Phakomatous Choristoma

Phakomatous Charistoma is a very rare non-cancerous tumor of the eyelid that is typically present at birth. The first recorded case was documented by Lorenz Zimmerman in 1971. He was the first person to correctly identify that the tumor is comprised of ectodermal cells that typically form the crystalline lens of the eye. Today, this disease is also known as Zimmerman’s tumor to honor his discovery, yet it is still just as rare.  In total, there have only been about twenty reported cases, which has made it difficult for scientists and doctors to learn more about it.      

Although the cause is unknown, it has been proven that Zimmerman was correct in believing that the tumor is comprised of cells destined to comprise the lens of the eye. When this disorder occurs, the ectodermal cells form a mass in the eyelid or orbit of the eye instead of forming correctly. Basically, the cells that are supposed to form the lens of the eye quickly multiply and enlarge during eye development and create an abnormal lump. 

There are three main theories that explain how this might happen. One theory states that the outer layer of eyelid skin dips down too far and enters the middle layer while the eyelid is developing.  This causes the tissue to continue growing within the eyelid, which then causes the abnormal lump. Another theory is that the lens tissue of the eye travels through the closing optic fissure. The resulting abnormal eye development then produces extra lens tissue that grows in the eyelid, causing the abnormal lump.  A final theory states that some of the invaginating lens tissue begins to form in an area that is supposed to form the nasal lower lid. This would again cause an abnormal lump in the eyelid.

Phakomatous Charistoma is typically diagnosed after redness or swelling occurs in the eyelid.  It is most often diagnosed in newborns, but in some cases, an abnormality of the eye is not noticed until the child is a few months older.  In most cases, however, phakomatous charistoma typically occurs before the child is six months of age. 

Without knowing the exact cause of the abnormal eye development, there is no known way to prevent the disorder. However, it can easily be treated by surgically removing the lumpy mass at a very young age.  The average age that babies receive the surgery is 6.3 months, and the oldest recorded patient undergoing the operation was only thirteen months old.  In all reported cases, the surgery was successful with no complications from either the surgery or the tumor. The patients’ visions were not affected, and there does not appear to be any reoccurring cases.

Since there are so few reported cases on this disorder, the statistics and information about it are limited. In fact, it is often misdiagnosed as a cyst or a different form of lesion or tumor. However, with the proper diagnosis and treatment, Phakomatous Charistoman does have a positive outlook with no known lasting effects on the patients.