Introduction and importance: Castleman's disease was first reported by Benjamin Castleman et al., in 1954 and described it as a sporadic lymphoproliferative disorder. The pathophysiology to this day is still unknown, although IL-6 is suspected to play an important role. Preoperative diagnosis is challenging due to its non-specific symptoms, and that imaging cannot clearly distinguish the disease from other processes. High clinical awareness is necessary to reach a diagnosis. If the disease is localized, complete recovery can be achieved through surgery. Case presentation: Patient is a 68-year-old woman with a three-month history of recurrent episodes of fever, myalgias, and night sweats. She started to experience lower abdominal pain and presented to the emergency room. A contrast-enhanced abdominal computed tomography revealed a 5 cm well-circumscribed focal heterogeneously enhancing hyperplastic mass between the portal vein and the inferior vena cava. After successful laparoscopic surgery, the mass was resected, and the patient fully recovered. Unicentric Castleman's disease was the final diagnosis. Discussion and conclusion: Castleman's disease is an uncommon pathology with a challenging diagnosis. When approaching an abdominal mass, unicentric Castleman's disease should always be a differential diagnosis, as treatment can be curative with surgical resection. With the advent of laparoscopic and robotic surgery, these techniques can improve patients' outcomes in these rare pathologies, especially when they appear in complex regions.