1. ¹Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, IN, USA
2. ²Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
3. ³Department of Pathology, Yale University, New Haven, CT, USA

Correspondence: Dr L Cheng, MD, Department of Pathology and Laboratory Medicine, Indiana University Medical Center, University Hospital, Room 3465, 550 North University Boulevard, Indianapolis, IN 46202, USA. E-mail: lcheng@iupui.edu

Received 28 December 2004; Revised 31 May 2005; Accepted 1 June 2005; Published online 22 July 2005.

Abstract

The proto-oncogene c-kit encodes a tyrosine kinase receptor, c-kit (CD117), which has been implicated in the development of a number of human malignancies. While the preferential expression of this protein has been well documented in testicular seminomas, there is little data concerning its expression in dysgerminomas of the ovary. We examined the expression of c-kit in 30 cases of ovarian dysgerminomas using immunohistohemical staining with a polyclonal anti-CD117 antibody. Staining was graded in a semiquantitative manner as follows: negative (no staining), 1+ (1–10% staining), 2+ (10–29% staining), 3+ (30–50% staining), or 4+ (>50% staining). Of the 30 cases examined, 26 (87%) demonstrated immunoreactivity for CD117. In total, 10 (33%) demonstrated 4+ staining; 9 (30%) demonstrated 3+ staining; 3 (10%) demonstrated 2+ staining; 4 (13%) demonstrated 1+ staining; and 4 (13%) demonstrated no staining. In conclusion, CD117 immunoreactivity was detected in 87% of ovarian dysgerminomas, a finding that correlates with previously reported frequencies of CD117 expression in seminomas (78–100%). Thus, antibodies to c-kit may be a useful diagnostic marker for ovarian dysgerminoma. Although the prognosis of patients with dysgerminoma is generally good, this receptor could potentially serve as a target for site-specific immunotherapy as an alternative and/or complement to conventional treatment options.