Synchronous Uterine Leiomyosarcoma and Pulmonary Adenocarcinoma: A Rare Oncological Puzzle

The occurrence of dual primary malignancies is an uncommon clinical phenomenon. This case report details a 65-year-old female presenting with both uterine leiomyosarcoma (LMS) and pulmonary adenocarcinoma, initially misdiagnosed as a metastatic spindle cell tumor.

The patient presented with foul-smelling vaginal discharge, irregular menses, lower limb swelling, and a nonproductive cough. Imaging and biopsies revealed a necrotic uterine mass diagnosed as LMS and a left upper lobe lung mass identified as adenocarcinoma. Genetic testing of the lung tumor showed an epidermal growth factor receptor (EGFR) exon 19 deletion mutation. Treatment included chemotherapy targeting both malignancies, surgical resection of the uterine tumor, and targeted therapy for the lung adenocarcinoma.

This case underscores the importance of thorough diagnostic evaluation in patients with multiple tumors to distinguish between metastatic disease and dual primary malignancies, as treatment strategies differ significantly.