Article Details

Background: Carcinoma of Unknown Primary (CUP) syndrome is a rare and complex oncological challenge characterized by an unidentified primary site, accounting for 1-2% of invasive cancers. Secondary cardiac involvement in cancer is more common, often driven by metastasis, and is associated with various malignancies.

Case Presentation: A 64-year-old male with CUP syndrome initially presented with right cervical tumor. Histological examination revealed a poorly differentiated squamous cell carcinoma with high PD-L1 expression. The subsequent PET-CT showed a malignancy-suspect lesion in the free right atrial wall. According to the tumor board decision, the tumor was completely resected and the right atrial wall and the superior vena cava were reconstructed using bovine pericardium. The post-operative course was uneventful and the patient was discharged on postoperative day 9. The final diagnosis was a poorly differentiated squamous cell carcinoma in the right atrium.

Conclusion: This case emphasizes the importance of a multidisciplinary approach, combining clinical evaluation and advanced imaging, in managing complex scenarios of CUP with secondary cardiac malignancies. Ongoing research and standardized diagnostic and treatment approaches are needed for these rare and intricate clinical presentations. Accumulating more cases and data is essential to improve the understanding and management of such complex conditions, potentially including emerging therapies like immune checkpoint inhibitors.

Keywords: Carcinoma of unknown primary; CUP syndrome; Secondary cardiac involvement; Right atrial metastasis; Multidisciplinary approach; Immune checkpoint inhibitors