Ganglioglioma

Ganglioglioma is a rare, slow-growing primary central nervous system (CNS) tumor that most often occurs in the temporal lobe of children and young adults .

Ganglioglioma
Ganglioglioma

classification

Gangliogliomas are usually benign WHO grade I tumors ; The presence of anaplastic changes in the glial component is considered to represent WHO grade III (anaplastic ganglioglioma). Criteria for WHO Grade II have been suggested but not established. Malignant transformation of spinal ganglioglioma has been observed only in a select few cases . Poor prognostic factors for adults with gangliogliomas include prognosis, male sex, and malignant histologic features.

histopathology

Histologically, ganglioglioma is composed of both neoplastic glial and ganglion cells that are disorganized, variably cellular, and non-infiltrating. Sometimes, it can be challenging to differentiate ganglion cell tumors from infiltrating gliomas with trapped neurons. The presence of neoplastic ganglion cells forming the presence of abnormal clusters of binucleation and malformed neurons are useful clues to favor ganglioglioma over glioma. The glial component of ganglioglioma includes fibrous astrocytes with varying degrees of cellular atypia . Neoplastic neuronal components are often clustered or randomly oriented. fibrovascularThe stroma is limited to the neuronal component, perivascular lymphocytic infiltration, and small foci of calcification are common, as is immunopositivity for synaptophysin , neuron-specific enolase, and chromogranin A. Elevated Ki-67 and p53 labeling index is associated with more aggressive tumor behavior in both children and adults with gangliogliomas. The rare event of malignant transformation is confined to the glial cell population, and is characterized by increased cellularity and mitotic activity , endothelial proliferation and necrosis.

Diagnosis

Computed tomography (CT) is not a generally recommended method for the diagnosis and evaluation of spinal cord tumors. Evaluation with magnetic resonance (MR) usually demonstrates a solid or mixed solid and cystic mass spread over a long segment of the cord with hypointense T1 signal and hyperintense T2 signal in the solid component. Enhancement patterns are highly variable, ranging from minimal to marked, and may be solid, rimmed, or lumpy. Adjacent bone swelling and syringomyelia and peritumoral cysts may be present in addition to reactive scoliosis.

It is nearly impossible to differentiate ganglioglioma from other more common intramedullary neoplasms based on imaging alone. Astrocytoma and ependymoma are the more familiar intramedullary tumors that share many of the same characteristics as ganglioglioma, including T2 hyperintensity, enhancement, tumoral cysts, and cord edema. Poorly defined margins may be more suggestive of astrocytoma, whereas a central location in the spinal cord, hemorrhage, and hemosiderin staining are often seen with ependymoma. Hemangioblastoma and paraganglioma are less common intramedullary tumors, but since they are encountered more often than ganglioglioma, they should also be included in the differential diagnosis.

treatment

Definitive treatment for ganglioglioma requires gross total surgery , and when this is achieved a good prognosis is usually expected. However, unclear tumor margins and the desire to preserve normal spinal cord tissue, motor and sensory function may prevent complete resection of the tumor. According to a series by Lang et al reviewing several patients with resected spinal cord ganglioglioma, the 5- and 10-year survival rates after total resection were 89% and 83%, respectively. [3] In that study, patients with spinal ganglioglioma had a 3.5-fold higher relative risk of tumor recurrence than patients with supratentorial ganglioglioma .Was . It has been recognized that postoperative outcome is closely related to preoperative neurological status as well as the ability to achieve complete resection.

With the exception of WHO grade III anaplastic ganglioglioma, radiation therapy is generally considered to have no role in the treatment of ganglioglioma. In fact, radiation therapy can induce malignant transformation of a recurrent ganglioglioma many years later. Adjuvant chemotherapy is also generally reserved for anaplastic gangliogliomas, but has been partially used in low-grade spinal gangliogliomas that show evidence of disease progression.