What is Pilomatricoma?

Pilomatricoma is a rare malformation which occurs when the brain develops into a small structure called a cranial nerve center (CNC). These structures are located in the back of the head. They are responsible for controlling movements such as breathing, heartbeat, heart beat, swallowing and even some basic senses like vision. However they do not control other functions such as speech or movement of muscles.

The CNCs develop from the same cells that form the brain stem. When these cells divide, they produce new tissue with the shape of a brain stem. This type of development is known as neuroepithelial transformation. The result is that most people have one or two cranial nerve centers (CNC) instead of having all three brains in their heads. A few individuals do not develop a CNC but still retain part of their normal brains inside them.

In most cases, the cranial nerves are not affected and do not need to be controlled. Some individuals may experience problems if they try to move the eyes, ears or mouth while others will have no problem in doing so. For example, someone who loses part of their brain might still feel emotions such as joy or sadness. People with this condition often suffer from depression and sometimes even suicide attempts due to feelings of helplessness and isolation.

In some cases, the CNC is not a small structure but rather a larger mass of brain tissue. This condition is known as pilomyxoid astrocytoma and it is normally found in older people. Unlike pilomatricoma, pilomyxoid astrocytomas are usually serious and associated with a lower life expectancy than average.

What are the symptoms?

Pilomatricoma usually does not cause any symptoms for most people. Almost always they are completely unaware of having this abnormality unless they have a brain scan or similar medical test. Sometimes the tumors can cause headaches, nausea, vomiting or even visual disturbances. In some cases, individuals may also feel dizzy and fall if they stand up quickly due to low blood pressure.

It is important to note that some people may feel painful sensations if they have tumors inside their brain tissue. These people should see a doctor and get a detailed examination.

What causes it?

The cause of pilomatricoma is not yet known, however the process begins during fetal development. Almost all embryos have three parts to their brains – the forebrain, midbrain and hindbrain. During its development, some of the tissue from the hindbrain is transformed into a different part of the brain known as the CNC. These CNCs then begin to develop into tumors. Normally the process is automatic and each embryo usually forms three small tumors with one inside each hindbrain. In pilomatricoma, only one of these tumors grows out into a larger mass.

Who gets it?

The condition is inherited and almost always affect men and women equally. It is also rare with only a few dozen cases ever reported throughout history. Most of the time, the tumors are not cancerous although in some cases they can be.

Diagnosis and treatment

The CNCs are usually located at the base of the skull and control some of the fundamental functions such as heartbeat, breathing and even movements such as blinking and swallowing. Usually the tumors are benign and do not need to be treated. However, there have been cases where pilomatricomas are cancerous and in these cases the mass must be removed as soon as possible.

Treatment usually involves surgery to remove the tumor. During the procedure, only part of the skull is removed and after recovery most people feel almost the same as before the operation. They may however experience fatigue due to loss of bone marrow during surgery.

After surgery, the patient is usually prescribed painkillers and if necessary antidepressant medication. They will normally be told to avoid activities which may cause head injury or concussion such as sports.

The future:

Currently, there is no known cure for pilomatricoma syndrome. However, ongoing research should shed more light on this rare condition as well as similar conditions in the future.

If you, or someone you know is suffering from pilomatricoma, please see a doctor as soon as possible.

Please be sure to share this article with your friends and family so that they may also be aware of the condition.

Sources & references used in this article:

Morphological stages of pilomatricoma by S Kaddu, HP Soyer, S Hödl, H Kerl – The American journal of …, 1996 – journals.lww.com

Pilomatricoma of the head and neck: a retrospective review of 179 cases by MY Lan, MC Lan, CY Ho, WY Li… – … of Otolaryngology–Head …, 2003 – jamanetwork.com

Malignant pilomatricoma by MG Wood, B Parhizgar, H Beerman – Archives of dermatology, 1984 – jamanetwork.com

Giant pilomatricoma by GP Lozzi, HP Soyer, J Fruehauf… – The American journal …, 2007 – journals.lww.com

The common ultrasonographic features of pilomatricoma by JY Hwang, SW Lee, SM Lee – Journal of ultrasound in …, 2005 – Wiley Online Library

Pilomatricoma with a bullous appearance by S Inui, R Kanda, S Hata – The Journal of Dermatology, 1997 – Wiley Online Library