%0 Journal Article %T Sex Cord-Stromal Tumors of the Ovary: An Update and Review. Part I - Pure Ovarian Stromal Tumors. %A Devins KM %A Young RH %A Oliva E %J Adv Anat Pathol %V 31 %N 4 %D 2024 Jul 1 %M 38369847 %F 4.571 %R 10.1097/PAP.0000000000000435 %X In two separate reviews, we review the time-honored but still frequently challenging features of ovarian sex cord-stromal tumors, and also emphasize new developments including unusual morphologic appearances that, despite the relative rarity of many of the tumors, result in a disproportionate number of differential diagnostic problems, variant immunohistochemical profiles, and specific molecular and syndromic associations. These neoplasms are also of historical interest as current knowledge is still based in significant part on the contributions of 2 giants of gynecologic pathology, Dr Robert Meyer and Dr Robert E. Scully. In part I, we present the major clinical, pathologic, and genomic features of the pure ovarian stromal tumors including comments on differential diagnosis and briefly note significant historical contributions. In part II we will discuss pure sex cord and sex cord-stromal tumors.