Retinoblastoma

          

          The retina is a lining on the inside of the eye.  The nerve tissue senses light coming through the eye and sends it to the brain and turns it into an image.  Retinoblastoma is a cancer of the eye that starts in the retina.  It is a genetic mutation that causes the bad cells to grow and multiply while the good cells die.  It occurs most common in children and very rarely occurs in adults.  It can occur in one or both eyes.

          Retinoblastoma appears as a white spot in the eye when light hits the area.  Other symptoms include swelling and redness of the eye, poor vision, or crossed eyes.  Having retinoblastoma once increases your chances of it reoccuring.  If the tumor continues to grow it can cause permanent blindness in the affected eye.

Craniopharyngioma

Craniopharyngioma

          A rare, slow growing tumor that occurs in children more often than adults is called a craniopharyngioma.  It is a benign tumor that grows aggressively on the pituitary gland.  It affects the structures around it causing damage to them.  An extreme downside to a craniopharyngioma is that there are no early symptoms.  Late symptoms that occur are vision problems and hormonal changes which is consistent with other pituitary pathologies.

          Treatment of this tumor has to be done through radiation therapy, chemotherapy, or surgery.  Surgery is the first choice to get rid of the benign, aggressive tumor.

MRI T1 weighted image

Acoustic Neuroma

Acoustic Neuroma

                An acoustic neuroma affects hearing and balance.  It is a benign tumor that grows on the 8^th cranial nerve.  They normally develop slowly and only affect one side of the head.  If there is an acoustic neuroma present on both sides of the head, it is called neurofibromatosis type 2, which causes tumors to develop and affect the nervous system.

                Ear, nose and throat doctors usually run several tests to diagnose an acoustic neuroma.  MRI is the best detailed test to diagnosis acoustic neuromas.  The test uses gadolinium to better see tumors in the head. Other tests the ENT might try are Brainstem auditory evoked response, CT, and an Audiometry or hearing test. 

                Treatment includes observation to watch the growing of tumors, surgery to remove a large tumor or possibly stereotactic radiosurgery which gives radiation to the tumor to stop growth.

 T1 weighted MRI image with gadolinium

Medulloblastoma

Medulloblastoma is a series of tumors found in the cerebella.  It is more common in children than adults.  It is the most common malignant tumor affecting children.  The tumors usually occur in the cerebellum and posterior fossa of the brain.  Medulloblastoma has been known to metastasize to the bone. It can also spread throughout the Central Nervous System.

A common complication of this tumor is hydrocephalus.  Since it spreads through the CSF it causes intracranial pressure.  Some treatments of the hydrocephalus compression include a ventricular shunt or an endoscopic third ventriculostomy.  (http://emedicine.medscape.com)

 

Axial CT image of lesion in posterior fossa

 

Sagittal MRI image showing medulloblastoma in cerebellum

Cavernous Angioma

Cavernous Angioma

            Cavernous Angiomas (also called cavernous malformations) are developmental malformations of the vascular bed.  In other words, they are blood vessels that have formed abnormally or where they don't belong.  The malformation is known to leak blood and possibly cause small hemorrhages that do not usually amount to anything.  They are known to enlarge slowly over time as a result of the small hemorrhages.

            Most patients who have a cavernous angioma do not know they have one because they are asymptomatic.  Some possible symptoms include headaches and seizures. More serious symptoms occurring if the patient has a large hemorrhage are numbness, weakness, and vision changes depending on the location of the cavernous malformation.

            Treatment involves either observation or surgery if treatment is a possibility.  Most cases are minor and do not need treatment.  The more severe cases will undergo surgery if the location is easy to reach.  Other cases can undergo observation by getting annual MRI exams.

            MRI is the preferred exam to visualize a cavernous angioma.  CT is not the first choice because of the lack of specificity.  Particularly in MRI, a T2 weighted gradient echo sequence should be performed to find lesions that may not be seen on a standard spin echo sequence. 

Gradient echo axial MRI image showing multiple cavernous angiomas:

 Can you name the locations?  :)