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The month of November is dedicated to raising awareness about carcinoid tumors, the most common type of neuroendocrine tumors. These solid masses develop when highly specialized neuroendocrine cells (nerve cells that respond to certain signals by releasing hormones into the blood) begin to grow and divide uncontrollably. The resulting accumulation of cells can bind together and form a hormone-producing (functional) or non-hormone-producing (nonfunctional) tumor, which may be benign or cancerous.

Carcinoid tumors can form in the gastrointestinal tract, lungs or thymus. Because these masses typically grow very slowly, symptoms usually do not become apparent for several years. Oftentimes, the condition is diagnosed incidentally during the evaluation of an imaging study that was ordered for an unrelated reason, such as suspected appendicitis.

In general, carcinoid tumor symptoms occur only if hormones produced by a tumor are filtered into the blood through the liver. The signs, which can vary based on a tumor’s cellular makeup and the types of hormones released, may include:

  • Unexplained weight gain
  • Abdominal pain or fullness
  • Gastrointestinal distress
  • Severe diarrhea
  • Shortness of breath
  • Wheezing
  • An accelerated heartbeat
  • Fatigue
  • Flushing (redness) or a feeling of warmth in the face or neck
  • Swelling of the feet or ankles

Because carcinoid tumors are relatively rare, many people are unaware of the condition and its symptoms. In November, you are reminded that you can make a difference by simply spreading the word. Take some time to talk with your family members and friends about carcinoid tumors. You might also choose to “show your stripes” by wearing a zebra-striped awareness ribbon, which you’ll probably find is a great conversation piece.

You might be wondering why the zebra was chosen to promote carcinoid tumor awareness. Here’s the story behind it: While studying in medical school, many students are told, “When you hear hoof beats, think horses, not zebras.” In other words, physicians are taught to focus on the most likely possibilities, rather than the unusual ones, when making a diagnosis. However, in some situations, it is appropriate to look for a “zebra,” such as a rare carcinoid tumor. The zebra-stripe serves as a bold reminder of that fact to everyone.

At Moffitt Cancer Center, we’re proud to join in the mission of awareness, education, support and advocacy for patients who are diagnosed with carcinoid tumors. If you have questions or are experiencing possible symptoms, the experts in our Gastrointestinal Oncology Program can help. You can request an appointment with or without a referral by calling 1-888-MOFFITT or completing a new patient registration form online.