Signs and Symptoms of Gastrointestinal Carcinoid Tumors

Carcinoid tumors have always seemed to me as having a weird spelling. It made my fingers itch to take up the medical dictionary (because, I am old school kid and don’t believe in Google) and find out the origin of the word. I never did (a good, solid reason to use Google is the profound layer of laziness that coats my neurons deeply and wholly). Carcinoids are weird, nonetheless. It is essentially an enigmatic group of tumors that characteristically secretes Serotonin; a chemical, formed in our body. Serotonin is a neurotransmitter (this is where the blog goes all Greek and Latin) which is mainly involved in keeping you happy (I would like to be more technical here and state that Serotonin precisely prevents depression rather than giving a kick). So, you can assume it is the Happiness Hormone, just like Oxytocin, which is the Love Hormone.

Clinical Manifestations of Gastrointestinal Carcinoid Tumors

I know what instantaneously sprouts into one’s mind:

if serotonin is the Happiness hormone, and we are getting loads of it, should we not feel ripples in our fat laden tummies with frequent paroxysms of laughter? The answer is no, because life has an incorrigible habit of handing us stale lemons we can’t make lemonade of. Gastrointestinal Carcinoid tumors cause weird symptoms in the body, and definitely not cause hysterical joy in a sane human.

A Brief Pathos-mechanism

Note: I know readers will willfully shoot me for coming up with incomprehensible and utterly useless obsession with explaining why a disease occurs, I will simply go on and keep doing it. It is a shame though, that I can’t be shot online (much to my delight and your despair).

In parts of gut, some tumors develop that have weird properties (pathologists like to complicate their lives by calling them Neuroendocrine tumors) and start emitting Serotonin (also known as 5-hydroxytryptamine, which is a monoamine neurotransmitter). These travel to all the organs via blood and cause symptoms. Also, they cause a clinical picture very similar to Niacin Deficiency (Niacin is a vitamin, technically known as Vitamin B3), since the tumor cells use up all the niacin, provided by the body to make serotonin. Niacin deficiency is known as pellagra, and interestingly, causes skin lesions in the form of a necklace!

Symptomatology of Gastrointestinal Carcinoid

  • Diarrhoea:

This and more diarrheas! This is a bad, intractable diarrhea that is secretary in nature. Patients have about a liter of diarrhea a day (imagine that!) it is difficult to appreciate the effect it has on quality of life when you do not have such persistently nasty bowel motion all day, but the patient can feel his/her quality of life drastically plummeting.

  • Flushing:

Carcinoid’s hallmark is flushing, along with the bowel motion. Patients often have a sudden, deep red flush of the face and neck. It often is, associated with a feeling of warmth over the same area. These episodes are more marked and frequent when the patient takes Serotonin rich food such as banana, cheese or alcohol; or SSRI (which is a group of drugs specifically used to increase the levels of Serotonin) for Clinical Depression.

  • Another very weird symptom of Carcinoid is wheeze and asthma-like features. It is caused by serotonin working on smaller airways and causing bronchoconstriction. It is pretty weird, like, “Hey! I am a tumour in your gut, but will make funny musical sounds in your lungs, and won’t let you breathe peacefully.”


  • Pellagra:

like skin lesions like scaly skin and the necklace shaped hyperpigmentation of the neck occur in some patients. Pellagra is principally a deficiency of Vitamin B3 (huh, I have already stated that fact, right!) and causes symptoms like Dermatitis, Dementia, Diarrhoea. I know it seems pretty weird- like Pellagra decided to causes only symptoms stating from the alphabet D.

  • Abdominal pain:

It  is one infrequent symptoms, and is one of the vaguest and nonspecific one. So, patients who generally come with chief complaint of abdominal pain (although others symptoms must be present, too), the diagnosis is usually, delayed a bit.


  • Heart murmurs:

Of all complicated matters of the heart, murmurs are the most convoluted. the great solace to a patient is that they never have to find their murmur (am being plain insensitive to patients here? Like hey, you have got a carcinoid tumour and a heart murmur, but you should revel in the fact that you don’t have to listen to your heart squeaking and make a diagnosis!!). Heart is involved, and sometimes the patient may feel palpitations and a sense of impending doom. It is scary, nonetheless. Symptoms occur due to inflammation of the heart, thanks to the outpouring of all the Serotonin from the tumor.


  • The most significant of all test that your doctor is going to run is a 24 hour urinary 5-HIAA excretion. This essentially is due to increased serotonin, which will eventually get, converted to the 5-Hydroxy Indole Acetic Acid (now, I very well know that I just spelled out a name you will surely never need, or remember, because I like to complicate lives, thank you).

How inconvenient can life get when you have to store all the urine you pass out in a day. People have been doing research to find out if a lesser amount can also provide the same result. It becomes easy for the patient and the pathologist. Imagine having a 2-liter bottle on your desk, filled with someone’s urine.

  • Your doctor might need to run other tests, specially an ECHO to rule out any cardiac lesions.
  • Mostly, your doctor will search for signs of serotonin excess in your body.


  • Life is better with a carcinoid tumour (my humour is so basic!).
  • Most carcinoids are amenable to surgical resection. Even if they are not, plenty of drugs in the market can do away with the excess serotonin, and you can be grateful to Pharma industry then.
  • You should know the symptoms of the syndrome, be a smart human and see a physician early.


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