your doctor at Southwest Scoliosis and Spine Institute can identify the root issue and suggest a strategy to provide a remedy.

Southwest Scoliosis and Spine Institute Specializes in Performing Complex Spine Surgery

If you think you or a loved one might need surgery to correct a complex spine surgery, it’s important to contact a surgeon who is skilled in performing these kinds of complicated and specialized procedures — especially a spinal hemangioblastoma.

Southwest Scoliosis and Spine Institute’s board-certified, fellowship-trained orthopedic surgeons, Richard Hostin, MD, Devesh Ramnath, MD, Ishaq Syed, MD, Shyam Kishan, MD, and Kathryn Wiesman, MD, have the expertise and surgical skills necessary to diagnose and treat these cases.

They’ve performed more than 16,000 successful spine surgeries and helped more than 100,000 patients get back to living a normal, pain-free life. So, if you have been told that there is no hope, call the Southwest Scoliosis and Spine Institute with offices in  Dallas, Plano, and Frisco, Texas.  for an evaluation.

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Radiopaedia: Spinal Hemangioblastoma