Ovarian Hemangiomas Do Not Harbor EWSR1 Rearrangements

Abstract

Hemangiomas of the ovary are rare with a majority described as individual reports of unusual clinical presentations or morphologic findings. Both the expected and unexpected pathologic features of these tumors in the ovary are not well detailed. Therefore, we collected the largest series of ovarian hemangiomas to comprehensively define their clinicopathologic associations and examine the significance of hormone receptors in their pathogenesis. In addition, a novel EWSR1-NFATC1 fusion has recently been described in a case of hemangioma of bone. To our knowledge, EWSR1 rearrangement has not been evaluated in hemangiomas of other sites or in a case series. Accordingly, we used fluorescence in situ hybridization to investigate EWSR1 status in a majority of our cases. Clinical presentation was variable and dependent on tumor size. Patient age ranged 48 to 87 yr (median 63 yr). Tumors involved the right (n=6) and left (n=3) ovaries with laterality unknown in 1 case, and size ranged from 0.2 to 5.0 cm (median 1.0 cm). Three of 4 radiologic reports were either equivocal or could not exclude malignancy. Seven cases were of the cavernous type and 3 were mixed cavernous and capillary type. All lesions formed a single discrete, circumscribed mass that displaced the surrounding cortical stroma. The cavernous type showed dilated, thin-walled vessels and vascular thrombi, some of which were associated with dystrophic calcification. In addition to cavernous morphology, the mixed form exhibited features of capillary hemangioma such as lobulated growth of capillary-sized vascular spaces that lacked atypia or multilayering and were linked to a larger feeding vessel. Each tumor expressed CD31, CD34, FLI-1, ERG, but not D240. The hemangioma stromal cells, but not endothelium, expressed estrogen and progesterone receptors in every case. Stromal luteinization was seen in 2 cases. Follow-up ranged 1 to 139 mo and all patients were disease free. All cases were negative for EWSR1 rearrangement; however, 2 cases demonstrated additional intact copies of EWSR1 indicating aneusomy 22 or a structural abnormality of chromosome 22 resulting in apparent duplication of the EWSR1 gene region (at 22q12). Although an uncommon entity, awareness of ovarian hemangioma's unique and diverse clinical presentation as well as its potential to radiologically imitate malignant ovarian neoplasms are important.