Avoiding Inappropriate Anticoagulant Regime: A Case Report on Pericatheter Fibrous Sheath in a Cancer Patients

Case Presentation We report the case of a 63–year–old female with diagnosis of uterine leiomyosarcoma. Following total hysteroannessectomy, she commenced chemotherapy using a port–a–cath. A transthoracic echocardiogram revealed a 2 cm hyperechoic mass protruding into the right atrium. This finding was confirmed by transesophageal echocardiography, which identified the mass originating from the tip of the intravascular device. While D–dimer levels were mildly elevated, consistent with her neoplastic condition, and electrocardiogram and echocardiogram showed no overt signs of pulmonary embolism, a pulmonary angio–CT scan was performed, effectively ruling out pulmonary thromboembolism. The patient was subsequently started on anticoagulation with enoxaparin for a presumptive diagnosis of catheter–related thrombosis. However, during low–molecular–weight heparin therapy, she developed a retroperitoneal hematoma complicated by hemorrhagic shock, necessitating embolization of the inferior epigastric artery, the source of bleeding. The port–a–cath was removed during her hospitalization. Subsequent pathological examination of the catheter revealed the hyperechoic formation to be a fibrous sheath. Discussion This case underscores a critical diagnostic challenge in managing pericatheter vascular hyperechoic formations. A fibrous sheath is an inevitable consequence of central venous catheter implantation. In asymptomatic patients, a pericatheter hyperechoic structure is approximately five times more likely to be a fibrous sheath than a catheter–related thrombosis. While pericatheter thrombosis can be asymptomatic, it often correlates with vessel wall adherence, ultrasound compressibility, higher echogenicity, a greater thickness–to–length ratio, and demonstrable color doppler flow defects. Given these distinguishing features, color doppler ultrasound offers superior sensitivity and specificity for differentiating between these entities compared to computed tomography. Conclusion This case powerfully illustrates the urgent need for prompt differential diagnosis between a fibrous sheath and catheter–related thrombosis. Especially in oncological patients, who are at high risk for both thrombotic and hemorrhagic complications, an accurate diagnosis is paramount to avoid exposing them to potentially inappropriate anticoagulation therapies that could lead to severe adverse events.