Lump on the arm: Should I worry?

Q: I am a 35-year-old man with a painless lump on my right forearm. I have had it for about five years now and it is slowly increasing in size (it is currently the size of a marble). A doctor reviewed it several months ago and suggested that I have it removed. A second doctor was of the opinion that I apply a ‘watch and wait’ approach—suggesting that I only intervene if it begins to give me problems. Recently, my cousin was diagnosed with sarcoma of the leg and is at risk of getting his leg amputated. He told me that he had a lump on his thigh for six months and had ignored it thinking it was just a lump of fat. The diagnosis of cancer was a shock to him and all of us. I am now a worried man. Could this lump also be a sarcoma? Should I get it urgently removed? Do I risk losing function of my hand after surgery?

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The diagnosis of cancer in a family tends to cause us to worry. Sarcoma refers to a soft tissue cancer that can affect muscles, fat, cartilage, tendons, vessels and connective tissue. Some bone cancers are also referred to as sarcomas. They tend to be aggressive tumours and need prompt treatment for best outcome.

Although there is a genetic element that predisposes one to get these cancers, the fact that your cousin has a sarcoma does not mean with that you also have the same condition.

I would suggest that you go back for a review. A doctor will then assess the physical characteristics of the lump and see if it affecting the function or blood supply to the hand. Do an ultrasound for the doctor to see what the lump looks like on the inside.

If there are concerns for invasion of the lump into tissues deep in the arm, there may be need for other scans such as MRI. In some cases, a biopsy is needed to confirm diagnosis. A biopsy is a procedure in which a small specimen is taken from the lump and assessed under a microscope before it is removed.

If a lump is small and has no worrisome features on imaging, it can be removed without a biopsy.

That said, all lumps (once removed), must be taken to the lab for comprehensive assessment.

Which lumps need to be removed?

• Lumps that are increasing in size
• Painful lumps
• Lumps that are affecting the function of the hand
• Lumps that are compressing nerves or blood vessels
• Lumps that are suspicious for cancer
• Lumps that are causing cosmetic concerns

During removal of a lump, does one need numbing of the whole arm?

Usually, no. In most cases, numbing the skin around the lump is sufficient to allow for its painless removal. The only time numbing the whole limb or general anaesthesia is required is when removing large or deep lumps that may have invaded other tissues.

Does the doctor need to remove healthy tissue together with the lump?

Removal of healthy tissue surrounding a lump is only done in cancer cases.

In this case, it is important that you do not leave microscopic deposits of cancer in the tissues. This can only be achieved if you remove some healthy surrounding tissue. In lumps that are not cancerous, you only need to remove the tissue forming the lump and leave the healthy tissue around it intact.

Does removal of a lump lead to loss of function of the affected limb?

Usually, no. Only cancerous lumps that require aggressive surgery have the possibility of leading to some degree of loss of limb function.

What are the common complications of lump removal ?

The most common complication is infection at the site of surgery. Rarely, allergies to the solution used to clean the skin may occur.

What are the most common types of lumps in the arm?

Non-cancerous soft tissue tumours like lipomas (lumps consisting primarily of fat) Cysts (these are usually non-cancerous: most common sub-types are the sebaceous and epidermoid) Infections like boils/abscesses (these are usually short-lived, painful and cause warmth and redness in the skin. Treatment is draining the abscess and antibiotics) Traumatic swellings (after injury) Skin manifestation of arthritis like gouty tophi Skin cancer (more common in Caucasians but can occur in any race) Soft tissue cancers (sarcomas)