Late recurrence of primary cardiac paraganglioma 8 years after resection with a low ki-67 index: a case report

Introduction and importance: Primary cardiac paraganglioma (PCP) is an extremely rare neuroendocrine tumor (<1% of cardiac neoplasms). Its long-term biological behavior, particularly in tumors with low proliferative activity, remains poorly defined. We report a rare case of late recurrence 8 years after the initial resection, despite a low Ki-67 index, highlighting the necessity for lifelong surveillance. Case presentation: A 69-year-old woman presented with a 1-week history of chest tightness. Eight years prior, she underwent macroscopically complete resection of a right atrial PCP (Ki-67 index of 2–3%). Contrast-enhanced computed tomography (CT) revealed a 5.4 cm × 4.4 cm mass in the right atrium with marked intratumoral vascularity, compressing the right coronary artery (RCA). A second surgery was successfully performed to achieve total resection and RCA reconstruction. Histopathological examination confirmed recurrence of PCP. The postoperative course was uneventful. Clinical discussion: This case demonstrates that recurrence can occur despite a relatively low Ki-67 index, emphasizing that even tumors with low levels of proliferative markers require vigilant long-term surveillance. The 8-year interval suggests a highly indolent yet persistent growth pattern. Advanced imaging, particularly contrast-enhanced CT, is valuable for identifying intratumoral vascular structures, aiding in planning complex reoperations involving coronary reconstruction. Conclusion: A low Ki-67 index in PCP should not be interpreted as a guarantee of a permanent cure, as late recurrence remains a significant risk. Consequently, lifelong clinical and radiological follow-up is mandatory for all PCP patients. Additionally, preoperative identification of coronary involvement is critical for achieving surgical success in recurrent cases.