Thyroid cancer in HCV-related mixed cryoglobulinemia patients

Objective. The prevalence of thyroid cancer in a series of unselected HCV-related mixed cryoglobulinemic patients was investigated in comparison with a control group. Methods. Among 107 consecutive patients with mixed cryoglobulinemia (MC), 94 were eligible for the study. A control group was obtained from a sample of the general population (2,401 subjects), age > 50 years, who had undergone thyroid ultrasonography (582 subjects); 5 sex-matched controls were randomly assigned to each MC patient (470 individuals). The mean age was similar in the MC patients and controls (64.2 +/- 10.0 vs. 63.4 +/- 7.0). Results. The prevalence of thyroid nodules was higher, although not significantly so, in control subjects than in MC patients (65.3 vs. 54.8%). Two patients with papillary thyroid cancer were found in the MC series, while no case was observed among controls (p = 0.001, chi-square P value; p = 0.02, Fisher's exact test). In both MC patients with papillary thyroid cancer lymphocytic infiltration was observed in the thyroid tissue. Conclusions. The possible association between HCV-related MC and thyroid cancer indicates that a careful monitoring of the thyroid would be opportune during the clinical follow-up of HCV-associated MC patients, especially in those with signs of thyroid autoimmune disorders.