Occult oncocytic papillary thyroid carcinoma with lymphoid stroma (Warthin-like tumor): report of a case with concomitant mutations of BRAF V600E and V600K.

Warthin-Like tumor of the thyroid is a recently described rare variant of papillary thyroid cancer. The distinct histological feature of this variant is papillary architecture lining oncocytic epithelial cells with nuclear characteristics of papillary carcinoma, accompanied by prominent lymphocytic infiltration in the papillary stalks. Here, we present a case of occult Warthin-like papillary thyroid carcinoma, 0.5-cm in maximum dimension, underwent left thyroid lobectomy in a 65 years old Chinese woman. In this case, there was no extrathyroid extension, vascular invasion and lymphatic metastasis, as well as no complication of lymphocytic thyroiditis. Immunohistochemistry staining revealed that the tumor cells were positive for Leu-M1, HBME-1, 34ßE12, and MIB-1 labeling index was low. RET/PTC expression was absent in tumor cells. Furthermore, activated point mutations of BRAF V600E and V600K were concurrently detected by DNA sequencing. Further studies are needed to elucidate the prevalence and role of BRAF(V600K) mutation in papillary thyroid carcinoma, and long-term follow-up for the patient is needed to clarify the biological behavior of this variant with dual BRAF mutations.

Expression of gelatinases (MMP-2, MMP-9) and cyclooxygenases (COX-1, COX-2) in some benign salivary gland tumors.

Salivary gland tumors, most of which are rare benign tumors, represent a histologically heterogenous group with the greatest diversity of morphological and cellular features. The aim of this study is to analyse the expression and possible interactions between gelatinases (MMP-2, MMP-9) and cyclooxygenases (COX-1, COX-2) in some benign salivary gland tumors. We investigated the expression of gelatinases and cyclooxigenases in control salivary gland, Pleomorphic adenoma and Warthin's tumor through immunohistochemistry and Reverse Transcription - Polymerase Chain Reaction (PCR). We identified the expression of both classes of enzyme in normal samples and in the two types of pathological samples without any quantitative differences. From the present data no significant differences emerge in the expression of these enzymes among the different pathologies examined. Nevertheless, due to the small number of samples included in this study, general statements regarding correlation between the degree of severity of the tumoral pathology and the quantitative expression of these potential tumoral markers can not be made.

Peroxiredoxin I is overexpressed in oncocytic lesions of salivary glands.

BACKGROUND: Oncocytic lesions, particularly frequent in the salivary glands, are characterized by cells with an atypical accumulation of mitochondria. This accumulation has been recognized as a compensatory mechanism to intrinsic functional defects of these organelles, resulting in energy production impairment and increased generation of reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)). Peroxiredoxin I (Prx I) is a H(2)O(2) scavenging protein and the expression of its yeast homolog was reported to be influenced by mitochondrial function. METHODS: In this study, we evaluated Prx I expression in oncocytic lesions of salivary glands by immunohistochemistry. RESULTS: Our results showed that Prx I is overexpressed in oncocytes regardless of the salivary gland lesion where they appear. CONCLUSIONS: These results suggest that Prx I expression in oncocytes is related to its ability to decompose mitochondrial-derived H(2)O(2) and that it could provide to the cells a protective role in an environment that, by continuously producing potential DNA-damaging ROS, predisposes to genome instability and cellular transformation.

Cyclooxygenase-2 expression in Warthin's tumour.

OBJECTIVES: To determine whether cyclooxygenase-2 (COX-2) is overexpressed in Warthin's tumours, and to characterize its pattern of expression. METHODS: Twenty-one paraffin-embedded Warthin's tumour specimens were analysed by immunohistochemical staining for expression of human COX-2. Semi-quantitative analysis of the staining was performed. RESULTS: In all of the specimens, we found that there was overexpression of COX-2 within the epithelial component of the tumours, with no expression in the lymphoid components. There was also overexpression of COX-2 in the salivary duct system of normal parotid tissue. CONCLUSIONS: Our results suggest that COX-2 is up-regulated in the epithelial component of Warthin's tumours. Our findings support the hypothesis that Warthin's tumours originate from heterotopic ductal epithelial cells of the parotid gland. The role of COX-2 expression in the pathogenesis of Warthin's tumours remains to be determined.

Thallium-201 chloride (Tl-201) accumulation and Na+/K+-ATPase expression in tumours of the head and neck.

OBJECTIVES: The purpose of this report was to evaluate the relationship between the tumour retention index of thallium-201 chloride (Tl-201) scintigraphy and the Na+/K+-ATPase expression in tumours of the head and neck. METHODS: Tl-201 scintigraphy was performed in 146 patients (129 with malignant tumours, ten with benign tumours and seven with inflammation). The tumour retention index was obtained from the early and delayed dynamic Tl-201 scans. The Na+/K+-ATPase expression was evaluated immunohistochemically in 61 of 129 patients with malignant tumour. Furthermore, another 22 patients with benign tumour were evaluated immunohistochemically as a benign control. Comparison of the correlations between the grade of histopathological differentiation of tumour, the tumour retention index of Tl-201 scintigraphy and the Na+/K+-ATPase expression was performed. RESULTS: The grade of histopathological differentiation of tumour, the tumour retention index of Tl-201 scintigraphy and the expression of Na+/K+-ATPase showed a good correlation indicating that Na+/K+-ATPase plays an important role in transportation for Tl-201 to go through the tumour cell membrane. CONCLUSIONS: Na+/K+-ATPase is one of the most important factors for Tl-201 accumulation in tumour.

Expression of type 2 nitric oxide synthase and p53 in Warthin's tumour of the parotid.

Although the pathogenesis of Warthin's tumour is not fully understood, it is generally thought that the tumour arises from heterotopic salivary ducts within pre-existing lymphoid tissue. Prolonged nitric oxide (NO) production by the enzyme type 2 nitric oxide synthase (NOS2) has been implicated in the pathogenesis of many solid tumours, but not in Warthin's tumour. Since NO and NOS2 are known to be associated with p53, the immunohistochemical expression of both NOS2 and p53 was investigated in 23 cases of Warthin's tumour. Widespread diffuse cytoplasmic immunostaining for NOS2 was found in tumour epithelial cells of all 23 cases studied, and it was additionally expressed in normal salivary duct epithelium. p53 staining was localised to the nuclei of tumour epithelium in 16 cases, with a similar pattern of distribution to tumour NOS2 expression. A significant correlation was found between NOS2 and p53 staining in the tumours (P < 0.001). In contrast to NOS2, p53 was not expressed by normal salivary ductal cells in any of the cases studied. NOS2 is widely expressed by the tumour epithelium of Warthin's, and its association with p53 expression is discussed. The role of NO in the pathogenesis of Warthin's tumour remains to be established.

Immunohistochemical study of the distribution of endogenous biotin and biotin-binding enzymes in ductal structures of salivary gland tumours.

To clarify the pathologic value of endogenous biotin in the salivary gland, we examined in a series of neoplasms of the salivary gland by immunohistochemical staining the distribution of endogenous biotin and of biotin-binding enzymes, namely, acetyl CoA carboxylase (AC), which is a cytosolic enzyme, and pyruvate carboxylase (PC), which is a mitochondrial enzyme. In pleomorphic adenoma, we found biotin and PC in ductal epithelial elements, while AC was found mainly in myoepithelial elements. Carcinoma ex pleomorphic adenoma, adenocarcinoma and mucoepidermoid carcinoma were frequently immunopositive for biotin, PC and AC, while adenoid cystic carcinoma was rarely immunopositive for biotin, PC or AC. These results indicate that endogenous biotin might be associated with the mitochondrial enzyme, which is present at high levels in ductal cells of the salivary gland. However, the neoplastic cells in adenoid cystic carcinoma seemed to have an unusual expression of biotin and related enzymes.

Immunohistochemical evaluation of transglutaminase C in tumours of salivary glands.

Transglutaminase C (TGase C), a family of Ca(2+)-dependent enzymes and an essential component in the cross-linking of peptide bonds, has been found to be a marker of epithelial differentiation with a possible role in cellular apoptosis, extracellular matrix stabilisation and Ca2+ binding, thereby having a potential role in tumour growth, differentiation and invasive behaviour. The expression of TGase C was evaluated in normal human salivary glands and their neoplastic lesions which included pleomorphic adenoma (n = 30), Warthin's tumour (n = 5), adenoid cystic carcinoma (n = 10), acinic cell carcinoma (n = 5), mucoepidermoid carcinoma (n = 5) and control tissue specimens of normal oral mucosa and squamous cell carcinoma, using polyclonal antibody, the specificity of which was determined by Western blotting, generated by immunising rabbits with purified transglutaminase. The TGase C was observed in the epithelial cells in the control tissue specimens examined. Pleiomorphic adenoma revealed reaction products in luminal tumour cells, the non-luminal or modified myoepithelial cells and their plasmacytoid variants, squamous metaplastic cells and chondroid cells. Adenoid cystic carcinomas had tumour cells in the luminal cells of tubular and cribriform structures and the acinic cell carcinoma had from low to moderate immunoreactivity in the tumour cell component and a diffuse immunoreactivity in the stroma for TGase C. Mucoepidermoid carcinoma showed no reaction products in the mucous-producing cells, while intermediate and epidermoid cells had immunoreactivity in the cell cytoplasm. As the presence of TGase C in salivary gland tumours was confined to those tumour cells which form the predominant histomorphology in each tumour subtype, it may be suggested that these enzymes may have a potential role in the regulation of cellular function in neoplastic salivary tissues affecting tumour growth, differentiation and neoplastic behaviour.

Over-expression of glutathione S-transferases, DT-diaphorase and an apparently tumour-specific cytosolic class-3 aldehyde dehydrogenase by Warthin tumours and mucoepidermoid carcinomas of the human parotid gland.

Cytosolic class-3 aldehyde dehydrogenase (ALDH-3) may help to protect organisms from certain environmental aldehydes by catalysing their detoxification. Consistent with this notion are the reports that relatively high levels of this enzyme are present in tissues, e.g. stomach mucosa and lung, that are so-called ports of entry for such agents. Further, it is found in human saliva. The present investigation revealed that small amounts of this enzyme are also present in human salivary glands; mean values for ALDH-3 activities (NADP-dependent enzyme-catalysed oxidation of benzaldehyde) in cytosolic fractions prepared from submandibular and parotid glands were 52 (range: 29-92) and 44 (range: 13-73) mIU/g tissue, respectively. Essentially identical or slightly lower levels of this enzyme activity were found in pleomorphic adenomas, an undifferentiated carcinoma, and an adenocystic carcinomas, of the parotid gland. On the other hand, Warthin tumours, and mucoepidermoid carcinomas of the parotid gland exhibited relatively elevated levels of ALDH-3 activity; mean values were 1200 (range: 780-1880) and 810 (range: 580-1200) mIU/g tissue, respectively. The ALDH-3 found in normal salivary glands was, as judged by physical, immunological and kinetic criteria, identical to human stomach mucosa ALDH-3 whereas the ALDH-3 present in Warthin tumours, and mucoepidermoid carcinomas, of the parotid gland appeared to be a subtle variant thereof. Qualitatively paralleling the relatively elevated ALDH-3 levels in mucoepidermoid carcinomas and Warthin tumours were relatively elevated levels of glutathione S-transferase (alpha and pi) and DT-diaphorase. As was the case with ALDH-3 levels, glutathione S-transferase (alpha and pi) and DT-diaphorase levels were not elevated in pleomorphic adenomas. Glutathione S-transferase mu was not detected in the two normal parotid gland samples, or in the single pleomorphic adenoma sample, tested. It was found in the single mucoepidermoid carcinoma sample, and in one of the two Warthin tumour samples tested. Cellular levels of ALDH-3, glutathione S-transferases and/or DT-diaphorase could be useful criteria when the decision to be made is whether a salivary gland tumour is a mucoepidermoid carcinoma. ALDH-3 and glutathione S-transferases are known to catalyse the detoxification of two agents that are used to treat salivary gland tumours, viz. cyclophosphamide and cisplatin, respectively. Thus, elevated levels of these enzymes in the mucoepidermoid carcinomas must account for, or at least contribute to, the relative ineffectiveness of these agents when used to treat this tumour.

Synthesis and degradation of basement membranes in benign and malignant salivary gland tumours. A study by in situ hybridization.

In this study we investigated the mRNA expressions of 72 kD and 92 kD type IV collagenases, alpha 1(IV) chain of type IV collagen, and laminin B1 chain mRNAs in a set of malignant and benign salivary gland tumours and compared the results with non-neoplastic salivary gland tissue. While only a few cases expressed 72 kD type IV collagenase mRNA or alpha 1(IV) chain of type IV collagen mRNA in tumour cells, 92 kD type IV collagenase and laminin mRNA synthesis could be seen in the neoplastic cells of many tumours. Stromal fibroblasts or endothelial cells demonstrated mRNA synthesis for all these proteins to a variable degree except for Warthin's tumours, in which no synthetic activity for any of the proteins could be seen. Since signals for 92 kD type IV collagenase mRNA could be seen in non-neoplastic epithelial cells of the salivary gland, the synthesis of 92 kD type IV collagenase by tumour cells can be regarded as an intrinsic property of salivary gland epithelial cells. The pattern of mRNA synthesis for 72 kD and 92 kD type IV collagenases follows that observed in other tumours, in which the stromal cells also mainly synthesize 72 kD type IV collagenase while epithelial tumour cells more readily express 92 kD type IV collagenase mRNA. The synthesis of type IV collagenases by malignant tumours has been suggested to be of crucial importance for invasion and metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased expression of the enzyme beta 1-4-galactosyltransferase is associated with human parotid neoplasms.

Human biopsy samples of parotid gland neoplasms were examined for the level of enzyme activity of the glycosyltransferase, beta 1-4-galactosyltransferase. An analysis of an adenoid cystic carcinoma, Warthin's tumor, mucoepidermoid carcinoma, and five pleomorphic adenomas all revealed elevated levels of enzyme activity. Evidence for plasma membrane beta 1-4-galactosyltransferase activity was provided by membrane fractionation as well as intact cell enzyme assays. On the other hand, the major protein of human saliva, salivary alpha-amylase, was substantially reduced in the same tissue compared with adjacent normal parotid gland tissue. The trichloroacetic acid-soluble proteins isolated from gland homogenates were also reduced in two of the carcinoma samples but increased in the pleomorphic adenomas. Additionally, the proliferation of these cells, in vitro, could be retarded by culturing in media containing the galactosyltransferase specific modifier protein, alpha-lactalbumin, or the nucleotide sugar, UDP-galactose.

Localization of salivary amylase and epithelial membrane antigen in salivary gland tumours by means of immunoperoxidase and immunogold-silver techniques.

A series of 87 salivary glands was examined using an immunogold-silver technique for salivary gland amylase (SGA) and epithelial membrane antigen (EMA) and an indirect immunoperoxidase technique for both antigens. The specimens comprised 21 pleomorphic adenomas, 3 monomorphic adenomas, 25 adenolymphomas, 5 mucoepidermoid carcinomas, 3 acinic cell tumours, 8 adenoid cystic carcinomas, 2 adenocarcinomas and 8 undifferentiated carcinomas. In addition 5 normal salivary glands and 6 salivary glands showing benign lymphoepithelial lesions were included.

Immunohistochemical demonstration of steroid C-21 hydroxylase in normal and neoplastic salivary glands.

The presence of steroid C-21 hydroxylase in normal and neoplastic salivary glands was investigated immunohistochemically with the use of antibody against cytochrome P-450 specific for steroid 21-hydroxylation (P-450C21). In normal salivary glands, P-450C21 was exclusively present in the excretory duct system (intercalating, striated and large excretory ducts), and not observed in acini. In salivary gland tumors, P-450C21 was observed in most epithelial cells of duct origin within pleomorphic adenomas including cells of amorphous groups scattered in myxoid areas, and in adenolymphoma. Some mucous cells in mucoepidermoid tumor also were positive for this enzyme. These findings in the normal and neoplastic salivary gland suggest that the expression of P-450C21 is closely related to ductal differentiation.

Immunohistochemical investigation of lysozyme, lactoferrin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and ferritin in parotid gland tumors.

Presence of lysozyme, lactoferrin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and ferritin was examined by the immunoperoxidase method in 15 consecutive parotid gland tumors as well as in normal parotid gland tissue. Lysozyme and lactoferrin were detected in intercalated duct cells of normal tissue and in the epithelial component of pleomorphic adenomas. alpha 1-antitrypsin, alpha 1-antichymotrypsin and ferritin were found in both epithelial and mesenchymal components of pleomorphic adenomas but not in normal parotid tissue. In the epithelial component of adenolymphoma only alpha 1-antichymotrypsin and lactoferrin were observed. The results would support a tentative histogenetic link between the intercalated duct cell and the epithelial component of the pleomorphic adenoma.

Characteristics of the epithelial component of parotid adenolymphoma.

Parotid adenolymphoma is composed of two histologic components, epithelial and lymphoid. Although some theories regarding the histogenesis of this tumor have long been disputed, there have been no definite conclusions. The purpose of this study was to clarify the origin of the epithelial components of this tumor using histochemical and immunopathological techniques, electron microscopy and a survey of HE-stained tumor sections. The results obtained indicated that the functions of the epithelial components were similar to those of the striated duct of the normal parotid gland, and morphological studies showed that the origin of the epithelial components may arise from parotid ductal inclusion in the lymphnodes in or around the parotid gland.

[Oncocyte cells in salivary tumors: frequency, histoenzymological and ultrastructural characteristics]. / Les tumeurs salivaires à cellules oncocytaires: fréquence, caractères histo-enzymologiques et ultrastructuraux.

Two types of salivary monomorphic adenomas, the so-called adenolymphoma and oncocytoma (75 cases in a series of 873 salivary gland tumors) were studied. These tumors were almost always located in major salivary glands (essentially in the parotid gland). They were much more common in men (85%) than in women. The oncocyte represented the characteristic cell in these two neoplasms. By electron microscopy, they were seen to contain numerous and abnormal mitochondriae and well-developed lysosomal systems. These findings were correlated with a high level of activity of oxidative enzymes and of acid phosphatases. The histogenesis of these tumors was discussed. They seemed to arise from aberrant striated ducts embedded in heterotopic lymph nodes. The tumoral oncocytes would suffer a primary disturbance of their oxidative metabolism followed by a compensative mitochondrial hypertrophy.

[Parotid cystadenolymphomas : histo-enzymological and ultrastructural study in 6 cases (author's transl)]. / Cystadénolymphomes parotidiens. Etude histo-enzymologique et ultrastructurale. 6 observations.

Histo-enzymological and ultrastructural studies in 6 cases of cystadenolymphoma were able to confirm the marked metabolic activity of the oncocytic cells, which from the major part of these tumours. The oncocytes demonstrate greatly enhanced enzymatic activity, particularly of those enzymes concerned with oxydative metabolism and the diaphorases. Electron microscopy of the oncocytes shows that they are filled with mitochondria of very varied size and form, sometimes associated with the presence of several intracytoplasmic crystalloids. The second, lymphoplasmocytic component of these tumours present no particular morphological features.

[Simultaneous estimations of flowrate, protein, immunoglobulin a and lysozyme secretion of human parotid glands with whartin tumours and scintigraphic and sialographic examinations (author's transl)]. / Biochemische Befunde der Sekrete menschlicher Ohrspeicheldrüsen mit Zystadenolymphomen im Vergleich zu Sialographie und Szintigraphie

7 patients with uni- and bilateral Whartin tumors are examined. In comparison to sialographic and scintigraphic findings simultaneous estimations of flowrate, total protein, immunoglobulin A and lysozyme excretion of these glands in rest and under stimulation are done. Thereby the following results were found: 1. Flowrate is normal like in glands with pleomorphic adenomas. 2. Total protein secretion is significant lower in stimulated secretions. 3. Immunoglobulin A secretion is diminished in stimulated secretions, lysozyme is diminished under rest and stimulation.