An immunohistochemical study of epithelial membrane antigen, cytokeratin, and vimentin in papillary thyroid carcinoma. Recognition of lethal and favorable prognostic types

Diagnostic and prognostic value of Stanniocalcin 1 expression in papillary thyroid cancer

PURPOSE

To evaluate the potential role of immunohistochemical changes in stanniocalcin 1 (STC1) and stanniocalcin 2 (STC2) expressions in papillary thyroid cancer (PTC) tissues in the disease's diagnosis and to investigate their relationship with classical clinicopathological prognostic factors.

METHODS

The study included 100 patients with PTC. Normal thyroid tissue adjacent to the tumor was taken as the control group. Clinicopathological prognostic features at the time of diagnosis of patients were recorded. STC1 and STC2 expressions of tumor tissue and adjacent normal tissue were determined immunohistochemically.

RESULTS

The sensitivity of STC1 in the diagnosis of PTC was 93%, the specificity was 94%, positive predictive value (PPV) 93.9%, and negative predictive value (NPV) 93.1%. It was determined that the STC1 staining score in tumor tissue was positively correlated with the disease TNM stage score (r = 0.259, p = 0.009) and the increase in STC1 staining score were independent risk factors that increased the risk of lymph node metastasis (R² = 0.398, p < 0.001). While 21% of the tumor tissues were stained with STC2, none of the normal thyroid tissues adjacent to the tumor tissue showed any staining with STC2. No correlation was found between STC2 immunohistochemical staining of tumor tissue and clinicopathological risk factors for the disease.

CONCLUSION

Increased STC1 expression in thyroid lesions may be helpful in diagnosing PTC. In addition, since increased STC1 expression in PTC tissues is associated with the risk of lymph node metastasis, it may be an efficient marker for predicting the prognosis of the disease.

Can We Predict Differentiated Thyroid Cancer Behavior? Role of Genetic and Molecular Markers

Thyroid cancer is ranked in ninth place among all the newly diagnosed cancer cases in 2020. Differentiated thyroid cancer behavior can vary from indolent to extremely aggressive. Currently, predictions of cancer prognosis are mainly based on clinicopathological features, which are direct consequences of cell and tissue microenvironment alterations. These alterations include genetic changes, cell cycle disorders, estrogen receptor expression abnormalities, enhanced epithelial-mesenchymal transition, extracellular matrix degradation, increased hypoxia, and consecutive neovascularization. All these processes are represented by specific genetic and molecular markers, which can further predict thyroid cancer development, progression, and prognosis. In conclusion, evaluation of cancer genetic and molecular patterns, in addition to clinicopathological features, can contribute to the identification of patients with a potentially worse prognosis. It is essential since it plays a crucial role in decision-making regarding initial surgery, postoperative treatment, and follow-up. To date, there is a large diversity in methodologies used in different studies, frequently leading to contradictory results. To evaluate the true significance of predictive markers, more comparable studies should be conducted.

Cancer Vaccines, Adjuvants, and Delivery Systems

Vaccination was first pioneered in the 18th century by Edward Jenner and eventually led to the development of the smallpox vaccine and subsequently the eradication of smallpox. The impact of vaccination to prevent infectious diseases has been outstanding with many infections being prevented and a significant decrease in mortality worldwide. Cancer vaccines aim to clear active disease instead of aiming to prevent disease, the only exception being the recently approved vaccine that prevents cancers caused by the Human Papillomavirus. The development of therapeutic cancer vaccines has been disappointing with many early cancer vaccines that showed promise in preclinical models often failing to translate into efficacy in the clinic. In this review we provide an overview of the current vaccine platforms, adjuvants and delivery systems that are currently being investigated or have been approved. With the advent of immune checkpoint inhibitors, we also review the potential of these to be used with cancer vaccines to improve efficacy and help to overcome the immune suppressive tumor microenvironment.

Post-translational modifications such as citrullination are excellent targets for cancer therapy

Under conditions of cellular stress, proteins can be post-translationally modified causing them to be recognized by the immune system. One such stress-induced post-translational modification (siPTM) is citrullination, the conversion of arginine residues to citrulline by peptidylarginine deiminase (PAD) enzymes. PAD enzymes are activated by millimolar concentrations of calcium which can occur during apoptosis, leading to precipitation of proteins, their subsequent uptake by B cells and stimulation of antibody responses. Detection of anti-citrullinated protein antibodies (ACPAs) is a diagnostic of rheumatoid arthritis (RA), where immune complexes stimulate inflammation around the joints. More recently, autophagy has been shown to play a role in the presentation of citrullinated peptides on MHC class II molecules to CD4⁺ helper T cells, suggesting that citrullination may be a way of alerting immune cells to cellular stress. Additionally, inflammation-induced IFNγ and concomitant MHC class II expression on target cells contributes to immune activation. Stressful conditions in the tumor microenvironment induce autophagy in cancer cells as a pro-survival mechanism. Cancer cells also over express PAD enzymes and in light of this the hypothesis that citrullinated peptides stimulate CD4⁺ T cell responses that would recognize these siPTM's produced during autophagy has been investigated. The induction of potent citrullinated peptide-specific CD4 responses has been shown in both humans and HLA transgenic mouse models. Responses in mouse models resulted in potent anti-tumour responses against tumours expressing either constitutive or IFNγ-inducible MHC class II. The anti-tumour effect relied upon direct recognition of tumours by specific CD4 T cells suggesting that citrullinated peptides are attractive targets for cancer vaccines.

Vimentin Diversity in Health and Disease

Vimentin is a protein that has been linked to a large variety of pathophysiological conditions, including cataracts, Crohn's disease, rheumatoid arthritis, HIV and cancer. Vimentin has also been shown to regulate a wide spectrum of basic cellular functions. In cells, vimentin assembles into a network of filaments that spans the cytoplasm. It can also be found in smaller, non-filamentous forms that can localise both within cells and within the extracellular microenvironment. The vimentin structure can be altered by subunit exchange, cleavage into different sizes, re-annealing, post-translational modifications and interacting proteins. Together with the observation that different domains of vimentin might have evolved under different selection pressures that defined distinct biological functions for different parts of the protein, the many diverse variants of vimentin might be the cause of its functional diversity. A number of review articles have focussed on the biology and medical aspects of intermediate filament proteins without particular commitment to vimentin, and other reviews have focussed on intermediate filaments in an in vitro context. In contrast, the present review focusses almost exclusively on vimentin, and covers both ex vivo and in vivo data from tissue culture and from living organisms, including a summary of the many phenotypes of vimentin knockout animals. Our aim is to provide a comprehensive overview of the current understanding of the many diverse aspects of vimentin, from biochemical, mechanical, cellular, systems biology and medical perspectives.

Papillary Thyroid Carcinoma and Related Thyroid Neoplastic Lesions: A Light Microscopic Study with Emphasis on Nuclear Changes

A total of 187 thyroid lesions consisting of 2 cases of Grave's disease, 21 cases of multinodular goiter, 40 follicular adenomas and 124 low-grade papillary thyroid carcinomas were studied to identify intermediate neoplastic lesions in the spectrum of nuclear changes between benign reactive thyroid follicles and low-grade thyroid papillary carcinoma. The lesions were examined and classified on the basis of the following nuclear features: fine chromatin seen in the thyroid papillary carcinomas and coarse chromatin seen in follicular carcinomas. Cases with Hürthle cell changes were excluded from the study. Cases with nuclei containing coarse chromatin were classified in the group of follicular adenomas with a coarse chromatin pattern. The neoplastic thyroid lesions containing fine chromatin showed a spectrum of nuclear changes ranging between reactive follicular lesions and papillary thyroid carcinoma with lymph node metastasis. Such lesions were classified as follicular adenomas with a fine chromatin pattern. The nuclei of these lesions were graded into mild to marked "nuclear atypia with a fine chromatin pattern". The degree of atypia depended on the degree and extent of nuclear changes. Encapsulated follicular adenomas with a fine chromatin pattern and with mild atypia (11 cases), moderate atypia (13 cases), marked atypia (27 cases), and encapsulated or nonencapsulated papillary thyroid carcinoma were characterized by uniform nuclei; with mild, moderate and marked nuclear atypia in less than 2/3 of the cell population and marked nuclear atypia in more than 2/3 of the cell population; and measuring 5.4-6.3, 6.0-7.2, 6.3-9 and 7.2-10 microns in diameter, respectively. Follow-up of cases of papillary thyroid carcinoma fulfilling the above criteria showed lymph node metastasis in 33% of cases, whereas follicular adenomas with a fine chromatin pattern, including cases originally diagnosed as papillary carcinoma, showed no evidence of lymph node or distant metastasis in a follow-up period of 30 months to 15 years. In the thyroid tissue surrounding papillary thyroid carcinoma or encapsulated follicular adenoma with a fine chromatin pattern and marked atypia, adenomatous nodules with a fine chromatin pattern and with low-grade nuclear atypia were identified. The adenomatous nodules with a fine chromatin pattern and with mild, moderate and marked atypia showed architectural, cytoplasmic and nuclear features similar to those of follicular adenoma with a fine chromatin pattern of the same grade. Of interest, a large number of cases of follicular adenoma with a fine chromatin pattern had areas with features of follicular adenoma with a coarse chromatin pattern.

Complex temporal changes in TGFβ oncogenic signaling drive thyroid carcinogenesis in a mouse model

Despite recent advances, understanding of molecular genetic alterations underlying thyroid carcinogenesis remains unclear. One key question is how dynamic temporal changes in global genomic expression affect carcinogenesis as the disease progresses. To address this question, we used a mouse model that spontaneously develops follicular thyroid cancer similar to human cancer (Thrb (PV/PV) mice). Using complementary DNA microarrays, we compared global gene expression profiles of thyroid tumors of Thrb (PV/PV) mice with the age- and gender-matched thyroids of wild-type mice at 3 weeks and at 2, 4, 6 and 14 months. These time points covered the pathological progression from early hyperplasia to capsular invasion, vascular invasion and eventual metastasis. Microarray data indicated that 462 genes were upregulated (Up-cluster genes) and 110 genes were downregulated (Down-cluster genes). Three major expression patterns (trending up, cyclical and spiking up and then down) and two (trending down and cyclical) were apparent in the Up-cluster and Down-cluster genes, respectively. Functional clustering of tumor-related genes followed by Ingenuity Pathways Analysis identified the transforming growth factor β (TGF β)-mediated network as key signaling pathways. Further functional analyses showed sustained activation of TGFβ receptor-pSMAD2/3 signaling, leading to decreased expression of E-cadherin and increased expression of fibronectin, vimentin, collagens and laminins. These TGFβ-induced changes facilitated epithelial-to-mesenchymal transition, which promotes cancer invasion and migration. Thus, complex temporal changes in gene expression patterns drive thyroid cancer progression, and persistent activation of TGFβ-TGFRβII-pSMAD2/3 signaling leads to EMT, thus promoting metastasis. This study provides new understanding of progression and metastatic spread of human thyroid cancer.

Vimentin in cancer and its potential as a molecular target for cancer therapy

Vimentin, a major constituent of the intermediate filament family of proteins, is ubiquitously expressed in normal mesenchymal cells and is known to maintain cellular integrity and provide resistance against stress. Vimentin is overexpressed in various epithelial cancers, including prostate cancer, gastrointestinal tumors, tumors of the central nervous system, breast cancer, malignant melanoma, and lung cancer. Vimentin's overexpression in cancer correlates well with accelerated tumor growth, invasion, and poor prognosis; however, the role of vimentin in cancer progression remains obscure. In recent years, vimentin has been recognized as a marker for epithelial-mesenchymal transition (EMT). Although EMT is associated with several tumorigenic events, vimentin's role in the underlying events mediating these processes remains unknown. By virtue of its overexpression in cancer and its association with tumor growth and metastasis, vimentin serves as an attractive potential target for cancer therapy; however, more research would be crucial to evaluate its specific role in cancer. Our recent discovery of a vimentin-binding mini-peptide has generated further impetus for vimentin-targeted tumor-specific therapy. Furthermore, research directed toward elucidating the role of vimentin in various signaling pathways would reveal new approaches for the development of therapeutic agents. This review summarizes the expression and functions of vimentin in various types of cancer and suggests some directions toward future cancer therapy utilizing vimentin as a potential molecular target.

Simultaneous immunohistochemical expression of HBME-1 and galectin-3 differentiates papillary carcinomas from hyperfunctioning lesions of the thyroid

AIMS

The histological diagnosis is critical for the postsurgical management and follow-up of thyroid malignancies. The differential diagnosis between papillary carcinoma and hyperfunctioning lesions, either with papillary hyperplasia or with a follicular architecture, can create real diagnostic difficulty. The aim of this study was to evaluate the expression of several antibodies considered to be markers of malignancy in malignant and hyperfunctioning thyroid neoplasms and to include the most effective of them in a diagnostic panel.

METHODS AND RESULTS

One hundred resected thyroid nodules--58 hyperfunctioning benign lesions and 42 papillary carcinomas (14 follicular variant, 14 macrofollicular variant and 14 classic type)--were immunohistochemically studied for HBME-1, galectin-3, cytokeratin (CK) 19 and RET-proto-oncogene. HBME-1 and galectin-3 showed 92.8% and 89% sensitivity, respectively, and their coexpression was present in 36 out of 42 papillary carcinomas (85.7%) and absent in non-malignant lesions. Their association increased sensitivity to 94.7% and the diagnostic accuracy to 97.9% and involved the highest number of cases (95%) in comparison with two other panels including, respectively, three (HBME-1, galectin-3, CK19) and all four antibodies.

CONCLUSION

An immunohistochemical panel consisting of HBME-1 and galectin-3 can make a correct distinction between malignant and hyperfunctioning thyroid neoplasms with high diagnostic accuracy.

Follicular adenoma with papillary architecture: a lesion mimicking papillary thyroid carcinoma

AIMS

The purpose of this study was to investigate the significance of 'benign' encapsulated follicular thyroid nodules with papillary structures.

METHODS AND RESULTS

Twenty-one cases of encapsulated neoplastic thyroid nodules with papillary structures and nuclear features not diagnostic of papillary thyroid carcinoma (PTC) were obtained. All cases were reviewed with particular attention to nuclear features (fine chromatin pattern, optical clearing, grooves and inclusions). Representative sections were submitted for measurement of the maximum diameter of 200 round or nearly round nuclei and for immunostaining for MIB1, CK19, HBME and Ret oncogene protein. Nine cases displayed scattered optically clear nuclei or nuclear grooves in less than 30% of total neoplastic cells. They were grouped in the category of thyroid nodules with limited nuclear features of papillary thyroid carcinoma (PTC), but not diagnostic of PTC. The other 12 cases had fine or coarse chromatin, but lacked other features of nuclei in PTC. The diameter of the nuclei ranged from 5.6 to 7.2 microm and were smaller than those of PTC (6.3-10.0 microm). Immunostaining revealed positive reactivity for MIB1 in the papillary structures. Immunostaining for CK19 and HBME varied from negative or focally weak to diffusely moderate reactivity. Ret oncogene protein immunostaining showed focal and weak reactivity in one case and was negative in other cases of the study. Clinical follow-up from 6 months to 15 years revealed no evidence of metastasis.

CONCLUSIONS

The papillary structures in the study cases are unlikely to represent degenerative changes due to their proliferative activity. In view of (i) the encapsulation and the uniformity of the constituent cells, (ii) the varying degrees of immunoreactivity for CK19 and HBME and negative immunoreactivity for Ret oncogene protein, and (iii) the absence or insufficiency of nuclear criteria for the diagnosis of PTC and the absence of lymph node metastasis in all study cases, we believe that these lesions represent the papillary variant of follicular adenoma. Recognition of this pathological entity is important to avoid an over-diagnosis of PTC.

Hyalinizing trabecular adenoma and papillary carcinoma of the thyroid gland express different cytokeratin patterns

It has recently been suggested that hyalinizing trabecular adenoma of the thyroid is an encapsulated variant of papillary carcinoma because of certain similarities of their histology, the occasional occurrence of both tumors in the same gland, and their similar pattern of expression of cytokeratins, including staining for cytokeratin 19. To investigate this notion further, we examined immunocytochemically the expression of a series of cytokeratins in 12 hyalinizing trabecular adenomas and six papillary carcinomas. Hyalinizing trabecular adenoma showed no or minimal reactivity for cytokeratin 19, whereas papillary carcinoma was almost always strongly reactive. Also, hyalinizing trabecular adenoma showed no staining for high-molecular-weight (HMW) cytokeratin, whereas papillary carcinoma was strongly positive. Thus, there are different patterns of cytokeratin 19 and HMW cytokeratin expression in hyalinizing trabecular adenoma and papillary carcinoma. The findings do not support the suggestion that hyalinizing trabecular adenoma is an encapsulated variant of papillary carcinoma.

Papillary Thyroid Carcinoma Overexpresses Fully and Underglycosylated Mucins Together with Native and Sialylated Simple Mucin Antigens and Histo-Blood Group Antigens

We studied the immunohistochemical expression of mucins (MUC1, underglycosylated MUC1, MUC2, MUC5AC, and MUC6), simple mucin antigens (Tn, sialyl Tn, and T), and histo-blood group antigens (type 1-Lewis(a) and sialyl Lewis(a) type 2-Lewis(x) and sialyl Lewis(x)) in a series of 26 papillary thyroid carcinomas (PTC), 6 follicular carcinomas, and a control group of 32 cases of "normal" thyroid parenchyma adjacent to the tumors. PTC expressed more often, more intensively, and more extensively every antigen but MUC6, which was not observed in any case. The expression of MUC5AC was also extremely rare. MUC1 expression was related to the expression of underglycosylated MUC1, MUC2, Lewis(a), and sialyl Lewis(a). A trend toward an association between the expression of MUC1 and that of type 2 histo-blood group antigens was also observed. Whenever there was a dissociation between the expression of type 1 and type 2 Lewis antigens, MUC1 appeared closely related to type 1 and independent from type 2 histo-blood group antigens. We conclude that MUC1 plays a pivotal, though not exclusive, role in the glycosylation features of well differentiated thyroid carcinomas. Despite the prominent expression of mucins and carbohydrate antigens in PTC, no significant differences were observed between PTC and follicular carcinoma thus ruling out the possibility of using the aforementioned antigens as diagnostic markers per se.

Clinicopathologic and Prognostic Significance of the Expression of Mucins, Simple Mucin Antigens and Histo-Blood Group Antigens in Papillary Thyroid Carcinoma

We have previously analyzed the expression of MUC1, underglycosylated MUC1, MUC2, MUC5AC, Tn, sialyl Tn, Lewis(a), sialyl Lewis(a), Lewis(x), and sialyl Lewis(x) in papillary thyroid carcinoma (PTC). The present study of 26 thoroughly scrutinized cases of PTC with "good" or "bad outcome" and a minimum of 10 yr of follow-up (or until death of the patients) was undertaken in an attempt to find if there is any relationship between the expression of the aforementioned antigens and the clinicopathologic and morphologic features of the cases and to evaluate the prognostic significance of the immunohistochemical pattern of PTC. We observed a significant or suggestive association between the expression of MUC1, underglycosylated MUC1, MUC2, Lewis(a), and Lewis(x) and the older age of the patients, and a suggestive association between Lewis(x) expression and lymph node metastasis and venous invasion. There was also a strong correlation between extrathyroid invasion, lymph node metastasis, intrathyroid dissemination, and venous invasion and patients outcome thus demonstrating, once more, the prominence of the classic clinicopathologic and morphologic features in the prognostic evaluation of PTC. The immunohistochemical study of mucins, simple mucin antigens, and histo-blood group antigens did not provide additional prognostic information, but for the significant association of Lewis(x) immunoreactivity to the group of "bad outcome."

Alpha-1-antichymotrypsin immunoreactivity in papillary carcinoma of the thyroid gland

AIM

Papillary thyroid carcinoma (PTC) is the most common malignant tumour of the thyroid gland. The immunohistochemical profile of PTC is characterized by immunoreactivity of tumour cells for cytokeratins, thyroglobulin, vimentin, EMA and S100 protein. Recently, the presence of a serum protease inhibitor, alpha-1-antitrypsin (A1AT), has been demonstrated in tumour cells of PTC. The aim of our study was to test immunoreactivity of PTC for another inhibitor of proteases, alpha-1-antichymotrypsin (A1ACT).

METHODS AND RESULTS

Serial paraffin sections of nine consecutive cases of PTC were tested with anti-A1AT and anti-A1ACT antibodies. No immunoreactivity for A1AT and A1ACT was found in the normal thyroid tissue surrounding each tumour. In seven out of nine cases, tumour cells of PTC showed cytoplasmic immunoreactivity for A1ACT. In two cases, A1ACT was detected even in the nuclei. Immunoreactivity for A1AT was found only in three cases. Two cases of PTC showed no staining for both A1ACT and A1AT. No significant correlation of A1ACT staining was found with various prognostic indices (age of patients, histological pattern, tumour size, presence of regional lymph node metastases). The two cases showing a lack of staining for both A1ACT and A1AT showed a more aggressive clinical behaviour.

CONCLUSIONS

Our preliminary study shows that A1ACT is expressed by tumour cells in a large proportion of papillary carcinomas of the thyroid gland. Its significance remains, to the best of our knowledge, still unknown. The observation of a more aggressive behaviour in the two cases characterized by the absence of immunoreactivity for both A1ACT and A1AT suggests that the presence or absence of protease inhibitors could play a role in controlling tumour progression in PTC.

Chronic thyroiditis as a favorable prognostic factor in papillary thyroid carcinoma

A subgroup of patients with papillary thyroid carcinoma (PTC) also has chronic thyroiditis (CT) as an associated disease of the thyroid. To assess the prognostic value of CT in patients with PTC, we reviewed the histological slides of 2225 patients with PTC who had undergone surgery between 1971 and 1992. Of the 2225 patients, 692 were excluded from the analysis because regional lymph nodes and/or nonneoplastic thyroid tissues were unavailable for histological assessment. The series included 281 patients with CT in nonneoplastic thyroid tissue and 1252 without CT. We performed statistical analyzes by the log-rank test and Cox's proportional-hazard method. Sixty-two (5.0%) of the 1252 patients without CT died of metastatic disease during the follow-up period and the relapse-free 10-year survival rate was 85%. By contrast, only 2 (<1.0%) of the 281 patients with CT died, and their relapse-free 10-year survival rate was 95%. The difference between patients with CT and those without CT in terms of relapse-free and overall survival was statistically significant (p < 0.0001). Risk factors for unfavorable outcome were age 45 years or more, absence of psammoma bodies, and absence of CT (p < 0.0001), followed by vascular invasion (p = 0.0007), male sex (p = 0.0013), and metastasis to regional lymph nodes (p = 0.047). Multivariate analysis indicated that all of these factors with the exception of gender were independent factors in the final model for overall survival. Chronic thyroiditis in the nonneoplastic thyroid of patients with PTC is a powerful prognostic factor for both relapse-free and overall survival.

Papillary microcarcinoma of the thyroid gland

Papillary microcarcinomas are a specific subgroup of papillary thyroid cancer. They have the same histological features as papillary thyroid cancer but are 1.0 cm or less in diameter. These tumours are a common incidental finding at autopsy and in thyroid glands excised for other pathology. This tumour can metastasize to regional lymph nodes but its ability to cause significant morbidity and mortality has been questioned. As papillary microcarcinomas can represent up to 30 per cent of all papillary cancers seen in a thyroid surgeon's practice, they are an important group. The aim of this review article is to outline the natural history of papillary microcarcinoma and to offer therapeutic management strategies.

Tall cell variant of papillary thyroid carcinoma: a reassessment and immunohistochemical study with comparison to the usual type of papillary carcinoma of the thyroid

A review of 92 consecutive cases of papillary thyroid carcinoma diagnosed at The Methodist Hospital revealed 11 tall cell variant (TCV) cases in nine women and two men. There was a greater average age and larger tumor diameter of TCV cases compared with papillary thyroid carcinoma of the usual type (UPTC), but these differences were not statistically significant. Extrathyroidal extension of tumor was noted in nine of 11 TCV cases and was intraoperatively evident in five cases. The presence of extrathyroidal extension represented a statistically significant difference between TCV and UPTC (p = 0.0001) in a multivariate stepwise logistic regression analysis, with controls for variables of age, sex, tumor size, and lymph node metastases. In 11 TCV patients, tumor recurrence was present in two cases, and there was one tumor-associated death with 1 to 4 years of follow-up. Immunohistochemical stains for thyroglobulin, vimentin, keratins, and Leu-7 were positive in all TCV cases and in 16 of 16 UPTC. Immunoreactivity with antibodies to Leu M1 antigen, a myelomonocytic marker included in cluster designation group (CD 15), which is present in many adenocarcinomas, was present diffusely in all TCV, in contrast to UPTC (with sparse immunostaining in only one of 16 cases). Immunoreactivity with antibodies to ZC-23, an anti-carcinoembryonic antigen (CEA) monoclonal antibody with cross-reactivity to nonspecific cross-reacting antigen and biliary glycoprotein antigen, was present in all TCV but was not present in UPTC. COL-1, a CEA-specific monoclonal antibody, was nonimmunoreactive with all TCV and UPTC cases. Epithelial membrane antigen (EMA) was present in all TCV but was also present focally in eight of 16 UPTC, sometimes in a membranous pattern in epithelium surrounding cystic or hemorrhagic spaces. Strong immunoreactivity with antibodies to Leu M1 and EMA in papillary carcinomas of the thyroid has been associated with advanced stages of disease and tumor-associated mortality. The pattern of immunoreactivity in TCV is dissimilar to that in UPTC and is supportive evidence that TCV is a neoplasm that is distinct from papillary thyroid carcinoma of the usual type.

Alpha 1-antitrypsin expression in human thyroid papillary carcinoma

Alpha 1-antitrypsin is a plasma serine protease inhibitor originally used as a marker for tumors of histiocytic origin. Our casual finding of immunoreactive alpha 1-antitrypsin in one case of thyroid papillary carcinoma led us to investigate its presence in 10 thyroid papillary carcinomas by applying immunocytochemical and immunochemical techniques to tissue sections and Western blots of tissue homogenates prepared from neoplastic tissue and from uninvolved normal areas in the vicinity of each tumor. The immunocytochemical study was performed in both thyroid tissue and metastatic regional lymph nodes. This analysis revealed immunoreactivity for alpha 1-antitrypsin in nine of the 10 cases studied. Immunoreactivity was intense in some of the cells forming the papillar and follicular structures. These cells were intermingled with completely unstained tumoral cells. In contrast to neoplastic tissue, the normal thyroid tissue present in the vicinity of each tumor showed no staining for alpha 1-antitrypsin. The electrophoretic analysis performed on homogenates prepared from both tumoral and normal thyroid tissue revealed a drastic reduction in the band corresponding to thyroglobulin in the tumoral tissue compared with normal thyroid extracts, where it represented the major protein. Western blotting and immunoprinting with a polyclonal alpha 1-antitrypsin antibody confirmed the results obtained with immunocytochemistry about the presence of this protease inhibitor in neoplastic thyroid tissue. Immunoprinting with the anti-alpha 1-antitrypsin antibody revealed an intense immunoreactive band of 53 kDa in the extracts prepared from tumoral tissue. This band had exactly the same apparent molecular mass previously described by others for alpha 1-antitrypsin purified from plasma and was identical to the molecular mass of the purified commercial standard employed.

The immunohistochemical localization of S100 in the diagnosis of papillary carcinoma of the thyroid

In general, the diagnosis of papillary carcinoma of the thyroid is readily achieved based on a defined aggregate of histopathologic features. A papillary architecture is an important but not pivotal component of the diagnosis. The recognition of classic nuclear features is the essential diagnostic element. However, both the architectural and cytological hallmarks may be encountered in other conditions and produce problems in histopathologic interpretation. A papillary architecture may be encountered in hyperplastic areas of follicular neoplasms, multinodular goiter, and Graves' disease. Moreover, there may be scattered cells within several thyroid lesions that display some of the nuclear characteristics of papillary carcinoma. The distinction of these lesions from papillary carcinoma has important implications for clinical management. Thus, the availability of supportive diagnostic evidence would be helpful. In the authors' experience, the strong expression of S100 is of value in identifying papillary neoplasia and distinguishing it from examples of papillary hyperplasia. It is of supportive but not conclusive use in distinguishing follicular adenoma from the follicular variant of papillary carcinoma. The authors stress that the overwhelming factor in the distinction remains the identification of the nuclear characteristics of a papillary carcinoma. However, the authors have encountered several cases wherein the latter are either focal or absent for reasons addressed previously and have found immunohistochemistry a valuable adjunct to diagnosis. In examining papillary foci within Graves' disease, caution must be exercised; S100 expression is a phenomenon of the hyperplastic, hyperfunctional state.

Selective expression of CD44 cell-adhesion molecule in thyroid papillary carcinoma fine-needle aspirates

Recent descriptions of numerous pitfalls in the cytologic diagnosis of thyroid papillary carcinoma on fine-needle aspiration biopsy specimens have prompted studies of new ancillary diagnostic methods. We evaluated the potential use of immunocytochemical staining of thyroid fine-needle aspiration biopsy specimens for CD44, a glycosylated cartilage link protein associated with extracellular matrix adhesion and lymphocyte homing. Fourteen of 16 (88%) classic, surgically confirmed, thyroid aspiration biopsies stained intensely positive for this marker, whereas 0 of 30 (0%) similarly-processed benign aspirates from colloid nodules showed immunoreactivity for CD44 antigen. From this study, we conclude that most papillary carcinomas of the thyroid express the celladhesion molecule CD44, which may be of clinical value in confirming the diagnosis on borderline fine-needle aspiration specimens. Further study of CD44 expression may prove of significant interest in explaining the unusual mode of spread and clinical course of this disease.

The immunology of thyroid cancer

This article reviews the immunologic aspects of thyroid cancer, including thyroid-specific effector elements on thyroid cancer, and discusses the potential antigens, unique molecular markers, and transcription factors that could serve as targets for immunotherapy. The potential role of this type of treatment for thyroid cancer is examined also.

Differentiation of thyroid neoplasms by evaluating epithelial membrane antigen, Leu-7 antigen, epidermal growth factor receptor, and DNA content

The expression of epithelial membrane antigen (EMA), Leu-7 antigen, epidermal growth factor receptor (EGFr), and deoxyribonucleic acid (DNA) content in 40 thyroid nodules was investigated to identify those factors that might differentiate these lesions or correlate to their prognosis. There were 22 carcinomas (16 papillary, 4 follicular, 1 anaplastic, 1 medullary) and 18 benign lesions prospectively obtained between 1989 and 1993. Patients' charts were reviewed to establish a database of known clinical prognostic indicators. Expression of EMA and Leu-7 was significant in malignant lesions when compared to benign lesions (P < 0.02 and P < 0.001). EMA was expressed significantly more frequently by follicular carcinomas than by follicular adenomas (P < 0.03). Leu-7 antigen was expressed by all papillary carcinomas. Neither of these antigens showed any association with known clinical prognostic indicators. EGFr expression neither differentiated benign from malignant lesions nor correlated with prognostic factors. The presence of aneuploidy correlated with poor tumor differentiation (P < 0.02), but did not distinguish benign from malignant lesions. These results suggest that EMA expression may be useful for confirming malignancy in follicular neoplasms and that the expression of Leu-7 antigen can assist in distinguishing papillary carcinoma from benign lesions with pseudopapillae.