A Study of Mixed Mullerian Tumor with Thirteen Oncogene Probes. S. Faruqi¹, C. Harsch¹, H. Spector², J. Noumoff¹. 1) OB/GYN, Div Gynecologic Oncol, Crozer-Chester Medical Ctr, Upland, PA; 2) Department of Histology Crozer-Chester Medical Ctr, Upland, PA.
   Mixed Mullerian tumors often present with multiple elements, principally including carcinoma and sarcoma. Little is known genetically about the induction of the oncogenic process or the differentiation/evolution of the tumor elements. We present here a study of a mixed Mullerian tumor (MMT) with a panel of 13 oncogenic DNA probes, selected on their potential for abnormality in general gynecologic cancers (and in MMTs). Sections of this tumor were hybridized with DNA probes for fluorescence in-situ hybridization (FISH). Probes used were single probes her-2/neu, p53, RB-1 (13q14), ZNF217 (20q13.2), c-myc, n-myc, Inversion 16 (inv16), and Cyclin D1, Multiple oncogene probes used were PML/RARA, LAvysion, Igh/myc, 15q22/6q21, 19q13/17p13, and FIP/CHIC/PDGFRA. Probes that showed significant deviation from the expected response of a healthy cell included that of ZNF217, a zinc finger protein gene recently implicated in several tumors with a relation to the female steroid hormones, and her-2/neu, also found to be amplified in breast and ovarian cancers. The multi-target probes of 15q22/6q21 and FIP/CHIC/PDGFRA showed significant amplification as well. Several other probes showed low-level amplification, defined as having an average probe count per cell of more than 2.3, but fewer than 3. The single probe for tumor suppressor gene p53 showed a low level deletion. Additionally, the dual probe 19q13/17p13 (p53) suggested deletion of at least one copy of p53 in all cells, and a low level deletion in 19q13. In general, these results have indicated areas that may be involved in the various stages of evolution and differentiation that are seen in a mixed Mullerian tumor.