Background: No consensus exists on the association betweenHashimoto's thyroiditis (HT) and cancer. To resolve this controversy, this review aimed to evaluate the relationship between the two conditions.
Methods:Using pub-med database, we searched studies relevant to the topic focusing on the association between HT and papillary thyroid cancer (PTC), as well as the association between HT and primary thyroid lymphoma (PTL).Findings: Both HT and PTC are common worldwide, and the two conditions may be closely related. However, the relationship remains controversial. Some studies found that PTC coexisted with HT 2.8-fold more frequently, with variable prevalence ranging from 0.5 to 30%. In contrast to surgical and pathological series that suggested a positive correlation between the two diseases and even a cause-and-effect relationship, the other studies evaluating fine-needle aspirate specimens did not find a statistically significant correlation. On the other hand, the relationship between PTL and HT appears well established.
Conclusion:The existing data provide inconsistent evidence favoring a causal relationship between HT and PTC. Prospective studies are needed to further elucidate the relationship. However patients with HT are at risk for PTL. Therefore careful observation and follow-up of HT patients is recommended.