Guang-Qian Xiao, MD, PhD
Professor of Clinical Pathology

Department of Pathology and Laboratory Medicine
Keck Medical Center
University of Southern California, Los Angeles, CA
Phone: 323.442.9610


Sept.1984 - June 1989 M.D.  Clinical Medicine College of Medicine, Nanchang University, Nanchang, China
Sept.1989 - June 1992 M.S. Immunology College of Medicine, Beijing University, Beijing, China
Sept.1996 - June 2001 Ph.D. Molecular and Cellular Biology State University of New York-Downstate Health Science Center, New York
July 2005 - June 2006   Fellowship Subspecialty:Cytopathology, Mount Sinai Medical Center, New York, NY
July 2001 - June 2005   Residency Specialty: Anatomic and Clinical Pathology, Mount Sinai Medical Center, New York, NY


Dr. Xiao is a Professor of Clinical Pathology in the Department of Pathology, Keck Medical Center of the University of Southern California, Los Angeles. He graduated from Jiangxi Medical College of Nanchang University in China. He completed his pathology residency and fellowship training at the Icahn School of Medicine at Mount Sinai in New York City.  Before moving to USC, he was an associate professor of pathology at the University of Rochester Medical Center in New York.  He has broad interests and expertise in the pathologic diagnosis of genitourinary and pulmonary diseases. His research focuses include the pathogenesis of these diseases, particularly urologic (prostate, bladder, kidney and testicle) as well as lung cancers, the underlying mechanisms of chemo/radiation-resistance and progression of these cancer, as well as tumor biomarkers.

Research Interest

  • Genitourinary Pathology
  • Pulmonary pathology
  • Head and Neck Pathology

Scientific Activities

July 2006 - June 2008 Assistant Professor and Attending Pathologist Staten Island University Hospital, Staten Island, NY
July 2008 – Nov. 2013   Assistant Professor Mount Sinai Medical Center, New York, NY
Dec. 2013 – Aug. 2016 Associate Professor University of Rochester Medical Center, Rochester, NY
Sept. 2016 – Professor of Clinical Pathology University of Southern California, Los Angeles, CA
Honours And Awards

Anatomic and Clinical Pathology (Certified in 2005;re-certified in 2016 (voluntary program))
Cytopathology(Certified in 2006; re-certified in 2016)
New York State Certificate of Qualification for Clinical Laboratory Director


  1. Xiao GQ, BarrettMM, Yang Q, Unger P. MClinicopathologic and immunohistochemical study of combined small cell carcinoma and urothelial carcinoma molecular subtype. 2017  Pathol Oncol Res. 2017 Dec 16. doi: 10.1007/s12253-017-0369-1. [Epub ahead of print]
  2. Gordetsky J, Sanfrancesco J, Epstein JI, Trevino K, Xu H, Osunkoya A, Xiao GQ, Kao CS, Unger P, Hashemi-Sadraei N, Albany C, Jorns JM, Lu DY, Matoso A, Rais-Bahrami S, Schwartz LE, Ulbright TM, Idrees MT. Do Nonseminomatous Germ Cell Tumors of the Testis With Lymphovascular Invasion of the Spermatic Cord Merit Staging as pT3?
    Am J Surg Pathol. 2017 Oct;41(10):1397-1402. doi: 10.1097/PAS.0000000000000917.
  3. Xiao GQ, Priemer DS, Wei C, Aron M, Yang Q, Idrees MT. ZBTB16 is a sensitive and specific marker in detection of metastatic and extragonadal yolk sac tumor. . Histopathology.2017 Oct;71(4):562-569
  4. Ronaghy A, Xiao GQ, Santagada E, Hasanovic A, Unger P. Expression of GATA-3 in Testicular and Gynecologic Mesothelial Neoplastic and Non-neoplastic Tissues.Int J Gynecol Pathol. 2017 Jun 2. doi: 10.1097/PGP.0000000000000403. [Epub ahead of print]
  5. Xiao GQ, Patel S. Seromucinous hamartoma presenting as an obstructive endobronchial mass.  Int J Respir Pulm Med. 2017, 4:10-11
  6. Xiao GQ, Unger PD. Focal Signet Ring Cell High-Grade Prostatic Intraepithelial Neoplasia on Needle Biopsy.Int J Surg Pathol. 2017 Jun;25(4):344-347.
  7. Guancial EA, Kilari D, Xiao GQ, Abu-Farsakh S, Baran A, Messing EM, Kim ES. Platinum concentration, copper transporter 1 expression, and pathologic response to cisplatin-based neoadjuvant chemotherapy in muscle-invasive bladder cancer. PLoS One. 2016 May 17;11(5):e0155503.
  8. Xiao GQ,Li F, Unger PD, Katerji H, Yang Q, McMahon L, Burstein DE. ZBTB16: a novel sensitive and specific biomarker for yolk sac tumor.Mod Pathol. 2016 Jun;29(6):591-8
  9. Wang L, Bansal M,  Xiao GQ. Endobronchial Lipoma in a Never-Smoker. Int J Respir Pulm Med. 2015, 2:4
  10. Yeh CR, Slavin S, Da I, Hsu I, Luo J, Xiao GQ, Jie D, Chou FJ, Yeh SY.Estrogen receptor α in cancer associated fibroblasts suppresses prostate cancer invasion via reducing macrophage infiltration, CCL5 and IL6 in the tumor microenvironment. Mol Cancer. 2016 Jan 20;15(1):7.
  11. Ye B., Cappel J., Findeis-Hosey J., McMahon L, Yang Q, Xiao GQ, Xu HD, Li FQ. hASH1 is a specific immunohistochemical marker for lung neuroendocrine tumors. Hum Pathol. 2016 Feb;48:142-7
  12. Yeh CR, Ou ZU, Xiao GQ, Yeh SY. Infiltrating T cells promotes renal cell carcinoma (RCC) progression via altering the estrogen receptor β-DAB2IP signals. Oncotarget. 2015 Dec 29;6(42):44346-59.
  13. Wu M, Si S, Li Y, Schoen S, Xiao GQ, Wu M, The B, Wu G, Chen JD. Flcn-deficient renal cells are tumorigenic and sensitive to mTOR suppression. Oncotarget.  2015;Oct 20;6(32):32761-73.
  14. Xiao GQ, Li F, Findeis-Hosey J, Hyrien O, Unger PD, Xiao L, Dunne R, Kim ES, Yang Q, McMahon L, Burstein DE.. Downregulation of cytoplasmic PLZF correlates with less tumor differentiation and lymph node metastasis in non-small cell lung carcinoma. Hum Pathol. 2015 Nov;46(11):1607-15
  15. Xiao GQ, Rashid H. Bladder neck urothelial carcinoma: A urinary bladder subsite carcinoma with distinct clinicopathology. Int J Surg Pathol. 2015 Oct;23(7):517-23.
  16. Chen JD, Huang DC, Rubera I, Futami I, Wang P, Schoen SR, Yang XJ, Zhou M, Xiao GQ, Williams BO, Furge KA, Teh BT. Disruption of tubular FLCN expression as a mouse model for renal tumor induction. Kidney International.Kidney Int. 2015 Nov;88(5):1057-69
  17. Xiao GQ, Jean-Gilles J, Wu G. Unilateral hypoplastic kidney and ureter associated with diverse mesonephric remnant hyperplasia.Am J Clin Exp Urol 2015 Aug 8;3(2):107-11.
  18. Kottmann KM, Sharp J, Owens K, Salzman P, Xiao GQ, Phipps RP, Sime PJ, Brown EB. Second
    harmonic generation microscopy reveals altered collagen microstructure in usual interstitial pneumonia versus healthy lung. Respir Res. 2015 May 27;16(1):61.
  19. Yeh CR, Hsu I, Song W, Chang H, Miyamoto H, Xiao GQ, Li L, Yeh SY. . Fibroblast ERα promotes bladder cancer invasion via increasing the CCL1 and IL-6 signals in the tumor microenvironment, Am J Cancer Res. 2015;5(3):1146-57  
  20. Xiao GQ, Unger P, Kinoshita Y, McMahon L, Burstein D. Loss of PLZF Expression in prostate cancer by immunohistochemistry correlates with tumor aggressiveness and  metastasis. PLOS ONE. 2015 Mar 25;10(3):e0121318
  21. Galati SJ, Said M, Gospin R, Babic N, Brown K, Geer EB, Kostakoglu L, Leibowitz AB, Muller S, Owen RP, Pertsemlidis DS, Wilck E, Xiao GQ, Levine AC, Inabnet WB. The Mount Sinai Clinical Pathway for the Management of Pheochromocytoma.Endocr Pract. 2014 Oct 8:1-33.
  22. Khachaturov V, Xiao GQ, Kinoshita Yx, Unger P, Burstein DE. Histone H1.5, A Novel Prostatic Cancer Marker: An Immunohistochemical Study. Human Pathol. 2014 Oct;45(10):2115-9.
  23. Aganathan A, Chaurasia P, Xiao GQ, Philizaire M, Lu X, Yao S, Burnstein KL, Liu DP, Levine  AC, Mujtaba S. Coactivator MYST1 Regulates NF-κB and AR Functions during Proliferation of Prostate Cancer Cells.Mol Endocrinol. 2014 Jun;28(6):872-85
  24. Xiao GQ, Ko HB, Unger PD. Telangiectatic Oncocytoma: a previously undescribed variant of renal oncocytoma.Am J Clin Pathol. 2013 Jul;140(1):103-8
  25. Xiao GQ, Chow J, Maniar KP, Unger PD. Micropapillary variant of embryonal carcinoma: clinicopathological correlation and histochemical study. Int J Surg Pathol. 2013 Dec;21(6):599-602.
  26. Rosenkrantz AB, Haghighi M, Huang WC, Somberg MB, Melamed J. Xiao GQ, Taouli B. Utility of Quantitative MRI Metrics for Assessment of Stage and Grade of Urothelial Carcinoma of the Bladder: Preliminary Results. American Journal of Roentgenology. 2013 Dec; 201(6):1254-9
  27. Xiao GQ, Granato RC, Unger PD.  Bilateral Sertoli cell tumours of the testis - a likely new   extracolonic manifestation of familial adenomatous polyposis. Virchows Arch. 2012 Dec;461(6):713-5.
  28. Hechtman J, Xiao GQ, Unger PD, Burstein D. Glutamate Receptor 2 as a New Potential    Diagnostic Marker for Prostatic Adenocarcinoma: A Pilot Immunohistochemical Study. Appl Immunohistochem Mol Morphol. 2012 Jul;20(4):344-9
  29. Xiao GQ, Chow J, Unger PD. Metastatic tumor to the urinary bladder: Clinicopathologic study of 11 cases. Int J Surg Pathol. 2012 Aug;20(4):342-8.
  30. Kazi S., Unger PD., Endres P., Xiao GQ. Urothelial metaplasia of the seminal vesicles: a report of two cases.  Ann Diagn Patho. 2012 Apr;16(2):145-7.
  31. Maniar KP, Unger PD, Samadi DB, Xiao GQ. Incidental Paraganglia of Prostate in Radical Prostatectomy Specimens: A Diagnostic Pitfall.Int J Surg Pathol. 2011 Dec;19(6):772-4.
  32. Xiao GQ, McCash S, Unger PD. Paraganglia mimicking metastatic seminomatous tumor. Int J  Surg Pathol. 2011 Aug;19(4):534-7.
  33. LaveryHJ, Xiao GQ, Mikulasovich M, Nabizada-Pace F, Unger P, SamadiDB. “Mohs Surgery of the Prostate”: The Utility of In-situ Frozen Section Analysis During Robotic Prostatectomy. BJU Int. 2011 Mar;107(6):975-9.
  34. McCash S,Unger PD, Dillon R,  Xiao GQ. Undifferentiated carcinoma of the renal pelvis with osteoclast-like giant cells: A report of two cases.APMIS.  2010 May;118(5):407-12.
  35. Xiao GQ, Unger PD. Renal Pelvic Urothelial Carcinoma with Divergent Morphology. Ann Diagn Pathol. 14(2):74-80. 2010
  36. Xiao GQ, Huan Y, Stone N, Stock R, Unger PD. Histological patterns and associated PSA levels for prostatic adenocarcinoma following brachytherapy. Pathol Res Pract. 2009;205(12):843-6.
  37. Xiao GQ, Emanuel PO. Cervical parakeratosis/hyperkeratosis as an important cause for false negative results of Pap smear and human papillomavirus test. Aust N Z J Obstet Gynaecol. 2009 Jun;49(3):302-6.
  38. Xiao GQ. Fine-needle aspiration of cystic pancreatic mucinous tumor: Oncotic cell as an aiding diagnostic feature in paucicellular specimens. Diagn Cytopathol. 2009;37(2):111-6.
  39. Xiao GQ, Burstein DE. Cytological findings of rhabdoid meningioma in cerebrospinal fluid. Acta Cytologica, Acta Cytol. 2008;52(1):118-9
  40. Xiao GQ. Cytomorphology of urothelial carcinomatous peritoneal effusion. Cytopathology, 2008;19(2):131-3.
  41. Nagi C, Xiao GQ, Li G, Genden E, Burstein DE. Immunohistochemical detection of X- linked inhibitor of apoptosis in head and neck squamous cell carcinoma. Ann Diagn Pathol. 2007;11:402-6.
  42. Xiao GQ, Unger PD, Burstein DE.  Immunohistochemical analysis of XIAP in neoplastic and other disorders of thyroid. Ann Diagn Pathol. 2007;11: 235-40.
  43. Xiao GQ, Zhang D, Burstein DE.  Intracytoplasmic lumina in metastatic medullary thyroid carcinoma. Diagnostic Cytopathology. 2007;35(4):252-3.
  44. Xiao GQ, Burstein DE, Miller LK, Unger PD. Nephrogenic adenoma: immunohistochemical evaluation for its etiology and differentiation from prostatic adenocarcinoma. Arch Pathol Lab Med. 2006;130(6):805-10.
  45. Xiao, GQ, Pertsemlidis, DS, Unger, PD. A functioning adrenocortical oncocytoma-A case report and reviewof the literature. Ann Diagn Pathol. 2005; 9(5):295-7.
  46. Xiao GQ, Birns DR, Warner RP, Selleck W, Unger, PD. Testicular metastasis of primary cecal carcinoid tumor. Ann Diagn Pathol. 2004, 8(2):102-7.
  47. Xiao GQ, Strauchen JA. Pathologic quiz case: a 72-year-old woman presenting with intestinal obstruction and perforation. Small cell neuroendocrine carcinoma of small intestine. Arch Pathol Lab Med. 2003;127(8):e357-8.
  48. Xiao GQ, Savage SJ, Gribetz ME, Burstein DE, Miller LK, Unger PD. The nested variant of urothelial carcinoma: clinicopathology of 2 cases. Arch Pathol Lab Med. 2003;127(8):e333-6.
  49. Xiao GQ, Mochly-Rosen D, Boutjdir M. PKC isozyme selective regulation of cloned human cardiac delayed slow rectifier K current. Biochem Biophys Res Commun. 2003; 306(4):1019-25.
  50. Xiao GQ, Zinberg JM, Unger PD. Asymptomatic sarcoidosis presenting as massive splenomegaly. Am JMed. 2002;113(8):698-9.
  51. Xiao GQ, Qu Y, Sun ZQ, Mochly-Rosen D. Boutjdir M. Evidence for functional role of epsilon PKC isozyme in the regulation of cardiac Na(+) channels.  Am J Physiol Cell  Physiol. 2001; 281(5):C1477-86.
  52. Qu Y, Xiao GQ, Chen L, Boutjdir M.  Autoantibodies from mothers of children with congenital heart block downregulate cardiac L-type Ca channels.  J Mol Cell Cardiol. 2001;33(6):1153-63.
  53. Xiao GQ, Qu Y, Hu K, Boutjdir M. Down-regulation of L-type calcium channel in pups born to 52 kDa SSA/Ro immunized rabbits.  FASEB J. 2001; 15(9):1539-45.
  54. Xiao GQ, Hu, K, Boutjdir M.  Direct inhibition of expressed cardiac L- and T-type calcium channels by IgG from mothers whose children have congenital heart block. Circulation. 2001; 103(11):1599-604.
  55. Guo YP and Xiao GQ. The Effect of CD4 molecule on the development of thymic T cells. Journal of ChuanBai Medical college(Chinese) 1997, 13 (3): 10-11.
  56. Guo YP, Xiao GQ, Lui J.  The Effects of Anti L3T4monoclonal Antibody on the Development of Splenic Cells in the Mice. Journal of ChuanBai Medical college (Chinese)  1997, 13 (4): 8-10.
  57. Yin JZ, Song HF, Xiao GQ, Bai XW, Zhou H. Effect of CD4 monoclonal antibody on the distribution and function of the subsets of thymic T cells in neonatal mice. Chinese Journal of Microbiology and Immunology (Chinese)1996, 3: 24-26.
  58. Xiao GQ, Guo YP, Effect of CD4 on the development of mouse thymic and splenic lymphocytes.  Shanghai Immunology Journal(Chinese) 1993, 2: 14-16.
  59. Xiao GQ, Long ZZ, The biologic role of Anti-CD4 monoclonal antibody. International Journal of Immunology (Chinese) 1991, 6:24-27.
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