Introduction
Malignant mixed mullerian tumors (MMMT) are also known as malignant mixed mesodermal tumors, carcinosarcomas, or sarcomatoid carcinomas. They are relatively rare tumors typically occurring in nulliparous and postmenopausal women. The most common site is the uterus. In ovaries, the reported incidence in the literature is <2 % of ovarian malignancies. However, the highest incidence of 4 % is reported in one series [1].
Histologically, they show both carcinomatous and sarcomatous elements. Their behavior and management is controversial [2].
We report a case of MMMT of the ovary with a recurrent metastatic tumor in the large intestine.
Case Report
A 55-year-old female, multigravida, postmenopausal, presented with a history of recurrent abdominal pain, weight loss, and decreased appetite. There was no history of altered bowel motion, bladder habits or bleeding per vaginam or per rectum.
The routine hematologic and biochemical parameters were normal.
The serum CA125 level was 138 IU/ml (normal: 0–35).
Abdominal CT scan showed a large multilocular solid and cystic mass measuring 15.2 × 11.2 × 8 cms. A right ovarian malignancy was suspected.
A total abdominal hysterectomy with bilateral salphingo oophrectomy and omentectomy was performed.
Grossly: The uterus, cervix, and left adenexa appeared unremarkable. The right ovarian mass was seen. It measured 15 × 12 × 9 cms and weighed 900 g. The external surface was bosselated. No papillae were seen. The cut surface showed solid and cystic areas. The cyst was unilocular, 10 cms in diameter. The solid area measured 4.8 × 9.5 cms in diameter. It was fleshy, yellowish white, and showed areas of necrosis (Figs. 1, 2).
Fig. 1.
Intraoperative right-sided ovarian mass showing bosselated external surface
Fig. 2.
Cut surface of the right ovarian mass showing cystic as well as fleshy solid areas
The histopathologic examination showed a biphasic tumor. Sections from the solid area showed nests of malignant cells' (carcinomatous) element infiltrating the surrounding stroma. The stroma was composed of pleomorphic, anaplastic spindle cell (sarcomatous) element. The spindle cells showed abnormal mitosis and myofibroblastic differentiation (Fig. 3). Large areas of necrosis were also observed. The cyst wall revealed complex papillae lined by many layers of malignant cuboidal cells.
Fig. 3.
HPE of the right-sided ovarian mass showing both sarcomatous and carcinomatous elements. (H&E ×100)
The tumor was seen abutting on the serosal surface of the appendix. The pelvic lymph nodes and omentum were free of tumor.
A final diagnosis of Malignant Mixed Mullerian Tumor of the right ovary (homologous)—Stage 1C was offered.
The patient was started on chemotherapy. The drugs given were Carboplatin (75 mg/m2) and Paclitaxel (135 mg/m2) as intravenous infusion. After three cycles of chemotherapy, the patient again presented with obstructive symptoms and a lump in the right iliac fossa.
USG showed a well-defined oval, complex lesion 3.5 × 2 cms in the right mid quadrant at the ileoceal junction. A hemicolectomy was performed.
The specimen consisted of part of the ileum, cecum, and colon, totally measuring 29 cms in length. There was a gray-white solid mass on the serosal aspect of the cecum, giving a fungating appearance on the luminal surface.
Microscopic examination showed an infiltrating anaplastic sarcomatoid tumor replacing the normal mucosal elements. Large necrotic areas were evident. There was no carcinomatous component. The surrounding mucosa was normal (Fig. 4).
Fig. 4.
HPE of the hemicolectomy specimen showing metastatic deposit and the neighboring normal colonic mucosa. (H&E ×40)
A final diagnosis of deposits of MMMT (predominantly sarcomatous elements) was offered.
Discussion
MMMT of the ovary is, relatively, a rare tumor affecting the elderly population and has a poor prognosis [1, 2]. The tumors are highly aggressive. There are many theories regarding their histogenesis. The collision theory suggests that carcinoma and sarcoma are two independent tumors. The combination theory says that both components are derived from single stem cells which undergo divergent differentiation. The conversion theory suggests that a sarcomatous element is obtained from the carcinoma during the evolution of tumors. The least acceptable view is that the spindle cell component is just a pseudosarcomatous stromal reaction to an invasive carcinoma.
Out of these, combination and conversion theories are proved to be the prime modes of histogenesis [3]. The malignant mesenchymal component can be homologous or heterologous. If the sarcomatous part contains elements resembling the mullerian duct system (e.g., fibrosarcoma, leiomyosarcoma, endometrial stromal sarcoma), it is termed homologous. If the tumor has elements not normally found in the ovary (e.g., cartilage, bone, skeletal muscle differentiation, etc.), it is called heterologous. Our tumor was homologous. It has been suggested that heterologous tumors have a worse prognosis. However, some studies [2, 3] have not shown such association.
The metastatic foci usually show a carcinomatous component. Pure sarcomatous elements in metastatic foci are rare [3]. Our case showed a pure sarcomatous component in the colonic metastasis. Some workers have speculated that sarcomatous differentiation in metastatic lesions is dependent on the anatomic sites. The peritoneum, vagina, and hollow spaces typically show polypoidal neoplasms with sarcomatous differentiation as was evident in our case.
There is no well-established consensus regarding the treatment regimen. It is usually directed against the carcinomatous component rather than the sarcomatous component [3]. Different chemotherapy regimens are used. The response to Platinum-based chemotherapy is 25 % [1]. The role of therapeutic radiotherapy is not established [2]. Our patient developed metastatic disease when on chemotherapy. Clinical trials to establish the role of chemotherapy and radiotherapy are necessary, but may be difficult due to the rarity of the disease. The overall median survival is 8.2–8.7 months [1, 2].
References
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