ACTA ENDOCRINOLOGICA (BUC)

Context. Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer due to its high fibrotic content; it can affect the blood flow resistance. Objective. To introduce duplex Doppler ultrasonography (DDUS) parameters of papillary thyroid carcinoma (PTC) and their correlation with size. Design. The study was designed as a prospective study. Subjects and Methods. Thyroid nodules of the patients who were already scheduled for thyroid surgery either for malignant thyroid nodules or multinodular goiter were evaluated for DDUS parameters. Size, systolic to diastolic flow velocity (S/D) ratio, pulsatility index (PI), and resistive index (RI) of each nodule were recorded. Nodules were diagnosed as PTC or benign nodules based on histopathology. DDUS parameters were compared between PTCs versus benign nodules and micro PTCs (≤ 10 mm) versus large PTCs (> 10 mm). A correlation analysis was performed between the size and DDUS parameters. Results. 140 thyroid nodules (30 PTCs, 110 benign nodules) were obtained. The mean S/D ratio, PI, and RI values were significantly higher in PTC than in benign nodules (p values were 0.0001, 0.0003, and 0.0001 respectively). The optimal cut-off values of S/D (0.732), PI (0.732), and RI (0.738) had accuracy rates of 71%, 69%, and 69%, respectively. There was no statistically significant difference between micro PTC and large PTC with regards to DDUS parameters. The size and DDUS parameters of PTC showed no significant correlation. Conclusions. PTC has a high resistive flow pattern regardless of its size; however the clinical utility of DDUS to differentiate a PTC from benign nodule is limited.

When the laboratory results are not compatible with the clinical features of the patient, the presence of assay interference should be considered. Patient and Methods. Here, we report a case of macro-thyroid stimulating hormone (macro-TSH) in a 31 yearold woman who had hypothyroidism due to thyroidectomy as well as discordant TSH levels with the clinical findings. Her TSH level was spuriously high with low levels of free T3 and T4 on levothyroxine treatment and she had only mild fatigue. To screen for the presence of interference, we performed TSH measurements in different platforms and serial dilution of the sample. Her rheumatoid factor was found to be negative. Results. The testing for heterophile blocking and non-specific anti TSH antibodies suggested lack of interference. We did further test for the clinical suspicion of interference and TSH decreased to 29.8 μIU/mL from 210.5 μIU/mL (recovery: 14.1%) after polyethylene glycol (PEG) precipitation indicating the existence of macro-TSH. After two months of increased dosage of levothyroxine, her TSH level was still very high (192.0 μIU/mL), but free T3 and free T4 increased to normal levels. PEG precipitation test was reperformed and TSH was decreased to 46.0 μIU/mL from 192.0 μIU/mL (recovery: 24.0 %). Her levothyroxine replacement dosage was not increased since free T3 and T4 levels were normal. Conclusions. If there is a suspicion for the discordant TSH level, the presence of macro-TSH by PEG precipitation should be investigated even though first step investigations for interference were found to be negative.

Context. Thyroid incidentaloma is a common disorder in endocrinology practice. Current literature regarding the risk of thyroid cancer in incidentalomas found in patients with non-thyroid cancer is limited. Objective. The aim of the present study was to investigate the frequency of thyroid malignancy in thyroid incidentalomas detected in patients with non-thyroid cancer. Design. Case control study. Subjects and Methods. The database of 287 thyroid nodules from 161 patients with a history of nonthyroid cancer followed between 2008 and 2014 were retrospectively evaluated. Results. From 287 thyroid nodules, 69.7 % had a benign final cytology. Thyroid cancer detected in one nodule while follicular neoplasia detected in 4 nodules, atypia of unknown significance (AUS) detected in 10 nodules, Hurthle cell neoplasia detected in 5 nodules and suspicious for malignancy detected in 6 nodules according to fine needle aspiration biopsy results. Metastasis of the non-thyroid cancer to the thyroid gland was detected in 4 nodules. Twenty seven nodules from 15 patients were removed with surgery. There were 3 malignant nodules found after surgery (1 papillary, 1 follicular and 1 medullary cancer). In addition to these three thyroid cancers, two patients with benign nodules had co-incidental thyroid cancer detected after surgery. Finally, 11.1 % of thyroid nodules which underwent thyroid surgery had malignant histopathology except for co-incidental and metastatic cancers. Conclusions. The frequency of thyroid malignancy seems not to be substantially increased in incidental thyroid nodules detected in patients with non-thyroid cancer when these patients were evaluated in nodule-based approach.

Objective. Ectopic posterior pituitary gland (EPP) is usually characterized by an abnormal pituitary stalk and hypoplasia of the anterior hypophysis. The genetic mechanisms involved in the development of EPP remain uncertain. The aim of this study is to determine whether mutations in the three genes, PROP-1, LHX2, and POU1F1, are associated with the risk for and the characteristics of EPP. Methods. In the Endocrinology Outpatient Clinic of “Dr. Behcet Uz” Children’s Hospital, 27 patients with EPP were submitted to sequencing analyses of the PROP-1, LHX2, and POU1F1 genes. Results. Growth hormone, thyrotropin, corticotropin, gonadotropin, and vasopressin deficiency were observed in 22 (81.5%), 23 (85.2%), 17 (63%), 14 (51.9%), and two (7.4%) patients. Thirteen patients (48.1%) presented with hyperprolactinemia. Fourteen patients (51%) had a history of birth dystocia, and 12 cases (42.1%) had a history of breech presentation. Central nervous system abnormalities included five cases with corpus callosum agenesis, one case with schizencephaly, and one case with Chiari type 1 malformation. We identified a homozygous p.S109* mutation in exon 2 in one male patient with EPP and two different PROP1 gene polymorphisms (A142T or c.109+3 G>A polymorphism) in thirteen patients. Conclusions. Our results suggest that PROP1 gene abnormalities might explain the genetic mechanisms involved in the development of EPP.

Introduction. Our goal was to evaluate and compare the diagnostic utility of thyroid hormone withdrawal (THW) and recombinant thyroid-stimulating hormone (rhTSH) methods in detecting recurrence/persistence (R/PD) of differentiated thyroid carcinoma (DTC). Methods. The study included 413 patients with DTC who underwent total thyroidectomy and had remnant ablation. DxWBS, s-Tg levels, R/PD were evaluated retrospectively. A s-Tg level≥2 ng/mL was considered as “positive s-Tg”. Results. DxWBS and s-Tg levels were evaluated with rhTSH in 116 and THW in 297 subjects, respectively. The sensitivity and specificity of “positive s-Tg” for R/PD in THW group were 77.3% and 92.7%, with 90.3% accuracy, respectively. The sensitivity and specificity of “positive s-Tg” for R/PD in rhTSH group were 58.8% and 100% with 93.9 % accuracy, respectively. An uptake outside thyroid bed at WBS showed a sensitivity of 17.1%, specificity of 100% for R/PD with 89.4% accuracy in THW group. An uptake outside thyroid bed at WBS showed a sensitivity of 7.7%, specificity of 100% for R/PD with 88.8% accuracy in rhTSH group. Conclusion. Method of TSH stimulation did not influence the reliability of DxWBS. The “positive s-Tg level” had a higher sensitivity with THW when compared to rhTSH in detecting R/PD.