Xiaopei Zhu

Washington University in St. Louis, San Luis, Missouri, United States

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Publications (12)44.97 Total impact

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    Omar Hameed · Arie Perry · Ruma Banerjee · Xiaopei Zhu · John D Pfeifer ·
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    ABSTRACT: Rare breast neoplasms resembling the tall-cell variant of papillary thyroid carcinoma have been reported. In addition, papillary carcinoma of the breast occasionally displays nuclear features reminiscent of papillary thyroid carcinoma. In this study, we evaluated 33 intraductal/intracystic papillary carcinomas of the breast for the presence and extent of nuclear overlap, grooves, clearing, and inclusions, as well as features of the tall-cell or columnar-cell variants of papillary thyroid carcinoma. RET rearrangements were assessed in a subset of these cases. Paired probes localizing to the centromeric and telomeric ends of the RET gene on chromosome 10 were used for FISH using a break-apart approach. Single round and nested PCR was performed to detect RET/PTC1, RET/PTC2, RET/PTC3 and ELKS-RET fusion transcripts. Nuclear overlap, grooves, stratification, and clearing were identified in 24 (73%), 14 (42%), 11 (33%), and 9 (27%) cases respectively, whereas nuclear inclusions and 'tall-cell' features were each seen in only one (3%) and two (6%) cases, respectively. Four of 19 tested cases displayed split FISH signals in a low percentage of cells and were considered borderline for RET rearrangement. All 19 tested cases with amplifiable RNA were negative for the four RET fusion transcripts evaluated by RT-PCR. Although papillary carcinomas of breast often display one or more cytoarchitectural features of papillary thyroid carcinoma, there is no evidence that RET rearrangements are involved.
    Modern Pathology 07/2009; 22(9):1236-42. DOI:10.1038/modpathol.2009.91 · 6.19 Impact Factor
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    ABSTRACT: Primary neuroendocrine carcinomas of the colon are rare but highly aggressive malignancies. The recent observations that c-kit protooncogene, a tyrosine kinase, is overexpressed in a subset of small cell lung cancer and that selective kinase inhibitors block the in vitro growth of small cell lung cancer cell lines prompted us to investigate the expression and mutation status of the c-kit gene in colorectal neuroendocrine carcinomas. Sixty-six cases of primary colorectal neuroendocrine carcinoma were collected from 13 institutions, including 36 small cell carcinomas and 30 moderately differentiated neuroendocrine carcinomas. Immunohistochemical studies using a polyclonal antibody against c-kit protein (CD117) demonstrated a strong and diffuse cytoplasmic staining in 15 cases (23%), which were relatively equally distributed in the small cell and moderately differentiated subgroups. As controls, 25 conventional colorectal adenocarcinomas, 26 colorectal adenomas and 19 colorectal carcinoid tumors were all negative, whereas 15 gastrointestinal stromal tumors were all positive, for kit expression. In contrast to gastrointestinal stromal tumors, kit-overexpressing neuroendocrine carcinomas showed no mutations in the juxtamembrane domain (exon 11) of the c-kit gene as determined by mutational analysis. Kaplan-Meier analysis with the log-rank test revealed that the patients with kit-positive tumors did not differ significantly in survival from those with kit-negative tumors (P = 0.77). These results indicate that c-kit overexpression observed in a subset of colorectal neuroendocrine carcinomas may not be mediated via activating mutations, and does not appear to be an initiating event during tumorigenesis because of lack of c-kit expression in other types of colorectal epithelial neoplasms. More importantly, our observations may have potential therapeutic implications since specific tyrosine kinase inhibitors have shown promise in the management of patients with kit-expressing malignancies.
    American Journal of Surgical Pathology 01/2004; 27(12):1551-8. DOI:10.1097/00000478-200312000-00008 · 5.15 Impact Factor
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    ABSTRACT: To determine the prevalence and typing of HPV DNA in pregnant women with a diagnosis of atypical squamous cells (ASC) and to assess whether pregnancy-related changes contribute to the diagnosis of ASC. HPV testing was performed on residual specimens from the ThinPrep Pap test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) in pregnant women diagnosed as ASC (study group, n = 105), low and high grade squamous intraepithelial lesion (LSIL and HSIL) (positive control, n = 33) and negative for epithelial cell abnormality (negative control, n = 20). All cases were reviewed by 2 cytopathologists to obtain consensus diagnoses using the Bethesda System 2001 criteria. The study group cases were further subcategorized into ASC of undetermined significance (ASCUS, n = 99) and ASC cannot exclude HSIL (ASC-H, n = 6). HPV testing was also performed on an ASC control group consisting of 68 consecutive ASC cases in nonpregnant women, matched by age. Mean patient age was 23.7 years for the study group and 25.6 years for the ASC control group. HPV DNA was detected in 88.6% of cases in the study group, including 87.9% of ASC-US and 100% of ASC-H cases. Of the HPV positive cases, 79.6%, 4.3%, 5.4% and 10.8% had high-risk, mixed high- and low-risk, low-risk and unknown HPV types, respectively. The most frequent HPV types detected were: types 52 (31.2%), 16 (15.1%), 39 (11.8%), 53 (10.8%), and 18 and 58 (9.7% each). Multiple viral types were detected in 43.0% of cases. The prevalence of HPV DNA in the positive and negative controls in pregnant women was 100% and 55%, respectively. HPV DNA was detected in 83.8% of the ASC control group. Regardless of pregnancy-related changes, the prevalence of HPV DNA in pregnant women (88.6%) was similar to that found in ASC in nonpregnant women of the same reproductive-age group (83.8%), and the high-risk types accounted for the vast majority of cases (83.9%). These findings demonstrate that pregnancy-related changes do not contribute to the diagnosis of ASC in this subset of women. Furthermore, the high HPV DNA prevalence in reproductive-age women (< 40 years) suggests that HPV testing may have limited utility in effective management of these patients.
    Acta cytologica 11/2003; 47(6):1008-16. DOI:10.1159/000326637 · 1.56 Impact Factor
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    ABSTRACT: Dermatofibrosarcoma protuberans (DFSP) is an uncommon infiltrative tumor of the dermis with characteristic cytogenetic features, specifically the translocation t(17;22)(q22;q13) which often manifests as a supernumerary ring chromosome r(17;22). The translocation results in the fusion of two genes, collagen type I alpha 1(COL1A1) and platelet-derived growth factor B-chain (PDGFB). The trunk and extremities are the anatomic sites of predilection for DFSP, whereas the vulva and groin are quite uncommon sites of involvement. This investigation evaluated seven DFSPs (four vulvar and three groin) for the presence of COL1A1-PDGFB fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR), using archival formalin-fixed, paraffin-embedded tissue. Six of seven cases (three vulvar, three groin) contained a COL1A1-PDGFB fusion transcript. Sequence analysis of the PCR products revealed that the break-point of the COL1A1 gene was located after exon 40 in two patients, after exon 42 in one patient, after exon 44 in one patient, and after exon 47 in two patients; the break-point in the PDGFB gene was before exon 2 in all cases. No fusion transcript could be amplified in one case. As in DFSP at other sites, COL1A1- PDGFB chimeric fusion transcripts are present in vulvar and groin DFSP. The transcripts can be detected in formalin-fixed, paraffin-embedded tumor tissues, and have the same general pattern of exon boundaries as in DFSP at other sites.
    Journal of Cutaneous Pathology 04/2003; 30(3):190-5. DOI:10.1034/j.1600-0560.2003.00037.x · 1.58 Impact Factor
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    ABSTRACT: The strong correlation of specific reciprocal translocations with individual tumor types and the demonstration that polymerase chain reaction (PCR)-based methods can detect translocations in tissue samples have stimulated interest in the role of molecular genetic testing in diagnostic surgical pathology. To evaluate the clinical utility of PCR-based molecular analysis of soft tissue neoplasms in routine surgical pathology, 131 consecutive soft tissue tumors submitted for molecular genetic testing at a tertiary care teaching hospital were prospectively analyzed over a 36-month period. RT-PCR was used to test tumor RNA for fusion transcripts characteristic of malignant round cell tumors (including Ewing sarcoma/primitive neuroectodermal tumor, desmoplastic small round cell tumor, and alveolar rhabdomyosarcoma), spindle cell tumors (including synovial sarcoma and congenital fibrosarcoma), and fatty tumors (myxoid liposarcoma). DNA sequence analysis was used to confirm the identity of all PCR products, and the PCR results were compared with the histopathologic diagnosis. We found that sufficient RNA for RT-PCR-based testing was recovered from 96% of the 131 cases and the percentage of tumors that tested positive for the associated characteristic fusion transcript was in general agreement with those reported in the literature. DNA sequence analysis of PCR products identified both variant transcripts and spurious PCR products, underscoring the value of product confirmation steps when testing formalin-fixed, paraffin-embedded tissue. Only in rare cases did testing yield a genetic result that was discordant with the histopathologic diagnosis. We conclude that PCR-based testing is a useful adjunct for the diagnosis of malignant small round cell tumors, spindle cell tumors, and other miscellaneous neoplasms in routine surgical pathology practice.
    American Journal of Surgical Pathology 09/2002; 26(8):965-77. DOI:10.1097/00000478-200208000-00001 · 5.15 Impact Factor
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    ABSTRACT: Scatter factor (SF), also known as hepatocyte growth factor (HGF), has been shown to induce proliferation, scattering and invasiveness in human prostate cancer cell lines. In this study we determined the serum level of SF-HGF in men with metastatic prostate cancer compared to those with localized prostate cancer and without prostate cancer. Serum samples were obtained from men with biopsy proved adenocarcinoma of the prostate and radiographic evidence of metastatic disease, those with biopsy proved adenocarcinoma of the prostate and clinically localized disease, and those with negative sextant prostate biopsies. Serum SF-HGF was determined using a commercially available enzyme-linked immunosorbent assay kit. Of the 108 men enrolled in our study 52 had negative sextant biopsies, 36 had clinically localized cancer and 20 had metastatic disease. The serum level in men with metastatic disease was significantly elevated (mean 2,117 pg./ml., range 820 to 6,403) compared to that in men with localized cancer and without prostate cancer (mean 974 pg./ml., range 437 to 2,132 and 700, range 272 to 1,875, respectively, p = 9.5 x 10(-15)). Logistic regression analysis demonstrated that the association of ln (SF-HGF) with prostate cancer persisted after controlling for patient age and ln (prostate specific antigen) (p = 3.1 x 10(-4)). Serum SF-HGF is increased in men with metastatic prostate cancer. SF-HGF levels are associated with metastatic prostate cancer independent of the prostate specific antigen level and patient age. These data imply that SF-HGF may be an important serum marker for prostate cancer.
    The Journal of Urology 05/2001; 165(4):1325-8. DOI:10.1097/00005392-200104000-00078 · 4.47 Impact Factor
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    ABSTRACT: Spindle cell sarcomas often present the surgical pathologist with a considerable diagnostic challenge. Malignant peripheral nerve sheath tumor, leiomyosarcoma, fibrosarcoma, and monophasic synovial sarcoma may all appear similar histologically. The application of ancillary diagnostic modalities, such as immunohistochemistry and electron microscopy, may be helpful in the differentiation of these tumors, but in cases in which these adjunctive techniques fail to demonstrate any more definitive evidence of differentiation, tumor categorization may remain difficult. Cytogenetic and molecular genetic characterization of tumors have provided the basis for the application of molecular assays as the newest components of the diagnostic armamentarium. Because the chromosomal translocation t(X;18) has been observed repeatedly in many synovial sarcomas, it has been heralded as a diagnostic hallmark of synovial sarcoma. To formally test the specificity of this translocation for the diagnosis of synovial sarcoma, RNA extracted from formalin-fixed, paraffin-embedded tissue from a variety of soft tissue and spindle cell tumors was evaluated for the presence of t(X;18) by reverse transcriptase-polymerase chain reaction. Although 85% of the synovial sarcomas studied demonstrated t(X;18), 75% of the malignant peripheral nerve sheath tumors in our cohort also demonstrated this translocation. We conclude that the translocation t(X;18) is not specific to synovial sarcoma and discuss the implications of the demonstration of t(X;18) in a majority of malignant peripheral nerve sheath tumors.
    Modern Pathology 02/2001; 13(12):1336-46. DOI:10.1038/modpathol.3880247 · 6.19 Impact Factor
  • Xiaopei Zhu · Peter A Humphrey ·
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    ABSTRACT: Scatter factor (hepatocyte growth factor) (SF/HGF) is a multifunctional polypeptide growth factor that has been implicated in tumor proliferation, angiogenesis, invasiveness, and metastasis. Little is known of the expression of SF/HGF in human prostatic carcinoma. The aims of this investigation were to quantitate the level of SF/HGF expression in benign versus malignant human prostatic tissues and to assess regulation of SF/HGF expression by human prostatic stromal myofibroblasts. We determined the level of SF/HGF expression in 10 human prostatic tissue samples (5 benign, 5 carcinoma) by Western blot analysis. Five purified growth factors-basic fibroblast growth factor (bFGF), interleukin-1beta (IL-1beta), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and endothelial growth factor (EGF)-were tested for their capacity to induce SF/HGF expression by a human prostatic stromal myofibroblastic cell line, as assessed by enzyme-linked immunosorbent assay. Supernatant from the normal PrEC prostatic epithelial cell line and the DU 145 carcinoma cell line were assayed for SF/HGF-inducing activity. SF/HGF exhibited a mean fourfold overexpression in carcinoma tissues compared with benign prostatic tissue. Significant stimulation of SF/HGF expression by prostatic stromal myofibroblasts was detected for IL-1beta (8.1-fold), PDGF (6.2-fold), bFGF (4.0-fold), VEGF (3. 7-fold), and EGF (2.9-fold). DU 145-conditioned media, but not the PrEC-conditioned media, contained SF/HGF-inducing activity, which was determined to include IL-1beta, bFGF, and PDGF by antibody-blocking experiments. SF/HGF is overexpressed in human prostatic carcinoma tissues. Prostatic carcinoma cell stimulation of SF/HGF expression by adjacent benign myofibroblastic cells as a type of epithelial-stromal paracrine interaction could potentially influence prostatic carcinoma cell behaviors.
    Urology 01/2001; 56(6):1071-4. DOI:10.1016/S0090-4295(00)00795-0 · 2.19 Impact Factor
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    ABSTRACT: Atypical adenomatous hyperplasia (AAH) of the prostate, a small glandular proliferation, is a putative precursor lesion to prostate cancer, in particular to the subset of well-differentiated carcinomas that arise in the transition zone, the same region where AAH lesions most often occur. Several morphological characteristics of AAH suggest a relationship to cancer; however, no definitive evidence has been reported. In this study, we analyzed DNA from 25 microdissected AAH lesions for allelic imbalance as compared to matched normal DNA, using one marker each from chromosome arms 1q, 6q, 7q, 10q, 13q, 16q, 17p, 17q, and 18q, and 19 markers from chromosome 8p. We observed 12% allelic imbalance, with loss only within chromosome 8p11-12. These results suggest that genetic alterations in transition zone AAH lesions may be infrequent. This genotypic profile of AAH will allow for comparisons with well-differentiated carcinomas in the transition zone of the prostate.
    American Journal Of Pathology 10/1999; 155(3):967-71. DOI:10.1016/S0002-9440(10)65196-6 · 4.59 Impact Factor
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    ABSTRACT: Triton tumors are rare variants of malignant peripheral nerve sheath tumor (MPNST) with muscle differentiation, often seen in patients with neurofibromatosis 1 (NF1). Individuals affected with NF1 harbor mutations in the NF1 tumor suppressor gene and develop neurofibromas and MPNSTs. The NF1 gene is expressed in Schwann cells and its expression is lost in schwannian neoplasms, suggesting a role in malignant development. Separately, there is evidence that p53 suppressor gene mutations are involved in MPNSTs. To determine the role of the NF1 and p53 genes in the development of the malignant Triton tumor we examined 2 such tumors, 1 from a 3-year-old boy without clinical manifestations of NF1 and another from a 24-year-old man with NF1. Histological analysis of these tumors showed both neural and muscle differentiation with S-100 and desmin immunoreactivity, respectively. Reverse transcribed RNA polymerase chain reaction (RT-PCR) of NF1 mRNA showed NF1 expression in the sporadic tumor. Strong nuclear immunoreactivity for p53 was observed throughout the malignant population in both tumors. This was confirmed by loss of heterozygosity for p53 in the non-NF1 patient, suggesting that p53 is involved in both hereditary and sporadic Triton tumors. The finding of preserved NF1 gene expression in the non-NF1-related Triton tumor suggests that different genetic events predispose to the development of this rare neoplasm in sporadic cases.
    Human Pathlogy 09/1999; 30(8):984-8. DOI:10.1016/S0046-8177(99)90255-1 · 2.77 Impact Factor

  • Journal of Urologic Pathology 01/1998; 9(1):73-82. DOI:10.1385/JUP:9:1:73
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    ABSTRACT: Primitive neuroectodermal tumor (PNET), the second most common type of sarcoma in the first two decades of life, rarely presents as an organ-based neoplasm. Rather, it is seen typically in the soft tissues of the chest wall and paraspinal region. We report a case of primary PNET of the kidney in a 17-year-old girl who presented with abdominal pain, hematuria, and an abdominal mass. Nodules and sheets of monotonous-appearing primitive round cells and the formation of rosettes focally were the principal microscopic features. The tumor cells were uniformly immunoreactive for vimentin, cytokeratin, neuron-specific enolase, and 013 (CD99). In addition, the characteristic translocation of PNET and Ewing sarcoma, t(11;22)(q24;q12), was detected by polymerase chain reaction (PCR). Eight previous examples of renal PNET have been reported in the literature in the past 2 years, but only three of these cases have had complete immunohistochemical evaluation with the demonstration of 013 positivity. To our knowledge the present case is the only one to date demonstrating the recurrent translocation t(11;22)(q24;q12) by PCR. Assuming that the previous cases in the literature are bona fide examples of PNET, the kidney may be another site of predilection for this usual soft-tissue neoplasm. We are once again confronted with the dilemma about the nature of the progenitor cell.
    American Journal of Surgical Pathology 04/1997; 21(3):354-9. DOI:10.1097/00000478-199703000-00013 · 5.15 Impact Factor

Publication Stats

402 Citations
44.97 Total Impact Points


  • 1997-2009
    • Washington University in St. Louis
      • • Department of Pathology and Immunology
      • • Department of Surgery
      San Luis, Missouri, United States
  • 2003
    • Barnes Jewish Hospital
      San Luis, Missouri, United States