Abstract
BACKGROUND: Pseudo-Meigs syndrome (PMS) is a rare condition in which the primary tumor is most commonly ovarian teratoma, struma ovarii, ovarian metastatic tumor, or leiomyoma. Cases of PMS associated with ovarian borderline mucinous tumors or early-stage mucinous cystadenocarcinomas are exceedingly rare, with only two reported to date. CASE PRESENTATION: This article presents the cases of two young women in 30s who sought medical attention due to progressively worsening dyspnea or abdominal distension. Preoperative serum tumor marker levels and imaging suggested advanced ovarian cancer; however, pathological examination of tissue and effusion fluid showed no evidence of malignancy. Postoperative pathological examination revealed stage IA ovarian borderline mucinous cystadenoma and stage IIB ovarian mucinous cystadenocarcinoma (microinvasive carcinoma). Postoperatively, the pleural effusion disappeared within a few months and there were no signs of recurrence. CONCLUSION: Primary borderline mucinous ovarian tumors or early mucinous cystadenocarcinomas associated with PMS are rare and can be easily confused with advanced ovarian cancer. To avoid unnecessary chemotherapy, it is essential to obtain histological or liquid-based cytological confirmation of malignant tumors before treatment. This case report highlights the importance for clinicians to consider the possibility of low-grade ovarian malignant mucinous tumors associated with PMS.