Thyroid cancer is a rare type of cancer that affects the thyroid gland, a small gland at the base of the neck. The most common symptom of cancer of the thyroid is a painless lump or swelling that develops in the neck. Other symptoms only tend to occur after the condition has reached an advanced stage including this gastrointestinal symptom to be aware of.
In a study published in Karger, diarrhoea as an initial presentation in patients with thyroid cancer was analysed.
Tumoral secretion of various molecular factors, such as calcitonin, can cause diarrhoea in patients with medullary thyroid cancer, reported the study.
It added: “Two patients with elevated calcitonin had no diarrhoea.
“The link between tumour humoral secretion and diarrhoea is not well established in patients with thyroid cancer.
“Diarrhoea is more common in patients with metastatic disease and improves after resection of the tumour.
“Diarrhoea may result from elevated circulating levels of calcitonin or other substances, such as prostaglandins or serotonin.
“Other proposed mechanisms include decreased absorption in the colon secondary to gastrointestinal motor disturbances.
“In conclusion, thyroid cancer should be considered when evaluating chronic diarrhoea.”
Chronic diarrhoea is when symptoms last for more than four to six weeks.
One case study found a 36-year-old male with no notable medical history who started with diarrhoea with three to four stools a day, some during the night, without blood, mucus or pus.
He had no abdominal pain, nausea, vomiting or fever.
On physical examination, his abdomen was soft, non-tender and with no palpable masses or organomegaly.
A broader study was ordered including an abdominal ultrasound.
A CT scan of the chest and abdomen was performed with the scan showing liver nodules, osteoblastic bone lesions and a thyroid nodule, all of which is indicative of a neuroendocrine tumour.
Each year, around 2,700 people are diagnosed with thyroid cancer in the UK.
It’s most common in people aged 35 to 39 years and in those aged 70 years or over.
Women are two to three times more likely to develop thyroid cancer than men.
The reason for this is unclear but it may be a result of the hormonal changes associated with the female reproductive system.