Post-transplant lymphoproliferative disorders with naso- and oropharyngeal manifestation.

The nasopharyngeal/oropharyngeal lymphatic tissues represent the anatomical site of Epstein-Barr virus (EBV) entry. Post-transplant lymphoproliferative disorders (PTLD) are often associated with EBV, but little is known about the characteristics of nasopharyngeal/oropharyngeal mass-forming PTLD. Retrospective evaluation of our own PTLD database (n = 79) and the PubMed(®) database (n = 61) has been performed. Sinonasal/oro-/nasopharyngeal lymphatic masses were early lesions (n = 54/140, 38.5%), polymorphic PTLD (n = 32/140, 23%), monomorphic B-PTLD (n = 47/140, 33.5%) and T-PTLD (n = 7/140, 5%). One-fourth of lesions manifested as masses in the Waldeyer's ring, and in two-thirds of cases, swelling of tonsils was related to manifestation of benign early lesions. Tonsil infiltration by polymorphic PTLD and monomorphic PTLD was present in one-third of cases. Extratonsillar masses were mainly monomorphic PTLD. Meta-analysis of our data in combination with previously published data revealed that lung transplantation and young patients are at a higher risk for earlier manifestation of monomorphic PTLD. Therapy is similar to PTLD therapy strategies, in general reduced immunosuppression and chemotherapy for polymorphic and monomorphic PTLD, and diagnostic and therapeutic surgical gross tumour resection of tonsillar/adenoid lesions. In summary, it is relevant for the clinical differential diagnosis that oro-/nasopharyngeal aggressive PTLD manifested in ~30% as tonsillar masses and >90% at extratonsillar sites.

Posttransplant lymphoproliferative disorder in pediatric patients.

Transplantation of solid organs and hematopoietic stem cells is accompanied by profound disturbance of immune function mediated by immunosuppressive drugs or delayed immune reconstitution. Disturbed T cell control of Epstein-Barr virus (EBV)-infected B cells leads to posttransplant lymphoproliferative disorder (PTLD) in up to 10% of patients. Children are at a higher risk because they are more often EBV-naïve before transplantation. Patients with PTLD often present with unspecific symptoms (pain and organ/graft dysfunction). Depending on the onset of PTLD, manifestations vary between mainly nodal (late PTLD) and extranodal sites (early PTLD). Histology, immunohistology, EBER in situ hybridization and molecular pathology are required for diagnosis and subclassification of PTLD. The three major types are early lesions (resembling reactive proliferations in immunocompetent patients), polymorphic PTLD (proliferation of B and T cells with effacement of histoarchitecture) and monomorphic PTLD (presenting as malignant lymphomas, mainly high-grade B cell lymphomas). In a subfraction of cases, including monomorphic PTLD, reduction of immunosuppressive medication alone is sufficient to induce remission. Surgical debulking of tumor mass and anti-CD20-antibody treatment with or without chemotherapy (usually at lower dosages than in immunocompetent patients) constitute the basis of additional therapy.

Expression of caspase 14 and filaggrin in oral squamous carcinoma.

Caspase 14 is one of the latter discovered members of the caspase enzyme family and, although sharing sequence homologies with the other caspases, it is not involved in apoptosis. Together with its co-factor filaggrin, it plays an important role in skin barrier formation. It is already known that caspase 14 proteins are reduced during neoplastic dedifferentiation in cervical intraepithelial neoplasms and in invasive cervical carcinomas. Oral squamous carcinoma tissues have not been systematically evaluated for caspase 14 expression yet. Formalin-fixed and paraffin-embedded samples from oral squamous carcinomas (n = 36 tumours from 34 patients), metastases (n = 15) and controls (leukoplakia, n = 10) were analysed by immunohistochemistry. In carcinomas, human papilloma virus (HPV) infection was tested by PCR. Here we demonstrate that, in oral epithelia, caspase 14 is expressed mainly by cells of the intermediate and superficial cell layers while filaggrin is expressed only in keratinising foci in leukoplakia. Caspase 14 and filaggrin are co-localised. In invasive oral carcinomas, reduced expression of caspase 14 was detectable in 47 % of tumours but was not associated with keratinisation, tumour differentiation or HPV infection. Filaggrin was detectable in a subfraction of tumours (56 %) and was restricted to keratinising areas of the carcinomas. In summary, in contrast to cervical carcinomas, partial loss of caspase 14 is not associated with dedifferentiation in neoplastic lesions of the oral mucosa or HPV infection.

Risk factors and prognosis in T-cell posttransplantation lymphoproliferative diseases: reevaluation of 163 cases.

BACKGROUND: Posttransplantation lymphoproliferative diseases (PTLD) are mainly Epstein-Barr virus (EBV)-associated disorders of B-cell origin. Due to the rarity of monomorphic T-cell PTLD (T-PTLD), knowledge about pathogenesis, risk factors, therapy, and prognosis relies predominantly on case reports and small series. Therefore, we aimed to provide an overview and a retrospective analysis of this rare PTLD subtype. METHODS: We analyzed all available articles on T-PTLD in the PubMed database as well as in our own databases (Institute of Pathology/Department of Paediatric Haematology and Oncology, Hannover Medical School) from 1988 to 2010. Reevaluated parameters were gender, age, transplanted organ, immunosuppressant regimen, time between transplantation and T-PTLD manifestation, T-PTLD subtype, virus positivity, localization, therapy, and follow-up. RESULTS: A total of 163 cases were evaluated. We found that hematopoietic stem cell transplantation was associated with early-onset T-PTLD, whereas late onset occurred after immunosuppression with steroids and azathioprine without administration of calcineurin inhibitors. The major independent favorable prognostic factors were T-PTLD of the large granular lymphocytic leukemia subtype, young age, and a combination of radiotherapy/radiochemotherapy and reduced immunosuppression, whereas the hepatosplenic T-cell lymphoma subtype and cases with involvement of bone marrow, the central nervous system, or graft had an adverse prognosis. CONCLUSION: T-PTLD is a heterogeneous group of different aberrant T-cell proliferations and represents a significant complication following transplantation, showing a uniformly poor prognosis.