A rare synchronous occurrence: ovarian and renal primary tumors detected simultaneously: a rare case report.

Introduction and importance: Multiple primary malignancies (MPMs) are separate malignant tumors in the same patient that are not caused by metastasis or recurrence; they represent between 1.84% and 3.9% of all malignancies. Synchronous MPMs, where the tumors are detected at the same time, are even rarer, with a rate of about 0.7%. Moreover, synchronous primary neoplasms involving both the kidneys and ovaries are extremely rare and have been reported in only a few cases in medical literature. Presentation: We present the first case to be reported in Syria as multiple primary tumors of a 62-year-old woman who presented with heaviness in her lower abdomen and right hypochondrium and was found to have synchronous primary tumors, left renal clear cell carcinoma and right ovarian papillary serous cystadenocarcinoma based on computed tomography-scan and histopathology. The patient underwent left radical nephrectomy and resection of the right ovary and will receive adjuvant chemotherapy, with regular follow-up recommended to monitor for any signs of recurrence or metastasis. Discussion: Based on our literature review, the co-occurrence of ovarian tumor with renal cell carcinoma is uncommon. Distinguishing between metastatic tumors and simultaneous primary tumors presents a significant diagnostic challenge. Achieving a precise diagnosis requires the observation of markedly different histologies to confirm the presence of concurrent primary tumors. Conclusion: This case serves as a reminder that when a patient presents with multiple masses, it is important to consider the possibility that they could be separate primary tumors despite their rarity.