ABSTRACT
Background: Diagnosis of thymiditis is rather difficult since it can simulate any other thyroid disease. This study was conducted to determine the clinico-pathological features of thyroiditis and to evaluate the efficacy of the various modalities utilizedfor diagnosis of the disease
Patients and Methods: The study included 59 patients with the clinical diagnosis of thyroiditis. Ten patients had subacute thyroiditis SAT and 49 had chronic thyroiditis [CHT]. Investigations included serum levels of T3, T4 and TSH, anti-chromosomal antibodies [AMA], anti-thyroglobulin antibodies [ATGA], Ultrasonography for the thyroid gland and FNAC. Twenty-four patients improved by conservative treatment while 35 needed thyroidectomy where histopathology for the excised glands confirmed the diagnosis of thyroiditis
Result: The mean age of patients with SAT was significantly lower than that of those with CHT [2813 +/- 5.82 years vs. 44.1 +/- 8.36 years, respectively] [t: 5.62, p=0.002]. Seventy one percent of patients with CHT had concomitant autoimmune disease, and nine of the 10 patients with SAT had history of recent upper respiratory tract infection. There was an obvious tendon; towards hyperthyroidism associated with CHT and towards hyperthyroidism associated with SAT. Both AMA and ATGA were significantly higher in patients with CHT as compared to those with SAT [P<0.05]. Hypoechoic sonographic pattern of the goiters formed the majority in both groups [33/49 and 8/10 for CHT and SAT respectively] [X2=26.612, P<0.001] fNAC could diagnose 30 out of 49 cases of CHT with a sensitivity of 59.2% a specificity of 90%, a positive predictive value of 96.7% and a negative predictive value of 31%. It did not diagnose any of the ten SAT
Conclusions: Diagnosis of thyroiditis requires a high index of suspicion. A history of concomitant autoimmune disease could associate CHT. An upper respiratory tract infection nay well precede a SAT. CHT is associated with a significant rise of AMA and ATGA. Hypoechoic sonographic petten is found in a significant number of patients with thyroiditis. FNAC is specific yet insensitive test for the diagnosis of thyroiditis