Hi everyone. Today I want to talk about growths on the skin that are not necessarily skin cancer, but are related to cancers on your internal organs.
Many diseases, such as high cholesterol or diabetes, can have manifestations on the skin. Sometimes, cancer of the internal organs can have skin manifestations as well. I want to briefly touch on a few of these to show how your skin can reflect what is going on inside your body.
Tumors that grow on any internal organ can spread to the skin, either by direct invasion of the skin or through the bloodstream. Skin metastases occur in up to 5% of cancer patients. These lesions usually appear on the skin as firm, hard nodules. They may be flesh colored or may have a reddish to black appearance. By the time the cancer has spread to the skin, the prognosis is usually poor because if you're seeing signs of the cancer on your skin, it has most likely spread to other organs as well. The trunk and scalp are the most commonly affected areas (rarely do you find the metastases on your arms and legs).
In women, breast cancer is the most common internal cancer that is metastatic to the skin. In many cases, it is from the direct extension of the breast cancer to the chest wall and through the skin. In these cases, one or several firm nodules may be found. If surgery has been performed for the breast cancer, these skin tumors can appear near the incision sites. Breast cancer is also associated with several specific red rash-like lesions that can emerge on the chest. One type, termed "carcinoma erysipelatoides" looks like a superficial skin infection with redness and warmth that occurs on the breast. Another is called "Paget's disease" and this appears as a one sided scaliness and dryness of the skin near and around the nipple. It is often confused with eczema and is usually diagnosed as such before the breast cancer is discovered.
Cancers of the gastrointestinal tract can also be associated with certain skin growths. Seborrheic keratoses are benign growths on the skin that can at times look like melanoma. Tthese growths are benign and are extremely common - many people have dozens of them on their body. The "Sign of Leser-Trelat" is the sudden appearance of many (dozens) of these seborrheic keratoses in a matter of days to weeks. In this case, the growths are associated with several different types of cancer, particularly cancer of the stomach. Another finding associated with stomach cancer is known as the "Sister Mary Joseph Nodule", which is a tumor found near the belly button that indicates an aggressive underlying stomach cancer. (This is named after the nurse who over 100 years ago made the wise observation that patients with a specific nodule near the belly button usually had stomach cancer).
Another internal cancer that shows up on the skin is leukemia. Signs of leukemia are multiple flesh-colored to red nodules on the skin known as "leukemia cutis." It is important to note, though, that these skin findings can rarely be found before the leukemia has fully developed. In a specific type of leukemia, one may develop green colored papules on the skin. These are known as "chloromas."
There are many other examples of skin tumors and rashes that indicate internal cancer or disease and I hope that this brief discussion allows you to see that your skin may reflect more about you than what is just "skin deep." These conditions I have mentioned are very rare and while I encourage you to see your local dermatologist with any concerns, I do not want this discussion to alarm anyone into thinking that a new growth on their body indicates a deeper cancer! Just be aware that you can at times learn about your overall health from your skin.