The word “tumor,” which entered medical terminology and everyday use from Latin, literally means swelling. Abnormal swellings and masses in the hand, whether benign or malignant, are called hand tumors. The majority of hand tumors are benign. Tumors in the hand can appear as warts or moles on the skin, or as masses originating from soft tissue or bone under the skin.

The most common masses seen in the hand are ganglion cysts (Figure 1). These cysts are sacs containing gelatinous material. While usually seen in the wrist, they can originate from tendon sheaths and pulleys in the fingers.

The second most common tumor is the giant cell tumor. These masses are hard and may be lobulated. They can occur anywhere, but are most commonly seen around the tendon sheath. They are benign and slow-growing tumors. Another common tumor is epidermal inclusion cysts. These are benign tumors that originate from under the skin after cuts and injuries. Skin cells normally secrete a protective, thick substance called keratin. During skin shedding due to environmental factors, new skin cells replace the dead ones. If skin cells remain under the skin (after cuts, skin damage), they begin to produce keratin and multiply as if skin shedding were occurring. Dead skin cells and keratin form a cystic structure under the skin. The cyst grows due to increased keratin production and an increase in dead cells. This is called an inclusion cyst.

Benign tumors such as lipomas (benign sebaceous cysts), neuromas (nerve ending tumors), nerve sheath tumors, fibromas, nail bed tumors (glomus tumors), and hemangiomas (tumors formed from capillary tangles – Figure 2) are frequently encountered in the hand. Masses may be seen due to bone spurs caused by arthritis and trauma. Swelling may occur due to foreign body reactions.

When patients feel a lump in their hand, they wonder whether it is malignant or benign. Malignant cancers are rare in the hand. Most lumps are benign. The most common malignant tumors are skin cancers such as squamous cell carcinoma, basal cell carcinoma, and melanoma. Other malignant tumors are sarcomas of bone and soft tissue. Sarcomas have a rapid spreading characteristic. They most frequently metastasize to the lungs. Distant metastasis from other areas can occur in the hand. Even if most are thought to be benign, a sample should be taken from all lumps in the hand for pathological examination.

When evaluating lumps in the hand, examinations such as direct radiography, CT (computed tomography), and MRI (magnetic resonance imaging) can be performed after a physical examination. Generally, if the tumor is not very large, the procedure performed is total removal of the lump. In general, complete removal of the lump provides sufficient treatment. Some lumps in the hand have a recurrent nature. Therefore, maintaining regular records of every tumor surgically removed and sending them for pathological examination is crucial for postoperative follow-up.