Hashimoto thyroiditis (HT) is a chronic autoimmune thyroid gland inflammation  it considered the most common endocrine disorder  and the most common cause of hypothyroidism .
In this study, we retrospectively studied 96 pathologically proved cases of Hashimoto thyroiditis (8% males & 92% females, main age 36 year) & compared them with 100-control case (32% males & 77% females: main age 39 year). We reported that HT is significantly more common in females. This was similar to many previous studies [8, 15, 16].
About 8% of cases (8 of 96) are below 20 years, four of them below 15 years. This matches with studies done by Januś et al. , Zdraveska et al. , Zois et al. , all reported that prevalence of chronic type of autoimmune thyroiditis has been assessed as 4–9.6% in adolescents.
Regarding laboratory assessment of study cases, we reported that most of cases (44%) were hypothyroid, (35%) euthyroid & 21% hyperthyroid. The majority of cases being in hypothyroidism state matches what stablished about HT to be the most common cause of hypothyroidism [2, 16, 20]. In study done by Staii et al.  they reported that only 6% of HT cases showed clinical hypothyroidism and 46% of HT cases show euthyroid, compared to only (36%) of our study cases, this could be explained by in cases showing euthyroidism with extra-thyroid manifestations, clinicians not frequently refer them for thyroid ultrasound.
Sonographic features of Hashimoto thyroiditis are established & discussed in many studies [8, 14, 15, 21]. These features include enlarged thyroid gland, parenchymal micronodularity, parenchymal septations, parenchymal hypo-echogenicity, surface Undulation as well as altered vascularity.
We used these sonographic criteria in our study to compare patients with HT & control cases. In the present study, Thyroid gland’s sonographic parenchymal abnormalities (septations, undulation of gland surface & micronodularity) were significantly higher in Hashimoto cases compared to control group. Parenchymal hypo echogenicity & undulation of thyroid gland margin were the most sensitive sonographic signs seen in about 72% of studied cases (69/96) followed by Parenchymal micronodularity seen in about 71% (68/96). Parenchymal septations seen only in 50% of cases (48/96). The least sensitive sign is the presence of sizable nodule seen only in 24% of cases (23/96). This was comparable to study done by Patel et al.  who reported that parenchymal heterogeneity and diffuse hypoechogenicity were the most sensitive sonographic features of HT.
In our study, about 73% of cases show parenchymal hypo echogenicity “47% grade 1 & 25% grade 2.” This matches with Pedersen et al. , Schiemann et al.  and Loy et al. , Who reported a strong relationship between gland hypoechogenicity and HT. According to their studies, parenchymal hypoechogenicity is an index reflecting the degree of gland autoimmune involvement. We support this theory as well as it may be due to element of gland fibrosis secondary to chronic inflammatory process.
In current study TSH level was significantly higher in cases with grade 2 parenchymal echogenicity compared to cases with grad 0 (normal echogenicity) as well as control group. This matches with what reported by Loy et al. , who reported that hypothyroid patients have significantly lower parenchymal echogenicity compared with euthyroid healthy group.
Regarding the enlarged para tracheal lymph nodes, it was significantly high in HT group compared to control group, however it found only in 27% of cases of HT. this mismatches with what reported by SERRES-CRE ´IXAMS, et al.  who found that PLNs were seen in 184 of 199 patients in cases with auto-immune thyroiditis group (about 95%). We found that presence of PLNs is strongly suggestive of HT but not frequently seen, this may be due to increased incidence of PLNs in other autoimmune thyroiditis other than HT, which not included in our study. In our reported cases with PLNs, TSH level was significantly higher compared to cases with normal PLNs & control group.
The thyroid gland vascularity was significantly higher in cases of HT (about 58% of cases have increased vascularity) on Doppler study. In such cases, TSH & T4 levels were significantly higher compared to cases with average vascularity. This means that vascularity is increased in cases with hyper & hypothyroidism compared to euthyroid cases but not specific to one of them, this was similar to study done by Acar et al.  who found that the thyroid gland vascularity was higher in patients with hyperthyroidism and in the patients in the hypothyroid state.
Regarding sizable thyroid gland nodules, we reported only 23 cases (24% of cases) having sizable nodules. Four per cent of these nodules (1 cases/23) pathologically proved to be malignant (papillary carcinoma) and remaining 22 cases classified according to TIRADS classification (6 cases TIRADS 2, 15 cases TIRADS 3 and 1 case TIRADS 4) this may be partially matches with study done by Anderson et al.  who reported that 16% only of thyroid nodules in HT were malignant (papillary carcinoma & lymphoma). It also partially similar to study done by Patel et al.  who reported that most malignant nodules were papillary carcinoma (89% of all malignancies), yet no matches with them in reporting that (44% of cases with nodules) were malignant, but this may be caused by their study group were suspected to have malignancy from the start. Additionally, our study lake of histopathological examination for nodules subjected by TIRADS classification to follow-up not biopsy. On follow-up (22 from 22 cases) show stationary course.
Limitation of our study was the small sample size & being single centre study.