Browsing by Author "Yamashita, Shunichi (35392475600)"

A growing body of evidence suggests a role of the von Hippel–Lindau (VHL) tumor suppressor gene in the progression of papillary thyroid carcinoma (PTC). Our previous study of VHL in PTCs showed that lower VHL expression was associated with aggressive tumor features, but we found no evidence for VHL downregulation through common genetic or epigenetic modifications. Several studies pointed to a role of microRNA-92a (miR-92a) in the regulation of VHL expression in different cancers. In the present study, we examined the expression levels of VHL mRNA and miR-92a in 42 pairs of PTCs and matched non-tumor thyroid tissues by means of quantitative RT-PCR. We explored the correlation between them and their association with clinicopathological parameters. The results revealed that both VHL and miR-92a were either up- or downregulated in PTCs compared to corresponding non-tumor tissues. On univariate analysis, lower VHL levels were significantly associated with extrathyroid spread (P = 0.022) and capsular invasion (P = 0.032). Multivariate analysis confirmed the association of low VHL with extrathyroid spread (OR 0.246, 95% CI 0.069–0.872, P = 0.038). Higher miR-92a among PTC tissues associated with the presence of nodal metastases (univariate analysis: P = 0.012; multivariate: OR 4.703, 95% CI 1.109–19.938, P = 0.036). A negative correlation between VHL and miR-92a was observed in a subgroup of PTCs having vascular invasion (P = 0.033, r = − 0.673). The data here reported demonstrate that the expression of both VHL and miR-92a is deregulated in PTC tissues and that in some PTCs they may have opposite roles. These roles, as well as their diagnostic and/or prognostic utility, remain to be clarified. © 2017, Springer Science+Business Media, LLC, part of Springer Nature.

A growing body of evidence suggests a role of the von Hippel–Lindau (VHL) tumor suppressor gene in the progression of papillary thyroid carcinoma (PTC). Our previous study of VHL in PTCs showed that lower VHL expression was associated with aggressive tumor features, but we found no evidence for VHL downregulation through common genetic or epigenetic modifications. Several studies pointed to a role of microRNA-92a (miR-92a) in the regulation of VHL expression in different cancers. In the present study, we examined the expression levels of VHL mRNA and miR-92a in 42 pairs of PTCs and matched non-tumor thyroid tissues by means of quantitative RT-PCR. We explored the correlation between them and their association with clinicopathological parameters. The results revealed that both VHL and miR-92a were either up- or downregulated in PTCs compared to corresponding non-tumor tissues. On univariate analysis, lower VHL levels were significantly associated with extrathyroid spread (P = 0.022) and capsular invasion (P = 0.032). Multivariate analysis confirmed the association of low VHL with extrathyroid spread (OR 0.246, 95% CI 0.069–0.872, P = 0.038). Higher miR-92a among PTC tissues associated with the presence of nodal metastases (univariate analysis: P = 0.012; multivariate: OR 4.703, 95% CI 1.109–19.938, P = 0.036). A negative correlation between VHL and miR-92a was observed in a subgroup of PTCs having vascular invasion (P = 0.033, r = − 0.673). The data here reported demonstrate that the expression of both VHL and miR-92a is deregulated in PTC tissues and that in some PTCs they may have opposite roles. These roles, as well as their diagnostic and/or prognostic utility, remain to be clarified. © 2017, Springer Science+Business Media, LLC, part of Springer Nature.

Thyroglossal duct cyst (TDC) carcinoma is a comparable rare entity and treatment strategies have not been standardized. Here, we report a favorable outcome of TDC carcinoma patients based on our therapeutic strategy. Twelve patients with TDC carcinoma treated in our department from 1986 to 2012 were enrolled. Ten patients underwent Sistrunk's procedure in other institutions and referred to our institution for re-operation after the diagnosis of TDC carcinoma and the remaining two underwent initial surgery in our institution. Eleven patients were diagnosed as papillary and one as follicular carcinoma originating from TDC. We performed total thyroidectomy for 11, and limited thyroidectomy for one patient. Three patients (25%) had carcinoma lesions in the thyroid. We routinely dissected level I bilaterally and 6 of 11 patients (55%) with papillary carcinoma-type TDC carcinoma had metastasis. Level II/III nodes were biopsied and if positive, we performed level II-IV dissection. Of the 5 patients positive for level II/III, 2 were also positive for level IV. For the 3 patients with synchronous carcinoma in the thyroid, we performed level VI dissection and two had metastasis in this level. To date, 1 patient showed a recurrence to the lung, but none of the patients in our series died of carcinoma. For surgery of TDC carcinoma, Sistrunk's procedure, total thyroidectomy with level I dissection is mandatory. Whether level II-IV dissection is performed depends on pathology of biopsied level II/III nodes. Level VI dissection is also recommended especially when carcinoma lesions are pre/intra operatively detected in the thyroid. ©The Japan Endocrine Society.

Thyroglossal duct cyst (TDC) carcinoma is a comparable rare entity and treatment strategies have not been standardized. Here, we report a favorable outcome of TDC carcinoma patients based on our therapeutic strategy. Twelve patients with TDC carcinoma treated in our department from 1986 to 2012 were enrolled. Ten patients underwent Sistrunk's procedure in other institutions and referred to our institution for re-operation after the diagnosis of TDC carcinoma and the remaining two underwent initial surgery in our institution. Eleven patients were diagnosed as papillary and one as follicular carcinoma originating from TDC. We performed total thyroidectomy for 11, and limited thyroidectomy for one patient. Three patients (25%) had carcinoma lesions in the thyroid. We routinely dissected level I bilaterally and 6 of 11 patients (55%) with papillary carcinoma-type TDC carcinoma had metastasis. Level II/III nodes were biopsied and if positive, we performed level II-IV dissection. Of the 5 patients positive for level II/III, 2 were also positive for level IV. For the 3 patients with synchronous carcinoma in the thyroid, we performed level VI dissection and two had metastasis in this level. To date, 1 patient showed a recurrence to the lung, but none of the patients in our series died of carcinoma. For surgery of TDC carcinoma, Sistrunk's procedure, total thyroidectomy with level I dissection is mandatory. Whether level II-IV dissection is performed depends on pathology of biopsied level II/III nodes. Level VI dissection is also recommended especially when carcinoma lesions are pre/intra operatively detected in the thyroid. ©The Japan Endocrine Society.

Background: 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.Case presentation: 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).Normal and cancerous thyroid tissues were tested for BRAF and RAS mutations by direct sequencing, and for RET/PTC rearrangements by RT-PCR/Southern blotting. A KRAS 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.Conclusion: 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. © 2012 Stanojevic et al.; licensee BioMed Central Ltd.

Background: 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.Case presentation: 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).Normal and cancerous thyroid tissues were tested for BRAF and RAS mutations by direct sequencing, and for RET/PTC rearrangements by RT-PCR/Southern blotting. A KRAS 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.Conclusion: 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. © 2012 Stanojevic et al.; licensee BioMed Central Ltd.