Clinical Focus

  • Pathology
  • Genitourinary Pathology

Academic Appointments

  • Assistant Professor - Med Center Line, Pathology

Administrative Appointments

  • Director of Genitourinary Pathology, Department of Pathology (2017 - Present)

Honors & Awards

  • ASCP 40 under Forty, ASCP (2016)

Professional Education

  • Fellowship:Massachusetts General Hospital (2015) MA
  • Board Certification: Pathology, American Board of Pathology (2014)
  • Residency:Indiana University School of Medicine and Affilated Hospitals (2014) IN
  • Medical Education:Indiana University School of Medicine and Affilated Hospitals (2010) IN

Research & Scholarship

Current Research and Scholarly Interests

Genitourinary tumors with a special interest in Testicular tumors


2017-18 Courses


All Publications

  • Clinicopathologic Characteristics of Fumarate Hydratase-Deficient and Hereditary Leiomyomatosis and Renal Cell Carcinoma-Associated Renal Cell Carcinoma: A Series of 10 Cases Lau, H., Williamson, S. R., Kunder, C., Fan, A. C., Kao, C. NATURE PUBLISHING GROUP. 2018: 358
  • Evaluation of Diagnostic Accuracy and a Practical Algorithmic Approach for the Diagnosis of Renal Masses by Fine Needle Aspiration Lau, H., Kong, C., Kao, C. NATURE PUBLISHING GROUP. 2018: 155
  • Variant morphology in upper urinary tract urothelial carcinoma: a fourteen-year case series of biopsy and resection specimens. Human pathology Hayashi, H., Mann, S., Kao, C., Grignon, D., Idrees, M. T. 2017


    Upper urinary tract urothelial carcinoma exhibiting variant morphology, especially in higher-grade tumors, is a recognized phenomenon but has not been comparatively studied in biopsy versus resection material. We studied the morphologic patterns and clinicopathological features, and provide a comparison between biopsy and resection specimens. Consultation cases were evaluated separately to investigate for possible consultation bias. A total of 383 in-house cases from 352 patients including 314 resection specimens and 69 biopsies from 2001-2014 were reviewed from a single institution. Histologic type, tumor grade, invasion, pathologic stage, nodal status, metastasis, and the presence and type of variant morphology for each case were evaluated. Variant morphology was identified in 5 biopsy specimens (7.2%) and 42 resection specimens (13.4%). The most common variant morphologic pattern was squamous differentiation (16 cases, 4.5%) followed by an inverted growth pattern (8 cases, 2.2%). The presence of variant morphology in resection specimens had a significant association with higher tumor grade, higher pT stage, and non-papillary configuration. Out of 69 patients with biopsies, 31 had a subsequent resection. In comparison, 181 consultation cases from 168 patients showed variant morphology in six biopsies (7.1%) and twenty-seven resections (28.1%). In conclusion, the frequency of recognizing variant morphology in biopsies is about one-half of that in resections. The inclusion of consultation cases can inflate the incidence of variant morphology. As a result, the frequency of variant morphology in our in-house cases is lower than the percentage reported in the literature, most likely secondary to a consultation bias.

    View details for DOI 10.1016/j.humpath.2017.05.001

    View details for PubMedID 28506733

  • Evidence of a dual histogenetic pathway of sacrococcygeal teratomas HISTOPATHOLOGY Emerson, R. E., Kao, C., Eble, J. N., Grignon, D. J., Wang, M., Zhang, S., Wang, X., Fan, R., Masterson, T. A., Roth, L. M., Cheng, L. 2017; 70 (2): 290-300

    View details for DOI 10.1111/his.13062

    View details for Web of Science ID 000394982000017

  • "Dissecting Gonadoblastoma" of Scully: A Morphologic Variant That Often Mimics Germinoma. American journal of surgical pathology Kao, C., Idrees, M. T., Young, R. H., Ulbright, T. M. 2016; 40 (10): 1417-1423


    Dr Robert E. Scully, who recognized and defined gonadoblastoma (GB), used the term "dissecting gonadoblastoma" (DGB) to describe variants with either an infiltrative type or diffuse pattern instead of the usual small nested arrangement. These patterns have not been emphasized in the literature. To investigate the features of DGB we examined 50 GBs microscopically and performed immunohistochemistry (IHC) in some. DGB was found in 38 (76%) GBs and was represented by 3 patterns. The most frequent was solid/expansile (n=26), consisting of large coalescent nests of germ cells, often (92%) interrupted by fibrovascular septa, with usually minor numbers of sex cord cells. Less frequent were small anastomosing nests (n=24) and cord-like arrangements (n=22) of germ cells irregularly distributed in a prominent stroma and with mostly inconspicuous sex cord cells. Most DGBs (24) showed >1 pattern and demonstrated the characteristic globular deposits of basement membrane, although these were often subtle. The germ cells in all patterns varied from spermatogonium-like to seminoma-like; OCT3/4 was positive only in the latter (7/7). The sex cord cells were small with dense, oval or angulated nuclei, inconspicuous nucleoli, and positivity for inhibin (9/9, strong), FOXL2 (9/9, strong), SF1 (8/9, strong), SOX9 (9/9, weak and focal), WT1 (5/7, variable), and calretinin (3/7, variable). Granulomas were present in 84% of germinoma foci, 13% of DGB foci, and 8% of classic GB foci. Twenty two of 38 DGBs had associated germinoma; 3 also had embryonal carcinoma, yolk sac tumor, and choriocarcinoma, respectively. Follow-up of 2 cases lacking an invasive tumor showed that both patients were disease free at 13 and 4.8 years after bilateral gonadectomy. We conclude that DGB is commonly seen with classic GB and displays identical IHC features, supporting it as a morphologic variant of GB. It appears likely that cord-like DGB is the earliest phase in a GB developmental continuum that may proceed successively into anastomosing, nested (classic GB), and solid/expansile patterns. DGB often mimics germinoma because of the large size of the nests, pseudoinfiltrative pattern of some cases, and inconspicuous sex cord cells. The presence of sex cord cells (identification aided by IHC for sex cord markers), the heterogenous morphology of the germ cells, and globules of basement membrane are useful differential features. The lack of a granulomatous reaction also favors DGB over germinoma. Mistaking DGB for GB with invasive germinoma may result in more aggressive therapy than warranted. The likely relationship of DGB to the relatively recently described concept of so-called "undifferentiated gonadal tissue" is discussed herein.

    View details for DOI 10.1097/PAS.0000000000000704

    View details for PubMedID 27454939