Introduction/Background Recent studies in China have reported an incidence of approximately 1% for multiple primary tumors. However, it is important to note that the current prevalence in China might be underestimated due to regional variations and limited case numbers. Synchronous primary cancers of the endometrium and cervix with different histomorphology are particularly rare in the female reproductive system.

Methodology A 73-year-old woman was admitted to Gansu Provincial Maternity and Child-care Hospital with complaints of vaginal bleeding for two weeks, occasional lower abdominal discomfort, and dizziness. We performed serological, imaging, and histopathological tests on this patient. To further investigate whether cancer sites were primary or metastatic, we utilized a dual-gene methylation detection system (CISPOLY, China) to analyze pathological tissues from different areas.

Results Serological tests revealed elevated levels of carcinoembryonic antigen and CA-125. Transvaginal ultrasound (TVS) showed abnormalities in the uterine cavity and cervical canal. Pelvic MRI revealed diffuse occupancy of the uterine cavity and cervical canal, indicating a likelihood of endometrial cancer. Pathological biopsy revealed the presence of inflammatory cells, consistent with endometrial cancer. Surgical and pathological results confirmed tumor sites as follows: invasion of the muscle layer in the uterine cavity, adenocarcinoma in situ, and chronic cervicitis. We observed positive gene methylation results in other sites, indicating molecular-level changes that have not yet manifested as tissue alterations.

Conclusion Both gene methylation technology and traditional histopathology were employed for simultaneous detection. The results of gene methylation analysis may provide further insights in determining whether the reproductive tract tumors originate primarily or secondarily. Essentially, the presence of positive methylation in other areas may suggest a potential cancer progression within a specific timeframe, which can serve as a basis for assessing the likelihood of cancer metastasis. However, further clinical cases are needed to substantiate the role of methylation in considering the cancer foci metastasis possibility.

Disclosures No potential conflict of interest was reported by the authors.