p53 Overexpression in an Ovarian Adult Granulosa Cell Tumor Without Anaplastic Morphology: A Marker of Aggressive...

Adult granulosa cell tumor (AGCT) is a pure-type sex cord tumor of the ovary that shows a low-grade morphology. Despite being classified as malignant, it typically demonstrates indolent clinical behavior. Histologic grading is not traditionally useful for prognostication, as most tumors are low-grade with multiple morphologically bland patterns. However, high-grade transformation, characterized by marked cytologic atypia and elevated mitotic activity, is considered indicative of aggressive clinical behavior. This high-grade transformation is closely associated with TP53 abnormalities detected by p53 immunohistochemistry. We herein describe a case of AGCT with p53 overexpression in the absence of an anaplastic or high-grade morphology. The findings of this case show that high-grade genomic alterations, including TP53 abnormalities, may occur earlier in the tumorigenic process of AGCT, even before the development of overt high-grade morphologic features. Further accumulation and analysis of similar cases are required to clarify the clinicopathological significance of p53 abnormalities in AGCT.