Pure stromal tumors are rare neoplasms derived from or display differentiation towards stromal cells. The tumors in this category exhibit a great diversity of patterns with a long array of mimickers, and accordingly may pose a diagnostic challenge. Some of the derivative cells are involved in hormone production under physiologic conditions; therefore, some tumors under this category produce excess hormones, which may lead to the development of hormone-mediated syndromes. Awareness of the diagnostic criteria and the differential diagnosis of the pure stromal tumors is an important task. This chapter highlights pure stromal tumors, with an emphasis on the clinicopathologic characteristics and advances in molecular features of each entity, as well as a detailed discussion of differential diagnostic considerations, and the utility and limitations of immunohistochemical markers and ancillary studies in their diagnostic work-up.