Müllerian adenosarcoma arising from the uterine cervix

Müllerian adenosarcomas are rare tumors that occur in only 8% of uterine sarcomas (1). This tumor is an uncommon variant of mixed mesodermal tumor (MMT) of the uterus, and exhibits a malignant stroma and a benign glandular element. In usual cases, the origin has been reported to be the endometrium. However, very few cases have been reported arising from the uterine cervix (2). Myometrial invasion has been recognized as one of the most important risk factors in endometrial adenosarcomas (1). We report here a case of an unusual adenosarcoma arising from the uterine cervix, which invaded deeply into the uterine myometrium. However, our patient has been alive for 5 years without any apparent recurrence. A 42-year-old Japanese woman, gravida 0, complained of left lower abdominal pain. Both Papanicolaou smears of the cervix and the endometrium were judged as class II, and an endometrial biopsy revealed no malignancy. Magnetic resonance imaging (MRI) revealed an enlarged uterus (13 × 12 × 14 cm), a polypoid mass (3 × 4 × 3 cm) in the cervix and an adenomyosis-like mass in the myometrium of the corpus. We could not obtain a definitive diagnosis. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was then performed. Macroscopically, an elastic, hard polypoid tumor in the cervix and adenomyosis-like tissues in the corpus were seen (Fig. 1). After surgery, an adenosarcoma arising from the uterine cervix was diagnosed. On microscopic examination, the cervical mass showed an atypical stroma and a benign epithelium. The benign glands varied in size from small to large, were cystically dilated, and were composed of epithelial cuboidal cells. The stromal cells exhibited moderate degrees of nuclear atypia and homologous components. This malignant sarcomatous stromal component showed round- to spindle-shaped cells. The mitotic rates of the stromal cells were 5–9/10 high-power fields (HPF). These tumor cells with benign glands and malignant stromas extended diffusely into the deep myometrium in the uterine corpus. Thus the adenomyosis-like mass in the corpus was determined to be an invading adenosarcoma. However, this tumor exhibited no sarcomatous overgrowth, no heterologous elements and no myxomatous changes. A main tumor, measuring 3 × 4 × 3 cm, showed polypoid growth in the cervix, and adenomyosis-like tissues were determined to be an invasive tumor in the corpus. The patient did not require any additional therapy. She has been alive for 5 years without any recurrence. Adenosarcomas arising from the uterine cervix are very rare. Adenosarcomas usually arise in the endometrium, but rarely in the endocervix (9%) or in the myometrium (4%) (3). To our knowledge, only 24 cases have been reported in the cervix (2). In the present case, cervical cytology and biopsy did not detect any atypical cells. Furthermore, our tumor simulated an adenomyosis uteri by MRI. In the few previous reports of MRI of an endometrial adenosarcoma, it was not detected as an adenomyosis-like mass but rather as a polypoid-enhancing mass in the endometrial cavity (3). Therefore, we could not diagnose it before primary surgery. Myometrial invasion and sarcomatous overgrowth have been recognized as important risk factors in endometrial adenosarcomas (1). Other risk factors for adenosarcomas have been reported; for instance, a high mitotic index (4), a high-grade sarcoma (5), heterologous elements (4), necrosis (5) and myxomatous changes (6). Adenosarcoma has been regarded as a low-grade neoplasm with a favorable prognosis and little metastatic potential. Jones et al. insisted that myometrial invasion by the cervical adenosarcoma was a risk factor (2). In the present case, however, the patient has been alive for 5 years without any apparent recurrence, despite the presence of deep myometrial invasion from the cervix to the corpus. The patient had no extrauterine metastasis, and did not receive additional chemotherapy or radiation therapy. Additionally, this case showed neither sarcomatous overgrowth, heterologous elements, numerous atypia, a high mitotic index nor myxomatous changes. Therefore, clinicians should recognize the risk factors as not only myometrial invasion but also complex factors. Further research is needed to determine these risk factors.