Question

A four year-old girl presents with five days of total blindness. There was no history of trauma, and intracranial pressure is normal. An MRI is taken and reveals a large suprasellar mass compressing upon the lateral ventricles and pituitary fossa. Urgent surgery is performed and her eyesight is eventually recovered. This tumor was most likely which of the following? A. Medulloblastoma B. Craniopharyngioma C. Glioblastoma multiforme D. Optic nerve glioma

Short answer

The tumor was most likely a Craniopharyngioma.

Step-by-step solution

Analyzing the Symptoms and MRI Findings

Identify the key symptoms: a four-year-old girl with five days of total blindness, no history of trauma, and normal intracranial pressure. Note that MRI reveals a large suprasellar mass compressing the lateral ventricles and pituitary fossa.

Understanding the Location of the Mass

The suprasellar region is located above the sella turcica, where the pituitary gland sits. A mass in this region affecting vision points to structures surrounding the pituitary fossa, possibly involving the optic chiasm.

Considering Tumor Types in the Supra-sellar Region

Evaluate the given tumor types: Medulloblastoma, Craniopharyngioma, Glioblastoma multiforme, and Optic nerve glioma. Knowing typical locations is key: Medulloblastomas are usually found in the cerebellum, Glioblastoma multiforme usually arises in the cerebral hemispheres, and Optic nerve gliomas involve the optic nerve itself.

Matching Symptoms with the Most Likely Tumor

Given the location (suprasellar), symptoms (impairment of vision due to compression on optic pathways), and the nature of the tumor, Craniopharyngioma is the most likely candidate. They are known to occur in the suprasellar region and can compress the optic chiasm and pituitary gland.

Key concepts

craniopharyngioma

Craniopharyngiomas are benign (non-cancerous) tumors that typically occur in the suprasellar region of the brain, which is located just above the sella turcica where the pituitary gland sits. These tumors usually arise from embryonic tissue remnants and are most commonly diagnosed in children and adolescents.

A craniopharyngioma can grow large enough to compress surrounding structures, such as the optic chiasm and the pituitary gland. Symptoms often include headaches, vision problems, and hormonal imbalances due to the tumor's pressure on these critical areas.

Treatment typically involves surgery to remove the tumor, sometimes followed by radiation therapy to manage any remaining tumor tissue.

optic chiasm compression

The optic chiasm is the part of the brain where the optic nerves partially cross, allowing for the visual information from the right and left eye to be properly processed. When a mass such as a craniopharyngioma compresses this area, it can lead to various visual disturbances or even total blindness, as seen with our patient.

Compressing the optic chiasm can lead to bitemporal hemianopsia, a condition where the outer (temporal) halves of the visual field in both eyes are lost, causing 'tunnel vision'.

The urgency to relieve this compression, typically through surgery, is crucial to restoring vision and preventing permanent damage.

intracranial tumors

Intracranial tumors are abnormal growths within the skull, and they can be either benign (non-cancerous) or malignant (cancerous). Common symptoms include headaches, seizures, vision problems, and balance issues, depending on the tumor's location.

In the context of the exercise, identifying the type of tumor is essential based on its location and the presenting symptoms. For example:

• Medulloblastomas are typically found in the cerebellum and often cause balance and coordination issues, usually in children.
• Glioblastoma multiforme, a highly aggressive cancer, is usually located in the cerebral hemispheres and presents with rapid growth and significant symptoms.
• Optic nerve gliomas are found along the optic nerve but not typically in the suprasellar region.

Understanding these details helps in diagnosing the condition accurately and deciding on the appropriate treatment.

pediatric oncology

Pediatric oncology refers to the field of medicine focused on diagnosing and treating cancers in children. This specialty considers the unique aspects of childhood cancers, which often differ from those in adults.

In the case of intracranial tumors like craniopharyngiomas, treatment plans are tailored to minimize long-term effects and focus on preserving the quality of life. This often involves multidisciplinary teams including pediatric neurosurgeons, oncologists, and endocrinologists.

Successful treatment requires careful monitoring and follow-up as growing children are particularly vulnerable to the side effects of cancer therapies, such as growth deficiencies and hormonal imbalances. Pediatric oncology aims to provide care that addresses both the immediate tumor and the long-term well-being of the child.