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Alberto G Ayala - One of the best experts on this subject based on the ideXlab platform.
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Flat pattern of nephrogenic adenoma: previously unrecognized pattern unveiled using PAX2 and PAX8 immunohistochemistry
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Luan D TruongAbstract:Nephrogenic adenoma is a benign lesion of the urinary tract, particularly the urinary bladder. It is a gross and microscopic mimicker of urothelial neoplasm or metastatic carcinoma. Several histological patterns (tubular, tubulocystic, polypoid, papillary, fibromyxoid) have been recognized, but a flat pattern has not been described. Histologically, nephrogenic adenoma consists of tubules, cysts or papillae lined by flat to polygonal cells with frequent hobnail appearance. The stroma is often edematous or has a granulation tissue-like appearance with acute or chronic inflammation. By immunohistochemistry, nephrogenic adenomas are positive for renal epithelial markers CK7, CD10 and alpha-methylacyl-coenzyme A racemase, and negative for bladder urothelium or prostate markers. Recent studies have shown that nephrogenic adenomas are positive for PAX2 and PAX8. We encountered an interesting case of tubular nephrogenic adenoma with adjacent areas suspicious of flat urothelial atypia. Immunohistochemistry for PAX2 and PAX8 were positive in these areas, unveiling a flat pattern of nephrogenic adenoma. This case prompted us to study 15 cases of nephrogenic adenoma to determine additional instances of flat pattern and to assess the value of PAX2 and PAX8 immunoreactivity to diagnose nephrogenic adenoma. PAX2 and PAX8 immunostaining was positive in 14/15 and 15/15 cases, respectively. The flat pattern was present at least focally adjacent to tubular, polypoid and papillary areas, in 8/15 cases of nephrogenic adenoma. In conclusion, the flat pattern is a common finding in nephrogenic adenomas, but easily under recognized by morphologic examination and may be confused with flat urothelial lesions with atypia. Immunostains for PAX2 and PAX8 are useful in the detection of nephrogenic adenomas and particularly unveil those nephrogenic adenomas with flat pattern.
Meinrad Busslinger - One of the best experts on this subject based on the ideXlab platform.
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nephric lineage specification by pax2 and pax8
Genes & Development, 2002Co-Authors: Maxime Bouchard, Abdallah Souabni, Markus Mandler, Annette Neubuser, Meinrad BusslingerAbstract:The mammalian kidney develops in three successive steps from the initial pronephros via the mesonephros to the adult metanephros. Although the nephric lineage is specified during pronephros induction, no single regulator, including the transcription factor Pax2 or Pax8, has yet been identified to control this initial phase of kidney development. In this paper, we demonstrate that mouse embryos lacking both Pax2 and Pax8 are unable to form the pronephros or any later nephric structures. In these double-mutant embryos, the intermediate mesoderm does not undergo the mesenchymal-epithelial transitions required for nephric duct formation, fails to initiate the kidney-specific expression of Lim1 and c-Ret, and is lost by apoptosis 1 d after failed pronephric induction. Conversely, retroviral misexpression of Pax2 was sufficient to induce ectopic nephric structures in the intermediate mesoderm and genital ridge of chick embryos. Together, these data identify Pax2 and Pax8 as critical regulators that specify the nephric lineage.
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functional equivalence of the transcription factors pax2 and PAX5 in mouse development
Development, 2000Co-Authors: Maxime Bouchard, Peter Pfeffer, Meinrad BusslingerAbstract:Pax2 and PAX5 arose by gene duplication at the onset of vertebrate evolution and have since diverged in their developmental expression patterns. They are expressed in different organs of the mouse embryo except for their coexpression at the midbrain-hindbrain boundary (MHB), which functions as an organizing center to control midbrain and cerebellum development. During MHB development, Pax2 expression is initiated prior to PAX5 transcription, and Pax2(−/−) embryos fail to generate the posterior midbrain and cerebellum, whereas PAX5(−/−) mice exhibit only minor patterning defects in the same brain regions. To investigate whether these contrasting phenotypes are caused by differences in the temporal expression or biochemical activity of these two transcription factors, we have generated a knock-in (ki) mouse, which expresses a PAX5 minigene under the control of the Pax2 locus. Midbrain and cerebellum development was entirely rescued in Pax2(5ki/5ki) embryos. PAX5 could furthermore completely substitute for the Pax2 function during morphogenesis of the inner ear and genital tracts, despite the fact that the PAX5 transcript of the Pax2(5ki)allele was expressed only at a fivefold lower level than the wild-type Pax2 mRNA. As a consequence, the Pax2(5ki)allele was able to rescue most but not all Pax2 mutant defects in the developing eye and kidney, both of which are known to be highly sensitive to Pax2 protein dosage. Together these data demonstrate that the transcription factors Pax2 and PAX5 have maintained equivalent biochemical functions since their divergence early in vertebrate evolution.
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transcriptional repression by PAX5 bsap through interaction with corepressors of the groucho family
The EMBO Journal, 2000Co-Authors: Dirk Eberhard, Gerardo Jimenez, Barry Heavey, Meinrad BusslingerAbstract:PAX5 (BSAP) functions as both a transcriptional activator and repressor during midbrain patterning, B-cell development and lymphomagenesis. Here we demonstrate that PAX5 exerts its repression function by recruiting members of the Groucho corepressor family. In a yeast two-hybrid screen, the groucho-related gene product Grg4 was identified as a PAX5 partner protein. Both proteins interact cooperatively via two separate domains: the N-terminal Q and central SP regions of Grg4, and the octapeptide motif and C-terminal transactivation domain of PAX5. The phosphorylation state of Grg4 is altered in vivo upon PAX5 binding. Moreover, Grg4 efficiently represses the transcriptional activity of PAX5 in an octapeptide-dependent manner. Similar protein interactions resulting in transcriptional repression were also observed between distantly related members of both the Pax2/5/8 and Groucho protein families. In agreement with this evolutionary conservation, the octapeptide motif of Pax proteins functions as a Groucho-dependent repression domain in Drosophila embryos. These data indicate that Pax proteins can be converted from transcriptional activators to repressors through interaction with corepressors of the Groucho protein family.
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pax2 and homeodomain proteins cooperatively regulate a 435 bp enhancer of the mouse PAX5 gene at the midbrain hindbrain boundary
Development, 2000Co-Authors: Peter L Pfeffer, Maxime Bouchard, Meinrad BusslingerAbstract:Pax and homeodomain transcription factors are essential for the formation of an organizing center at the midbrain-hindbrain boundary (mhb) which controls the genesis of the midbrain and cerebellum in the vertebrate embryo. Pax2 and PAX5 are sequentially activated in this brain region, with Pax2 expression preceding that of PAX5. Using a transgenic reporter assay, we have now identified a conserved 435 bp enhancer in the 5′ flanking region of mammalian PAX5 genes which directs lacZ expression in the correct temporal and spatial pattern at the mhb. This minimal enhancer is composed of two distinct elements, as shown by protein-binding assays with mhb-specific extracts. The proximal element contains overlapping consensus binding sites for members of the Pax2/5/8 and POU protein families, whereas a distal element is bound by homeodomain and zinc finger transcription factors. Expression analysis of transgenes carrying specific mutations in these recognition motifs identified the Pax- and homeodomain-binding sites as functional elements which cooperatively control the activity of the mhb enhancer. lacZ genes under the control of either the minimal enhancer or the endogenous PAX5 locus were normally expressed at the mhb in PAX5 mutant embryos, indicating that this enhancer does not depend on autoregulation by PAX5. In Pax2 mutant embryos, expression of the endogenous PAX5 gene was, however, delayed and severely reduced in lateral aspects of the neural plate which, on neural tube closure, becomes the dorsal mhb region. This cross-regulation by Pax2 is mediated by the Pax-binding site of the minimal enhancer which, upon specific mutation, resulted in severely reduced transgene expression in the dorsal part of the mhb. Together these data indicate that Pax2 and homeodomain proteins directly bind to and cooperatively regulate the mhb enhancer of PAX5.
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pax2 5 and pax6 subdivide the early neural tube into three domains
Mechanisms of Development, 1999Co-Authors: Martin K. Schwarz, Gonzalo Alvarezbolado, Gregory R. Dressler, Meinrad Busslinger, Pavel Urbánek, Peter GrussAbstract:The nested expression patterns of the paired-box containing transcription factors Pax2/5 and Pax6 demarcate the midbrain and forebrain primordium at the neural plate stage. We demonstrate that, in Pax2/5 deficient mice, the mesencephalon/metencephalon primordium is completely missing, resulting in a fusion of the forebrain to the hindbrain. Morphologically, in the alar plate the deletion is characterized by the substitution of the tectum (dorsal midbrain) and cerebellum (dorsal metencephalon) by the caudal diencephalon and in the basal plate by the replacement of the midbrain tegmentum by the ventral metencephalon (pons). Molecularly, the loss of the tectum is demonstrated by an expanded expression of Pax6, (the molecular determinant of posterior commissure), and a rostral shift of the territory of expression of Gbx2 and Otp (markers for the pons), towards the caudal diencephalon. Our results suggest that an intact territory of expression of Pax2/5 in the neural plate, nested between the rostral and caudal territories of expression of Pax6, is necessary for defining the midbrain vesicle.
Jae Y Ro - One of the best experts on this subject based on the ideXlab platform.
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Flat pattern of nephrogenic adenoma: previously unrecognized pattern unveiled using PAX2 and PAX8 immunohistochemistry
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pax2 and pax8 expression in primary and metastatic renal tumors a comprehensive comparison
Archives of Pathology & Laboratory Medicine, 2012Co-Authors: Ayhan Ozcan, Gustavo De La Roza, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Context.—The diagnosis of renal cell carcinoma (RCC) remains problematic, especially in the context of metastasis or small-needle biopsies. PAX2 and PAX8 transcription factors are known to be expressed by several histologic types of renal neoplasms. Objective.—To evaluate the diagnostic utility of PAX2 and PAX8 relative to one another, which has not been studied. Design.—Consecutive tissue sections from the archival samples of 243 primary and 99 metastatic renal neoplasms were submitted to PAX2 and PAX8 immunostain. Results.—Within the primary neoplasms, PAX2 versus PAX8 expression was noted in 90 of 95 (95%) versus 92 of 95 (97%) for clear cell RCC, 29 of 38 (76%) versus 38 of 38 (100%) for papillary RCC, 14 of 25 (56%) versus 22 of 25 (88%) for chromophobe RCC, 3 of 7 (43%) versus 5 of 7 (71%) for collecting duct RCC, 6 of 8 (75%) versus 8 of 8 (100%) for acquired cystic kidney disease–related RCC, and 7 of 13 (54%) versus 11 of 13 (85%) for oncocytoma. Regardless of histologic subtype, PAX8 staining wa...
Luan D Truong - One of the best experts on this subject based on the ideXlab platform.
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PAX8 Expression in Thyroid Tumors: Comparison with PAX2, TTF-1, and Thyroglobulin
Journal of Interdisciplinary Histopathology, 2017Co-Authors: Ayhan Ozcan, Steven S. Shen, Ashraf Khan, Luan D TruongAbstract:Objective: Diagnostic markers for thyroid differentiation remain in development. Paired box (PAX8) is a member of a transcription factor family instrumental for fetal development and probably neoplastic transformation of the kidney, müllerian organs, and thyroid. Expression of PAX8 in thyroid tissue is evaluated and compared with traditional thyroid markers which are thyroglobulin and thyroid transcription factor-1 (TTF-1). Materials and Methods: Consecutive tissue sections of non-neoplastic thyroid tissue (n = 131), adenomatous nodule (n = 26), follicular neoplasms (n = 25), papillary carcinoma (n = 13), medullary carcinoma (n = 6), poorly differentiated carcinoma (n = 16), undifferentiated carcinoma (n = 6), and benign parathyroid tissue (n = 15) were submitted for PAX8, PAX2, TTF-1, and thyroglobulin immunostain. Staining extent (% of cells stained) and intensity (score 0-3) were evaluated. Results: PAX2 was not seen in any specimens. Strong (intensity score 3) (and diffuse 100% of cells) nuclear staining for PAX8 was noted in every case of non-neoplastic thyroid tissue and differentiated thyroid tumors. Staining for TTF-1 was similar to that of PAX8 in term of frequency, but the extent and intensity were less for some variants of papillary carcinoma or less differentiated follicular neoplasms. Thyroglobulin was noted in every case of non-neoplastic thyroid tissue and differentiated thyroid tumors, but the staining (which is cytoplasmic) was weak and focal in 66 cases of them, and this staining was often masked by strong staining of the adjacent colloid. For undifferentiated carcinoma, PAX8 was the only expressed marker, but in only 1/6 cases. For medullary carcinoma, PAX8 was not seen in any case, but TTF-1 and thyroglobulin were noted in 67% and 33% of cases, respectively. For parathyroid tissue, PAX8 was noted in 80% of cases, but the staining was weak and focal in each; TTF-1 and thyroglobulin were not seen. Conclusions: (1) PAX8 is a very sensitive marker for thyroid differentiation, regardless of diagnoses, (2) PAX8 is the only available marker, albeit of limited sensitivity, for undifferentiated thyroid carcinoma, (3) Both PAX8 and TTF-1 are sensitive markers for thyroid differentiation; with a diagnostic advantage for PAX8; and both are superior to thyroglobulin, (4) PAX8 may be the only marker needed for evaluating thyroid differentiation, and (5) In spite of an ontogenic similarity with PAX8, PAX2 is not expressed by thyroid tissue. [J Interdiscipl Histopathol 2017; 5(2.000): 29-35
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Flat pattern of nephrogenic adenoma: previously unrecognized pattern unveiled using PAX2 and PAX8 immunohistochemistry
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Luan D TruongAbstract:Nephrogenic adenoma is a benign lesion of the urinary tract, particularly the urinary bladder. It is a gross and microscopic mimicker of urothelial neoplasm or metastatic carcinoma. Several histological patterns (tubular, tubulocystic, polypoid, papillary, fibromyxoid) have been recognized, but a flat pattern has not been described. Histologically, nephrogenic adenoma consists of tubules, cysts or papillae lined by flat to polygonal cells with frequent hobnail appearance. The stroma is often edematous or has a granulation tissue-like appearance with acute or chronic inflammation. By immunohistochemistry, nephrogenic adenomas are positive for renal epithelial markers CK7, CD10 and alpha-methylacyl-coenzyme A racemase, and negative for bladder urothelium or prostate markers. Recent studies have shown that nephrogenic adenomas are positive for PAX2 and PAX8. We encountered an interesting case of tubular nephrogenic adenoma with adjacent areas suspicious of flat urothelial atypia. Immunohistochemistry for PAX2 and PAX8 were positive in these areas, unveiling a flat pattern of nephrogenic adenoma. This case prompted us to study 15 cases of nephrogenic adenoma to determine additional instances of flat pattern and to assess the value of PAX2 and PAX8 immunoreactivity to diagnose nephrogenic adenoma. PAX2 and PAX8 immunostaining was positive in 14/15 and 15/15 cases, respectively. The flat pattern was present at least focally adjacent to tubular, polypoid and papillary areas, in 8/15 cases of nephrogenic adenoma. In conclusion, the flat pattern is a common finding in nephrogenic adenomas, but easily under recognized by morphologic examination and may be confused with flat urothelial lesions with atypia. Immunostains for PAX2 and PAX8 are useful in the detection of nephrogenic adenomas and particularly unveil those nephrogenic adenomas with flat pattern.
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pax2 and pax8 expression in primary and metastatic renal tumors a comprehensive comparison
Archives of Pathology & Laboratory Medicine, 2012Co-Authors: Ayhan Ozcan, Gustavo De La Roza, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Context.—The diagnosis of renal cell carcinoma (RCC) remains problematic, especially in the context of metastasis or small-needle biopsies. PAX2 and PAX8 transcription factors are known to be expressed by several histologic types of renal neoplasms. Objective.—To evaluate the diagnostic utility of PAX2 and PAX8 relative to one another, which has not been studied. Design.—Consecutive tissue sections from the archival samples of 243 primary and 99 metastatic renal neoplasms were submitted to PAX2 and PAX8 immunostain. Results.—Within the primary neoplasms, PAX2 versus PAX8 expression was noted in 90 of 95 (95%) versus 92 of 95 (97%) for clear cell RCC, 29 of 38 (76%) versus 38 of 38 (100%) for papillary RCC, 14 of 25 (56%) versus 22 of 25 (88%) for chromophobe RCC, 3 of 7 (43%) versus 5 of 7 (71%) for collecting duct RCC, 6 of 8 (75%) versus 8 of 8 (100%) for acquired cystic kidney disease–related RCC, and 7 of 13 (54%) versus 11 of 13 (85%) for oncocytoma. Regardless of histologic subtype, PAX8 staining wa...
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pax2 and pax8 expression in primary and metastatic mullerian epithelial tumors a comprehensive comparison
The American Journal of Surgical Pathology, 2011Co-Authors: Ayhan Ozcan, Donna Coffey, Nathan Liles, Steven S. Shen, Luan D TruongAbstract:: PAX2 and PAX8 are transcription factors that are essential in embryonic development of mullerian organs. They may also play a role in tumor development in these organs. The diagnostic utility of PAX2 and PAX8 relative to one another has not been comprehensively studied. Archival tissue samples for normal or non-neoplastic tissue (251), primary epithelial neoplasms (316 for PAX2 and 357 for PAX8), and metastatic epithelial neoplasms (16), all of mullerian origin, were subjected to PAX2 and PAX8 immunostaining. The staining frequency, extent, and intensity for these markers were compared. Virtually identical PAX2 and PAX8 expressions were noted in non-neoplastic tissue. They were constantly seen in most epithelial cells (but not in stromal cells) of the endocervix, endometrium, fallopian tube, paratubal cyst, endosalpingiosis, endometriosis, and endometrial polyp. Within the primary epithelial neoplasms, PAX2 and PAX8 expression was noted in 55% and 98% of serous tumors, 25% and 94% of endometrioid tumors, 19% and 100% of clear cell tumors, 11% and 67% of transitional/undifferentiated tumors, and 10% and 22% of mucinous tumors, respectively. Regardless of histologic subtypes, PAX2 staining was noted in fewer cells and with less staining intensity compared with PAX8. No tumor showed only PAX2 staining. Within the metastatic carcinomas, PAX2 and PAX8 expression was noted in 38% and 98% of cases, respectively, with a diffuse and strong staining for PAX8, contrasting with a patchy and weak PAX2 expression. PAX2 and PAX8 are constantly expressed in normal or non-neoplastic tissue of mullerian origin. For primary and metastatic mullerian epithelial tumors, PAX8 shows strong and diffuse staining in most cases of all histologic subtypes, except in mucinous tumors. In contrast, PAX2 expression is always less than PAX8, and exclusive staining for PAX2 is not seen. PAX8 supersedes PAX2 as probably the best epithelial marker hitherto for primary or metastatic mullerian epithelial tumors.
Steven S. Shen - One of the best experts on this subject based on the ideXlab platform.
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PAX8 Expression in Thyroid Tumors: Comparison with PAX2, TTF-1, and Thyroglobulin
Journal of Interdisciplinary Histopathology, 2017Co-Authors: Ayhan Ozcan, Steven S. Shen, Ashraf Khan, Luan D TruongAbstract:Objective: Diagnostic markers for thyroid differentiation remain in development. Paired box (PAX8) is a member of a transcription factor family instrumental for fetal development and probably neoplastic transformation of the kidney, müllerian organs, and thyroid. Expression of PAX8 in thyroid tissue is evaluated and compared with traditional thyroid markers which are thyroglobulin and thyroid transcription factor-1 (TTF-1). Materials and Methods: Consecutive tissue sections of non-neoplastic thyroid tissue (n = 131), adenomatous nodule (n = 26), follicular neoplasms (n = 25), papillary carcinoma (n = 13), medullary carcinoma (n = 6), poorly differentiated carcinoma (n = 16), undifferentiated carcinoma (n = 6), and benign parathyroid tissue (n = 15) were submitted for PAX8, PAX2, TTF-1, and thyroglobulin immunostain. Staining extent (% of cells stained) and intensity (score 0-3) were evaluated. Results: PAX2 was not seen in any specimens. Strong (intensity score 3) (and diffuse 100% of cells) nuclear staining for PAX8 was noted in every case of non-neoplastic thyroid tissue and differentiated thyroid tumors. Staining for TTF-1 was similar to that of PAX8 in term of frequency, but the extent and intensity were less for some variants of papillary carcinoma or less differentiated follicular neoplasms. Thyroglobulin was noted in every case of non-neoplastic thyroid tissue and differentiated thyroid tumors, but the staining (which is cytoplasmic) was weak and focal in 66 cases of them, and this staining was often masked by strong staining of the adjacent colloid. For undifferentiated carcinoma, PAX8 was the only expressed marker, but in only 1/6 cases. For medullary carcinoma, PAX8 was not seen in any case, but TTF-1 and thyroglobulin were noted in 67% and 33% of cases, respectively. For parathyroid tissue, PAX8 was noted in 80% of cases, but the staining was weak and focal in each; TTF-1 and thyroglobulin were not seen. Conclusions: (1) PAX8 is a very sensitive marker for thyroid differentiation, regardless of diagnoses, (2) PAX8 is the only available marker, albeit of limited sensitivity, for undifferentiated thyroid carcinoma, (3) Both PAX8 and TTF-1 are sensitive markers for thyroid differentiation; with a diagnostic advantage for PAX8; and both are superior to thyroglobulin, (4) PAX8 may be the only marker needed for evaluating thyroid differentiation, and (5) In spite of an ontogenic similarity with PAX8, PAX2 is not expressed by thyroid tissue. [J Interdiscipl Histopathol 2017; 5(2.000): 29-35
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Flat pattern of nephrogenic adenoma: previously unrecognized pattern unveiled using PAX2 and PAX8 immunohistochemistry
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flat pattern of nephrogenic adenoma previously unrecognized pattern unveiled using pax2 and pax8 immunohistochemistry
Modern Pathology, 2013Co-Authors: Sergio Pinaoviedo, Alberto G Ayala, Steven S. Shen, Luan D TruongAbstract:Nephrogenic adenoma is a benign lesion of the urinary tract, particularly the urinary bladder. It is a gross and microscopic mimicker of urothelial neoplasm or metastatic carcinoma. Several histological patterns (tubular, tubulocystic, polypoid, papillary, fibromyxoid) have been recognized, but a flat pattern has not been described. Histologically, nephrogenic adenoma consists of tubules, cysts or papillae lined by flat to polygonal cells with frequent hobnail appearance. The stroma is often edematous or has a granulation tissue-like appearance with acute or chronic inflammation. By immunohistochemistry, nephrogenic adenomas are positive for renal epithelial markers CK7, CD10 and alpha-methylacyl-coenzyme A racemase, and negative for bladder urothelium or prostate markers. Recent studies have shown that nephrogenic adenomas are positive for PAX2 and PAX8. We encountered an interesting case of tubular nephrogenic adenoma with adjacent areas suspicious of flat urothelial atypia. Immunohistochemistry for PAX2 and PAX8 were positive in these areas, unveiling a flat pattern of nephrogenic adenoma. This case prompted us to study 15 cases of nephrogenic adenoma to determine additional instances of flat pattern and to assess the value of PAX2 and PAX8 immunoreactivity to diagnose nephrogenic adenoma. PAX2 and PAX8 immunostaining was positive in 14/15 and 15/15 cases, respectively. The flat pattern was present at least focally adjacent to tubular, polypoid and papillary areas, in 8/15 cases of nephrogenic adenoma. In conclusion, the flat pattern is a common finding in nephrogenic adenomas, but easily under recognized by morphologic examination and may be confused with flat urothelial lesions with atypia. Immunostains for PAX2 and PAX8 are useful in the detection of nephrogenic adenomas and particularly unveil those nephrogenic adenomas with flat pattern.
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pax2 and pax8 expression in primary and metastatic renal tumors a comprehensive comparison
Archives of Pathology & Laboratory Medicine, 2012Co-Authors: Ayhan Ozcan, Gustavo De La Roza, Steven S. Shen, Jae Y Ro, Luan D TruongAbstract:Context.—The diagnosis of renal cell carcinoma (RCC) remains problematic, especially in the context of metastasis or small-needle biopsies. PAX2 and PAX8 transcription factors are known to be expressed by several histologic types of renal neoplasms. Objective.—To evaluate the diagnostic utility of PAX2 and PAX8 relative to one another, which has not been studied. Design.—Consecutive tissue sections from the archival samples of 243 primary and 99 metastatic renal neoplasms were submitted to PAX2 and PAX8 immunostain. Results.—Within the primary neoplasms, PAX2 versus PAX8 expression was noted in 90 of 95 (95%) versus 92 of 95 (97%) for clear cell RCC, 29 of 38 (76%) versus 38 of 38 (100%) for papillary RCC, 14 of 25 (56%) versus 22 of 25 (88%) for chromophobe RCC, 3 of 7 (43%) versus 5 of 7 (71%) for collecting duct RCC, 6 of 8 (75%) versus 8 of 8 (100%) for acquired cystic kidney disease–related RCC, and 7 of 13 (54%) versus 11 of 13 (85%) for oncocytoma. Regardless of histologic subtype, PAX8 staining wa...
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pax2 and pax8 expression in primary and metastatic mullerian epithelial tumors a comprehensive comparison
The American Journal of Surgical Pathology, 2011Co-Authors: Ayhan Ozcan, Donna Coffey, Nathan Liles, Steven S. Shen, Luan D TruongAbstract:: PAX2 and PAX8 are transcription factors that are essential in embryonic development of mullerian organs. They may also play a role in tumor development in these organs. The diagnostic utility of PAX2 and PAX8 relative to one another has not been comprehensively studied. Archival tissue samples for normal or non-neoplastic tissue (251), primary epithelial neoplasms (316 for PAX2 and 357 for PAX8), and metastatic epithelial neoplasms (16), all of mullerian origin, were subjected to PAX2 and PAX8 immunostaining. The staining frequency, extent, and intensity for these markers were compared. Virtually identical PAX2 and PAX8 expressions were noted in non-neoplastic tissue. They were constantly seen in most epithelial cells (but not in stromal cells) of the endocervix, endometrium, fallopian tube, paratubal cyst, endosalpingiosis, endometriosis, and endometrial polyp. Within the primary epithelial neoplasms, PAX2 and PAX8 expression was noted in 55% and 98% of serous tumors, 25% and 94% of endometrioid tumors, 19% and 100% of clear cell tumors, 11% and 67% of transitional/undifferentiated tumors, and 10% and 22% of mucinous tumors, respectively. Regardless of histologic subtypes, PAX2 staining was noted in fewer cells and with less staining intensity compared with PAX8. No tumor showed only PAX2 staining. Within the metastatic carcinomas, PAX2 and PAX8 expression was noted in 38% and 98% of cases, respectively, with a diffuse and strong staining for PAX8, contrasting with a patchy and weak PAX2 expression. PAX2 and PAX8 are constantly expressed in normal or non-neoplastic tissue of mullerian origin. For primary and metastatic mullerian epithelial tumors, PAX8 shows strong and diffuse staining in most cases of all histologic subtypes, except in mucinous tumors. In contrast, PAX2 expression is always less than PAX8, and exclusive staining for PAX2 is not seen. PAX8 supersedes PAX2 as probably the best epithelial marker hitherto for primary or metastatic mullerian epithelial tumors.