Low VHL mRNA Expression is Associated with More Aggressive Tumor Features of Papillary Thyroid Carcinoma

Alterations of the von Hippel-Lindau (VHL) tumor suppressor gene can cause different hereditary tumors associated with VHL syndrome, but the potential role of the VHL gene in papillary thyroid carcinoma (PTC) has not been characterized. This study set out to investigate the relationship of VHL expression level with clinicopathological features of PTC in an ethnically and geographically homogenous group of 264 patients from Serbia, for the first time. Multivariate logistic regression analysis showed a strong correlation between low level of VHL expression and advanced clinical stage (OR55.78, 95% CI 3.17-10.53, P<0.0001), classical papillary morphology of the tumor (OR52.92, 95% CI 1.33-6.44, P=50.008) and multifocality (OR51.96, 95% CI 1.06-3.62, P=50.031). In disease-free survival analysis, low VHL expression had marginal significance (P=50.0502 by the log-rank test) but did not appear to be an independent predictor of the risk for chance of faster recurrence in a proportion hazards model. No somatic mutations or evidence of VHL downregulation via promoter hypermethylation in PTC were found. The results indicate that the decrease of VHL expression associates with tumor progression but the mechanism of downregulation remains to be elucidated

Thermal analysis and thermodynamic prediction of phase equilibria in the ternary Au-Ga-Sb system

Phase transition temperatures of the selected samples with compositions along isopleths: GaSb-AuGa2, GaSb-AuGa, Au-GaSb, Sb-AuGa, GaSb-Au0.3333Sb0.6667 and Ga-Au0.5Sb0.5 were measured using differential scanning calorimetry (DSC). Experimentally determined phase transition temperatures were compared with the results of thermodynamic calculation. Also, predicted phase equilibria at room temperature were compared with the literature experimental data

Expression of <i>VHL</i> in thyroid cancers and its association with clinicopathological parameters.

<p>*P values less than 0.05 were considered significant, according to the Fisher's exact test for categorical data or Mann-Whitney test for continuous variables.</p><p>Expression of <i>VHL</i> in thyroid cancers and its association with clinicopathological parameters.</p

Baseline, cancer and treatment characteristics.

1<p>T category was not available in 15 cases. ²N category was not available in 20 cases. ³M category was not available in 5 cases. ⁴Tumor size was not available in 11 cases. ⁵Histopathological variant was not available in 1 case. ⁶Follow-up data were available for 159 patients. ⁷15 patients (75%) have shown recurrence to the regional or local lymph nodes, and 5 (25%) have demonstrated recurrence to distant organs such as the lung, bone, and brain. ⁸Radioiodine ablation was done only in 10.6% of patients due to limited availability of this treatment modality in the country at that time.</p><p>Baseline, cancer and treatment characteristics.</p

Disease-free survival of PTC patients with low <i>VHL</i> expression.

<p>Patients with low <i>VHL</i> expression had marginal significance (<i>P</i> = 0.0502 by the log-rank test) but did not appear to be an independent predictor of the risk for chance of faster recurrence in a proportion hazards model (<i>P</i>>0.9).</p

Unilateral follicular variant of papillary thyroid carcinoma with unique <it>KRAS</it> mutation in struma ovarii in bilateral ovarian teratoma: a rare case report

<p>Abstract</p> <p>Background</p> <p>Struma ovarii (SO) is a rare form of ovarian mature teratoma in which thyroid tissue is the predominant element. Because of its rarity, the differential diagnosis between benign and malignant SO has not been clearly defined. It is believed that malignant transformation of SO has similar molecular features with and its prognosis corresponds to that of malignant tumors originating in the thyroid.</p> <p>Case presentation</p> <p>We report 35-year-old woman with bilateral ovarian cysts incidentally detected by ultrasound during the first trimester of pregnancy. Four months after delivery of a healthy child without complication she was admitted to the hospital for acute abdominal pain. Laparoscopic left adnexectomy was performed initially in a regional hospital; right cystectomy was done later in a specialized clinic. Intraoperative frozen section and a final pathology revealed that the cyst from the left ovary was composed of mature teratomatous elements, normal thyroid tissue (>50%) and a non-encapsulated focus of follicular variant of papillary thyroid carcinoma (PTC).</p> <p>Normal and cancerous thyroid tissues were tested for <it>BRAF</it> and <it>RAS</it> mutations by direct sequencing, and for <it>RET/PTC</it> rearrangements by RT-PCR/Southern blotting. A <it>KRAS</it> codon 12 mutation, the GGT → GTT transversion, corresponding to the Gly → Val amino acid change was identified in the absence of other genetic alterations commonly found in PTC.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first time this mutation is described in a papillary thyroid carcinoma arising in struma in the ovarii. This finding provides further evidence that even rare mutations specific for PTC may occur in such tumors. Molecular testing may be a useful adjunct to common differential diagnostic methods of thyroid malignancy in SO.</p