Some clinical aspects in chronic autoimmune thyroiditis associated with thyroid differentiated cancer

The coexistence of Hashimoto's thyroiditis (HT) with differentiated thyroid cancer (DTC) was reported with a heterogeneous incidence. The wide distribution of this association may be related to differences in the level of morphological examination, autoimmunity used criteria, patient selection, surgical indication, genetic background, geographical and environmental factors.Some consider the coexistence of these two entities a coincidental one, others suspecting a causative link between these conditions.

This retrospective paper included 216 patients with HT, issued from an iodine-replete area. 21 cases of nodular HT were investigated by means of: thyroid functional tests (TFT), immunological determinations, thyroid ultrasonography (US) and cytological analysis.ALL CASES WERE OPERATED BECAUSE OF DIFFERENT REASONS: compressive symptoms and signs, suspicious sonographic features and certain cytological smears (malignant, indeterminate and non-diagnostic).

The morphologic investigation revealed 9 patients with DTC and 12 cases with benign thyroid disease (BTD).None of the US analyzed characteristics provided sufficient accuracy for the diagnosis of DTC in cases with HT. The preoperative cytological examination by means of fine-needle-aspiration biopsy (FNAB) showed a better sensitivity and specificity vs. US criteria.

The coexistence of HT with DTC represents a clinical reality with yet unknown significance. The difficulty of diagnosis imposes the corroboration of different types of investigations. The best diagnostic accuracy seems to be offered by thyroid US and thyroid cytological investigation.