Ultrasonographic assessment of the thyroid gland structure in inflammatory bowel disease patients

The etiopathogenesis of inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), is still not fully elucidated and seems to be multifactorial. It has been suggested that genetic, immunological and environmental factors participate in IBD development. IBD extraintestinal manifestations include rheumatic, metabolic, dermatologic, ophthalmologic, hepatobiliary, pancreatic, urologic, pulmonary, neurological, hematological and thromboembolic complications. Thyroid gland diseases have not been confirmed as extraintestinal manifestations of IBD. However, it is known that some thyroid diseases share an immunological background with IBD, and that dysfunction of the thyroid gland may induce gastrointestinal symptoms. Ultrasound examination is the gold standard for evaluation of thyroid gland morphology.

This study was designed to assess the prevalence of abnormalities in the structure of the thyroid gland in IBD patients and to compare it to the control group.

The study group consisted of 199 consecutive IBD patients (80 CD patients and 119 UC patients) hospitalized at the Department of Gastroenterology and Hepatology of Wroclaw Medical University (Poland). The control group consisted of 42 healthy volunteers and patients with functional gastrointestinal disorders.

The most common finding in the ultrasound examination in IBD patients were tumors. Tumors, which were smaller than or equal to 10 mm were present in 11.5% of IBD patients; and tumors larger than 10 mm were present in 13.1%. These results show that small tumors (less than 10 mm in diameter) of the thyroid gland are more frequent among patients with CD and UC compared to the control group (p = 0.0001 and p = 0.001, respectively). Additionally, enlargement of the thyroid gland occurs more often in UC patients compared to the control group (p = 0.003). There was no difference in the frequency of thyroid abnormalities between UC and CD patients.

In patients with inflammatory bowel diseases focal lesions relating to tumors of the thyroid gland are more common than in the control group. In patients with ulcerative colitis enlargement of the thyroid gland is more frequent than in the control group. Initial assessments of IBD patients should include ultrasound examinations of the thyroid gland.