Bio

Clinical Focus


  • Anatomic and Clinical Pathology

Academic Appointments


Administrative Appointments


  • Vice Chair of Pathology for Pediatric Pathology, Stanford University School of Medicine (2015 - Present)
  • Associate Medical Director of Pathology and Clinical Laboratories for Pediatrics, Stanford Children's Health/Stanford Health Care (2014 - Present)
  • Chief of Pathology, Lucile Packard Children?s Hospital, Stanford Children?s Health (2014 - Present)
  • Director of Pediatric Pathology, Stanford University Medical Center (2014 - Present)
  • Vice-Chairman for Anatomical Pathology, Medical College of Wisconsin, Milwaukee, WI (2012 - 2014)
  • Director of Anatomical and Surgical Pathology, Medical College of Wisconsin, Milwaukee, WI (2010 - 2014)
  • Director of Orthopedic Pathology, Yale University School of Medicine, New Haven, CT (2008 - 2009)
  • Director of Pediatric and Developmental Pathology, Yale University School of Medicine, New Haven, CT (2008 - 2009)
  • Assistant Director of Autopsy Services, Yale University School of Medicine, New Haven, CT (2007 - 2009)

Professional Education


  • Residency:Yale-New Haven HospitalCT
  • Board Certification: Pediatric Pathology, American Board of Pathology (2003)
  • Board Certification: Anatomic and Clinical Pathology, American Board of Pathology (2003)
  • Medical Education:Universidad Catolica de Santiago de Guayaquil (1992) Ecuador
  • Fellowship:Children's Hospital BostonMA
  • Board certification, Children's Hospital Boston/Harvard Medical School, Pediatric Pathology (2003)
  • Board certification, Yale-New Haven Hospital/Yale School of Medicine, Anatomical and Clinical Pathology (2002)
  • Professional Certificate, University of New Haven, Health Care Management (2001)
  • MSc, Vrije Universiteit Brussel, Brussels, Belgium, Molecular Biology (1994)
  • MD, Universidad Católica de Santiago de Guayaquil, Ecuador, Medicine and Surgery (1992)

Research & Scholarship

Clinical Trials


  • Radiation Therapy With or Without Combination Chemotherapy or Pazopanib Hydrochloride Before Surgery in Treating Patients With Newly Diagnosed Non-Rhabdomyosarcoma Soft Tissue Sarcomas That Can Be Removed by Surgery Recruiting

    This randomized phase II/III trial studies how well pazopanib hydrochloride, combination chemotherapy, and radiation therapy work and compares it to radiation therapy alone or in combination with pazopanib hydrochloride or combination chemotherapy in treating patients with newly diagnosed non-rhabdomyosarcoma soft tissue sarcomas that can be removed by surgery. Radiation therapy uses high energy x-rays to kill tumor cells. Drugs used in chemotherapy, such as ifosfamide and doxorubicin hydrochloride, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Pazopanib hydrochloride may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. It is not yet known whether radiation therapy works better when given with or without combination chemotherapy and/or pazopanib hydrochloride in treating patients with non-rhabdomyosarcoma soft tissue sarcomas.

    View full details

Teaching

2016-17 Courses


Publications

All Publications


  • Tumor-induced Osteomalacia in a 3-Year-Old With Unresectable Central Giant Cell Lesions. Journal of pediatric hematology/oncology Crossen, S. S., Zambrano, E., Newman, B., Bernstein, J. A., Messner, A. H., Bachrach, L. K., Twist, C. J. 2016: -?

    Abstract

    Tumor-induced osteomalacia (TIO) is a rare cause of hypophosphatemia involving overproduction of fibroblast growth factor 23. TIO has been described largely in adults with small mesenchymal tumors. We report a case of TIO in a child who presented with knee pain and radiographic findings concerning for rickets, and was found to have maxillomandibular giant cell lesions. The patient was treated with oral phosphorus and calcitriol, surgical debulking, and intralesional corticosteroids, which resulted in tumor regression and normalization of serum fibroblast growth factor 23and phosphorus. This case illustrates the occurrence of this rare paraneoplastic syndrome in children and adds to our knowledge about clinical manifestations and pathologic findings associated with pediatric TIO.

    View details for PubMedID 27820122

  • PAX7 Expression in Rhabdomyosarcoma, Related Soft Tissue Tumors, and Small Round Blue Cell Neoplasms. American journal of surgical pathology Charville, G. W., Varma, S., Forgó, E., Dumont, S. N., Zambrano, E., Trent, J. C., Lazar, A. J., van de Rijn, M. 2016; 40 (10): 1305-1315

    Abstract

    Rhabdomyosarcoma, the most common soft tissue malignancy of childhood, is a morphologically variable tumor defined by its phenotype of skeletal muscle differentiation. The diagnosis of rhabdomyosarcoma often relies in part on the identification of myogenic gene expression using immunohistochemical or molecular techniques. However, these techniques show imperfect sensitivity and specificity, particularly in scant tissue biopsies. Here, we expand the toolkit for rhabdomyosarcoma diagnosis by studying the expression of PAX7, a transcriptional regulator of mammalian muscle progenitor cells implicated in the pathogenesis of rhabdomyosarcoma. Immunohistochemical analysis of tissue microarrays using a monoclonal anti-PAX7 antibody was used to characterize PAX7 expression in 25 non-neoplastic tissues, 109 rhabdomyosarcomas, and 697 small round blue cell or other soft tissue tumors. Among non-neoplastic tissues, PAX7 was specifically expressed in adult muscle progenitor cells (satellite cells). In embryonal rhabdomyosarcoma, PAX7 expression was positive in 52 of 63 cases (83%), negative in 9 of 63 cases (14%), and focal in 2 of 63 cases (3%). PAX7-positive embryonal rhabdomyosarcoma cases included several showing focal or negative myogenin expression. PAX7 expression in alveolar rhabdomyosarcoma was positive in 6 of 31 cases (19%), negative in 14 of 31 cases (45%), and focal in 11 of 31 cases (36%). In addition, PAX7 was expressed in 5 of 7 pleomorphic rhabdomyosarcomas (71%) and 6 of 8 spindle cell rhabdomyosarcomas (75%). Among histologic mimics, only Ewing sarcoma showed PAX7 expression (7/7 cases, 100%). In contrast, expression of PAX7 was not seen in the large majority (688/690, 99.7%) of examined cases of other soft tissue tumors, small round blue cell neoplasms, and leukemias/lymphomas. In summary, immunohistochemical analysis of PAX7 expression may be a useful diagnostic tool in the assessment of skeletal muscle differentiation in human tumors.

    View details for DOI 10.1097/PAS.0000000000000717

    View details for PubMedID 27526298

  • First case of infectious endocarditis caused by Parvimonas micra ANAEROBE Gomez, C. A., Gerber, D. A., Zambrano, E., Banaei, N., Deresinski, S., Blackburn, B. G. 2015; 36: 53-55

    Abstract

    P. micra is an anaerobic Gram-positive cocci, and a known commensal organism of the human oral cavity and gastrointestinal tract. Although it has been classically described in association with endodontic disease and peritonsillar infection, recent reports have highlighted the role of P. micra as the primary pathogen in the setting of invasive infections. In its most recent taxonomic classification, P. micra has never been reported causing infectious endocarditis in humans. Here, we describe a 71 year-old man who developed severe native valve endocarditis complicated by aortic valvular destruction and perivalvular abscess, requiring emergent surgical intervention. Molecular sequencing enabled identification of P. micra.

    View details for DOI 10.1016/j.anaerobe.2015.10.007

    View details for Web of Science ID 000367027400009

  • Sarcoma Resection With and Without Vascular Reconstruction: A Matched Case-control Study ANNALS OF SURGERY Poultsides, G. A., Tran, T. B., Zambrano, E., Janson, L., Mohler, D. G., Mell, M. W., Avedian, R. S., Visser, B. C., Lee, J. T., Ganjoo, K., Harris, E. J., Norton, J. A. 2015; 262 (4): 632-640

    Abstract

    To examine the impact of major vascular resection on sarcoma resection outcomes.En bloc resection and reconstruction of involved vessels is being increasingly performed during sarcoma surgery; however, the perioperative and oncologic outcomes of this strategy are not well described.Patients undergoing sarcoma resection with (VASC) and without (NO-VASC) vascular reconstruction were 1:2 matched on anatomic site, histology, grade, size, synchronous metastasis, and primary (vs. repeat) resection. R2 resections were excluded. Endpoints included perioperative morbidity, mortality, local recurrence, and survival.From 2000 to 2014, 50 sarcoma patients underwent VASC resection. These were matched with 100 NO-VASC patients having similar clinicopathologic characteristics. The rates of any complication (74% vs. 44%, P?=?0.002), grade 3 or higher complication (38% vs. 18%, P?=?0.024), and transfusion (66% vs. 33%, P?

    View details for DOI 10.1097/SLA.0000000000001455

    View details for Web of Science ID 000367999800009

Footer Links:

Stanford Medicine Resources: