¹⁸F-FDG PET/CT for the Diagnosis of Malignant and Infectious Complications After Solid Organ Transplantation / 대한핵의학회잡지

PURPOSE: Infection and malignancy represent two common complications after solid organ transplantation, which are often characterized by poorly specific clinical symptomatology. Herein, we have evaluated the role of 18F-fluoro-2-deoxy-Dglucose (FDG) positron emission tomography/computed tomography (PET/CT) in this clinical setting.METHODS: Fifty-eight consecutive patients who underwent FDG PET/CT after kidney, lung or heart transplantation were included in this retrospective analysis. Twelve patients underwent FDGPET/CT to strengthen or confirma diagnostic suspicion of malignancies. The remaining 46 patients presented with unexplained inflammatory syndrome, fever of unknown origin (FUO), CMVor EBV seroconversion during post-transplant follow-up without conclusive conventional imaging. FDG PET/CT results were compared to histology or to the finding obtained during a clinical/imaging follow-up period of at least 6 months after PET/CT study.RESULTS: Positive FDG PET/CT results were obtained in 18 (31 %) patients. In the remaining 40 (69 %) cases, FDG PET/CT was negative, showing exclusively a physiological radiotracer distribution. On the basis of a patient-based analysis, FDG PET/CT's sensitivity, specificity, PPV and NPV were respectively 78 %, 90 %, 78 % and 90 %, with a global accuracy of 86 %. FDG PET/CT was true positive in 14 patients with bacterial pneumonias (n = 4), pulmonary fungal infection (n = 1), histoplasmosis (n = 1), cutaneous abscess (n = 1), inflammatory disorder (sacroiliitis) (n = 1), lymphoma (n = 3) and NSCLC (n = 3). On the other hand, FDG PET/CT failed to detect lung bronchoalveolar adenocarcinoma, septicemia, endocarditis and graft-versus-host disease (GVHD), respectively, in four patients. FDG PET/CT contributed to adjusting the patient therapeutic strategy in 40 % of cases.CONCLUSIONS: FDG PET/CT emerges as a valuable technique to manage complications in the post-transplantation period. FDG PET/CT should be considered in patients with severe unexplained inflammatory syndrome or FUO and inconclusive conventional imaging or to discriminate active from silent lesions previously detected by conventional imaging particularly when malignancy is suspected.

Post-transplant lymphoproliferative disorders following renal transplantation: 4 cases report and literatures review / 白血病·淋巴瘤

Objective To study the clinicopathologic features of post-transplant lymphoproliferative disorders (PTLD) following renal transplantation.Methods Four cases of PTLD following renal transplantation were studied and relevant literatures were reviewed.Results All the 4 cases had received 3-drug-immunosuppression after transplantation.The duration between renal transplantation and diagnosis of PTLD was 5-112 months,averagely 34 months.The patients were suffered from infective monocytic hyperplasialike PTLD,plasmacytic hyperplasialike PTLD,polymorphic PTLD and monomorphic PTLD respectively in morphology and had no specific symptoms.All the patients received therapy with dosage reduction of immunosuppressants and some received rituximab or chemotherapy.The case of monomorphic PTLD died in a short time after diagnosis.Conclusion PTLD is a lymphoproliferative disease with distinctive morphologic and clinical characteristics.The main treatments include the dosage reduction of immunosuppressive agents,biotherapy and chemotherapy.The prognosis of monomorphic PTLD is poor.

Clinicopathologic features of post-transplant lymphoproliferative disorders / 中华器官移植杂志

ObjectiveTo study the clinicopathologic features of post-transplant lymphoproliferative disorders (PTLD).Methods Three cases of PTLD in renal transplant recipients were studied.The clinical data,diagnosis and differential diagnosis,and relevant literatures were also reviewed.Results All the 3 cases studied had received cyclosporine A or Tac after transplantation.The duration between organ transplantation and diagnosis of PTLD was 10 years,4 years and 2 months respectively.Two cases were suffered from monomorphic PTLD and 1 from plasmacytic hyperplasialike PTLD in morphology.Two cases of monomorphic PTLD died within one year after diagnosis.Conclusion PTLD is a lymphoproliferative disease with distinctive morphologic and clinical characteristics.The main treatments included the dosage reduction of immunosuppressive agents,radiotherapy and chemotherapy.The prognosis of monomorphic PTLD was poor.

Clinical Characteristics of Monomorphic Post-transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLD) are a heterogeneous group of lymphoproliferative disorders associated with immunosuppression and Epstein-Barr virus infection. PTLD is classified into three major categories: early lesions, polymorphic PTLD, and monomorphic PTLD. The majority of monomorphic PTLD cases are non-Hodgkin's lymphoma of B-cell origin. This retrospective study was conducted to investigate the incidence, clinical manifestation, treatment, and outcomes of monomorphic PTLD among 5,817 recipients of solid organ or allogeneic hematopoietic stem cell transplantation from five institutions. Fourteen patients with monomorphic PTLD were identified (male:female 11:3; median age 42.6 yr, range 24-60). The overall incidence rate was 0.24%. The most common disease type was diffuse large B cell lymphoma (n=7). The median time between the transplant and diagnosis of PTLD was 85.8 months. However, all cases of PTLD after allogeneic hematopoietic stem cell transplantation occurred within 1 yr after transplantation. Ten of the 14 patients had EBV-positive tumor. Fourteen patients received combination systemic chemotherapy and four patients were treated with radiation therapy. Ten patients achieved a complete response (CR) and two patients a partial response (PR). The median follow-up period for surviving patients was 36.6 months. Nine patients remain alive (eight CR, one PR). Nine of 11 solid organ transplantations preserved graft function. The present study indicates a lower incidence rate and a longer median time before the development of PTLD than those of previous reports. Careful monitoring was needed after allogeneic hematopoietic stem cell transplantation for PTLD.

A Case of Mediastinal Tuberculous Abscess and Lymphadenitis after Bone Marrow Transplantation / 감염

After bone marrow transplantation (BMT), recipients can be complicated by infectious or non-infectious chest lesions such as mycobacterial infections or post- transplant lymphoproliferative disorders (PTLDs). BMT recipients usually face a lot of risks of mycobacterial infection because they have severely impaired cell- mediated immunity as a result of their underlying disease, chemotherapy, radiotherapy, acute or chronic graft-versus-host diesase (GVHD) and their treatment. We report a case of mediastinal tuberculous abscess and lymphadenitis after BMT, which mimicks PTLDs. 20 months before admission, BMT was performed on a 41 year-old woman who was diagnosed as chronic myelocytic leukemia. She showed acute and chronic GVHD with several infections of bacteria or viruses after BMT. In endemic area of tuberculosis such as Korea, PTLDs should be differentiated from pulmonary tuberculosis and tuberculous lymphadenitis.