Finding a bump on your hand that wasn’t there before can be scary, especially when you don’t know what it is. Thankfully, these bumps, or tumors, are almost never malignant (cancer), although they may not be particularly pleasant. Here’s some information on some of the most common hand tumors.
What are hand tumors?
A hand tumor is an abnormal bump or lump on the hand. The word “tumor” just means “swelling”.
They can vary in size from nigh unnoticeable to much bigger, and can be discolored or painful. A tumor on the skin may appear as a mole or a wart. A tumor on the bone may not appear at all. However, it can still be extremely painful. Luckily, only 1-2% of hand tumors are malignant, so while the bump on your hand may be painful, it probably isn’t cancerous.
The three most common hand tumors are ganglion cysts, epidermal inclusion cysts, and giant cell tumors of the tendon sheath.
A ganglion cyst is the most common type of hand tumor. These cysts most often occur at the top of the wrist, the palm side of the wrist, the base of the finger, and on top of the end joint of the finger, near the finger nail. From the outside, they look like bubbles underneath the skin.
It is unknown what causes ganglion cysts. They appear in patients of all ages equally. There is some speculation that they form due to tendon irritation. Ganglion cysts may grow or shrink in size, or even disappear completely. They may also hurt, but that is not always the case. They may be soft or hard, and may allow light to pass through them, which aids in diagnosis.
Epidermal Inclusion Cysts
An epidermal inclusion cyst (EIC) is a type of hand tumor that resides on or just beneath the skin. They are generally caused by some kind of trauma to the skin, and usually appear on the palm. This trauma can include cuts and puncture wounds, as well as some kinds of piercing. Men are more commonly affected, and while anyone can get an EIC, they are more often seen during middle age. An important thing to note is that while EICs can be caused by trauma to the skin, they may also develop without this factor.
An EIC is formed when the epidermis is pushed into the dermis, creating a cyst (a sac full of fluid). These can range in size from 5 millimeters to a centimeter. They may be raised above the skin and red. Thankfully, EICs are generally not painful or itchy. They are firm to the touch and usually easy to see.
Giant Cell Tumors of the Tendon Sheath
A giant cell tumor of the tendon sheath (GCTTS) is a type of tumor that can be found on the hand or in other joints, especially in the feet. It is generally painless, and is seen more often in women than in men, usually between the ages of 30-50. It is unsure why exactly a GCTTS develops, although it has been theorized that this is due to trauma or infection, to name a couple of ideas. They are, however, most likely linked to degenerative joint disease, also known as arthritis. The GCTTS is firm to the touch and grows slowly in size. Unlike ganglion cysts, you cannot shine a light through the tumor.