Pediatric mast cell sarcoma of temporal bone with novel L799F (2395 C>T) KIT mutation, mimicking histiocytic neoplasm.

Mast cell sarcoma (MCS) is an extremely rare neoplasm with a clinically aggressive course. Because of its rarity, its morphologic and molecular characteristics are still not well defined. We report a case of a 15-year-old girl with MCS of the temporal bone extending into the posterior fossa creating a mass effect.

Primary anaplastic large-cell lymphoma associated with breast implants.

Primary T-cell anaplastic large-cell lymphoma (ALCL) of the breast is a rare entity, which has been reported in association with breast implants. In a retrospective analysis of the City of Hope pathology database, we uncovered nine such patients, eight of whom had breast implants proximal to primary ALCL. The diagnosis of ALCL in the implant capsule occurred at a median of 7 years (range 5-30) following implant surgery, and median patient age was 45.

Practical immunohistochemistry in hematopathology: a review of useful antibodies for diagnosis.

This review article offers some useful panels of immunohistochemical stains and discusses their use in determining a hematopathology diagnosis. As a comprehensive review of the vast array of hematolymphoid malignancies is beyond the scope of this study, the suggestions are based on broad morphologic categories such as follicular proliferations, paracortical expansions, diffuse small-cell infiltrates, diffuse large-cell infiltrates, and Hodgkin-like infiltrates. The review article also discusses the most common hematolymphoid malignancies and their immunohistochemical profiles, and how to use immunophenotyping to differentiate them from other entities.

Accelerated telomere shortening precedes development of therapy-related myelodysplasia or acute myelogenous leukemia after autologous transplantation for lymphoma.

Purpose: Therapy-related myelodysplasia or acute myelogenous leukemia (t-MDS/AML) is a lethal complication of autologous hematopoietic stem-cell transplantation (aHCT) for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Here, we investigated the hypothesis that accelerated telomere shortening after aHCT could contribute to the development of t-MDS/AML.

Patients And Methods: A prospective longitudinal cohort was constructed to investigate the sequence of cellular and molecular abnormalities leading to development of t-MDS/AML after aHCT for HL/NHL.

Aberrant expression of CD7 in myeloblasts is highly associated with de novo acute myeloid leukemias with FLT3/ITD mutation.

Acute myeloid leukemia (AML) with normal cytogenetics represents approximately 40% to 50% of de novo AML. This heterogeneous AML subgroup constitutes the single largest cytogenetic group with an intermediate prognosis. Previous studies have suggested that the Fms-like tyrosine kinase-3 internal tandem duplication (FLT3/ITD) mutation-positive de novo AML may represent a distinctive subgroup of AML.

Clinical and pathologic analysis of 16 cases of relapsed chronic myeloid leukemia after stem cell transplantation.

Chronic myeloid leukemia (CML) is a myeloproliferative disease that originates in an abnormal pluripotent bone marrow stem cell and is characteristically associated with the Philadelphia chromosome and/or the bcr/abl fusion gene. Despite the exciting success of the bcr/abl tyrosine kinase-specific inhibitor imatinib for CML treatment, hematopoietic stem cell (bone marrow or peripheral blood stem cell) transplantation (HCT) remains the only "curative" approach for the majority of patients. Although HCT outcomes for patients with CML have improved considerably during the past 2 decades, relapse after HCT may occur.

Low CD27 expression in plasma cell dyscrasias correlates with high-risk disease: an immunohistochemical analysis.

Genome-wide expression studies using complementary DNA microarrays recently suggested a number of intriguing candidate genes for distinguishing plasma cell dyscrasias. Our objective was to test select markers using immunohistochemical analysis and a tissue microarray from paraffin-embedded bone marrow core biopsy specimens obtained from 8 patients with monoclonal gammopathy of undetermined significance, 17 with plasmacytoma, 160 with multiple myeloma, and 15 with plasma cell leukemia (PCL). We immunostained serial sections for CD138, CD27, CD56, p27, Ki-67, CD3, and CD20.

Extranodal Rosai-Dorfman disease involving the bone marrow: a case report.

Sinus histiocytosis with massive lymphadenopathy (SHML), also known as Rosai-Dorfman disease, is a very rare disorder of unknown etiology. Although classical SHML usually presents as massive, painless, bilateral neck lymph node enlargement, approximately 25% to 40% of SHML cases described to date present in extranodal organs or tissues, such as skin, upper respiratory tract, and bone etc. However, bone marrow as a site of initial presentation by SHML has not been described since the disease was initially recognized in 1969.

Composite recurrent hodgkin lymphoma and diffuse large B-cell lymphoma: one clone, two faces.

We describe a composite lymphoma with recurrent Hodgkin lymphoma and diffuse large B-cell lymphoma components manifesting as a single, perforated small intestinal tumor in a 56-year-old man with a history of classical Hodgkin lymphoma and recent relapse in the bone marrow. The resected mass had 2 morphologically and immunophenotypically distinct components; 1 showed a pleomorphic cellular infiltrate with fibrosis and contained numerous, large Hodgkin/Reed-Sternberg-like cells and variants. The tumor cells were CD30+ and focally positive for CD15 but CD20-, CD79a-, and PAX-5-.

An aggressive extranodal NK-cell lymphoma arising from indolent NK-cell lymphoproliferative disorder.

Indolent NK-cell lymphoproliferative disorder, also known as chronic natural killer (NK) cell large granular lymphocytosis (leukemia), is a very rare entity in the World Health Organization (WHO) Classification of Tumors of Hematopoietic & Lymphoid Tissues. Unlike aggressive NK-cell leukemia, which is malignant, the WHO does not specify whether indolent NK-cell lymphoproliferative disorder is reactive or neoplastic. Patients with indolent NK-cell lymphoproliferative disorder are usually asymptomatic older adults who have a nonprogressive, very stable clinical course.

Longitudinal assessment of hematopoietic abnormalities after autologous hematopoietic cell transplantation for lymphoma.

Purpose: Autologous hematopoietic cell transplantation (HCT) is being increasingly used as an effective treatment strategy for patients with relapsed or refractory Hodgkin's lymphoma (HL) or non-Hodgkin's lymphoma (NHL) but is associated with therapy-related myelodysplasia and acute myeloid leukemia (t-MDS/AML) as a major cause of nonrelapse mortality. The phenomenon of hematopoietic reconstitution after autologous HCT and the role of proliferative stress in the pathogenesis of t-MDS/AML are poorly understood.

Patients And Methods: Using a prospective longitudinal study design, we evaluated the nature and timing of alterations in hematopoietic progenitors and telomere length after HCT in patients undergoing autologous HCT at City of Hope Cancer Center (Duarte, CA).

Targeting plasma cells improves detection of cytogenetic aberrations in multiple myeloma: phenotype/genotype fluorescence in situ hybridization.

Standard fluorescence in situ hybridization (FISH) easily detects nonrandom karyotypic abnormalities in multiple myeloma (MM) at disease presentation, when tumor burden is high. In contrast, the detection of residual MM using the standard 200 unselected nonmitotic nuclei FISH approach correlates poorly with residual disease detected by morphology, flow cytometry, immunohistochemistry, or reverse-transcription polymerase chain reaction (RT-PCR). We have used sequential May-Grunwald Giemsa stain to identify plasma cell populations, followed by FISH analyses (target FISH or T-FISH) to detect immunoglobulin heavy-chain gene (IGH) rearrangements, 13q or 17p deletions, or hyperdiploidy.

KSHV/HHV8-associated lymphoma simulating anaplastic large cell lymphoma.

We report a unique, previously undescribed case of KSHV/HHV8-associated lymphoma in a 49-year-old HIV-seropositive patient. The cervical lymph node-based lymphoma displayed distinctive characteristic features of preferential sinusoidal infiltrate and anaplastic cellular morphology, closely resembling classic anaplastic large cell lymphoma of the WHO classification both histologically and immunophenotypically. Paraffin immunohistochemical study showed that the lymphoma cells were strongly positive for KSHV/HHV8 latency-associated nuclear antigen, and PCR analysis confirmed the presence of KSHV/HHV8 infection.

Histiocytic lesions involving the bone marrow.

Histiocytic lesions involving the bone marrow include a number of reactive and neoplastic disorders. This article discusses the morphologic, immunophenotypic, and genotypic features of a variety of diseases associated with histiocytes and/or monocytes. Lysosomal storage disorders and hemophagocytic syndromes are often first diagnosed by bone marrow examination.

Detection of NPM/MLF1 fusion in t(3;5)-positive acute myeloid leukemia and myelodysplasia.

Balanced translocations are rare in myelodysplasia (MDS) and acute myeloid leukemia (AML) with multilineage dysplasia; however, the t(3;5)(q25;q35) and insertion variant occur in a subset of patients. To evaluate the possible genes involved in this translocation, we studied 6 cases with a t(3;5) by fluorescence in situ hybridization with probes directed against the nucleophosmin (NPM), EVI1, and Ribophorin genes, as well as a newly developed myeloid leukemia factor 1 (MLF1) BAC clone. The histologic spectrum of the cases was variable, ranging from refractory cytopenia with multilineage dysplasia to AML with multilineage dysplasia in the World Health Organization classification.

Primary effusion lymphoma with subsequent development of a small bowel mass in an HIV-seropositive patient: a case report and literature review.

Primary effusion lymphoma is a distinct clinicopathologic entity usually characterized by presentation as a lymphomatous body cavity effusion in the absence of a solid tumor mass or dissemination during its clinical course. This lymphoma is typically present in human immunodeficiency virus (HIV)-infected patients and frequently associated with Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV8) viral sequences. Here we report a rare case of KSHV/HHV8-associated primary effusion lymphoma with secondary involvement of the small bowel as an obstructive tumor mass in an HIV-infected man.

Diagnostic utility of bilateral bone marrow examination: significance of morphologic and ancillary technique study in malignancy.

Background: To retrospectively evaluate the significance of morphologic examination and ancillary studies performed on bilateral bone marrow biopsy specimens, 1864 bone marrow samples were studied.

Methods: Bilateral bone marrow biopsy specimens included 883 specimens that were evaluated for involvement by non-Hodgkin lymphoma (NHL); 381 specimens that were evaluated for involvement by carcinoma (CA); 362 specimens that were evaluated for involvement by Hodgkin disease (HD); 94 specimens that were evaluated for involvement by sarcoma (SA); 56 specimens that were evaluated for involvement by multiple myeloma (MM); 53 specimens that were evaluated for involvement by acute and chronic leukemia, myelodysplasia, and/or myeloproliferative disorders (LEUK); and 35 specimens that were evaluated for other reasons.

Results: Of all 1864 specimens, 410 samples (22.