Bone marrow involvement in patients with posttransplant lymphoproliferative disorders: incidence and prognostic factors

A Pathology Experience of Posttransplant Lymphoproliferative Disorder From One Tertiary Hospital: Pathology Concepts and Diagnostic Approach

BACKGROUND

Solid organ transplantation and bone marrow/hematologic stem cell transplantation recipients face a heightened risk of developing malignancies or cancer as a result of immunosuppression. Posttransplant lymphoproliferative disorders (PTLD) are a range of disorders from benign lymphoid growth to lymphoma found post-transplant. Risk factors for PTLD include high immunosuppressive use and oncogenic effects of Epstein-Barr virus (EBV). There is a lack of comprehensive clinical and pathological documentation of PTLD cases among Saudi patients, and the available data are limited to a few case reports. As a result, a deeper understanding of this disease requires more clinicopathological information.

MATERIAL AND METHOD

In this review, we share our insights on cases diagnosed with PTLD at King Faisal Specialist Hospital and Research Center, a prominent tertiary center in the western region of Saudi Arabia, from 2005-2023.

RESULT

We have diagnosed a total of 14 cases of PTLD in our department, with an age range spanning from 3 to 62 years. These diagnoses were made based on biopsies or tumor resection procedures. The survival rate of patients is believed to be influenced by multiple factors, including histology, tumorigenesis, disease biology, and clinical stage. Additionally, Kaplan-Meier curve analysis indicates that female patients tend to have a higher estimated survival rate compared to males.

CONCLUSION

PTLD diagnosis and therapy have greatly improved in the past 20 years. PTLD is treated with reduced immunosuppression, rituximab, chemotherapy, adoptive therapy, surgery, antiviral therapy, and radiotherapy. In this study, we present our experience from a large tertiary center in the western region of Saudi Arabia. Moreover, we will go through etiology, clinical features, and pathologic morphology along with the corresponding genetics, prevention, and valid treatment options.

The clinical and pathological features of plasma cell myeloma post solid organ transplantation

Plasma cell neoplasms (PCNs), comprising plasma cell myelomas (PCMs) and plasmacytomas, which occur after solid organ transplantation, represent rare subtypes of monomorphic post-transplant lymphoproliferative disorders (M-PTLDs). Data regarding the clinical and pathological features of post-transplant (PT)-PCMs are limited. To gain a better understanding of disease biology, we performed comprehensive immunophenotypic analysis, reviewed cytogenetic analysis results and evaluated clinical outcomes of PT-PCMs diagnosed and treated at our institution. Fifteen PT-PCM (M: F - 4:1) and two PT-MGUS (two males) cases were identified. The median age of PT-PCM patients was 68 years (29-79 years) and PCMs presented at a median of 9.7 years (0.5-24.7 years) after transplantation. The PT-PCMs accounted for 11.6% of all M-PTLDs and the period prevalence was 9/3108 (0.29%), 3/1071 (0.28%), 2/1345 (0.15%) and 1/878 (0.11%) post kidney, heart, liver and lung transplantation. Lytic bone disease was observed in 1/11 (9%) patients. Marrow plasma cell infiltration ranged from 10%-70% (median 20%), with 10/15 (67%) and 5/15 (33%) cases manifesting immature and plasmablastic morphology. The immunophenotype of all cases and cytogenetic abnormalities, identified in 60% of cases, were similar to multiple myeloma (MM) of immunocompetent individuals. All PT-PCMs were EBER negative. Ten of 11 (91%) patients with active MM were treated, all with proteasome inhibitor-based therapy. Treatment response and 5-year overall survival (54.5%) was comparable to MM of immunocompetent individuals. However, the survival of patients with plasmablastic PCMs was inferior to those with immature PCMs. 0ur findings indicate PT-PCMs to be predominantly late onset PTLDs that have similar clinicopathologic characteristics as conventional MM.

Trisomy 3, a sole recurrent cytogenetic abnormality in pediatric polymorphic post-transplant lymphoproliferative disorder (PTLD)

Trisomy 3 has been previously reported in association with T-cell lymphomas and less commonly in different types of non-Hodgkin B-cell lymphomas. Trisomy 3 has also been reported in two cases of pediatric post-transplant lymphoproliferative disorder (PTLD). We present comprehensive clinicopathologic review of two pediatric patients with cardiac and liver/intestinal allografts that developed polymorphic PTLD characterized by trisomy 3. Both patients had Epstein-Barr virus (EBV) viremia and EBV was positive in tissue by EBER in situ hybridization. Using karyotype analysis and fluorescence in situ hybridization, we identified trisomy 3 in both patients. Both patients responded to treatment and are now free of the PTLD. Trisomy 3, an uncommon cytogenetic finding in pediatric polymorphic PTLD, may be a recurrent cytogenetic aberration if confirmed in a larger study of pediatric PTLDs. Further clinical follow up might help stratify significance of trisomy 3 as a prognostic factor.

Post-transplant lymphoproliferative disorder after solid-organ transplant in children

The post-transplant lymphoproliferative disorders (PTLD) are a diverse group of potentially life-threatening conditions affecting organ transplant recipients. PTLD arises in the setting of an attenuated host immunologic system that is manipulated to allow a foreign graft but then fails to provide adequate immune surveillance of transformed malignant or premalignant lymphocytes. The diversity of biological behavior and clinical presentation makes for a challenging clinical situation for those involved in the care of children with PTLD occurring after solid-organ transplantation. This review details a large transplant center's multidisciplinary approach to monitoring for PTLD and systematic approach to intervention, which has been essential for early recognition and successful treatment.