Clinical utility of fine needle aspiration cytology for thyroid lesions with emphasis on hashimoto´s thyroiditis

الملخص EN

Background Hashimoto´s thyroiditis (HT) is the commonest form of thyroiditis.

Clinically, the main manifestations are goiter and hypothyroidism.

Thyroid ultrasonography (US) does not correlate well with histopathologically findings.

Aim : the present work was to correlate clinical, US, hormonal status of the thyroid, to fine needle aspiration cytology (FNAC) status of the thyroid gland in HT Methods : the study was carried out on a total of 350 patients presented with thyroid disease.

Specifically, out of 350 FNAC reports for these patients, the files of 30 patients (24 women and 6 men, with a mean age of 47 ±12 years) with a definitive diagnosis of HT, were reviewed. Results : this study included 350 cases with thyroid lesions.

The cytological diagnoses included unsatisfactory diagnosis, benign thyroid nodules and colloid cystic nodules, De Cur van's thyroiditis, HT, suspicious cases and malignancy.

Clinically, out of 30 patients with HT, 24 (80%) had diffuse goiter, 4 (13%) patients had multi nodular goiter (MNG), and 2 (7%) had single thyroid nodule.

Twenty three (77%) patients with HT presented clinically with manifestations of hypothyroidism, or presented with euthyroid state on levothyroxine therapy. US examination of the thyroid gland revealed that 12 (40%) patients had MNG.

Also, we found that, 16 (35%) patients with diffuse goiter had hypo echogenicity on US examination, the majority [13 (43%) patients] of those had diffuse homogenous hypo echogenicity (DHOE), and the minority [3 (10%) patients] had diffuse heterogeneous hypo echogenicity (DHEE).

The efficacy of the FNAC technique in the current study was 88%, 98%, 100%, 100%, and 98% for sensitivity, negative predictive value (NPV), specificity, positive predictive value (PPV) and accuracy, respectively Conclusions: Clinical examination alone of the thyroid gland may miss the detection of thyroid nodules in patients with nodular HT, in about Two thirds of patients, compared with US examination of the thyroid gland.

Also, the presence of DHOE of the thyroid gland by US suggests the presence of hypothyroidism.

HT may not uncommonly present with MNG or even rarely as a single thyroid nodule. FNAC allows prompt identification of HT (with diffuse or nodular lesions), obviating unnecessary surgery in the majority of cases, and excluding carcinoma in the presence of MNG or adenoma in patients with single thyroid nodule.