Plasma Cell Myeloma Type Posttransplant Lymphoproliferative Disorder in an 18-Month-Old Heart Transplant Recipient: Case Report and Review of the Literature.

Plasma cell myeloma type posttransplant lymphoproliferative disorder (PTLD) is a rare subtype of monomorphic B-cell/plasmacytic-type PTLD. Only 10 cases of monomorphic plasmacytic-type PTLD have been previously reported in pediatric transplant recipients (kidney, liver, small bowel-liver, and heart). We present a case of Epstein-Barr virus positive monomorphic plasma cell myeloma type PTLD that developed 10 months after cardiac transplant in an 18-month-old boy.

Cytotoxic Molecule-positive Epstein-Barr Virus-associated Peripheral T-cell Lymphoma in a 20-Month-old Child: A Case Report and Review of the Literature.

Peripheral T-cell lymphoma (PTCL) is rare in children. Expression of cytotoxic molecules (CM) in nodal PTCL has unique clinicopathologic features, including an Epstein-Barr virus (EBV) association. However, CM+, EBV-associated PTCL is extremely rare in the childhood, with only 1 study having been reported to date, including both pediatric and adult patients.

Mast cell sarcoma in an infant: a case report and review of the literature.

Mast cell diseases comprise a spectrum of disorders including cutaneous mastocytosis, indolent or aggressive systemic variants including leukemia, and unifocal tumor formations such as benign extracutaneous mastocytoma or aggressive mast cell sarcoma (MCS). Many mast cell diseases are associated with aberrancy of c-KIT proto-oncogene resulting in tyrosine kinase activity, typically exhibiting point mutation in codon 816. MCS is an exceedingly rare clinicopathologic entity characterized by a unifocal accumulation of neoplastic mast cells that grow in a locally destructive manner.

Complete absence of KSHV/HHV-8 in posttransplant lymphoproliferative disorders: an immunohistochemical and molecular study of 52 cases.

Posttransplant lymphoproliferative disorders (PTLDs), a heterogeneous group of monoclonal or polyclonal lesions, occur in immunosuppressed patients after solid organ or bone marrow transplantation. Although most PTLDs are Epstein-Barr virus (EBV)+ and seem to represent EBV-induced proliferations of monoclonal (or less often polyclonal) B, T, or plasma cells, a subset of PTLDs is EBV-. Because Kaposi sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) has been described in association with the development of hematolymphoid and nonhematolymphoid neoplasms in HIV+ patients, we investigated whether there is an association between KSHV/HHV-8 and PTLDs.

Frequent expression of CD99 in anaplastic large cell lymphoma: a clinicopathologic and immunohistochemical study of 160 cases.

Originally described as a diagnostically useful marker for Ewing sarcoma, CD99 immunoreactivity has also been documented in a variety of other tumors, including hematopoietic neoplasms. By using conventional paraffin immunoperoxidase staining and tissue microarrays, we retrospectively investigated CD99 expression in a series of 160 anaplastic large cell lymphoma (ALCL) cases. Of the 160 cases, 103 (64.

CD3-positive large B-cell lymphoma.

It is not uncommon for some B-lineage non-Hodgkin lymphomas (NHLs) to aberrantly coexpress T-cell markers, particularly CD5, as well as CD7, CD2, CD4, and/or CD8 in rare cases. Cases of CD3-positive B-cell NHL, however, have not previously been described in the literature. We present 4 cases of large B-cell lymphoma aberrantly coexpressing T-cell marker CD3 and B-lineage markers as well as demonstrating clonal rearrangement of the immunoglobulin genes but not the gamma T-cell receptor gene.

Quick identification of Type I restriction enzyme isoschizomers using newly developed pTypeI and reference plasmids.

Although DNA-recognition sequences are among the most important characteristics of restriction enzymes and their corresponding methylases, determination of the recognition sequence of a Type-I restriction enzyme is a complicated procedure. To facilitate this process we have previously developed plasmid R-M tests and the computer program RM search. To specifically identify Type-I isoschizomers, we engineered a pUC19 derivative plasmid, pTypeI, which contains all of the 27 Type-I recognition sequences in a 248-bp DNA fragment.

5q- syndrome in a child with slowly progressive pancytopenia: a case report and review of the literature.

5q- syndrome is a rare myelodysplastic process occurring predominately in middle aged to elderly women. In children, myelodysplasia of all types is rare and 5q- syndrome is exceptionally rare. Only 6 cases of 5q- associated myelodysplasia have been reported in children and all 6 cases had blast counts >5% and/or additional cytogenetic abnormalities.

Hodgkin lymphoma-like posttransplant lymphoproliferative disorder (HL-like PTLD) simulates monomorphic B-cell PTLD both clinically and pathologically.

Although Hodgkin lymphoma-like posttransplantation lymphoproliferative disorder (HL-like PTLD) has been grouped with classic Hodgkin lymphoma type PTLD (HL-PTLD), controversy remains as to whether it is truly a form of HL or whether it should be more appropriately classified as a form of B-cell PTLD. Because only few cases of HL-like PTLD have been reported, their pathologic nature and clinical behavior have not been well defined. This report characterized 5 cases of HL-like PTLD with respect to their immunophenotype, EBV status, clonality, and clinical outcome.

Primary diffuse large B-cell lymphoma of the uterus presenting solely as an endometrial polyp.

We report a primary diffuse large B-cell lymphoma of endometrial polyp in a 44-year-old woman who presented with irregular vaginal spotting and was found to have a polyp protruding from the cervical os. Histology of the polyp showed an atypical diffuse infiltration by large, mononuclear cells within the stroma and between endometrial glands in one of the polypoid fragments. Immunohistochemistry and testing for immunoglobulin heavy chain gene rearrangement showed a B-cell lineage, consistent with diffuse large B-cell lymphoma.

Anaplastic large cell lymphoma associated with Epstein-Barr virus following cardiac transplant.

Posttransplantation lymphoproliferative disorders (PTLDs) eventually occur in approximately 5% of all organ transplant recipients. Most of cases are B-cell proliferations associated with the Epstein-Barr virus (EBV). T-cell PTLDs are relatively rare, although some estimate that up to 14% of posttransplantation malignant lymphomas are T-cell lymphomas even though only a few of these cases are described in the literature.

Primary anaplastic lymphoma kinase-negative anaplastic large cell lymphoma of the brain in a patient with acquired immunodeficiency syndrome.

Anaplastic large cell lymphoma is a unique diagnostic subcategory of the T-cell lymphomas in the current World Health Organization classification. Representing approximately 3% of adult and 10% to 30% of childhood non-Hodgkin lymphomas, anaplastic large cell lymphoma classically consists of CD30+ large lymphoid cells with abundant cytoplasm and pleomorphic, often horseshoe-shaped or kidney-shaped nuclei. Among the reported nodal and extranodal sites of occurrence, the gastrointestinal tract and central nervous system have rarely been noted.