Heterologous and Rare Homologous Sarcomas of the Uterine Corpus

Abstract

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.

Endometrial stromal sarcoma – the new genetic paradigm

“…total hysterectomy), when a mixed epithelial and mesenchymal tumour has been excluded after a reasonable sampling effort (at least one section per centimetre of tumour with directed sampling of the surface of the intracavitary tumour and adjacent endometrium), it is important to determine whether one is dealing with a pleomorphic uterine sarcoma or a monomorphic uterine sarcoma, based on low‐power examination. If significant nuclear pleomorphism is encountered, the differential diagnosis would include UUS, leiomyosarcoma, and distinctively rare heterologous sarcomas, such as pleomorphic rhabdomyosarcoma, among others . If there is no significant nuclear pleomorphism, the differential dianosis then includes ESS, smooth muscle tumour (leiomyosarcoma or intravascular leiomyomatosis), dedifferentiated/undifferentiated endometrial carcinoma, and the rare uterine PEComa and Ewing sarcoma …”

Dedifferentiated Leiomyosarcoma of the Uterus with Heterologous Elements: A Potential Diagnostic Pitfall

“…Also supportive of that classification was the presence of heterologous elements, which as previously noted are within the recognized spectrum of dedifferentiated leiomyosarcoma as well as other dedifferentiated neoplasms. Although primary uterine osteosarcomas are well described [12], heterologous osteoid elements are extraordinarily rare in the uterine leiomyosarcomas. Previously reported examples of this phenomenon include 2 cases of complex tumors, reported as mesenchymomas , with leiomyosarcomatous, osteosarcomatous, and liposarcomatous elements [13, 14], 1 case of a mixed osteosarcoma/leiomyosarcoma [15] and 1 case of a conventional uterine leiomyosarcoma that metastasized as a high-grade sarcoma with a multitude of heterologous malignant mesenchymal elements that included osteosarcomatous, chondrosarcomatous, and liposarcomatous areas [16].…”

Angiosarcoma primario uterino: revisión de la literatura y presentación de caso

“…El angiosarcoma es definido como una neoplasia mesenquimal originada de las células endoteliales presentes en los vasos sanguíneos y que pueden tener en su localización en el cuerpo uterino, una apariencia macroscópica polipoide o ser completamete intramurales con zonas de hemorragia, necrosis e incluso formaciones quísticas (3). Están compuestos por canales vasculares anastomosantes los cuales se encuentran tapizados por células tumorales cuboides que exhiben moderada a marcada atipia y que presentan altos conteos mitóticos (2-6), dichas zonas pueden alternar con áreas sóli-das que muestran células en un espectro que van desde ahusadas hasta epitelioides, que dependiendo de la representación de dichas áreas en la totalidad del tumor pueden representar la subvariante de angiosarcoma epitelioide (4,7).…”

“…Están compuestos por canales vasculares anastomosantes los cuales se encuentran tapizados por células tumorales cuboides que exhiben moderada a marcada atipia y que presentan altos conteos mitóticos (2-6), dichas zonas pueden alternar con áreas sóli-das que muestran células en un espectro que van desde ahusadas hasta epitelioides, que dependiendo de la representación de dichas áreas en la totalidad del tumor pueden representar la subvariante de angiosarcoma epitelioide (4,7). Son considerados tumores altamente agresivos, cuyo diagnóstico definitivo requiere demostración por inmunohistoquí-mica y/o microscopia electrónica (2)(3)(4)(5)8,9).…”