DISCUSSION
Carcinosarcomas also called malignant mixed Mullerian tumors are highly
aggressive biphasic neoplasms composed of high-grade, malignant,
epithelial, and mesenchymal elements. They usually occur in the uterus
and rarely involve the ovaries. Most patients with ovarian
carcinosarcomas are postmenopausal of low parity and older than 60
years. Our patient was a 52-year-old, nulliparous, and postmenopausal
woman. Only 10% of carcinosarcomas are bilateral as it was the case in
our patient. Carcinosarcomas frequently present with widespread
metastases at the time of diagnosis [4]. The most common symptoms
include abdominal pain, distension, nausea, vomiting, and weight loss
[5]. Our patient presented with a four-month history of abdominal
pain and distension. The pathogenesis of ovarian carcinosarcoma is still
debated. The collision theory stipulates that the two components of the
tumor are of different origin, whereas the combination theory suggests
that the two components of the tumor derive from a common epithelial
stem cell [6]. Some authors have reported an association between
ovarian carcinosarcoma and pelvic irradiation [7]. Approximately 74
to 90% of patients with ovarian carcinosarcoma will have an elevated
CA-125 as it was the case of our patient [4]. The radiological
features of ovarian carcinosarcomas are non-specific and are similar to
ovarian epithelial neoplasms. In the present case, ultrasonography and
contrast-enhanced computed tomography scan of the abdomen revealed
bilateral variegated ovarian masses with heterogeneous enhancement.
Grossly, these tumors are large (mean size, 14 cm) and predominantly
solid with frequent cystic degeneration and extensive hemorrhage and
necrosis [8]. Histologically, carcinosarcomas are composed of
high-grade carcinoma and sarcoma. One or the other may predominate. In
our case, the sarcomatous component predominated. Both components are
distinct but are typically intermingled with one another. The
carcinomatous component is most often a high-grade serous, endometrioid,
or undifferentiated adenocarcinoma and rarely clear cell adenocarcinoma
or squamous cell carcinoma [8]. The sarcomatous elements are
classified as homologous when the stromal component has a non-specific
appearance or heterologous when rhabdomyosarcoma, chondrosarcoma (these
being the most common), osteosarcoma, rarely liposarcoma or angiosarcoma
are present. The presence of heterologous components can be confirmed by
immunohistochemistry including desmin, myogenin and myo D1 for
rhabdomyosarcoma or S100 for chondrosarcoma [8]. There is no
existing consensus for the treatment of ovarian carcinosarcomas.
However, the mainstay of treatment relies on optimal surgical
cytoreduction followed by platinum-based chemotherapy. Combination
chemotherapy with ifosfamide and cisplatin or taxol and carboplatin is
favored. This results in improved progression-free survival according to
large retrospective series [9]. The prognosis of ovarian
carcinosarcoma is poor with a median survival reported in the majority
of the studies around 11 months [10]. The adverse prognostic factors
of carcinosarcomas include the presence of extra-ovarian sarcomatous
elements, the advanced stage and age, the suboptimal cytoreduction, the
stromal predominant tumors and tumors with serous epithelial component
[8].
In conclusion, ovarian carcinosarcoma is a very rare tumor with an
aggressive clinical course and a poor prognosis. The definitive
diagnosis of carcinosarcoma relies on the histopathological examination
of the resected specimen. The immunohistochemical study highlights the
biphasic components. The present case is significant owing to the
extreme rarity of this ovarian neoplasm. We must record such cases for
future reference with regard to the treatment provided and the outcome
achieved.