Reduced HBME-1 immunoreactivity of papillary thyroid carcinoma and papillary thyroid carcinoma-related neoplastic lesions with Hürthle cell and/or apocrine-like changes

BACKGROUND: We have recently observed that Hürthle cell tumours and papillary thyroid carcinoma with tumour cells showing decapitation of luminal portion of the cytoplasm (apocrine-like changes) display negative or decreased immunoreactivity for HBME. The purpose of this study is to correlate papillary thyroid carcinoma with positive and negative immunoreactivity for HBME with the histopathological features. METHODS AND RESULTS: Two hundred and five thyroid neoplasms including carcinoma and adenomas were grouped into Hürthle cell tumours, tumours with or without some features of Hürthle cells, tumours with apocrine-like changes and adenomas with or without limited nuclear features of papillary thyroid carcinoma but not diagnostic for papillary thyroid carcinoma. All neoplasms were submitted for immunostaining with cytokeratin 19 (CK19) and HBME. Papillary thyroid carcinoma, follicular carcinoma and follicular adenoma that have areas of limited nuclear features but not diagnostic for papillary thyroid carcinoma showed stronger immunostaining for HBME than their respective counterparts with Hürthle cell changes. All Hürthle cell tumours showed negative to focal reactivity. This decrease of reactivity for HBME was proportional to the levels of Hürthle cell changes. In addition, focal to extensive apocrine-like changes were seen in most Hürthle cell neoplasms and rarely seen in non-Hürthle cell neoplasms. Apocrine-like changes abolished or decreased HBME immunoreactivity of papillary thyroid carcinoma and tumours with limited nuclear features. Immunostaining for cytokeratin AE3 was not affected by Hürthle cell or apocrine-like changes. CONCLUSIONS: All papillary thyroid carcinomas without Hürthle cell or apocrine-like differentiation are reactive for HBME. Hürthle cell tumours and tumours with Hürthle cell or apocrine-like changes show negative or focal reactivity for HBME. Except for this limitation, HBME is a sensitive marker for papillary thyroid carcinoma and tumours with limited nuclear features.     

Breast tumor resembling the tall cell variant of papillary thyroid carcinoma: a case report

The breast tumor resembling the tall cell variant of papillary thyroid carcinoma is a very unusual mammary carcinoma whose histologic and predominant nuclear features mimic a papillary thyroid carcinoma. We report the case of a 64-year-old woman who presented with a palpable nodule in the right breast. Fine needle aspiration disclosed abundant cellularity with isolated cells, sheets, and papillary formations of epithelial cells with nuclear grooves. Histologically, the neoplastic cells were arranged in a solid to papillary architecture, with follicular-like and cribriform areas. The cells were columnar to cuboidal with eosinophilic cytoplasm, clear chromatin, nuclear grooves, and occasional nuclear pseudoinclusions. Tumor cells were positive for cytokeratins, alpha and beta-estrogen receptors, progesterone receptor, androgen receptor, CEA, and bcl-2. We searched for BRAF mutations with negative results. Recognizing the cytologic and histologic characteristics of these peculiar mammary tumors that mimic thyroid carcinomas can avoid unnecessary clinical investigations.     

Intraepithelial Neutrophils in Thyroid Fine-Needle Aspiration: A Portent of Aggressive Thyroid Cancer?

We report three patients with papillary thyroid carcinoma in whom fine-needle aspiration (FNA) showed neutrophils within tumor cells. All three patients presented with large neck masses; at excision, two proved to be tall cell variants of papillary cancer. Nodal metastasis, extrathyroidal extension, and vascular invasion were found in both cases. One patient has experienced recurrent disease; the other has an increasing thyroglobulin titer but no clinically appreciable recurrence. The third patient refused further therapy, but brain metastases were noted clinically; this patient died of disease. In each case, FNA showed tumor clusters with characteristic nuclear features, papillary groups, and psammoma bodies. Neutrophils were present in the cytoplasm of tumor cells in the absence of necrosis. Immunostaining for proliferating cell nuclear antigen (PCNA), MIB-1 (Ki-67), and p53 tumor suppressor gene product was markedly positive. Intraepithelial neutrophils have not been previously reported in differentiated thyroid tumors. We postulate that these neoplasms produce specific leukocyte-attracting cytokines analogous to those produced by anaplastic and poorly differentiated thyroid carcinomas. We believe the finding of intraepithelial leukocytes in the absence of necrosis in thyroid FNA specimens represents a characteristic of clinically aggressive differentiated papillary neoplasms; in our small series, each represented a tall cell variant of papillary carcinoma.     

TGFB,TGFB Receptors,Ki-67, and p27(Kip)l Expression in Papillary Thyroid Carcinomas

Although most papillary thyroid carcinomas behave as low-grade neoplasms and are generally associated with a good prognosis, some subgroups of these neoplasms represent more aggressive variants. In order to determine if differences in the behavior of these papillary carcinomas were related to expression of growth factors or cell-cycle proteins, we analyzed a series of papillary carcinomas including the conventional or usual type (n=27), tall cell (n=27), diffuse sclerosing (n=5), and columnar cell (n=2) variants for expression of transforming growth factor beta (TGFβ), TGFβ receptors (TGFβ-RI and II, the proliferation marker Ki-67, and for the cell-cycle inhibitory protein p27^Kip1 (p27). All groups of thyroid tumors expressed TGFβ and TGFβ-RI and RII by immunohistochemical staining. These was a marked increase in the Ki-67 labeling index after staining with antibody MIB-1 in the columnar cell tumors compared to the other groups, but this difference was not significant because of the small number of tumors in this group. The cell-cycle inhibitory protein p27 was expressed in all groups and was not significantly different between groups. Normal thyroid cells had a higher labeling index for p27 compared to papillary carcinomas. These results indicate that TGFβ and TGFβ receptors I and II are commonly expressed in the usual and in variant forms of papillary thyroid carcinomas, and that there is decreased expression of p27 protein in all of these neoplasms compared to normal thyroid. The biological basis for the more aggressive behavior of these variants of papillary thyroid carcinoma remains uncertain.     

Utility of immunohistochemistry in the evaluation of necrotic thyroid tumors

We have previously shown that necrotic tumors retain their immunoreactivity for a range of cytokeratin antibodies. Some thyroid tumors undergo extensive necrosis after fine-needle aspiration (FNA) procedures. We evaluated the sensitivity of antibodies on necrotic thyroid tumors by examining a series of thyroid tumors consisting of 10 Hurthle cell neoplasms, 8 carcinomas, and 2 follicular adenomas (12 with post-FNA necrosis). These were stained with antibodies to AE1/3, PANCK, thyroglobulin and S100. Four of the cases of papillary carcinoma were also stained with antibodies to CK19. As a control for the specificity of thyroglobulin immunoreactivity in necrotic tissue, we also stained 11 nonthyroid tumors with extensive necrosis (7 carcinomas, 1 lymphoma, 2 melanomas, 1 sarcoma) for thyroglobulin. Six of 8 thyroid carcinomas were positive for AE1/3 and PANCK; AE1/3 reactivity was retained in necrotic areas of 4 of 6. AE 1/3 was positive in necrotic portions of 5 of 10 Hurthle cell lesions, whereas PANCKwas negative in all but 1. Thyroglobulin reactivity was present in 18 of 20 cases, and was preserved in necrotic portions of 5 of 6 carcinomas, as well as 8 of 10 Hurthle cell neoplasms. S100 cytoplasmic reactivity was present in 4 Hurthle cell neoplasms and 1 papillary carcinoma; this staining was lost in necrotic areas. No staining by thyroglobulin was observed in the viable or necrotic areas of nonthyroid neoplasms. The preservation of cytokeratin reactivity, measured by AE1/3, in thyroid neoplasms is a diagnostically useful feature in spontaneous and post-FNA infarction. PANCK is not a well-preserved marker in necrotic thyroid tissue. This difference may be due to detection of keratin 19 by AE1/3. Thyroglobulin is preserved in some necrotic thyroid carcinomas and in Hurthle cell lesions. Preservation of thyroglobulin reactivity in necrotic tissue is specific in that no staining was observed in nonthyroid neoplasms. These results suggest that thyroglobulin is useful in demonstrating thyroid lineage of both primary and metastatic necrotic tumor masses.     

Expression of D2-40 in adjunct diagnosis of papillary thyroid carcinoma

The clinical pathologic criteria for nuclear features of papillary thyroid carcinoma are subjective and sometimes cannot distinguish carcinoma from adenomatous goiter and follicular neoplasms. No single antibody has demonstrated high sensitivity or specificity in making these distinctions. Using quantitative analysis of immunohistochemical staining with D2-40, a recently available monoclonal antibody used as a lymphatic endothelial marker, we examined 72 cases of papillary carcinoma. Controls included 36 follicular adenomas, 36 follicular carcinomas, and 20 adenomatous goiters with papillary hyperplasia. Cytoplasmic D2-40 immunoreactivity was present in 60 of 72 papillary carcinomas, 2 cases of follicular adenoma and 2 cases of follicular carcinoma, whereas no adenomatous goiter or normal thyroid glands contained positive epithelial cells. Overexpression of D2-40 in papillary thyroid carcinomas thus has potential diagnostic utility in differentiating these tumors from their potential histologic mimics.     

Dark and pale cerebriform nuclei in FNA smears of usual papillary thyroid carcinoma and its variants

The dark (hyperchromatic) cerebriform nucleus was recently described as a frequent finding in histopathology sections of papillary carcinoma of the thyroid. In the present study, we tried to determine the frequency of dark cerebriform nuclei in the fine-needle aspiration (FNA) smears of papillary thyroid carcinomas and compared it with those of other thyroid lesions, such as follicular neoplasms and benign hyperplastic lesions. In addition to the above-mentioned nuclear feature, pale (hypochromatic) cerebriform nucleus and other well-established cytomorphological criteria used in the diagnosis of papillary thyroid carcinomas were analyzed. FNA smears of a total of 102 cases comprising of 61 papillary carcinomas, 10 cases of suspicious papillary carcinomas, 12 follicular neoplasms, and 19 benign hyperplastic lesions were studied. Both the dark and pale cerebriform nuclei were found in a significantly higher number of cases of papillary thyroid carcinomas compared with follicular neoplasms (P = 0.0003 and P < 0.0001, respectively) or benign hyperplastic lesions (P = 0.0004 and P < 0.0001, respectively). Review sections available in 24 cases showed agreement between the cytopathological and the histopathological diagnoses in 18 (94.7%) of 19 papillary carcinomas. Thus, the dark and pale cerebriform nuclei can be regarded as useful cytomorphological parameters in the diagnosis of papillary thyroid carcinoma.     

A marker for primary choroid plexus neoplasms.

Primary choroid plexus (CP) tumors are rare neoplasms that present in childhood or, less frequently, in adult life. The majority are benign and amenable to complete surgical excision, but occasionally more invasive variants are encountered. Although generally pathologically distinct, occasionally primary CP neoplasms may be difficult to distinguish from metastatic papillary carcinomas or papillary ependymomas. Conventional cytologic markers are not sufficiently specific to permit accurate diagnosis of primary CP tumors. The authors have reported that the CP is the unique site of synthesis within the brain of transthyretin (TTR, prealbumin), a transport protein for thyroxine and retinol. They therefore investigated the utility of TTR as a biochemical marker for CP tumors. They detected intense immunoreactivity for TTR at high dilutions of primary antiserum in the neoplastic epithelium of all of nine primary CP tumors (six papillomas and three carcinomas), but not in eight cellular or three papillary intracerebral ependymomas, meningiomas, oligodendrogliomas, astrocytomas, primary extracerebral papillary carcinomas (three thyroid, two breast) or five of six cerebral metastases from systemic papillary carcinomas. In one case of cerebral metastasis from papillary thyroid carcinoma, rare isolated immunoreactive cells were observed. Faint staining of the stromal-ependymal junction was seen in myxopapillary ependymomas of the filum terminale, which were otherwise nonreactive. By in situ hybridization, TTR mRNA was abundant in neoplastic CP epithelium, confirming local TTR synthesis. The authors conclude that TTR is synthesized by neoplastic CP epithelium and is an excellent marker for primary CP neoplasms.     

Comparison of the WHO/ISUP classification and cytokeratin 20 expression in predicting the behavior of low-grade papillary urothelial tumors. World/Health Organization/Internattional Society of Urologic Pathology.

It has not been possible to identify those low-grade papillary transitional cell bladder tumors that will recur based on conventional histopathologic assessment. Both the new World Health Organization/International Society of Urologic Pathology (WHO/ISUP) classification of transitional cell papillary neoplasms and the pattern of tumor cytokeratin 20 (CK20) immunostaining have been suggested as means of improving prognostication in low-grade transitional cell tumors. Forty-nine low-grade, noninvasive papillary transitional cell tumors were identified for the period between 1984 and 1993. The recently described WHO/ISUP classification was applied, and the tumors were classified histologically as papilloma, papillary neoplasm of low malignant potential (LMP) or low-grade papillary carcinoma. After CK20 immunostaining, the expression pattern in the tumor was classified as normal (superficial) or abnormal. Of 49 tumors, 20 were classified as papillary neoplasms of LMP and five of these patients (25%) experienced a recurrence. Of 29 tumors classified as low-grade papillary carcinoma, 14 (48.2%) recurred. In 46 of 49 cases, the CK20 immunostaining could be evaluated. Sixteen tumors showed normal (superficial) pattern of CK20 expression, and four (25%) of these patients experienced a recurrence. In contrast, of 30 patients with abnormal CK20 staining of their tumors, 15 (50%) patients had one or more recurrences. In this study, papillary neoplasms of LMP (as per the WHO/ISUP classification system) had a lower recurrence rate than low-grade papillary transitional cell carcinoma. Similarly low-grade urothelial tumors showing a normal CK20 expression pattern recurred less frequently than tumors with an abnormal pattern of CK20 staining. Neither of these differences was statistically significant, and recurrences were observed in 20% of patients whose tumors were both classified as papillary neoplasms of LMP and showed normal CK20 immunostaining; thus they do not allow a change in our current management of patients with low-grade papillary urothelial tumors, with close follow-up for all patients.     

The association of well-differentiated thyroid carcinoma with insular or anaplastic thyroid carcinoma; evidence for dedifferentiation in tumor progression

The sequence of tumorigenesis in the thyroid is unclear. It has been proposed that anaplastic carcinomas of the thyroid develop by dedifferentiation in pre-existing differentiated carcinomas. We reviewed all anaplastic and insular (poorly differentiated) thyroid carcinomas in a consultation practice of thyroid pathology that included more than 400 thyroid cancers. Sixteen tumors (4%) were classified as anaplastic or insular (poorly differentiated) thyroid carcinomas. We examined these cases to determine whether these carcinomas were associated with well-differentiated neoplasms of follicular cell derivation. Ten patients were women and 6 were men, and ages ranged from 29 to 85 years; 10 patients with anaplastic carcinomas and 2 with insular carcinomas were 56 years or older, whereas 3 of the 6 patients with insular carcinomas were 31 years or younger. Four tumors were composed exclusively of anaplastic carcinoma; all were represented only by incisional biopsies. One insular carcinoma infiltrated and destroyed all underlying thyroid tissue. In the remaining total, subtotal, or hemithyroidectomy specimens, areas of well-differentiated papillary or follicular carcinoma were found. Some differentiated papillary lesions had a wide spectrum of morphologies, including Hurthle cell, tall cell, and columnar cell features. In the literature, simultaneous or previous occurrence of well-differentiated thyroid carcinomas with anaplastic carcinomas is extremely variable, ranging from 7–89% of cases. in experimental animals, serial transplantation of differentiated thyroid tumors has been shown to lead to anaplastic transformation. Our findings suggest that the majority of anaplastic thyroid carcinomas in humans arise from well-differentiated tumors. However, only a very small number of differentiated carcinomas progress to anaplastic lesions; the factors underlying this phenomenon remain to be identified.     

Quantitative image cell analysis of cytologic smears for DNA ploidy in renal parenchymal neoplasms.

Quantitative image cell analysis for DNA ploidy was performed on cytologic smears from a series of 19 histologically proven cases of renal parenchymal tumors. These cases included chromophobe-cell carcinoma (n = 5), oncocytoma (n = 5), papillary carcinoma (n = 2), and conventional renal-cell carcinoma (n = 7). All chromophobe renal-cell carcinomas were composed predominantly of hypodiploid cells, while the five oncocytomas were virtually entirely composed of diploid cells. The papillary and conventional renal-cell carcinomas, on the other hand, showed a variety of ploidy profiles. Scatterplots generated by plotting nuclear DNA mass against nuclear area produced patterns that correlated with the morphologic type of the neoplasms. These findings indicate that quantitative image cell analysis for DNA ploidy may provide valuable clues that could be helpful in arriving at a precise diagnosis of renal parenchymal tumors. Diagn. Cytopathol. 1999;21:223-229.     

The many faces and mimics of papillary thyroid carcinoma

This article provides an overview of the 15 histologic variants of papillary thyroid carcinoma listed by the 2004 World Health Organization (WHO) monograph on endocrine tumors. The histologic features, differential diagnosis, and clinical course of each variant are discussed in some detail. The follicular variants (conventional and macrofollicular) constitute a morphologic challenge because the majority of these tumors are encapsulated and, also, because, in many tumors, not all neoplastic cells show the nuclear features considered to be diagnostic of papillary carcinoma. As a result, most of these tumors are missed even by experienced pathologists. Moreover, hyperplastic thyroid lesions, follicular adenomas, and Hashimoto’s thyroiditis may contain cells with clear nuclei resembling those of papillary carcinoma. Papillary carcinomas composed entirely of hyperchromatic cells have been overlooked. The WHO monograph defines papillary carcinoma with focal spindle and giant cell carcinoma components but its clinical behavior is unknown. Papillary carcinoma with an insular pattern that does not show the artifactual separation of the cell nests has been misinterpreted as the solid variant of papillary carcinoma. Papillary microcarcinomas include not only the conventional type and the follicular variants but also the tall cell and columnar cell variants.     

The contribution of molecular pathology to the classification of thyroid tumors

Significant molecular advances have been undertaken for the past two decades in the field of thyroid follicular neoplasms, including a detailed genomic profile of papillary thyroid carcinoma (PTC) by The Cancer Genome Atlas (TCGA) project. These molecular discoveries led to a better understanding of the pathogenesis of thyroid neoplasms and resulted in reclassification of certain types of thyroid tumors. This review discusses how, 1) the molecular profiles of follicular-patterned lesions led to the reclassification of the follicular variant of PTC into non-invasive follicular thyroid neoplasm with papillary like nuclei, 2) the genotyping of Hürthle cell neoplasm provided the rationale to classify these tumors independently from follicular adenomas and carcinomas, and 3) BRAF and RAS molecular signatures have the potential of subclassifying PTC and poorly differentiated thyroid carcinoma into clinically relevant molecular subtypes.     

Galectin-3, a marker of well-differentiated thyroid carcinoma, is expressed in thyroid nodules with cytological atypia

AIMS: The distribution of galectin-3, a widely recognized marker of well-differentiated thyroid carcinoma, was investigated in 95 thyroid lesions including nodules with foci of cytoarchitectural atypia. METHODS AND RESULTS: Twenty-eight papillary carcinomas, five follicular carcinomas, one Hurthle cell carcinoma, three poorly differentiated carcinomas, one anaplastic carcinoma, 25 nodular hyperplasias and 27 follicular adenomas, including nodules with atypical features, three neoplasms of undetermined malignant potential and two thyroiditis cases were examined. By immunohistochemistry, galectin-3 was consistently found in carcinomas; otherwise benign nodules exhibited galectin-3-positive clusters of cells with poorly developed features of differentiated carcinoma (mainly of papillary type) such as nuclear chromatin clearing, nuclear clefting, pseudoinclusions, which, in each case, were not histologically sufficient to warrant a definitive diagnosis of malignancy. In other nodules galectin-3 staining was negative. The latter were either clearly benign or showed constantly a minor degree of chromatin clearing and of other atypical features when compared with galectin-3-positive cases. CONCLUSIONS: Galectin-3, a reliable marker of differentiated thyroid carcinoma as confirmed in our series of malignant neoplasms, appears expressed in nodules with an overall benign appearance but with focal areas suspicious for malignancy. The significance of such findings needs to be further investigated.     

Nuclear grooves in fine-needle aspiration biopsies of breast lesions: Do they have any significance?

Nuclear grooving is a recognized morphologic feature frequently seen in papillary carcinoma of the thyroid. This feature is also occasionally seen in other nonneoplastic and neoplastic conditions. Nuclear grooves have been described in tubular carcinoma of the breast. However, the significance of nuclear grooves in benign and malignant conditions of the breast has been rarely studied. In a retrospective study, we searched for the presence of nuclear grooves in Papanicolaou-stained and Diff-Quik-stained fine-needle aspiration biopsies (FNAB) of 50 cases of primary breast carcinoma, 25 cases of proliferative breast disease, and 25 cases of fibroadenoma. In addition, 10 cases of metastatic breast carcinoma diagnosed by FNAB were reviewed. Nuclear grooves were identified in 39 of 50 (78%) of the histologically confirmed primary breast carcinomas and in 9 of 10 (90%) of the cases of metastatic breast carcinoma in the Papanicolaou-stained smears. Nineteen of 50 (38%) of the cases of proliferative breast disease/fibroadenoma showed nuclear grooves in the Papanicolaou-stained smears. The difference between the percentage of cases showing nuclear grooves seen in the Papanicolaou-stained primary breast carcinomas and metastatic breast carcinomas compared with the benign breast lesions was statistically significant (P < 0.001 in the primary breast carcinoma cases and P < 0.01 in the metastatic breast cancer cases). Nuclear grooves were identified less often in the Diff-Quik-stained smears, and their presence in malignant lesions versus cases diagnosed as benign breast disease was not statistically significant. This study suggests that, although the presence of nuclear grooves is more frequently seen in malignant breast lesions, their presence cannot totally exclude the possibility of benign breast disease. The presence of nuclear grooves, however, may serve as a diagnostic clue in metastatic tumors of unknown primary. Diagn. Cytopathol. 1998;18:333–337. © 1998 Wiley-Liss, Inc.     

Genetic Changes in Chromosomes 1p and 17p in Thyroid Cancer Progression

Little is known about the genetic alterations that occur during the progression of thyroid neoplasms. To understand better the biology of thyroid tumors, we investigated several genetic loci in benign and malignant thyroid neoplasms. Forty-one thyroid tumors (6 adenomas, 16 papillary, 14 follicular, and 5 anaplastic carcinomas) were studied. Normal and tumor cells were microdissected from paraffin-embedded tissues. DNA was used for polymerase chain reaction-based loss of heterozygosity (LOH) analysis with the following markers: D1S243 (1p35–36), D1S165 (1p36) and D1S162 (1p32), TP53 (17p13), and INT-2 (11q13). Immunohistochemistry for Ki-67 was performed. The Ki-67 labeling index (LI) was the percentage of positive tumor cells. LOH at 1p was seen in 2 of 5 (40%) informative cases of anaplastic carcinoma (2 of 2 at D1S162 and 1 of 2 at D1S165) and in 2 of 11 (18%) informative cases of follicular carcinoma (2 of 7 at D1S243, 2 of 7 at D1S165, and 1 of 6 at D1S162). One anaplastic (20%) and two follicular carcinomas (14%) had LOH in at least two of the 1p loci analyzed. None of the adenomas and papillary carcinomas had LOH at these loci. LOH at 17p and 11q13 were infrequent. Ki-67 LI was 1.4, 7, 16, and 65% in adenomas, papillary, follicular, and anaplastic carcinomas, respectively. Allelic loss at 1p may occur in aggressive types of thyroid carcinoma and may be a marker of poor prognosis. LOH at 1p may represent a late genetic event in thyroid carcinogenesis. LOH at 17p and 11q13 (MEN gene locus) is uncommon in thyroid neoplasms.     

High level of tumour protein p53-induced nuclear protein 1 (TP53INP1) expression in anaplastic carcinoma of the thyroid

AIMS: Tumour protein p53-induced nuclear protein 1 (TP531NP1) is a stress-induced protein and plays a role in cell cycle arrest and p53-mediated apoptosis. In this study, we investigated TP531NP1 expression in human thyroid neoplasms. METHODS: We immunohistochemically investigated TP531NP1 in 197 cases of various thyroid neoplasms. RESULTS: Normal follicles did not express TP531NP1. All 39 (20 minimally invasive and 19 widely invasive) follicular carcinomas and 20 adenomas were negative for or expressed only low levels of TP531NP1 except for one widely invasive follicular carcinoma. Of 100 papillary carcinomas, only four (4%) expressed high levels of TP531NP1, and the remaining 96 (96%) were classified into the low group. There were no significant relationships between TP531NP1 expression and clinicopathological features of papillary carcinoma. However, 36 of the 38 (94.7%) anaplastic carcinomas expressed high levels of TP531NP1 and the incidence was significantly higher (p<0.0001) than that in other neoplasms. CONCLUSIONS: These findings suggest that TP531NP1 plays a significant role in the progression of anaplastic carcinoma or contributes to anaplastic transformation from papillary or follicular carcinoma, which is in sharp contrast to findings in previous in vitro and in vivo studies.     

Enzyme histochemistry and thyroid neoplasia

The authors have examined the enzyme histochemical staining of surgically removed human thyroid tissue in an attempt to identify markers that might be useful in the histopathologic diagnosis of thyroid neoplasms. Fresh thyroid glands and other tissues were fixed in cold (4 degrees C) 4% paraformaldehyde and embedded in glycol methacrylate. Forty-two specimens were studied in thin sections, which gave excellent histologic detail and enzyme preservation. Cytologic detail was similar to that in Papanicolaou-stained smears, with good definition of nuclear inclusions and grooves, particularly in cases of papillary carcinoma. The enzyme histochemical reactions studied were as follows: adenosine triphosphatase, alkaline and acid phosphatases, alpha-naphthyl acetate esterase, and 5'-nucleotidase. Thyroid epithelial cells and the benign neoplasms derived from them were typically positive for 5'-nucleotidase, alpha-naphthyl acetate esterase, and acid phosphatase, and negative for adenosine triphosphatase and alkaline phosphatase. Staining for adenosine triphosphatase was present in papillary and follicular carcinomas and was seen in benign glands only under certain circumstances such as Graves' disease. The adenosine triphosphatase reaction therefore appears to be helpful in distinguishing between benign and malignant neoplasms derived from thyroid epithelium in humans and may be a useful adjunct to routine morphology.     

Utility of galectin 3 expression in thyroid aspirates as a diagnostic marker in differentiating benign from malignant thyroid neoplasms

Galectin-3 is a 31kD beta-galactoside binding lectin, which is known to be expressed in various neoplasms including thyroid tumors. This study was conducted to study the role of galectin-3 in differentiating benign from malignant thyroid nodules onfine needle aspirates (FNAC). Galectin-3 immuocytochemistry was performed in 70 cases with adequate smears. The cytology diagnosis of these cases was: papillary carcinoma (25), follicular neoplasm (16), adenomatous goiter (20), hyperplastic nodule (5), medullary carcinoma (5) and anaplastic carcinoma (1). Galectin-3 positivity was seen in 80% of papillary carcinomas, 37.5% offollicular neoplasms and in 60% of benign nodules. The single case of anaplastic carcinoma was positive but all the cases of medullary carcinoma were negativefor galectin-3. Three of thefollicular neoplasms that were diagnosed on histology as carcinoma were positive on cytology and one case offollicular adenoma was also positive. Our study shows that galectin-3 is strongly expressed in smears of papillary carcinoma. However, since it is also expressed in a variety of benign lesions, its role as a pre-surgical markerfor differentiating benignfrom malignant thyroid nodules is limited.     

Hereditary and Sporadic Papillary Renal Carcinomas with c-met Mutations Share a Distinct Morphological Phenotype

Germline mutations of c-met oncogene at 7q31 have been detected in patients with hereditary papillary renal cell carcinoma. In addition, c-met mutations were shown to play a role in 13% of patients with papillary renal cell carcinoma and no family history of renal tumors. The histopathology of papillary renal cell carcinoma with c-met mutations has not been previously described. We analyzed the histopathology of 103 bilateral archival papillary renal cell carcinomas and 4 metastases in 29 patients from 6 hereditary papillary renal cell carcinoma families with germline c-met mutations and 6 papillary renal cell carcinomas with c-met mutations from 5 patients with no family history of renal tumors. Twenty-five sporadic renal tumors with prominent papillary architecture and without somatic c-met mutations were evaluated for comparison. All papillary renal cell carcinomas with c-met mutations were 75 to 100% papillary/tubulopapillary in architecture and showed chromophil basophilic, papillary renal cell carcinoma type 1 histology. Fuhrman nuclear grade 1-2 was seen in tumors from 23 patients, and nuclear grade 3 was observed focally in 8 patients. Seventeen patients had multiple papillary adenomas and microscopic papillary lesions in the surrounding renal parenchyma. Clear cells with intracytoplasmic lipid and glycogen were focally present in tumors of 94% papillary renal cell carcinoma patients. Clear cells of papillary renal cell carcinoma had small basophilic nuclei, and clear cell areas lacked a fine vascular network characteristic of conventional (clear) cell renal cell carcinoma. We conclude that papillary renal cell carcinoma patients with c-met mutations develop multiple, bilateral, papillary macroscopic and microscopic renal lesions. Renal tumors with c-met genotype show a distinctive papillary renal cell carcinoma type 1 phenotype and are genetically and histologically different from renal tumors seen in other hereditary renal syndromes and most sporadic renal tumors with papillary architecture. Although all hereditary and sporadic papillary renal cell carcinomas with c-met mutations share papillary renal cell carcinoma type 1 histology, not all type 1 sporadic papillary renal cell carcinomas harbor c-met mutations.