1/22. Epstein-Barr virus-associated leiomyosarcoma of the thyroid in a child with congenital immunodeficiency: a case report.We report an unusual case of multifocal leiomyosarcoma involving the thyroid gland, liver, and right lung in a child with congenital immunodeficiency disease. The smooth muscle nature of these neoplasms was confirmed by immunohistochemistry and electron microscopic studies. in situ hybridization showed large amounts of Epstein-Barr virus messenger rna within the tumor cells. Although Epstein-Barr virus-associated smooth muscle tumors have been reported in children with AIDS and after organ transplantation, we are unaware of any case report in congenital immunodeficiency disease.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/22. Involvement of the HMGI(Y) gene in a microfollicular adenoma of the thyroid.Follicular thyroid adenomas are epithelial tumors characterized by subgroups with specific chromosomal aberrations. Here we present a case with translocation t(1;6)(p35;p21). In 1p35 and 6p21, two genes of the high-mobility group of proteins are located. With P1-derived Artificial Chromosome (PACs) derived from the HMG17 gene located at 1p35 and HMGI(Y) located at 6p21, fluorescence in situ hybridization was performed. The breakpoints were located distal to HMG17 and proximal to HMGI(Y), but no rearrangement of the genes was shown by FISH. However, an overexpression of the HMGI(Y) gene was detected by RT-PCR as well as by immunohistochemistry techniques. This suggests a breakpoint in the proximity of the HMGI(Y) deregulating HMGI(Y) gene expression, a situation found in a variety of human benign mesenchymal tumors with involvement of chromosome band 6p21.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/22. Translocations (X;10)(p22;q24) and (1;10)(q21;q11) in a follicular adenoma of the thyroid without apparent involvement of the RET protooncogene.We report here the cytogenetic analysis of a follicular adenoma of the thyroid which revealed an abnormal clone with a t(X;10)(p22;q24) and a t(1;10)(q21;q11) together with normal cells. fluorescence in situ hybridization (FISH) with YACs 273E3 and 344H4, which are located on 10q11.2 and are specific for the RET protooncogene, showed no abnormalities. It would therefore appear that this gene is not involved in the particular tumor, as has been reported in a number of papillary thyroid carcinomas. Several chromosomal aberrations have been suggested as been specific for follicular thyroid adenoma. However, until now, only a few such cases have been reported which involve structural abnormalities of chromosomes 10q11.2 and 10q24. We believe this to be the first report of a follicular thyroid adenoma with a t(X;10)and a t(1;10).- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/22. Balanced translocation (3;7)(p25;q34): another mechanism of tumorigenesis in follicular thyroid carcinoma?Alterations of 3p are the most frequently observed changes in follicular thyroid carcinomas. Loss of 3p25-pter has been speculated to be a critical event in the malignant transformation of a subset of thyroid follicular neoplasms. The present report describes a minimally invasive follicular thyroid carcinoma (FTC) with a balanced t(3;7)(p25;q34) and dic(15;22)(p11;p11) as the only abnormalities. The alterations were present in all metaphases analyzed and were demonstrated by G-banding, spectral karyotyping (SKY), and fluorescence in situ hybridization (FISH). This study represents the second case of FTC where 3p25 is involved in a balanced translocation. The findings support the existence of a gene locus in this region which is involved in the tumorigenesis of thyroid carcinoma.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/22. Structural and numerical aberrations of chromosome 22 in a case of follicular variant of papillary thyroid carcinoma revealed by conventional and molecular cytogenetics.This study reports a case of papillary carcinoma with vesicular components showing multiclonal aberrations of chromosome 22 as revealed by RHG-banding cytogenetics and by fluorescence in situ hybridization (FISH; whole chromosome 22 and BCR-ABL-specific locus probes, multi-FISH). Four clones with chromosome 22 changes as the sole abnormality were seen. The main abnormal clone lacked the whole chromosome 22. A del(22)(q11) was observed in a second group of cells. The third clone had an idic(22). Finally, FISH revealed a fourth abnormal cell population with a der(17)t(?17;22). Some of these chromosome 22 alterations have been described in other solid tumors such as meningiomas and neurinomas, suggesting a common genetic pathway of tumor progression occurring in a multistep process. Chromosome 22 changes do not seem to be involved in pure papillary thyroid tumors and therefore could be related to the maintenance of a follicular-type histological pattern.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/22. A novel chromosomal translocation t(3;5)(q12;p15.3) and loss of heterozygosity on chromosome 22 in a multifocal follicular variant of papillary thyroid carcinoma presenting with skin metastases.Classic genetic rearrangements in papillary carcinoma of the thyroid involve the RET- or TRK proto-oncogenes. We report a novel chromosomal translocation t(3;5)(q12;p15.3), confirmed by fluorescence in situ hybridization, in a multifocal follicular variant of a papillary carcinoma of the thyroid in a 79-year-old woman, with skin metastases as a presenting symptom. Three years earlier, another cutaneous metastasis on her scalp was misdiagnosed as hidradenoma. Four tumour foci were recognized in the thyroid, two with a follicular variant of papillary carcinoma. To detect loss of heterozygosity, 14 chromosomes were investigated with 59 microsatellite markers. A clonal relationship was detected between the two foci of tumour in the thyroid gland containing follicular variant of papillary carcinoma and one of the skin lesions tested, all demonstrating loss of heterozygosity (LOH) in the same region of chromosome 22. Based on earlier reports, the low rate of LOH detected is in agreement with the diagnosis papillary carcinoma of the thyroid. Whole body scintigraphy performed after ablative therapy with radioiodine revealed multiple metastases in the lungs and skeleton. After repeated radioiodine therapy, thyroglobulin under thyroxine suppression became undetectable and post-therapeutic scintigraphy revealed important regression of metastases.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/22. Significance of trisomy 7 in thyroid tumors.Standard cytogenetic studies of a multifocal metastasizing papillary thyroid carcinoma revealed two clonal chromosome aberrations: rearranged 10q and trisomy 7. trisomy 7 seemed to be restricted to tumor nodule A, whereas era (10q) was detected in tumor nodule B and in a metastatic lymph node. We applied fluorescent in situ hybridization to ask whether trisomy 7 was a feature of the original tumor nodule or an in vitro phenomenon changing quantitatively during early passages and to see whether trisomy 7 was restricted to tumor nodule A. We used the biotinylated chromosome 7 alpha-satellite probe D7Z1 on freshly dropped slides from metaphase harvests from tumor nodule A,B, and the lymph node and on touch preparations from the frozen specimen of tumor nodule A. trisomy 7 was present in the original tumor nodule (6% of cells), as well as in early passages (P1-3) from both tumor nodules and the metastatic lymph node with a frequency of 10.7-13.2%. The detection of trisomy 7 as a stable component in short-term cell culture and its presence in the original tumor material indicates that this common numerical aberration is an in vivo phenomenon.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/22. Cushing's syndrome due to medullary thyroid carcinoma: diagnosis by proopiomelanocortin messenger ribonucleic acid in situ hybridization.Medullary thyroid carcinoma (MTC) rarely causes ectopic ACTH syndrome. We describe a 38-yr-old man with renal stones who had a 5-cm MTC removed in 1992. He was RET-protooncogene positive (codon 618). serum calcitonin was 1597 pg/ml postoperatively. In 1996 he had rib fractures, bruising, weakness, and three to four stools per day. Laboratory studies revealed an elevated 24-h urine-free cortisol (780 micro g/d), epinephrine (66 micro g/d), and calcium (558 mg/d). Baseline serum cortisol was 23.9 micro g/dl and decreased to 12.9 and 4.5 micro g/dl after 2 mg and 8 mg dexamethasone suppression, respectively. plasma ACTH was 170 pg/ml and decreased to 75 and 24 pg/ml after dexamethasone. bone density t-score was -4.3 (trochanter). Computed tomography scans showed multiple cervical nodes and 2-cm right adrenal nodule. magnetic resonance imaging (MRI) scan showed a prominent, homogeneous pituitary; the adrenal MRI scan was not typical for a pheochromocytoma. serum CRH was less than 6.6 pg/ml. Bilateral adrenalectomy revealed two adjacent right adrenal pheochromocytomas and corrected the elevated urine cortisol (30 micro g/d), epinephrine (0 micro g/d), and calcium (281 mg/d) but not plasma ACTH (125 pg/ml). neck dissection reduced calcitonin by 96% (5300 to 120 pg/ml) and ACTH by 91% (125 to 11 pg/ml). carcinoembryonic antigen was reduced from 32.0 to 2.3 ng/ml. Immunohistochemical stain was negative for ACTH in the MTC-positive lymph nodes and the pheochromocytoma. Proopiomelanocortin mRNA by in situ hybridization was positive in the MTC but not in the pheochromocytoma. A repeat pituitary MRI scan was normal. The differential diagnosis of ACTH-dependent Cushing's syndrome in this case included pituitary disease or ectopic ACTH, either from medullary thyroid carcinoma or pheochromocytoma. ACTH stains were unrevealing, but proopiomelanocortin mRNA in situ hybridization in MTC tissue and plasma ACTH response to neck dissection confirmed MTC as the source of ectopic ACTH.- - - - - - - - - - ranking = 6keywords = hybridization (Clic here for more details about this article) |
9/22. Thyrotoxic adenoma followed by atypical hyperthyroidism due to struma ovarii: clinical and genetic studies.OBJECTIVE: Atypical forms of hyperthyroidism represent a diagnostic challenge for clinicians. struma ovarii is an ovarian teratoma and constitutes a rare cause of ectopic thyroidal hormonal production. We describe a case of struma ovarii that combined two different sources of hyperthyroidism in the same patient and report genetic studies in order to contribute a better understanding of the autonomy and tumorigenesis of the struma ovarii. CASE REPORT: A 73-year-old nulliparous woman presented a thyroid toxic adenoma that was successfully treated with 10 mCi radioiodine. Unexpectedly, a new onset of hyperthyroidism prompted us to look for a second etiology. A whole-body scan with (123)I detected a pelvic hyperfixation suggesting struma ovarii, and a thyroid differentiated left ovarian teratoma 3 cm in size was surgically removed. We screened for mutations of thyroid-stimulating hormone receptor and Gs-alpha protein genes, as these mutations are common in thyroid adenomas. We did not identify any mutations. Androgen receptor study demonstrated a monoclonal status. comparative genomic hybridization did not reveal any chromosomal abnormality. However, loss of heterozygosity analysis showed several structural abnormalities, compared with the majority of benign ovarian teratomas, which show a normal karyotype. CONCLUSIONS: This is the first well-documented report of thyrotoxic struma ovarii revealed after treatment of a single thyroid toxic adenoma. We have shown in this case that struma ovarii originates from a single germ cell, and, albeit benign, this tumor presents several chromosomal abnormalities. struma ovarii-induced hyperthyroidism is likely to be mediated by mechanisms different from those of the classical thyroid toxic adenoma.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/22. Metastatic follicular carcinoma associated with hyperthyroidism.PURPOSE: A 68-year-old man with metastatic follicular thyroid carcinoma had T3 hyperthyroidism. MATERIAL AND methods: A bone scan showed intense uptake in the thyroid and multiple areas of increased uptake in the skeleton. hyperthyroidism persisted after total thyroidectomy. Treatment with I-131 induced a transient state of euthyroidism lasting approximately 9 months. Further tumor growth and relapse of hyperthyroidism eventually occurred and the patient died 25 months after surgery. Molecular and cytogenetic analyses were performed. RESULTS: No mutations were detected of either of the thyrotropin receptor or of the alpha subunit of the stimulatory guanine-nucleotide-binding proteins. hyperthyroidism was unlikely the result of thyroid-stimulating receptor antibodies. comparative genomic hybridization analysis showed that the tumor was characterized by multiple chromosomal imbalances. CONCLUSIONS: This is an unusual case of follicular thyroid carcinoma with initial high I-131 uptake by the thyroid and bone metastases and concurrent hyperthyroidism. Despite the increased I-131 uptake in the tumor, I-131 treatment only transiently controlled the hyperthyroidism and had no effect on tumor size. The cause of hyperthyroidism remained unknown. T3 predominance was unlikely the result of type 2 deiodinase overexpression because loss of genetic material was demonstrated at chromosome 14 long arm, where type 2 deiodinase is mapped.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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