Chondrosarcoma of the uterus: case report and literature review

High-grade uterine sarcoma with osteosarcomatous differentiation arising from a MED12-mutated leiomyoma, a case report

Uterine osteosarcoma has been reported, but it is an extremely rare tumor with highly aggressive behavior and poor prognosis. The pathogenesis of uterine osteosarcoma is not fully understood. Herein, we report on a high-grade uterine sarcoma with focal osteosarcomatous differentiation that developed from a long-standing MED12-mutated leiomyoma. A 47-year-old nulligravida woman, with known uterine leiomyoma presented with abdominal pain and distention. Imaging analyses revealed a tumor with a large cystic area in the uterine corpus and multiple metastases in intrapelvic and paraaortic lymph nodes, left ovary and left lung. With a clinical diagnosis of uterine sarcoma the patient underwent abdominal total hysterectomy, bilateral salpingo-oophorectomy, partial omentectomy and removal of the left obturator lymph node. Despite postoperative chemotherapy and radiation therapy, the tumor progressed rapidly. She died 18 weeks after the surgery. Histopathologic examination identified a high-grade pleomorphic sarcoma in which focal osteoid production was observed. This high-grade sarcoma with focal osteosarcomatous differentiation was located within the uterine leiomyoma, and Sanger sequencing showed the identical MED12 L36R mutation in both the osteosarcomatous and leiomyomatous components supporting the shared origin of these two components. We, therefore, concluded that the high-grade sarcoma with osteosarcomatous differentiation arose from the transformation of the precedent leiomyoma.

Characterizing sarcoma dominance pattern in uterine carcinosarcoma: Homologous versus heterologous element

OBJECTIVE

To examine significance of sarcoma dominance (SD) patterns in uterine carcinosarcoma (UCS).

METHODS

This is a secondary analysis of multicenter retrospective study examining women with stages I-IV UCS who underwent primary surgery. SD was defined as >50% of sarcoma component in uterine tumor. SD patterns were grouped as homologous sarcoma without SD (homo/non-dominance, n = 351), heterologous sarcoma without SD (hetero/non-dominance, n = 174), homologous sarcoma with SD (homo/dominance, n = 175), and heterologous sarcoma with SD (hetero/dominance, n = 189), and correlated to tumor characteristics and survival.

RESULTS

SD patterns were significantly associated with age, body habitus, carcinoma type, tumor size, depth of myometrial invasion, and nodal metastasis (all, P < 0.05). On univariate analysis, SD was associated with decreased progression-free survival (PFS) and cause-specific survival (CSS) in homologous cases (both, P < 0.05) but not in heterologous cases. On multivariate models, both homologous and heterologous SD patterns remained independent prognostic factors for decreased PFS (adjusted-hazard ratio [HR] ranges: homo/dominance 1.35-1.69, and hetero/dominance 1.47-1.64) and CSS (adjusted-HR ranges: 1.52-1.84 and 1.66-1.81, respectively) compared to homo/non-dominance (all, P < 0.05). Among stage I-III disease, when tumors had SD, adding radiotherapy to chemotherapy was significantly associated with improved PFS (adjusted-HR: homo/dominance 0.49, and hetero/dominance 0.45) and CSS (0.36 and 0.31, respectively) compared to chemotherapy alone (all, P < 0.05); contrary, this association was not observed with absence of SD (all, P > 0.05).

CONCLUSION

In UCS, SD impacts survival in homologous but not in heterologous type. Regardless of sarcoma types, SD was associated with decreased survival in UCS; adding radiotherapy to chemotherapy may be an effective postoperative strategy.

Heterologous and rare homologous sarcomas of the uterine corpus: a clinicopathologic review

Pure sarcomas of the uterine corpus are uncommon, constituting less than 3% of all malignancies at this site, and most of them are leiomyosarcomas and endometrial stromal sarcomas. Rare histotypes of homologous sarcomas and heterologous sarcomas are occasionally encountered, and the absence of significant accumulated experience with these histotypes at this location may potentially raise diagnostic and patient management difficulties. In this article, the clinicopathologic attributes of all earlier reported sarcomas of the uterine corpus other than leiomyosarcomas and endometrial stromal sarcomas are summarized. Included are embryonal rhabdomyosarcoma, pleomorphic rhabdomyosarcoma, angiosarcoma, alveolar soft part sarcoma, malignant perivascular epithelioid cell tumors (PEComas), osteosarcoma, chondrosarcoma, liposarcomatous tumors, malignant extrarenal rhabdoid tumors, Ewing sarcoma/primitive neuroectodermal tumor, and other rare histotypes. Embryonal rhabdomyosarcoma (20%), Ewing sarcoma/primitive neuroectodermal tumor (17%), angiosarcoma (14%), and pleomorphic rhabdomyosarcoma (13%) appeared to be more common than the others, although there was no single overwhelmingly prevalent histotype in the group. A subset, including embryonal rhabdomyosarcoma, alveolar soft part sarcoma, and PEComas, peak in the premenopausal years, but most of the others were observed in postmenopausal women. Favorable outcomes have been reported for the patients diagnosed with alveolar soft part sarcoma, and the prognosis for their counterparts with PEComa remains a matter of debate. Multimodal therapeutic approaches to contemporary patients with embryonal rhabdomyosarcomas have resulted in significantly improved outcomes. Unfortunately, most of the other sarcomas have been associated with rapid tumor progression and unfavorable patient outcomes. The differential diagnosis for these sarcomas is often extensive and varies by histotype, but their accurate diagnosis fundamentally requires the careful exclusion of biphasic malignancies.