BACKGROUND Malignant peritoneal mesothelioma (MPM) is a rare and aggressive neoplasm, with low-grade epithelioid subtypes presenting diagnostic and therapeutic challenges. With nonspecific symptoms and diagnostic challenges, definitive diagnosis relies on histopathological and immunohistochemical analysis. This study reviews the current research on the epidemiology, diagnosis, and treatment of MPM, focusing on preserving fertility and achieving successful childbirth following surgery, chemotherapy, and immunotherapy, despite immune-related adverse events. CASE REPORT We report the case of a 44-year-old nulliparous woman, initially diagnosed with a uterine leiomyoma, who was incidentally found to have MPM during surgery. Diagnostic laparoscopy and subsequent imaging revealed extensive peritoneal involvement, confirmed by histopathology and immunohistochemistry. The patient's desire to preserve fertility complicated the treatment approach, leading to chemotherapy followed by immunotherapy, with complete disease control. Without evidence of disease recurrence or metastasis, the patient proceeded with in vitro fertilization (IVF) and embryo transfer. During an emergency cesarean section at 30 weeks 2 days of gestation, performed due to preterm premature rupture of membranes, intraabdominal residual tumors were discovered and excised. No evidence of malignancy was found elsewhere. CONCLUSIONS MPM is a rare disease, often with a delayed diagnosed due to nonspecific symptoms. Treatments like cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) improve survival for operable cases, while systemic therapies and immune-checkpoint inhibitors (ICIs) are options for inoperable cases; however, further research on early-detection biomarkers and the impact of ICIs on fertility is needed to enhance clinical practice. This case highlights the intricate balance between oncologic control and fertility preservation in MPM, illustrating the need for individualized treatment strategies.