Primary angiosarcomas (AS) of the ovary are rare malignancies. Approximately 25% of them are associated with other neoplasms, e.g. mature cystic teratoma, [^1-3], mucinous cystadenoma, serous and mucinous carcinoma, [^4-6], or fibroma [⁷]. Metastases to the ovary from soft tissue AS rarely occur [⁸,⁹]. 60% of all reported AS were detected in stage III and IV [^1-4,⁶,^10-18]. Surgical debulking and chemotherapy provided only short disease-free intervals, and most patients died from lung metastasis within 9 months. Twelve reports with stage I disease indicated better outcome, with only two patients dying within one year [³,⁵,⁷,¹⁷,^19-23]. Ovarian AS usually affects premenopausal women or even children [²⁴], with only two reports in postmenopausal individuals [⁷,¹⁸] (Table 1). Here we describe the oldest patient reported with ovarian AS so far.

Ovarian angiosarcoma (AS) is with rare exceptions a disease of premenopausal woman. Only two patients have been reported in postmenopausal age [⁷,¹⁸] and the 81 years old woman described in this report is the oldest patient with this disease in the literature. AS of the ovary is very rare with only two small case series published so far, one with 4 and the other with 7 cases [³,¹⁷]. In both publications ovarian AS were described as morphological heterogenous tumors, a fact emphasized in a few other case reports too. The tumor described in this report represented high grade AS only in its central part, towards the periphery an atypical angiomatous proliferation was obvious, alternating with areas of intense fibrosis. A Mib-score of 60% and the marked pleomorphism with atypical mitotic figures in the central areas are striking features for malignancy, so there was no evidence for reactive angioma (Figure 5). Massive fibrosis may obscure a malignant tumor, leading to the misdiagnosis of fibroma or thecoma, similar to our case in the frozen section diagnosis, but nevertheless AS may coexist with true ovarian fibroma [⁷]. However, massive hemorrhage usually is present and suggests malignancy. Fusiform and fibrous aspects together with only sparse formation of capillary-like spaces, like in our tumor, may focally mimic myogenous origin or metastasis, respectively, but negativity of actin and expression of vascular markers supported the diagnosis of angiosarcoma. Synovial sarcoma was excluded by negative immunohistochemical staining for epithelial markers and inconspicuous SYT-SSX fluorescent in situ hybridisation [²⁵].

Of 31 reported cases of ovarian angiosarcomas, 23 were pure lesions without coexisting benign or malignant epithelial components. In 5 reports, angiosarcoma was found to be associated with mature cystic teratoma, and in this context it was discussed, whether angiosarcoma is a sarcomatous teratoma, particularly those tumors occurring in younger women[^1-3]. In another 3 cases mucinous cystadenoma, mucinous cystadenocarcinoma and borderline serous tumor were coexisting to ovarian AS, rendering the diagnosis adenosarcoma and carcinosarcoma, respectively [^4-6], and putting ovarian AS into the context of malignant mesodermal mixed tumor (MMMT) [²²]. Angiosarcoma itself may show epitheloid features and can therefore be mistaken for carcinoma or metastasis, and one published case had a predominant reticular growth pattern resembling yolk sac tumor [¹⁷].

These examples show that the suspicion of ovarian AS opens a broad range of differential diagnostic considerations. The correct histopathological diagnosis, however, is of importance because prognosis of ovarian AS is uniformly poor. This could be related to the fact that most patients are diagnosed with advanced disease in stage III or IV. Although patients with stage I disease were shown to survive and even become pregnant [³,²⁰], there are also reports on fatalities of patients with early stage disease.

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

The authors declare that they have no competing interests.

HB conceived the case report and drafted the manuscript, CG and SP carried out histology and immunohistochemistry, DW supplied clinical data, GW carried out molecular analyses, SH supervised the case report and participated in its design and coordination. All authors have read and approved the final manuscript.