Isolated pleural PTLD after cardiac transplantation

Clinicopathologic Spectrum of Pediatric Posttransplant Lymphoproliferative Diseases Following Solid Organ Transplant

CONTEXT.—

Posttransplant lymphoproliferative disorder (PTLD) remains a significant complication in pediatric patients undergoing solid organ transplant (SOT). The majority involve Epstein-Barr virus (EBV)-driven CD20+ B-cell proliferations, which respond to reduction of immunosuppression and anti-CD20-directed immunotherapy. Owing to the low overall incidence, prospective studies of pediatric PTLD are scarce, leading to a lack of comprehensive understanding of this disorder in pediatric populations. This review aims to bridge this knowledge gap by providing a comprehensive analysis of the clinical, morphologic, and molecular genetic features of PTLD in children, adolescents, and young adults after SOT.

OBJECTIVE.—

To examine the clinical features, pathogenesis, and classification of pediatric PTLDs after SOT.

DATA SOURCES.—

Personal experiences and published works in PubMed.

CONCLUSIONS.—

PTLD includes a broad and heterogeneous spectrum of disorders, ranging from nonmalignant lymphoproliferations to lymphomas. While most pediatric PTLDs are EBV+, an increasing number of EBV- PTLDs have been recognized. The pathologic classification of PTLDs has evolved in recent decades, reflecting advancements in understanding the underlying pathobiology. Nevertheless, there remains a great need for further research to elucidate the biology, identify patients at higher risk for aggressive disease, and establish optimal treatment strategies for relapsed/refractory disease.

Prophylaxis and Treatment of Pneumocystis jiroveci Pneumonia in Lymphoma Patients Subjected to Rituximab-Contained Therapy: A Systemic Review and Meta-Analysis

Pneumocystis jiroveci pneumonia (PCP) is frequently reported in lymphoma patients treated with rituximab-contained regimens. There is a trend toward a difference in PCP risk between bi- and tri-weekly regimens. The aims of this systemic review and meta-analysis were to estimate the risk for PCP in these patients, compare the impact of different regimens on the risk, and evaluate the efficacy of prophylaxis. The cohort studies with incept up to January 2014 were retrieved from the Cochrane Library, Medline, Embase, and Web of Science databases. Studies that compared the incidence of PCP in patients with and without rituximab treatment were conducted. Studies that reported the results of prophylaxis were concentrated to evaluate the efficacy of prophylaxis. Fixed effect Mantel-Haenszel model was chosen as the main analysis method. Funnel plots were examined to estimate the potential selection bias. Egger's test and Begg's test were used for the determination of possible small study bias. Eleven cohort studies that met the inclusion criteria were finally included. Results indicated that rituximab was associated with a significantly increased risk for PCP (28/942 vs 5/977; risk ratio: 3.65; 95% confidence interval 1.65 to 8.07; P=0.001), and no heterogeneity existed between different studies (I2=0%). Little significant difference in PCP risk was found between bi-weekly and tri-weekly regimens (risk ratio: 3.11; 95% confidence interval 0.92 to 10.52, P=0.068). PCP risk was inversely associated with prophylaxis in patients treated with rituximab (0/222 vs 26/986; risk ratio: 0.28; 95% confidence interval 0.09 to 0.94; P=0.039). In conclusion, PCP risk was increased significantly in lymphoma patients subjected to rituximab-contained chemotherapies. Difference in PCP risk between bi-weekly and tri-weekly regimens was not significant. Additionally, prophylaxis was dramatically effective in preventing PCP in rituximab-received lymphoma patients, suggesting that rituximab should be recommended for these patients.

Characterization of lymphoproliferative lesions of the conjunctiva: immunohistochemical and molecular genetic studies

BACKGROUND

Conjunctival lymphoproliferative lesions have not been selected for independent analysis with newer immunohistochemical and molecular genetic techniques to highlight their unique profile.

METHODS

Retrospective case series examined biopsies from 16 consecutive patients with conjunctival lymphoproliferative lesions. The histopathologic, immunohistochemical, and molecular genetic features were characterized, as well as the frequency of tumour type, prognostic implications, clinical features, and treatments offered.

RESULTS

The diagnosis was lymphoma in 12 cases, atypical lymphoid hyperplasia (ALH) in 1 case, and reactive lymphoid hyperplasia (RLH) in 3 cases. The primary lymphomas consisted of 4 mucosa-associated lymphoid tissue lymphomas (MALTL), 1 follicular lymphoma (FL), 2 diffuse large B-cell lymphomas (DLBCLs), 1 lymphoplasmacytic lymphoma, and 1 T-cell lymphoma. Primary lymphomas were treated with radiation (n = 7), surgery (n = 1), and topical chemotherapy (n = 1). Complete remission was achieved in 8 of 9 primary lymphomas. Two cases of recurrence to the other conjunctiva were treated with radiation and both remained disease free. Secondary lymphomas included 2 DLBCL and 1 MALTL. Complete remission was seen in 2 patients after radiation plus chemotherapy, while the patient treated with chemotherapy alone was lost to follow-up. The 1 case of ALH presented bilaterally and achieved complete remission after topical chemotherapy treatments. The 3 RLH cases were surgically managed and 2 of the 3 recurred and were subsequently excised. Eleven lymphomas were of B-cell lineage by immunophenotyping. Molecular genetic studies of immunoglobulin heavy chain (IgH) gene rearrangement by polymerase chain reaction (PCR) showed clonal bands in 6 of 12 lymphomas, 1 of 3 RLH (polyclonal by immunophenotyping) and 1 ALH. BCL2-IgH [t(14;18)] rearrangement was seen in 8 of 12 cases (1 FL, 3 DLBCLs, 4 MALTLs) by real-time quantitative PCR.

INTERPRETATION

Conjunctival lymphomas are predominantly B-cell type with a high prevalence of MALTL. An unexpected finding was the BCL2-IgH rearrangement seen in 4 of 5 MALTL cases in our series. The significance of this remains unclear.

Posttransplant lymphoproliferative disorder of the lung in a renal transplant recipient treated successfully with surgery

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid diseases that occur after solid organ and bone marrow transplantation. Lung-located PTLD has been reported in recipients of the heart, cord blood stem cells, lungs, and bone marrow transplants, but only four cases were reported previously after kidney transplantation. Thoracic location of PTLD must be regarded as an especially dangerous complication. The pathogenesis, and clinical and histological features of PTLD remain poorly defined but predisposing risk factors are becoming better understood. Namely, Epstein-Barr virus (EBV) and immunosuppressive agents appear to be such risk factors. There has been marginal success in treating PTLD using a number of treatment modalities, including combination chemotherapy with anti-CD20 or high-dose chemotherapy with stem cell rescue. We report a renal allograft recipient transplanted in March 2000, diagnosed with EBV-associated and lung-located PTLD. His initial immunosuppression consisted of tacrolimus, azathioprine, and steroids. Azathioprine was withdrawn in September 2001. In November 2001 a high-resolution computed tomography scan revealed two round masses in the right lung. The patient underwent right thoracotomy and resection of the lower and middle lobe. The diagnosis of PTLD was settled by intraoperative histopathological evaluation. The postoperative histological assessment confirmed the diagnosis and revealed positive staining for EBV. The patient remained in complete remission for 3 years with a well-functioning renal allograft, with current serum creatinine of 1.2 mg%. This case illustrates that the treatment of lung-located PTLD may be successful, but it depends on a combination of prompt diagnosis, reduction of immunosuppression, and of course surgery.

Lymphoproliferative disorder of the airway of an adolescent without immunodeficiency

Epstein-Barr virus (EBV) is a ubiquitous viral pathogen in humans that has a unique ability to immortalize B-cells. In immunosuppressed individuals, EBV can produce non-neoplastic lymphoproliferative disorders involving various organs. We describe a case report of EBV-associated lymphoproliferative disorder in an immunocompetent 14-year-old male. The case provides a description of EBV-associated lymphoproliferation affecting the upper and lower respiratory tract. The massive submucosal infiltration of B-cells in the lingual tonsils, trachea, and bronchi produced near-complete airway obstruction resulting in tracheotomy. Neither surgical reduction of lingual tonsils nor treatment with steroids was of benefit. An extensive evaluation for immunodeficiency and neoplasia was normal. Treatment with rituximab, an anti-CD20 antibody, resulted in near-complete resolution of the infiltrative process, sufficient to allow decannulation. Rituximab is a treatment option for the rare occurrence of non-neoplastic, EBV-associated, lymphoproliferative disorders.