Increased expression levels of tensin3 mRNA in thyroid functional adenomas as compared to non-functioning adenomas

Tensin3 is a member of tensin family which is localized in focal adhesion. In our previous study, a high level of tensin3 mRNA expression was observed in the thyroid but not in other tissues, thus, tensin3 gene was regarded as a novel thyroid-specific gene. The high expression level of tensin3 mRNA in normal thyroid tissue suggests some fundamental roles in thyroid functions. In fact, the expression level of tensin3 mRNA was low in most thyroid carcinomas and non-functioning thyroid follicular adenomas which do not produce thyroid hormone. In the present study, we measured the expression levels of tensin3 mRNA in twelve functional adenomas and compared the results with those in normal thyroid tissues, adenomatous goiters and non-functioning thyroid follicular adenomas. Tensin3 mRNA was expressed abundantly in all twelve functional adenomas at almost the same level as in normal thyroid tissues and adenomatous goiters, while its expression was significantly lower in non-functioning follicular adenomas. Considering these facts, an abundant expression of tensin3 mRNA is observed in tissues that produce thyroid hormone, which suggests some fundamental roles in basic thyroid functions.

Expression of S100A2 and S100A6 in thyroid carcinomas

AIMS

S100 calcium-binding proteins are known to play multiple roles in carcinoma development. In this study, we focused on two kinds of these proteins, S100A2 and S100A6, and investigated their expression in thyroid neoplasms.

METHODS AND RESULTS

We investigated S100A2 and S100A6 expression in 141 thyroid neoplasms by immunohistochemistry. S100A2 was not expressed in normal follicles or follicular tumours, with one exception. Although 89.5% of papillary carcinoma were positive for S100A2, the expression was heterogeneous except in two cases. In anaplastic carcinoma, 78.5% of cases expressed S100A2 diffusely, while the remaining cases were negative. In normal follicles, S100A6 expression was always low, while 8.3% of follicular adenomas and 39.5% of follicular carcinomas showed increased expression. In papillary carcinomas, S100A6 expression was increased in 75% of cases, but in anaplastic carcinomas it was decreased, with only 14.3% showing high expression.

CONCLUSIONS

The expression patterns of S100A2 and S100A6 in thyroid neoplasms are unique compared with those of other carcinomas, suggesting that: (i) S100A2 and S100A6 contribute to certain events in papillary carcinoma progression, and (ii) S100A2 expression is one of the biological characteristics of anaplastic carcinoma.

Tie-1 tyrosine kinase expression in human thyroid neoplasms

AIMS

To investigate tie-1 expression in human thyroid neoplasms. Recent studies have demonstrated that receptor-type tyrosine kinases (RTKs) contribute to carcinoma progression. Tie-1 is one of the RTKs and plays a role in angiogenesis, although its pathophysiological significance in human carcinoma is still to be elucidated.

METHODS AND RESULTS

Immunohistochemical expression of tie-1 was studied in various thyroid neoplasms. Tie-1 immunoreactivity was only occasionally observed in normal follicular cells. In papillary carcinoma, tie-1 was classified as positive in carcinoma cells in 55.7% of the cases and was more frequently expressed in those of smaller size with an absence of a poorly differentiated lesion. In contrast, tie-1 was positive in only 8.3% of anaplastic carcinoma and no cases of follicular carcinoma or adenoma were positive.

CONCLUSIONS

These results suggest that tie-1 has a role in thyroid tumorigenesis, especially in the early phase of papillary carcinoma, but it is not important in the progression of anaplastic carcinoma or follicular tumour.

Lower concentration of serum soluble CD8 in severe Hashimoto's disease

To investigate the roles of soluble CD4 (sCD4) and CD8 (sCD8) in the severity of autoimmune thyroid diseases, we examined serum concentrations of sCD4 and sCD8 in various degrees of severity of Hashimoto's disease (HD) and Graves' disease (GD) by enzyme immunoassay. The serum concentration of sCD8 was lower in euthyroid patients with HD undergoing treatment for hypothyroidism (severe HD) than in untreated, euthyroid patients with HD (mild HD), but the sCD4 concentration did not differ between patients with severe and mild HD. The serum sCD8 concentration was negatively correlated with the proportion of CD25(+) cells in CD8(+) cells in patients with severe HD. Serum sCD4 and sCD8 concentrations did not differ between euthyroid patients with GD in remission and those with intractable GD. These results indicate that serum sCD8 is involved in the severity of HD, possibly by down-regulating the function of cytotoxic T cells.

Decrease of CD154 intensity on peripheral CD4+ T cells in autoimmune thyroid disease

To clarify immunological differences among patients with Graves' disease (GD) and Hashimoto's disease (HD) at various levels of severity, we examined the expression of the CD154 molecules on peripheral T cells, which regulate B cell activation, B cell differentiation, and T-cell survival. We found decreases in the intensities of CD154 on peripheral CD4(+) cells from euthyroid patients with GD and HD, but we did not find any differences between patients with different disease severities. CD8(+) cells did not express CD154 molecules. Thus, CD154 expression on CD4(+) cells may be related to the pathogenesis of the autoimmune thyroid diseases, not to the disease severity.

PGP9.5 mRNA could contribute to the molecular-based diagnosis of medullary thyroid carcinoma

The protein gene product 9.5 (PGP9.5) is a ubiquitin hydrolase that is widely expressed in neuronal tissues at all stages of neuronal differentiation and is a known neuroendocrine marker. Medullary thyroid carcinoma (MTC) arises from parafollicular cells and is reported to overexpress several mRNAs such as RET, calcitonin, and CEA. These markers are thought to be useful in determining a molecular-based diagnosis of MTC. We examined the expression levels of PGP9.5 mRNA in 80 thyroid tissues using real-time quantitative reverse transcription (RT-PCR) and found that PGP9.5 mRNA was overexpressed in all 11 MTCs examined, both hereditary and sporadic, but not in other histological tumour types. Furthermore, by RT-PCR, PGP9.5 mRNA was detected only in aspirates from three medullary carcinomas, and not in aspirates from other tumour types. These results demonstrate that, in addition to the expression of RET, calcitonin and CEA, PGP9.5 mRNA expression may contribute to the molecular-based diagnosis of MTCs.

Polo-like kinase 1 overexpression is an early event in the progression of papillary carcinoma

Polo-like kinase 1 (PLK1) is one of the serine threonine kinases that contributes to cell mitosis and is regarded as a marker of cellular proliferation. However, its protein expression in human carcinoma has not been studied in depth. We investigated PLK1 expression in various thyroid neoplasms in order to elucidate its physiological significance in thyroid carcinoma. Normal follicular cells only occasionally expressed PLK1. In follicular tumours and anaplastic carcinoma, PLK1 overexpression was not a common event and only 5.9% of follicular adenoma, 7.1% of follicular carcinoma, and 11.8% of anaplastic carcinoma overexpressed this protein. However, 43.7% of papillary carcinoma overexpressed PLK1. Polo-like kinase 1 overexpression was more frequently observed in smaller papillary carcinoma lesions, and 62.5% of microcarcinoma (ranging from 4 mm to 1.0 cm) and even 66.7% of incidental carcinoma (less than 4 mm) overexpressed it, whereas this phenomenon could only be seen in 20.0% of lesions larger than 4.0 cm. Furthermore, PLK1 overexpression was not related to cell-proliferating activity evaluated by Ki-67 labelling index, but it was inversely linked to UICC stage, extrathyroidal invasion, and the presence of poorly differentiated lesion as proposed by Sakamoto et al. These findings strongly suggest that, unlike other carcinomas previously studied, PLK1 does not act as a cell cycle regulator but plays a constitutive role in papillary carcinoma especially in the early phase, and may contribute to the malignant transformation of this carcinoma.

Syndecan-1 expression in thyroid carcinoma: stromal expression followed by epithelial expression is significantly correlated with dedifferentiation

AIM

To investigate the expression of syndecan-1 in thyroid neoplasia. Syndecan-1 is a proteoglycan regulating cell adhesion. Previous studies have demonstrated that decreased expression of syndecan-1 is linked to malignant progression.

METHODS AND RESULTS

Syndecan-1 expression in thyroid neoplasia was studied immunohistochemically. Syndecan-1 was expressed in stromal cells as well as neoplastic epithelial cells. Stromal syndecan-1 expression was observed more frequently in papillary carcinomas larger than 10 mm in size than in microcarcinomas and in widely invasive than in minimally invasive follicular carcinomas. Furthermore, poorly differentiated carcinomas showed this phenomenon more than well-differentiated carcinomas, but the expression in undifferentiated carcinomas was similar to that of poorly differentiated carcinomas. Epithelial syndecan-1 expression was more frequently observed in anaplastic (undifferentiated) carcinomas than in papillary and follicular carcinomas. No significant difference in epithelial expression was found between well and poorly differentiated carcinomas, but undifferentiated carcinomas expressed epithelial syndecan-1 more frequently than did poorly differentiated carcinomas.

CONCLUSIONS

These results are in contrast to those previously reported for carcinomas at other sites. It is suggested that the role of syndecan-1 in thyroid carcinomas might be unique. Stromal syndecan-1 expression followed by its epithelial expression is significantly related to progression, including dedifferentiation of thyroid carcinoma.

Cyclooxygenase-2 expression in thyroid neoplasms

AIMS

Previous studies have demonstrated that cyclooxygenase-2 (COX-2) plays a role in carcinogenesis and carcinoma development. In this study, we investigated its expression in thyroid neoplasms in order to elucidate its role.

METHODS AND RESULTS

COX-2 expression was studied immunohistochemically in 20 anaplastic (undifferentiated) carcinomas, 49 papillary carcinomas, 22 follicular carcinomas and 15 follicular adenomas. Positive staining was only occasionally seen in normal follicles or stromal cells. COX-2 over-expression was found in only 20.0% of follicular adenomas and 40.9% of follicular carcinomas. In papillary carcinomas, the incidence (81.3%) was significantly higher (P < 0.0001) than in follicular carcinomas, although COX-2 expression was reduced in cases with old age (P = 0.0190), large size (P = 0.0028), advanced stage (P = 0.0225), satellite tumours (P = 0.0363), and the presence of solid, scirrhous or trabecular growth patterns (P = 0.0018). Undifferentiated carcinomas less frequently over-expressed COX-2 (P = 0.0004), with an incidence of 40.0%.

CONCLUSIONS

These results indicate that the up-regulation of COX-2 may contribute predominantly in the early phase of papillary carcinoma progression, whereas it plays a more adjuvant role in follicular carcinoma progression.

Expression of cdc25A and cdc25B proteins in thyroid neoplasms

Cdc25B and cdc25A phosphates are prominent stimulators of cell cycle progression and recent studies have also suggested their oncogenic roles. To elucidate the role of these proteins in thyroid neoplasms, we immunohistochemically investigated their expression, and neither protein was expressed in normal follicular cells. Cdc25B was frequently overexpressed in follicular adenoma and minimally invasive follicular carcinoma, but the incidence was significantly lower in widely invasive follicular carcinoma. Furthermore, the cdc25B expression level significantly decreased with the dedifferentiation of thyroid carcinoma. Cdc25A overexpression was observed in high incidences in all types of thyroid neoplasms. These results suggest that cdc25B and cdc25A play oncogenic roles in thyroid follicules and that cdc25B works predominantly in the early phase of the progression of thyroid carcinoma, whereas cdc25A plays a fundamental role in the development of thyroid neoplasms.

Caveolin-1 overexpression is an early event in the progression of papillary carcinoma of the thyroid

Caveolin-1 is a major structural component of caveolae, which are plasma membrane microdomains implicated in the regulation of intracellular signalling pathways. Previous in vitro and in vivo studies on the function of caveolin-1 in carcinoma showed controversial results, indicating that the physiological role of caveolin-1 varies according to the origin of carcinoma. In this study, we investigated caveolin-1 expression in thyroid neoplasms by means of immunohistochemistry using a rabbit polyclonal antibody against caveolin-1. Normal follicular cells did not express caveolin-1. In papillary carcinoma, caveolin-1 expression was observed in high incidence, and especially in microcancer (less than 1.0 cm in diameter), caveolin-1 was positive in all cases except one. In undifferentiated (anaplastic) carcinoma, its incidence was significantly reduced. On the other hand, all cases of follicular carcinoma and adenoma were classified as negative for caveolin-1. These results suggest that caveolin-1 may play a role predominantly in the early phase of papillary carcinoma, whereas it has little influence on follicular tumours.

DNA sequence of immunoglobulin heavy chain variable region gene in thyroid lymphoma

Patho-epidemiological studies have shown that thyroid lymphoma (TL) develops in thyroid affected by chronic lymphocytic thyroiditis (CLTH). CLTH is categorized as an organ-specific autoimmune disease, in which activated B-lymphocytes secrete a number of autoantibodies. Because antigenic stimulation might be involved in the pathogenesis of TL, the variable region in heavy chain (V(H)) genes was characterized in 13 cases with TL and 3 with CLTH. Clonal rearrangement of the V(H) gene was found in 11 cases of TL, and cloning study with sequencing of complimentary determining region (CDR) 3 revealed the presence of a major clone in 4. Three of the 4 cases used V(H) 3 gene, with the homologous germline gene of V3-30 in two cases and VH26 in one case. A biased usage of V(H) 3 and V(H) 4 genes with the homologous germline gene of VH26 in V(H) 3 gene was reported previously in cases with CLTH. A high level of somatic mutation (1-21%, average 12%) with non-random distribution of replacement and silent mutations was accumulated in all cases. The frequency of the occurrence of minor clones ranged from 29-44% per case, indicating the presence of on-going mutation. DNA sequencing of immunoglobulin V(H) gene suggests that TL develops among activated lymphoid cells in CLTH at the germinal center stage under antigen selection.

Overexpression of kα1 tubulin mRNA in thyroid anaplastic carcinoma

The expression levels of (k)alpha1 tubulin in 84 benign and malignant thyroid tissues were measured by means of real-time quantitative reverse transcription-polymerase chain reaction. An increased expression of (k)alpha1 tubulin mRNA was observed in all of five anaplastic carcinomas and some of the papillary carcinomas. Expression levels of (k)alpha1 tubulin relative to thyroglobulin mRNA were slightly increased in papillary carcinomas and greatly increased in anaplastic carcinomas. Chemotherapeutic agents which are targeted to microtubules may be considered as an alternative choice for the treatment of anaplastic carcinomas and some differentiated carcinomas in which increased expression of (k)alpha1 mRNA is observed.

[Extremely high level of serum thyroglobulin after surgery in a patient with follicular thyroid carcinoma. Recurrence, distant metastasis, or other etiology?]

A 67-year-old female patient with a tumor of the thyroid underwent right lobectomy of the thyroid. The tumor was histologically diagnosed as a follicular carcinoma of the thyroid. Serum studies revealed very high (> 8,000 ng/ml) levels of thyroglobulin after surgery. We suspected distant metastases from follicular carcinoma or recurrence in the left lobe of the thyroid. She therefore underwent left lobectomy of the thyroid. No recurrence of follicular carcinoma was recognized in the resected thyroid tissue, but severe autoimmune thyroiditis was diagnosed histologically. Total-body 131I scintigraphy did not show abnormal distant uptake. Serum studies revealed very low levels of thyroglobulin (< 2.0 ng/ml) after the second surgery. We speculate that silent thyroiditis might have occurred after the first surgery, resulting in the high levels of serum thyroglobulin. Silent thyroiditis should be considered as a possible cause of high serum thyroglobulin levels.

Frequent mutations of Fas gene in thyroid lymphoma

Fas (Apo-1/CD95) is a cell-surface receptor involved in cell death signaling through binding of Fas ligand. Mutation of the Fas gene results in accumulation of lymphoid cells and thus might contribute to lymphomagenesis. Thyroid lymphoma (TL) is supposed to arise from active lymphoid cells formed in the preceding autoimmune chronic lymphocytic thyroiditis (CLTH). We examined the open reading frame of Fas cDNA in 11 cases of CLTH and 26 cases of TL. These patients were admitted to the hospital with varying degrees of goiter. All of the CLTH patients were female, with median age of 65 years, and all but five cases of TL were female, with median age of 61 years. Mutations of the Fas gene were detected in 3 (27.3%) of 11 cases of CLTH and 17 (65.4%) of 26 of TL. The Fas mutations comprised 18 frameshift, 3 missense, and 1 nonsense mutation. Frameshift mutations were caused by insertion of 1 bp (A) at nucleotide 1095 in 10 cases and by lack of exon 8 in 8 cases. The insertion of 1 bp (A) at nucleotide 1095 has never been reported in other kinds of malignancies. Thus, this might be unique in TL and CLTH and might be mutational hotspots in these diseases. All mutations occurred in the cytoplasmic region (death domain) known to be involved in the apoptotic signal transduction and thus could be loss-of-function mutations. These findings suggested that accumulation of lymphoid cells in CLTH with Fas mutation provides a basis for development of TL.

Gene expression profiles in thyroid carcinomas

The gene expression profiles of human thyroid carcinomas were analysed by serial analysis of gene expression (SAGE) which allows quantitative and simultaneous analysis of a large number of transcripts. More than 29,000 transcripts derived from a normal thyroid tissue and four thyroid tumours were analysed. While extensive similarity was noted between the expression profiles of the normal thyroid tissue and three differentiated thyroid tumours, many transcripts, such as osteonectin, a-tubulin, glyceraldehyde-3-phosphate dehydrogenase, glutathione peroxidase, and thyroglobulin, were expressed at extremely different levels in differentiated and undifferentiated carcinomas. These data provide new information that might be used to identify genes useful for the diagnosis and treatment of thyroid carcinomas.

Role of hypermethylation of DAP-kinase CpG island in the development of thyroid lymphoma

Death-associated protein-kinase (DAP-Kinase) is a serine/threonine kinase with a death domain that is involved in apoptosis induced by interferon-gamma, TNF-alpha, and Fas ligand. Epigenetic down-regulation of DAP-Kinase gene expression by hypermethylation of its promoter region was reported in B-cell malignancies. Previous pathoepidemiologic studies indicated that thyroid lymphoma (TL) evolves among active lymphoid cells in chronic lymphocytic thyroiditis (CLTH). With use of methylation-specific polymerase chain reaction, the methylation status of DAP-Kinase CpG island was examined in thyroid lesions of 19 cases with TL and 9 with CLTH. The frequency of methylation was higher in TL cases (16 of 19, 84.2%) than in CLTH cases (2 of 9, 22.2%) (p < 0.01). DNA extracted from peripheral blood leukocytes from TL and CLTH cases never showed methylation, indicating that the methylation occurred somatically in the lesional lymphocytes in thyroid. These findings suggested that methylation of the DAP-Kinase promoter region might be involved in the development of TL from CLTH.

Unilateral surgery supported by germline RET oncogene mutation analysis in patients with sporadic medullary thyroid carcinoma

Compared to hereditary medullary thyroid carcinoma (MTC), sporadic MTC tends to be unicentric and confined to one lobe. Patients with sporadic MTC usually undergo total thyroidectomy because of a possible hereditary or bilateral process. We evaluated the usefulness of germline RET oncogene mutation analysis in surgery for apparently sporadic MTC and performed unilateral surgery on patients without detectable mutation. In 36 patients with a preoperative diagnosis of apparently sporadic MTC, we performed germline RET oncogene mutation analyses: before surgery in 8 recent patients and after surgery in 28 who had been treated before 1996. Of the latter, 5 had bilateral MTC. DNA samples were extracted from their peripheral blood, and the polymerase chain reaction products of the RET proto-oncogene were analyzed using single-strand conformation polymorphism analysis and the direct sequencing methods. Before 1996 we often performed total thyroidectomy but changed to hemithyroidectomy thereafter, except in one patient with associated Graves' ophthalmopathy. Our minimal standard practice included systematic central and ipsilateral neck dissection. The outcome was assessed in terms of gastrin- and calcium-stimulated plasma calcitonin levels. Germline RET mutations were found in six patients. Five of these patients had bilateral MTC, whereas all 30 patients without mutation had unilateral disease. Hemithyroidectomy in seven of our recent patients resulted in normalization of plasma calcitonin levels in all, although four were found to have microscopic lymph node involvement. In conclusion, hemithyroidectomy with systematic central and ipsilateral neck dissection is an appropriate procedure for patients with sporadic MTC without detectable germline RET mutations.

Expression of interleukin-7 and its receptor in thyroid lymphoma

Patho-epidemiological studies have shown that thyroid lymphomas (TL) develop in thyroids affected by chronic lymphocytic thyroiditis (CLTH). Cytokines produced in CLTH might play a pivotal role for lymphomagenesis, because previous reports indicate an important role of cytokines in lymphomagenesis. We examined the expression of interleukin-7 (IL-7), a pleiotropic cytokine that acts mainly on cells of the hematolymphoid system, and IL-7 receptor (IL-7R) in both TL and CLTH by RT-PCR. IL-7-specific transcripts were detected more frequently in TL than in CLTH lesions (p < 0.01). IL-7 expression was higher in TL than in CLTH. IL-7R and the common gamma chain were expressed in all but one TL and in all CLTH lesions, in similar levels. We established the sensitive in situ hybridization (ISH) method for detection of IL-7. ISH for IL-7 revealed cytoplasmic signals among cells in the germinal center and mantle zone of lymphoid follicles and interfollicular areas in the TL and CLTH lesions. In the lymphomatous areas of TL, similar numbers of scattered large and small lymphoid cells expressing IL-7 were found. The number of IL-7-expressing cells counted in 10 fields in TL (119.4 +/- 10.6 cells) was significantly higher than found in CLTH lesions (43.1 +/- 4.6) (p < 0.001). These findings suggest a pathogenetic role for IL-7 in the development of TL. ISH showed that the germinal center cells, interfollicular cells, and lymphoma cells expressed IL-7R, but mantle zone cells did not. Because lymphoid cells in lymphoid follicles and the interfollicular area formed in CLTH expressed IL-7, TL cells might proliferate via their own IL-7 and IL-7R, and via IL-7 from reactive lymphoid cells.

Microsatellite instability and k-ras, p53 mutations in thyroid lymphoma

Patho-epidemiological studies showed that thyroid lymphoma (TL) arises in inflammatory lesions of chronic lymphocytic thyroiditis (CLTH). Replication error (RER) is found in inflammatory lesions and associated cancer, suggesting that chronic inflammation could be a risk factor for neoplastic development through causing RER. To clarify whether RER is involved in the pathogenesis of TL, we examined the microsatellite instability (MSI) in 9 cases with CLTH and 19 with TL, including 10 diffuse large B-cell lymphoma (DLBL), 4 follicle center cell lymphoma, 3 marginal zone B-cell lymphoma of extranodal (MALT) type, and 2 lymphoplasmacytic type. Sixteen distinct microsatellite repeats were analyzed. Mutations of p53 and k-ras genes were also examined. When alterations at 2 or more microsatellite loci were judged as positive, only 5 DLBL cases exhibited MSI. The frequency of MSI in DLBL was significantly higher than that in other types of TL and CLTH (P < 0.05). Four of 19 cases (21.1%) showed point mutation of the k-ras gene. The k-ras mutations occurred in the cases with DLBL with RER, and four of five cases with RER had a k-ras mutation, indicating a close association between RER and k-ras mutation. p53 mutations were not found in the CLTH. Two of 19 TL cases showed mutations of p53 gene. There was no significant association between RER and p53 mutation. These findings indicate that genomic instability contributes to the progression of TL from low grade to high grade, but not to the development of low grade lymphoma in CLTH lesions.

Expression of oncofetal fibronectin messenger ribonucleic acid in fibroblasts in the thyroid: a possible cause of false positive results in molecular-based diagnosis of thyroid carcinomas

Oncofetal fibronectin (onfFN) messenger ribonucleic acid (mRNA) is abundantly expressed in thyroid papillary and anaplastic carcinomas. These carcinomas can be preoperatively diagnosed by the detection of onfFN mRNA in fine needle aspiration biopsies (FNABs). However, previous reports have noted that the expression of onfFN mRNA was observed in 3.7% of the FNABs that were diagnosed as negative cytology. To clarify this discrepancy, we examined the expression of onfFN mRNA in fibroblasts in the thyroid. By RT-PCR and real-time quantitative RT-PCR analyses, we detected a high copy number of onfFN mRNA in cultured fibroblasts obtained from the normal thyroid tissues dissected surgically. Thus, we conclude that the contaminated fibroblasts in FNABs due to tumor necrosis or acute or chronic inflammation may be a cause of false positive results in molecular-based diagnosis of thyroid carcinomas.

Diagnosis of thyroid malignant lymphoma by reverse transcription-polymerase chain reaction detecting the monoclonality of immunoglobulin heavy chain messenger ribonucleic acid

Distinguishing between thyroid malignant lymphoma and lymphocytic thyroiditis (Hashimoto's thyroiditis) is quite difficult and problematic. Molecular techniques to detect clonal lymphoid proliferation based on Ig heavy chain (IgH) gene rearrangement may be used to facilitate more accurate diagnosis of malignant lymphoma. We recently established a method for diagnosing thyroid tumors by analyzing ribonucleic acids (RNAs) extracted from the needles used for fine needle aspiration biopsy (aspiration biopsy-RT-PCR). By applying the aspiration biopsy-RT-PCR method to detection of the monoclonality of IgH messenger RNA (mRNA), an accurate molecular-based diagnosis of malignant lymphoma can be established as an adjunct to cytological diagnosis. We first studied RNAs from fresh tissues samples of 8 cases of Hashimoto's thyroiditis and 18 malignant lymphomas to detect the monoclonality of IgH mRNA by seminested RT-PCR. Monoclonality was detected in 8 of 18 (44.4%) malignant lymphomas, but in none of the 8 cases of Hashimoto's thyroiditis. We then studied aspirates from 10 cases of thyroid malignant lymphoma, 4 cases of Hashimoto's thyroiditis, and 1 case each of adenomatous goiter and papillary carcinoma. Monoclonality was detected in the aspirates from 4 of 10 malignant lymphomas (40%), but not from other tissues. Thus, RT-PCR detection of monoclonality of IgH mRNA in addition to cytological examination may be useful in diagnosing thyroid malignant lymphoma.

Preoperative diagnosis of thyroid papillary and anaplastic carcinomas by real-time quantitative reverse transcription-polymerase chain reaction of oncofetal fibronectin messenger RNA

The restricted expression of oncofetal fibronectin (onfFN) mRNA in thyroid papillary and anaplastic carcinomas was recently reported. In this study, we measured the copy number of onfFN mRNA in RNAs extracted from fine needle aspiration biopsies by real-time quantitative reverse transcription-PCR using thyroglobulin mRNA as an internal control. By measuring the onfFN:thyroglobulin mRNA ratio, preoperative aspirates from 31 papillary carcinomas and an anaplastic carcinoma can be distinguished from those from 5 adenomatous goiters, 5 follicular adenomas, and 4 follicular carcinomas. Thus, quantification of onfFN by real-time quantitative reverse transcription-PCR may be useful for the preoperative diagnosis of papillary and anaplastic carcinomas.

Screening of specific changes in mRNAs in thyroid tumors by sequence specific differential display: decreased expression of c-fos mRNA in papillary carcinoma

To examine the specific changes in gene expression in thyroid carcinomas, we performed sequence specific-differential display (SS-DD) analysis by using a specific degenerate primer for the superfamily of the small G protein. After subcloning and sequencing analysis, one of the genes that showed decreased expression in thyroid papillary carcinomas was revealed to be the proto-oncogene c-fos. Expression of c-fos mRNA in benign and malignant tissues was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blotting. The expression of c-fos was detected in all twelve normal thyroid tissues, whereas it decreased in thirteen of fifteen papillary carcinomas. These results indicate that the increased expression of c-fos mRNA is not necessarily to be an oncogenic feature of thyroid tumors. Further, its constant expression in normal thyroid tissues may play a role in the maintenance of thyroid function.

Rapid screening of specific changes in mRNA in thyroid carcinomas by sequence specific-differential display: decreased expression of acid ceramidase mRNA in malignant and benign thyroid tumors

Sequence specific-differential display (SS-DD) is a powerful method for screening significant changes in gene expression between normal and malignant tissues. Using this method, we detected 3 genes for which the expression is much decreased in thyroid tumors. After sub-cloning and sequencing analysis, one of the genes was revealed to be acid ceramidase (AC). The expression of AC in normal thyroids and thyroid tumors was examined by semi-quantitative reverse-transcription-polymerase-chain-reaction (RT-PCR). Obvious decreases in the expression of AC mRNA were observed in 5/6 follicular adenomas, 2/2 adenomatous goiters, 3/6 papillary carcinomas and 1/2 follicular carcinomas. To confirm this result, real-time quantitative PCR analysis (TaqMan PCR) was carried out. The relative expression level of AC mRNA compared with that of GAPDH mRNA was reduced in follicular adenomas, follicular carcinomas, and papillary carcinomas. Further, the expression of AC mRNA was extremely reduced in 2 anaplastic carcinomas. These results suggest a possible relationship between thyroid tumorigenesis and the expression of AC mRNA. Moreover, the increased expression of AC mRNA in normal thyroid tissues suggests some fundamental roles of AC in thyroid function.

gamma delta T-cell lymphoma: a clinicopathologic study of 6 cases including extrahepatosplenic type

We report 6 cases of gamma delta T-cell lymphoma (GDTL) among 115 peripheral T-cell lymphomas over a 12-year period. All patients exhibited extranodal lymphomas, comprising 3 hepatosplenic, 1 cutaneous, 1 intestinal, and 1 thyroidal lymphoma. Despite therapies, all but 1 patient died of disease within 16 months of diagnosis. The cytologic features of lymphoma cells in 4 of 5 cases examined were very similar: coarsely reticulated nuclear chromatin, multiple small nucleoli, abundant faintly eosinophilic granular cytoplasm, and focal angiocentric proliferation. All 6 lymphomas showed Cd3+CD4-CD8-/+ phenotype. CD56 was positive in 3 cases, 1 of which was also CD16 positive. Perforin and T-cell intracellular antigen-1 were positive in all 5 cases examined. Southern blot analysis revealed clonal gene rearrangements of the T-cell receptor delta-chain gene in all 5 cases examined. Based on these findings, together with a review of the literature, GDTLs seem to have several common lineage-specific features, although clinical presentation and course of GDTL are heterogeneous.

CD30 expression and interleukin-4 and interferon-gamma production of intrathyroidal lymphocytes in Graves' disease

We reported that serum levels of interleukin-5 (IL-5) and soluble CD30, mainly secreted from T helper 2 (Th2) cells, were increased in Graves' disease. To clarify the immune balance of Th1/Th2 within the Graves' thyroid gland, we have compared the expression of CD30, a preferential marker for T cells producing type 2 cytokines, and the production of interferon-gamma (IFN-gamma) and IL-4 between intrathyroidal lymphocytes (ITL) and peripheral blood lymphocytes (PBL). In PBL, none of these parameters were different between patients and normal subjects. The proportion of CD30+ cells in ITL was markedly higher (5.1%+/-2.8%, p < 0.0001) than that in patients' PBL (0.4%+/-0.3%). Likewise, both the proportions of IFN-gamma+ (14.8%+/-5.5%) and IL-4+ cells (2.4%+/-0.5%) in ITL were higher than those in PBL (9.6%+/-2.5%; p < 0.01, 1.5%+/-0.4%; p < 0.0001, respectively). The proportion of type 0 (both IFN-gamma and IL-4 positive, 1.0%+/-0.4% p < 0.001), type 1 (IFN-gamma positive, 14.0%+/-5.6%, p < 0.01) or type 2 cells (IL-4 positive, 1.4%+/-0.5%, p < 0.05) in ITL was significantly higher as compared with those in PBL (0.4%+/-0.1%, 9.0%+/-2.4%, 1.1%+/-0.3%, respectively). The ratios of ITL/PBL in CD30+ (23.3+/-30.6) and type 0 cells (2.5+/-1.2) were higher than the ratios in other subsets. The proportion of CD30+ cells correlated with the proportion of type 0 cells (r = 0.686, p < 0.01), but not with type 1 or type 2 cells. These findings suggest that there is no obvious deviation of Th2/Th1 profile in the Graves' thyroid gland, although intrathyroidal CD30+ T cells and Th0 cells may play some role in the development of autoimmune abnormalities in Graves' disease.

Measurement of the expression of oncofetal fibronectin mRNA in thyroid carcinomas by competitive reverse transcription-polymerase chain reaction

Abundant expression of oncofetal fibronectin mRNA has been observed in thyroid papillary and anaplastic carcinomas. In this study, we measured relative expression levels of oncofetal fibronectin mRNA in thyroid cancer tissues by competitive reverse transcription polymerase chain reaction (RT-PCR) using thyroglobulin mRNA as an internal control. By this method, all papillary and anaplastic carcinomas and 3 of 6 follicular carcinomas were distinguished from benign tissues, such as normal thyroid tissues, follicular adenomas, and adenomatous goiters. Furthermore, 2 anaplastic carcinomas were clearly distinguished from differentiated carcinomas. These results suggest the possibility of establishing a more accurate preoperative or postoperative diagnosis of papillary and anaplastic carcinomas by measuring the relative expression level of oncofetal fibronectin to thyroglobulin in thyroid tumors.

Preoperative diagnosis of medullary thyroid carcinoma by RT-PCR using RNA extracted from leftover cells within a needle used for fine needle aspiration biopsy

Fine needle aspiration Biopsy (FNAB) is commonly used to diagnose thyroid tumors. In some clinical situations, however, accurate diagnosis requires a more objective method than cytological examination alone. Medullary thyroid carcinomas (MTC) derive from C cells in the thyroid and express some specific messenger RNAs (mRNA), such as those transcribed from the RET proto-oncogene, the calcitonin gene, and the gene for carcinoembryonic antigen (CEA), which usually do not exist in normal thyroid follicular cells or thyroid tumors of follicular epithelial descent. Recently, we established a new method for the molecular diagnosis of thyroid tumors without additional invasion to the patient by extracting RNA for RT-PCR from the leftover cells inside the needles used for fine needle aspiration biopsy (Aspiration Biopsy-Reverse Transcription-Polymerase Chain Reaction, ABRP). By applying the ABRP method to the detection of RET, calcitonin, and CEA mRNAs, an accurate molecular-based diagnosis for MTC maybe established as an adjunct to cytological diagnosis. In this study, 35 aspirates were obtained at the time of surgery from thyroid tumors, including 11 MTCs. The expression of these mRNAs in the leftover cells inside the needles used for the aspiration was then examined. Transcripts from all three genes were detected in the samples from all 11 MTCs, but none of these mRNAs were detected in the other tumors or normal thyroid tissues. Furthermore, MTC was preoperatively diagnosed in three patients by ABRP detection of these mRNAs, and these diagnoses were confirmed by subsequent cytological and histopathological analyses. Thus RT-PCR detection of RET, calcitonin, and CEA mRNAs in FNABs may be an efficient molecular adjunct for diagnosing MTC.

Analysis of splice variants of the fibronectin gene in thyroid carcinomas by reverse transcription-polymerase chain reaction: increased expression of oncofetal fibronectin mRNA in papillary carcinomas is not caused by the alternation in splicing

The expression levels of each splice variant of the fibronectin gene in the normal thyroid and in thyroid tumors were examined by reverse transcription-polymerase chain reaction (RT-PCR). In thyroid papillary carcinomas, insertion of a variant exon in the ED-A and ED-B domains, and three of five types of splice variants in the IIICS domain were observed. In spite of the marked increase in the expression of oncofetal fibronectin mRNA with the IIICS sequence in papillary and anaplastic carcinomas in the previous reports, the relative expression levels of each splice variant with or without the IIICS sequence showed no difference among all the tumor types. Therefore, the much increased expression of oncofetal fibronectin mRNA in these carcinomas is not caused by the alternation in splicing, but may be caused by an increase in promoter activity or stability of mRNA of the fibronectin gene.

The role of ansa-to-recurrent-laryngeal nerve anastomosis in operations for thyroid cancer

OBJECTIVE

To study the recovery in phonation after reconstruction of the recurrent laryngeal nerve (RLN) in patients whose thyroid cancer was invading the nerve, and to evaluate the role of ansa cervicalis to RLN anastomosis (ARA) in operations for thyroid cancer.

DESIGN

Retrospective study.

SETTING

University hospital and private thyroid clinic hospital, Japan.

SUBJECTS

34 patients with thyroid cancer who underwent reconstruction of unilateral RLN and 331 consecutive patients operated on for thyroid cancer.

INTERVENTIONS

Reconstruction was direct anastomosis (DA), free nerve grafting (FNG), vagus-RLN anastomosis (VRA) or ARA, including anastomosis behind the thyroid cartilage.

MAIN OUTCOME MEASURES

Maximum phonation time (34 normal subjects and 26 patients with vocal cord paralysis served as controls), laryngoscopic examination, and the ratio of reconstruction in patients who needed resection of the RLN.

RESULTS

The maximum phonation time started to increase rapidly 2-5 months postoperatively in most cases as the patients' voices recovered, and 12 months after reconstruction was significantly longer than in those patients with vocal cord paralysis (P < 0.0001). It was comparable to that of the normal subjects, although the reinnervated cords were fixed in the median. The number of reconstructions in the series of 331 patients increased from 18% to 82% after we started doing ARA with the meticulous technique of anastomosis inside the thyroid cartilage.

CONCLUSIONS

ARA is as effective as DA or FNG in improving phonation in patients who need resection of a unilateral RLN. As ARA has several advantages over FNG it has a definite place in operations for thyroid cancer.

Accurate and objective preoperative diagnosis of thyroid papillary carcinomas by reverse transcription-PCR detection of oncofetal fibronectin messenger RNA in fine-needle aspiration biopsies

Recently, the restricted expression of oncofetal fibronectin mRNA was reported in thyroid papillary and anaplastic carcinomas. In this study, by extracting RNA from the leftover cells inside the needles used for fine-needle aspiration biopsy, we establish a new method for gene diagnosis of these carcinomas without further invasiveness to the patient (aspiration biopsy-reverse transcription-PCR, ABRP). RNA was extracted from 177 fine-needle aspiration biopsies of thyroid nodules that were suspicious for malignancy, and then the gene diagnoses made by reverse transciption-PCR detection of oncofetal fibronectin mRNA were compared with cytological diagnoses. Thirty-five (94.6%) of 37 samples that were diagnosed as papillary or anaplastic carcinomas by cytological examination showed a positive result by gene diagnosis, whereas only 4 (3.7%) of 109 samples that were cytologically diagnosed negative for both carcinomas showed a positive result. Among all of the cases, 50 patients underwent surgery, and a histological diagnosis was consequently made. The sensitivity and specificity of this method were 96.9 and 100%, respectively. A combined examination using both genetic and cytological approaches may contribute to a more precise preoperative diagnosis of papillary and anaplastic carcinomas.

Restricted expression of oncofetal fibronectin mRNA in thyroid papillary and anaplastic carcinoma: an in situ hybridization study

Restricted expression of oncofetal fibronectin mRNA in the tissues of thyroid papillary and anaplastic carcinoma has recently been shown by both Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR). Oncofetal fibronectin mRNA can be a target of gene diagnosis and targeted gene therapy, provided it is expressed in all cancer cells in the tissues. To investigate this criterion in thyroid cancer tissues, we measured their expression of oncofetal fibronectin mRNA using in situ hybridization. An abundant expression of oncofetal fibronectin mRNA was found in all the observed cancer cells of six papillary carcinomas and an anaplastic carcinoma, but not in the tissues of normal thyroid, Graves' disease, adenomatous goitre, follicular adenoma, follicular carcinoma or medullary carcinoma. This result encourages us to establish gene diagnosis of thyroid papillary and anaplastic carcinomas by detecting oncofetal fibronectin mRNA in biopsies.

Gene rearrangement of immunoglobulin as a marker of thyroid lymphoma

Thyroid lymphoma occurs most commonly in the thyroid gland in association with Hashimoto's thyroiditis. Histologic findings occasionally cannot distinguish lymphoma from Hashimoto's thyroiditis, which creates a serious problem of whether treatment should be initiated. For this study, we examined 33 lymphoma tissues and 10 thyroid tissues from patients with Hashimoto's thyroiditis for the presence of gene rearrangement of immunoglobulin, which represents clonality of B-cell-derived tumors. Genomic DNA from thyroid tissues was digested with Bam H1 and Hind III restriction enzymes followed by electrophoresis. A Southern blot was performed with an IgH-JH probe or IgL-J kappa probe to detect gene rearrangement. Of the 33 lymphoma tissues, 27 (85%) showed gene rearrangement of immunoglobulin, whereas none of Hashimoto's thyroiditis tissue showed gene rearrangement. Five patients with a positive histologic diagnosis of lymphoma showed a negative gene rearrangement and were treated as having lymphoma. We encountered one case of lymphoma (plasmacytoma) in which gene rearrangement (not histologic findings) was diagnostic. Gene rearrangement of immunoglobulin can be used to detect thyroid lymphoma, particularly when the histologic diagnosis is inconclusive. The sensitivity of detecting thyroid lymphoma by the Southern blot method was about 85% in the present series.

Rapid detection of specific messenger RNAs in thyroid carcinomas by reverse transcription-PCR with degenerate primers: specific expression of oncofetal fibronectin messenger RNA in papillary carcinoma

The search for mRNAs that are specifically expressed in cancer tissues is important for gene diagnosis and therapy. However, finding such mRNAs in human cancers is usually very difficult, both because of the limited volume of RNA obtainable from the tissues and the many technical difficulties of RNA analysis. To address these problems, the present study compared mRNA from thyroid cancer tissues with those from normal and benign tissues by reverse transcription-PCR using two degenerate primers. Amplified cDNAs were separated by electrophoresis with nondenaturing acrylamide gel, then three bands that are increased in cancer tissues were selected, reamplified by PCR, and cloned into T-vector. One of the bands was determined by sequencing analysis to be oncofetal fibronectin. The expression of oncofetal fibronectin mRNA in benign and malignant tissues was examined by Northern blot and reverse transcription-PCR using specific primers of its cDNA sequence, and its increased expression was observed only in papillary and anaplastic carcinomas. Thus, the present method rapidly detected specific mRNAs in cancer tissues, and one of these, oncofetal fibronectin mRNA, is a good target for gene diagnosis of papillary carcinoma.

Increased expression of CD44 variants in differentiated thyroid cancers

Expression of CD44 variants in thyroid tumors was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) with a fluorescent image analyzer. Increased expression of CD44 variants compared with normal thyroid tissues was observed in most thyroid follicular tumors, especially in follicular carcinomas, poorly differentiated papillary carcinomas and some follicular adenomas. However, variants were hardly detectable in an anaplastic carcinoma. Analysis with restriction enzymes revealed that the major PCR product, consisting of variant bands, was derived from CD44E. Therefore, the expression of CD44E may be associated with the proliferation of differentiated thyroid cells.

Thyroid cancer detected by ultrasound-guided fine-needle aspiration biopsy

A greater percentage of thyroid cancers can be detected by ultrasound-guided fine-needle aspiration biopsy (UG-FNAB) than by ordinary FNAB. A group of 678 patients were selected sequentially as having been diagnosed with benign nodules by the conventional FNAB method. We reexamined these patients by UG-FNAB and investigated the types of thyroid cancer that were missed by the conventional FNAB. Of the 678 patients diagnosed with benign nodules (using conventional FNAB), 571 (84.2%) demonstrated the same diagnosis when UG-FNAB was used. The remaining 107 patients (15.8%) studied were suspected of having a malignancy after UG-FNAB had been performed. Surgical specimen histology proved thyroid cancer in 99 of the 107 patients: 93 had papillary carcinoma, 4 had follicular carcinoma, 1 had medullary carcinoma and 1 had anaplastic carcinoma. Two drawbacks were noted when conventional FNAB was used: (1) cancer lesions difficult to palpate (n = 55) (e.g., small cancers with or without benign lesions or cancers associated with Hashimoto's thyroiditis or Graves' disease); and (2) palpable cancers with insufficient cell material for analysis (n = 44) (e.g., cystic carcinoma and cancers with calcified lesions. UG-FNAB is a powerful technique for detecting microcancers, cystic carcinomas, cancers associated with benign nodules, Hashimoto's thyroiditis, or coarse calcifications.

Treatment of 37 patients with anaplastic carcinoma of the thyroid

BACKGROUND

Most patients with anaplastic carcinoma of the thyroid die within several months of diagnosis, and aggressive treatment is uncommon. We evaluated the effect of active multimodal treatment (surgery, radiotherapy, and chemotherapy) on this disease, including one patient treated with autologous bone marrow transplantation and high-dose chemotherapy.

METHODS

The outcome was assessed in 37 patients with anaplastic thyroid carcinoma treated between 1971 and 1993. Patients without distant metastasis when initially seen underwent surgery followed by radiotherapy. From 1984, conventional radiotherapy was replaced by hyperfractionated radiotherapy.

RESULTS

All but three patients died within 1 year of diagnosis. Patients with primary lesions less than 5 cm in diameter who had complete resection and radiotherapy survived significantly longer than the other patients, and hyperfractionated radiotherapy was effective for local control.

CONCLUSION

Active multimodal therapy is indicated for early-stage anaplastic carcinoma of the thyroid.

The correlation between papillary thyroid carcinoma and lymphocytic infiltration in the thyroid gland

Ninety-five patients with papillary thyroid carcinoma (PTC) who received primary surgical treatment in 1983 at Kuma Hospital and were followed until 1992 were the subjects of this study. Initial therapy was tumor resection for 5 patients, lobectomy for 23 patients, total thyroidectomy with unilateral modified neck dissection for 60 patients, and total thyroidectomy with bilateral modified neck dissection for 7 patients. Clinical stage at diagnosis was as follows. Class I included 28 patients with intrathyroidal disease, class II included 60 patients with positive cervical lymph nodes, and class II included 7 patients with tumor invasion into tissue outside of the thyroid gland. Recurrence of the tumor was evaluated according to lymphocytic infiltration in the thyroid gland. Group A consisted of 36 patients with PTC associated with lymphocytic infiltration, 26 with infiltration surrounding the tumor, 3 with infiltration inside of the tumor, and 7 with both. Group B consisted of the remaining 59 patients with PTC with no lymphocytic infiltration. There were no differences in age, sex, initial tumor size, or initial treatment between groups A and B. Antithyroglobulin antibody and/or antimicrosomal antibody were positive in 16 patients from group A and 4 patients from group B (P < 0.001). Class I included 14 patients from each group, class II included 22 patients from group A and 38 patients from group B, and class III included 7 patients, all from group B. Recurrence of the tumor was found in only 1 group A patient (2.8%), but in 11 patients of group B (18.6%). The percentage of patients free from recurrence over the 10 yr of follow-up in group A was significantly higher than that in group B (by Cox-Mantel test, P < 0.01). The time between initial treatment and recurrence was 2-10 yr. In comparing the clinical stage at the time of initial treatment, recurrence was found in 1 class II patient from group A (4.5%) and in 1 class I (7.1%), 6 class II (15.8%), and 4 class III (57.1%) patients from group B. No patients died during the 10 yr of follow-up. In conclusion, 1) lymphocytic infiltration surrounding the tumor or inside the tumor in PTC might be of use as a means for predicting a favorable prognosis; and 2) class II or class III patients with no lymphocytic infiltration had a high rate of recurrence.

Sporadic activation of Epstein-Barr virus in thyroid lymphoma

The causal role of Epstein-Barr virus (EBV) in the development of B-cell lymphoma, especially in immunocompromised individuals, has been suggested. The purpose of the present study was to evaluate an association of EBV with thyroid lymphoma (TL) and chronic lymphocytic thyroiditis (CLTH) which is known to play an important role in the development of TL. Thirty cases with TL and 28 with CLTH were studied for presence or absence of EBV genome in the lesions using the polymerase chain reaction (PCR) and the in situ hybridization method. EBV genomes were detected by PCR in one and two cases with CLTH and TL, respectively. Subtyping of EBV genome was possible in one TL case showing B-type in EBNA-2 coding region. In situ hybridization revealed positive signals in the nucleus of lymphoma cells, which also expressed latent membrane protein-1. The present findings indicate that activation of EBV in TL is not common.

Primary thyroid lymphoma: evaluation with US, CT, and MRI

OBJECTIVE

Our goal was to determine the most effective radiologic workup in diagnosing and staging primary thyroid lymphomas and the value of knowing the extent of tumors for prognostic purposes.

MATERIALS AND METHODS

Magnetic resonance imaging, CT, US, and fine-needle aspiration (FNA) biopsy (palpation- or US-guided) findings were retrospectively reviewed in 14 patients with primary thyroid lymphomas (5 palpable, 9 nonpalpable). Survival was correlated with the presence or absence of extrathyroidal spread of lymphoma.

RESULTS

Thyroid lymphomas were detected in all patients with US and 12 (86%) each with CT and MRI. Histopathologic diagnosis was obtained with FNA in 11 patients (79%) and with surgical procedures in 3. Magnetic resonance imaging correctly diagnosed tumor involvement of the lymph nodes (four of four patients), muscle (five of five), esophagus (one of one), internal jugular vein (one of one), and carotid artery (one of one). Muscle invasion was missed with CT in one patient. Ultrasound was not accurate for diagnosing tumor invasion of the esophagus, carotid artery, and lymph nodes. The survival of patients without extrathyroidal spread was significantly (p < 0.05) better than that of patients (n = 5) with extrathyroidal spread.

CONCLUSION

Palpable thyroid masses should undergo palpation-guided FNA for diagnosis and nonpalpable masses US-guided FNA. Tumor extent and staging should be determined with MRI, which will contribute to initiating appropriate therapy and prediction of prognosis.

[A case of primary thyroid T-cell lymphoma with infiltration of lymphoma cells in peripheral blood: diagnosed by DNA analysis]

A 57-year-old woman came to our hospital with complaints of neck swelling and headache in 1991. She was diagnosed as having chronic thyroiditis in euthyroidism because she had a diffuse goiter with both antithyroglobulin antibody (TGHA) and antimicrosomal antibody (MCHA). In 1992, she complained of the rapid growth of her thyroid gland and a swallowing disturbance. Atypical lymphocytes were observed in 16.5% of leukocytes in peripheral blood and similar atypical cells were found in bone marrow. Although an ultrasound scan of the thyroid gland revealed a symmetrical enlargement without a pseudocystic appearance, cytological study with fine needle aspiration biopsy of the thyroid gland demonstrated an abundance of atypical lymphoid cells. A whole body scintigram with 67gallium citrate showed no significant accumulation except in the thyroid gland. With a diagnosis of suspected primary thyroid lymphoma, total thyroidectomy was performed. However the diagnosis of malignant lymphoma was not confirmed histologically. A study of lymphocytes subset with two-color flow cytometry, which was performed for both lymphocytes in peripheral blood and infiltrating lymphocytes in the resected thyroid gland, revealed abnormal increased CD4 positive T cells and decreased HLA-DR expression. Additionally, southern blot DNA analysis for abnormal lymphocytes using restriction enzymes, EcoRI and BamHI, demonstrated rearrangement of the T-cell antigen receptor, which indicates a monoclonal proliferation of lymphocytes. After total thyroidectomy, atypical lymphocytes in peripheral blood decreased, and circulating autoantibodies including TGHA and MCHA disappeared. From these data, this patient was finally diagnosed as having a primary T-cell lymphoma of the thyroid gland, which is a very rare type of thyroid lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Absence of p53 mutation in Japanese patients with malignant thyroid lymphoma

Abnormalities of the gene encoding the sequence-specific DNA-binding protein, nuclear phosphorprotein p53, are among the most common genetic alterations observed in human cancers. A mutation of this tumor suppressor gene has been reported with a low prevalence in differentiated thyroid carcinomas, while the prevalence was high in undifferentiated thyroid carcinomas. We used denaturing gradient gel electrophoresis (DGGE) to probe for mutations of p53 gene in order to determine its role in the genesis of malignant thyroid lymphoma. Involvement of 27 samples had been proven by histopathologic examination of specimen obtained by open biopsy of the thyroid gland or from cervical lymph nodes. DNA was extracted from tissues embedded in paraffin blocks and exons 5-8 of p53 gene were examined for the presence of mutations by DGGE following amplification by PCR using GC-clamped primers. To confirm accuracy of the method, samples with known p53 mutations were included in the study. No mutations were detected in any of the amplified exons of malignant thyroid lymphoma samples. These results suggest that p53 mutations are not present or are uncommon in Japanese patients with malignant thyroid lymphomas. The role of p53 in this form of carcinogenesis cannot be fully excluded since we have not examined the occurrence of mutations in regions upstream of exon 5.

Fate of untreated benign thyroid nodules: results of long-term follow-up

The fate of benign thyroid nodules has been unknown because there has been no study in this regard. We re-examined 134 patients with thyroid nodules who had had benign aspiration biopsy cytology 9 to 11 years ago. The thyroid gland was palpated by the same two thyroidologists throughout the study. Ultrasonography, fine-needle aspiration biopsy (FNAB), and ultrasound-guided FNAB were employed to examine the nature of nodules of 9 to 11 years' duration. Patients (n = 61) who had nodules difficult to palpate (small nodules), multiple nodules, or cystic nodules with papillomatous proliferation underwent ultrasound-guided FNAB; patients (n = 55) having a distinctly palpable single nodule underwent usual FNAB. None of the patients received any medical or surgical treatment. There were 86 single nodules, 14 multiple nodules, and 34 cystic nodules on the first examination. These benign nodules were reexamined for changes in size and cytology 9 to 11 years later. The most striking finding was a decrease in size or disappearance of the nodule in 42% to 79% of benign nodules. About 92% of nodules remained benign without changing cytologic classification. Only one case (0.9%) previously regarded as benign turned out to be malignant; this nodule grew in size compared with the previous examination. Among single and multiple nodules, 21% to 23% of the nodules increased in size; however, most patients with enlarged nodules (86%) showed the same class 2 cytology as before. Our present study indicates that biopsy-proved benign thyroid nodules remain benign over a prolonged period. Thus no medical or surgical treatment is required so long as the nodules do not grow.

Rapidly progressive thyroid failure in Graves' disease after painful attack in the thyroid gland

We studied a new type of Graves' disease: rapidly progressive thyroid failure after painful attack in the thyroid gland. Four women with the mean (+/- SD) age of 51 +/- 3.2 years had newly diagnosed hyperthyroid Graves' disease. A severe painful episode developed in the thyroid glands of two patients and permanent hypothyroidism occurred spontaneously within 2 or 3 months thereafter. Two to three episodes of pain developed in the thyroid glands of the other two patients during antithyroid drug therapy. There was a transient rise in serum thyrotropin level after each painful episode and permanent hypothyroidism developed 6 to 8 months after the initial painful attack. The clinical picture is characterized by moderate to severe pain in the thyroid gland with tenderness. Patients responded to steroid or anti-inflammatory therapy. During painful attack, increased or normal thyroid radioiodine uptake, elevated levels of C-reactive protein, and an elevated erythrocyte sedimentation rate were found, but there was no cytological evidence of subacute thyroiditis. After painful attack, serum thyroid stimulation antibody began to decrease in three of the patients while thyroid stimulation blocking antibody developed in one patient. This is a rapid and self-destructive process of the Graves' thyroid gland, which appears to be associated with painful attack in the thyroid gland.

Intrathyroidal lymphocyte subsets, including unusual CD4+ CD8+ cells and CD3loTCR alpha beta lo/-CD4-CD8- cells, in autoimmune thyroid disease

Intrathyroidal lymphocyte subsets were analysed in 13 euthyroid patients with autoimmune thyroid disease by two-colour flow cytometry and compared with subsets in peripheral blood. In both Graves' and Hashimoto's diseases, proportions of intrathyroidal CD5- B cells were higher than in peripheral blood. The numbers of such cells were correlated with serum levels of anti-thyroid microsomal antibodies. Proportions of T cells bearing alpha beta chains of T cell receptors (TCR alpha beta+ T; T alpha beta) and CD16+CD57+ natural killer (NK) cells were lower in the thyroid, but proportions of CD3hiTCR alpha beta-TCR gamma delta+ (T gamma delta) cells were not different. Proportions of CD4+Leu-8- helper T cells and CD4+CD57+ germinal centre T cells were higher and proportions of CD4+Leu-8+ suppressor-inducer T cells and CD8+CD57+ or CD8+CD11b+ suppressor T cells were lower than in the blood in both diseases. Proportions of CD5+ B cells were high in Graves' disease, and proportions of CD8+CD11b- cytotoxic T cells were high in Hashimoto's disease. Unexpectedly, CD4+CD8+ cells and CD3loTCR alpha beta lo/-CD4-CD8- cells were present in thyroid tissues of both diseases. These findings suggest that: (i) an imbalance in the numbers of regulatory T cells and of NK cells that had appeared in the thyroid resulted in the proliferation of CD5- B cells, which were related to thyroid autoantibody production; (ii) CD5+ B cells and cytotoxic T cells are important for the different pathological features in Graves' and Hashimoto's diseases, respectively; and (iii) intrathyroidal CD4+CD8+ cells and CD3loTCR alpha beta lo/-CD4-CD8- cells may be related to the pathogenesis of autoimmune thyroid disease.

[Treatment of recurrent laryngeal nerve paralysis by several types of nerve suture]

Although simple neurorrhaphy of the injured recurrent laryngeal nerve usually results in impaired movements of the vocal cord because of misdirected regeneration, phonation recovers because the vocal cord maintains tension during phonation. Simple neurorrhaphy is possible in only a few of patients who have had their nerve severed because of thyroid surgery for thyroid cancer. We tried free nerve grafting, vagus nerve-recurrent nerve suture and ansa cervicalis-recurrent nerve suture as well as the simple neurorrhaphy in 3, 1, 1 and 3 patients, respectively. All of the 8 patients who had repair of the recurrent nerve recovered from hoarseness. Maximum phonation times of these patients ranged from 17 to 41 sec with a mean of 26.5 +/- 9.6 sec, which were significantly longer than those of 23 patients without nerve repair. Each modality of the repair obtained similar good results, although the patient who underwent vagus-recurrent suture required a longer period for recovery. These results indicate that not only simple neurorrhaphy of the recurrent nerve but also free nerve grafting, vagus nerve-recurrent nerve suture, or ansa cervicalis-recurrent suture are effective in recovery of the phonation in patients with peripheral and unilateral recurrent nerve paralysis.

The occurrence of monocytoid B-lymphocytes in autoimmune disorders

Occurrence of monocytoid B-lymphocytes (MBL) in extranodal organs in various inflammatory diseases was examined. MBL were present in 5 (11.4%) of 44 patients with Graves' disease, 11 (36.7%) of 30 with Hashimoto's thyroiditis, 1 (8.3%) of 12 with lymphoid follicular hyperplasia (LFH) of stomach, 1 (10%) of 10 with cutaneous LFH, and 0 of 5 with LFH of lung. The MBL presented as irregularly shaped nodular collections of cells, directly surrounding secondary follicles. Immunohistochemistry revealed a B-cell nature of these cells which expressed the following antigens; CD3-, CD 15-, CD45RA+, CD45Ro-, CDw 75+, CD74+, Mx-PanB+, MB-1+, EMA-. There were no immunoglobulin light chain restriction among infiltrating lymphoid cells. MBL in 2 of 18 cases showed positive reaction for CD43. The patients with MBL were older than those without MBL in each organ site, though the difference was not statistically significant. These findings showed that the MBL could appear in nonlymphoid organs affected by long-standing inflammation. High frequency of the appearance of the MBL in Hashimoto's thyroiditis suggest that MBL proliferation correlates with an impaired immune status.