RESUMO
INTRODUCTION AND IMPORTANCE: Persistent left superior vena cava (PLSVC) is a rare vascular anomaly that affects systemic venous circulation. PLSVC typically is asymptomatic as the return of venous blood to the right atrium occurs through the coronary sinus. It is important to possess a comprehensive understanding of drainage as it can present challenges in catheter placement on the right side of the heart, aiming to prevent potential complications. CASE PRESENTATION: A 59-year-old female patient presented at the medical service with abdominal distention. During the examination, the presence of ascites was observed. Subsequent studies revealed peritoneal carcinomatosis of unknown origin. The patient underwent staging laparoscopy with biopsy sampling. Consequently, the placement of a catheter for chemotherapy was performed. A portable chest X-ray was obtained revealing the catheter extending along the left subclavian vein and progressing through the left paramediastinal regionThe presence of persistent left superior vena cava was confirmed after reviewing prior studies. CLINICAL DISCUSSION: The most common abnormality in the venous drainage system is PLSVC. Approximately 40 % of PLSVC cases have associated significant cardiovascular anomalies, with septal defects being the most common. Recognizing anomalies and anatomical variants with the involvement of a multidisciplinary team is critical to prevent vascular complications during endovascular procedures and to tailor techniques for patients in need of cardiac endovascular procedures or cardiac devices. CONCLUSION: PLSVC is often asymptomatic and discovered incidentally, it is essential to have a comprehensive understanding of this anomaly and perform meticulous imaging workup to prevent potential complications.