Atypical prediagnosis Epstein-Barr virus serology restricted to EBV-positive Hodgkin lymphoma.

An altered anti-Epstein-Barr virus (EBV) serologic profile preceding diagnosis is associated with an increased risk of Hodgkin lymphoma. It is unknown whether this atypical pattern predicts Hodgkin lymphoma risk further subdivided by determination of EBV in tumor cells. A nested case-control study of 128 incident Hodgkin lymphoma cases and 368 matched controls from active-duty military personnel with archived serum in the US Department of Defense Serum Repository was conducted to determine whether a panel of anti-EBV antibody titers differed in EBV(+) and EBV(-) Hodgkin lymphoma. Among 40 EBV(+) Hodgkin lymphoma cases and matched controls, statistically significant increased risks were associated with elevated anti-EBV VCA IgG antibody titers (relative risk = 3.1; 95% confidence interval [CI], 1.1-8.7), and an anti-EBNA-1/anti-EBNA-2 antibody ratio ≤ 1.0 versus > 1.0 (relative risk = 4.7; 95% CI, 1.6-13.8). In contrast, no significant associations were found among 88 EBV(-) Hodgkin lymphoma cases relative to their matched controls. In case-case analysis, EBV(+) disease was significantly associated with a low anti-EBNA-1/anti-EBNA-2 antibody ratio. This distinctive serologic response to EBV latent antigens, indicative of immune dysfunction in other clinical settings, is associated with an increased risk of developing EBV(+) but not EBV(-) Hodgkin lymphoma.

Activation-induced cytidine deaminase expression in diffuse large B-cell lymphoma with a paracortical growth pattern: a lymphoma of possible interfollicular large B-cell origin.

CONTEXT: Activation-induced cytidine deaminase, necessary for immunoglobulin somatic hypermutation and class switch recombination, is usually expressed within the follicular dendritic network but is also expressed in a population of interfollicular large B cells outside the germinal center. OBJECTIVE: To report 7 cases of diffuse large B-cell lymphoma with a distinct paracortical distribution. Expression of activation-induced cytidine deaminase, previously described in interfollicular large B cells, was evaluated. DESIGN: A panel of immunohistochemical markers, including double staining for activation-induced cytidine deaminase and CD20, was used to illustrate the cases. Molecular studies were performed by polymerase chain reaction in the paraffin-embedded tissue for t(14;18) chromosomal translocation and immunoglobulin heavy chain and T-cell receptor rearrangements. RESULTS: Patients included 3 males and 4 females ranging in age from 11 to 59 years (mean, 39 years). All specimens were lymph nodes (4 from the groin, 2 from the neck, and 1 from the axilla). Malignant lymphocytes were positive for CD20 and negative for CD5 and CD10. Staining for CD30, CD43, and BCL-2 was variable. The malignant cells showed at least focal staining with activation-induced cytidine deaminase. All cases were found to be monoclonal by immunoglobulin heavy-chain gene rearrangement or showed light-chain restriction. None of the tested cases showed t(14;18). CONCLUSIONS: Diffuse large B-cell lymphoma with a paracortical distribution is unusual and may be a distinct morphologic variant. More study is necessary to determine the stage of B-cell development and the cell of origin of these tumors. However, activation-induced cytidine deaminase expression suggests they may arise from a putative interfollicular large B cell.

Fluorescence immunophenotypic and interphase cytogenetic characterization of nodal lymphoplasmacytic lymphoma.

Lymphoplasmacytic lymphoma (LPL) is a small B-cell lymphoma with plasmacytic differentiation that does not fulfill the criteria for any other small B-cell lymphoma. Cytogenetic characterization of nodal LPL is limited and the distinction from marginal zone lymphomas with plasmacytic differentiation can be problematic. Thus, 17 cases of lymph node-based LPL were studied with fluorescence immunophenotypic and interphase cytogenetics for the investigation of neoplasia (FICTION) using a CD79a antibody and probes to detect trisomies of chromosomes 3 (15 cases), 12 (16 cases), and 18 (17 cases); rearrangements (R) of IgH (10 cases), BCL6 (6 cases), PAX5 (7 cases), and MALT1 (16 cases); and deletion 6q21 (7 cases). Cases with IgH R were further studied with an IgH/BCL2 probe. In cases without FICTION studies, previously reported fluorescence in situ hybridization results for IgH, PAX5, and deletion 6q21 were available from prior studies. The histopathology, immunophenotype, and available clinical data were also reviewed. Three pathologic categories were recognized: 5 classic LPL, 5 vaguely nodular polymorphous (VN-P), and 7 other. Among the classic LPL, 4/4 had an IgM paraproteinemia, 5/5 had bone marrow involvement (BM+), and 1/5 had +MALT1. One of one VN-P LPL had an IgM paraprotein, 2/4 were IgM+, 2/4 IgG+, 1/3 had BM+, and 1/5 had an IgH R. Among the other cases, 2/3 had a paraprotein, 2/7 were IgM+, 5/7 IgG+, and 0/3 had BM+. Of these cases, 1 showed +12, 1 +18, and 1 IgH/BCL2 rearrangement plus +18. None of the 17 cases had a 6q21 deletion or +3. Therefore, with rare exception, lymph node-based LPL with classic or more varied histopathologic features does not have the cytogenetic abnormalities frequently associated with bone marrow-based LPL/Waldenstrom macroglobulinemia or many of the marginal zone lymphomas. The search for better objective inclusionary criteria for LPL must continue.

Gene rearrangement and comparative genomic hybridization studies of classic Hodgkin lymphoma expressing T-cell antigens.

CONTEXT: Reed-Sternberg cells in classic Hodgkin lymphoma are enigmatic and difficult to study because they are so sparse. Tissue microdissection allows for the isolation of single Reed-Sternberg cells. Isolated Reed-Sternberg cells show clonal immunoglobulin gene rearrangement indicating a B-cell origin. Rarely, Reed-Sternberg cells in classic Hodgkin lymphoma express T-cell antigens, suggesting a possible T-cell origin. OBJECTIVE: To determine whether there is a difference in genotype between classic Hodgkin lymphoma and classic Hodgkin lymphoma expressing T-cell antigens and to document T-cell clonality. DESIGN: We studied 4 cases of Hodgkin lymphoma with a characteristic phenotype and immunoreactivity for CD2 and CD3. Single CD30+ Reed-Sternberg cells from each case were isolated by laser capture microdissection for immunoglobulin heavy chain and T-cell receptor-gamma genes by polymerase chain reaction studies. Comparative genomic hybridization was performed in all cases. RESULTS: Two of 4 cases showed clonal rearrangement of the T-cell receptor-gamma; none showed immunoglobulin heavy chain rearrangement. Two control cases were negative for T cell receptor-gamma but 1 showed immunoglobulin heavy chain rearrangement. Comparative genomic hybridization analysis revealed significant overlap in genomic alteration in Hodgkin lymphoma cases regardless of genotype or phenotype and several regions of imbalance specific to CD3+ Hodgkin lymphoma cases. All patients are alive with no evidence of disease from 10 to 44 months. CONCLUSIONS: Our findings suggest that a T-cell phenotype classic Hodgkin lymphoma can be supported by genotypic studies and that there may be cytogenetic differences between classic Hodgkin lymphoma and Hodgkin lymphoma expressing T-cell antigens.

Plasmablastic lymphoma: a clinicopathologic correlation.

Plasmablastic lymphoma (PBL) is an uncommon, recently described B-cell-derived lymphoma that displays distinctive affinity for extranodal presentation in the oral cavity. Plasmablastic lymphoma is strongly associated with human immunodeficiency virus (HIV) infection, but has been reported in HIV-negative individuals. Plasmablastic lymphoma may be poorly recognized by pathologists, which is partly attributable to its relatively rare occurrence and unusual immunophenotype. Five cases of oral cavity lymphomas conforming to the current World Health Organization morphological criteria for PBL were retrieved from the consultation files at the Armed Forces Institute of Pathology. An immunohistochemical panel consisting of CD3, CD20, CD30, CD38, CD45RB, CD79a, CD138, Bcl-2, Bcl-6, Alk-1, Ki-67, EBV-LMP-1, and HHV8 was performed. All 5 cases were immunoreactive for CD38 and/or CD138, confirming plasma cell differentiation of the tumor cells. CD20 was immunoreactive in 1 case, and CD79a was positive in 2 cases. HHV8 and EBV-LMP-1 were nonreactive in all cases. Follow-up revealed only 1 patient alive with no evidence of disease. Our cases show that PBL is an aggressive type of B-cell lymphoma predominantly found in the oral cavity. Plasmablastic lymphoma is often associated with HIV infection.

Deletion 6q is not a characteristic marker of nodal lymphoplasmacytic lymphoma.

Lymphoplasmacytic lymphoma (LPL) is a small B-cell neoplasm with plasmacytic differentiation that does not fulfill the criteria for any other type of B-cell leukemia or lymphoma. In many cases, LPL is associated with Waldenström macroglobulinemia (WM), although WM may also be associated with other types of lymphoma. Recent studies have demonstrated that del(6q) is the most common structural abnormality in patients with bone marrow-based LPL. It is unknown whether del(6q) might also be associated with nodal LPL. We, therefore, examined 10 well-characterized LPL involving lymph nodes or other extramedullary tissues for del(6q) using paraffin section interphase fluorescence in situ hybridization (FISH). Dual-color FISH was performed using a chromosome 6 centromere probe (CEP6) and a probe for 6q21 (RP11-91C23). The latter probe has previously been reported as deleted in up to 63% of cases of bone marrow-based LPL. In contrast, no nuclei containing a del(6q) pattern were identified in any case of extramedullary LPL examined in this study, and 89-98.5% of nuclei contained a normal signal pattern. These results indicate that del(6q) is at least uncommon in nodal LPL, and cannot be employed as a diagnostic marker to identify this type of lymphoma. Furthermore, these findings suggest that nodal LPL and bone marrow-based cases of LPL may be associated with different cytogenetic findings.

Histiocytic sarcoma: a study of five cases including the histiocyte marker CD163.

Histiocytic sarcoma (HS) is a rare but controversial hematopoietic neoplasm. In the past, malignancies have been misclassified as histiocytic tumors due to overlapping histologic features and inadequate phenotypic data. CD163, a recently characterized hemoglobin scavenger receptor, appears to be a 'specific' marker of histiocytic lineage and a promising diagnostic tool for evaluating histiocytic neoplasms. Five cases of HS were studied to further elucidate the clinicopathologic features of these rare tumors and to demonstrate the diagnostic utility of CD163. Criteria for diagnosis included histologic and immunohistochemical evidence of histiocytic differentiation, CD45 positivity, and exclusion of lymphoid, epithelial, melanocytic and dendritic cell phenotype. Sites of disease included the colon (two cases), palate, inguinal lymph node, and testis. The clinical course was aggressive in 4/5 patients (survival=2-15 months). One patient with localized disease of the palate, survived 17 years after diagnosis. All patients with poor survival had tumors > or =3.5 cm. Histologically, all cases showed diffuse architecture with large, discohesive polygonal cells. Spindling of cells was focally noted. Hemophagocytosis was identified in 3/5 cases. A prominent inflammatory background was present in 4/5 tumors. All cases were immunoreactive for CD45, CD163, CD68, and lysozyme. S-100 was focally positive in 4/5 cases. Antibodies for melanocytic, epithelial, lymphoid, and dendritic cell markers were negative. Molecular studies showed monoclonal IgH gene rearrangements in three cases. Our findings suggest that HS is an uncommon neoplasm frequently extranodal in presentation and aggressive in behavior, with rare exceptions. Stage of disease and possibly tumor size are significant prognostic indicators. Molecular studies remain controversial in the diagnosis. The morphologic and phenotypic features are relatively uniform; however, the diagnosis requires exclusion of more common neoplasms by extensive immunophenotypic studies. CD163 appears to be a specific histiocytic marker and is important in establishing the diagnosis of HS.

Ultrasound-accelerated formalin fixation of tissue improves morphology, antigen and mRNA preservation.

Formalin fixation and paraffin embedding are conventional tissue preservation and processing methods used for histologic diagnosis in over 90% of cases. However, formalin fixation has three disadvantages: (1) slow fixation (16-24 h) hinders intraoperative decision making, (2) slow quenching of enzymatic activity causes RNA degradation, and (3) extensive molecule modification affects protein antigenicity. Applying high-frequency, high-intensity ultrasound to the formalin fixative cuts fixation time to 5-15 min. Fixation of various tissues such as lymph node, brain, breast, and prostate suggests that, compared to the conventional method, implementation of ultrasound retains superior and more uniform tissue morphology preservation. Less protein antigenicity is altered so that rapid immunohistochemical reactions occur with higher sensitivity and intensity, reducing the need for antigen retrieval pretreatment. Better RNA preservation results in stronger signals in in situ hybridization and longer RNA fragments extracted from fixed tissues, probably due to rapid inhibition of endogenous RNase activity. Molecules extracted from ultrasound-fixed tissues are of greater integrity and quantity compared to conventionally fixed tissues, and thus better support downstream molecular analyses. Overall, ultrasound-facilitated tissue preservation can provide rapid and improved morphological and molecular preservation to better accommodate both traditional and molecular diagnoses.

HIV-associated Hodgkin lymphoma: a clinicopathologic and immunophenotypic study of 45 cases.

We retrospectively analyzed 45 cases of HIV-associated Hodgkin lymphoma (HIV-HL). HIV-HL generally is a disease of young white men (mean age, 40.1 years) who acquired HIV infection by homosexual or bisexual behavior (68%), intravenous drug use (24%), and/or blood transfusion (8%). The mean interval between the diagnosis of HIV and HIV-HL was 5.2 years. Morphologic classification of nodal biopsy specimens (2001 World Health Organization criteria) included 15 mixed cellularity Hodgkin lymphomas (MCHLs), 14 nodular sclerosis Hodgkin lymphomas (NSHLs), 9 lymphocyte depleted Hodgkin lymphomas (LDHLs), and 7 classic Hodgkin lymphomas, type not further categorized. The Hodgkin-Reed-Sternberg (HRS) cells expressed positive immunoreactivity with fascin (30/30 [100%]), CD30 (35/37 [95%]), CD15 (32/36 [89%]), bcl-X(L) (25/31 [81%]), bcl-2 (15/29 [52%]), CD20 (4/34 [12%]), bcl-6 (3/28 [11%]), and Epstein-Barr virus latent membrane protein-1 (32/33 [97%]) and were nonreactive for CD138/syndecan-1. CD4 and CD8 immunostaining showed an inverted CD4/CD8 ratio (<1/20) in all cases. At diagnosis, most patients (n = 27) had high-stage disease (IV(E)) associated with an aggressive course (16% 5-year survival). LDHL behaved more aggressively than MCHL and NSHL (15% vs 40%, 5-year survival, respectively), as did disease with a sarcomatoid pattern (11% 5-year survival). Chemotherapy and radiotherapy proved efficacious in a minority of these patients.

Lack of PAX5 rearrangements in lymphoplasmacytic lymphomas: reassessing the reported association with t(9;14).

A t(9;14)(p13;q32) involving the PAX5 and IGH genes has been described in association with lymphoplasmacytic lymphoma. Although often described as common, the incidence of this translocation in nodal lymphoplasmacytic lymphoma has never been investigated. Recent studies of patients with Waldenström's macroglobulinemia (often corresponding to marrow-based lymphoplasmacytic lymphoma) have failed to identify the t(9;14). These studies have suggested that either nodal and marrow-based lymphoplasmacytic lymphomas have distinct pathogenetic mechanisms or that the t(9;14) is less frequent in lymphoplasmacytic lymphoma than was believed previously. We therefore analyzed a series of nodal or other extramedullary lymphoplasmacytic lymphomas for the presence of the t(9;14) with paraffin section interphase fluorescence in situ hybridization. We developed a BAC contig probe spanning all previously described PAX5 breakpoints and validated this assay with the KIS-1 cell line that expresses a t(9;14). Analysis with the PAX5 probe showed a lack of PAX5 rearrangements in all cases that were analyzed successfully. Similarly, analysis by an IGH fluorescence in situ hybridization probe showed no evidence of translocations involving the IGH locus. These findings indicate that the t(9;14) is at least uncommon in lymphoplasmacytic lymphoma and should no longer be considered a characteristic finding in this type of lymphoma as defined by World Health Organization criteria.

Kimura disease: a clinicopathologic study of 21 cases.

Kimura disease is a rare form of chronic inflammatory disorder involving subcutaneous tissue, predominantly in the head and neck region and frequently associated with regional lymphadenopathy and/or salivary gland involvement. This condition has a predilection for males of Asian descent and may clinically simulate a neoplasm. Kimura disease is sometimes confused with angiolymphoid hyperplasia with eosinophilia, which occurs in the superficial skin of the head and neck region. Although sporadic cases have been reported in non-Asians, there is no large, comprehensive study of Kimura disease in the United States. We report 21 cases with nodal involvement that, histologically, are consistent with Kimura disease. There were 18 males and 3 females (male/female ratio 6:1), 8 to 64 years of age (mean, 32 years), and included 7 Caucasians, 6 Blacks, 6 Asians, 1 Hispanic, and 1 Arabic. Anatomic sites of involvement included posterior auricular (n = 10), cervical (n = 6), inguinal (n = 3), and epitrochlear (n = 2) lymph nodes, with two patients having associated salivary gland involvement. Most (n = 16) cases had peripheral blood eosinophilia. Consistent histologic features were follicular hyperplasia, eosinophilic infiltrates, and proliferation of postcapillary venules. Follow-up data on 18 patients revealed that 13 were alive without disease (3 had recurrence), mean follow-up, 10.9 years; 4 were alive with disease (2 had a recurrence), mean follow-up, 8.8 years; and 1 died with disease (12.7 years). Kimura disease has been described more often in Asians, but it does occur in non-Asians with a similar clinicopathologic presentation. It is a distinctive entity with no known etiology. Kimura disease has characteristic histologic features that are important to recognize and can be used to differentiate it from hypersensitivity and drug reactions and infections.

Littoral cell angioma of the spleen: CT features with clinicopathologic comparison.

PURPOSE: To evaluate the clinical, pathologic, and computed tomographic (CT) features of littoral cell angioma of the spleen in eight patients. MATERIALS AND METHODS: Two abdominal radiologists retrospectively reviewed the contrast material-enhanced CT images obtained in six, the contrast-enhanced and nonenhanced CT images obtained in two, and the photographs of gross pathologic specimens resected from seven patients. They also retrospectively reviewed clinical data (ie, demographic data, presenting signs and symptoms, physical findings, and medical histories). Histopathologic specimens from the eight patients were reviewed by a hematopathologist. The CT images were reviewed for the presence of splenomegaly. The number, size, and enhancement characteristics of the splenic masses at CT were compared with the histopathologic and gross pathologic specimen findings. RESULTS: All patients had laboratory evidence of hypersplenism. Seven patients (88%) had splenomegaly and innumerable splenic masses ranging from 0.2 to 6.0 cm in diameter at CT. The single patient with a normal spleen size had four splenic masses. The splenic masses were hypoattenuating relative to the normal spleen at CT in all patients and correlated with blood-filled nodules at gross pathologic examination and with blood-filled vascular channels of littoral cell angioma at histopathologic examination. The early and late portal venous phase CT images that were available in one case demonstrated progressive homogeneous contrast enhancement of the masses such that they were indistinguishable from the normal splenic parenchyma. CONCLUSION: Littoral cell angioma is a primary splenic neoplasm that most commonly manifests at CT as multiple hypoattenuating masses in an enlarged spleen. Histopathologically, these masses represent blood-filled vascular channels.

Non-Hodgkin's lymphoma of the appendix: clinical and CT findings with pathologic correlation.

OBJECTIVE: The purpose of this report is to describe the clinical, CT, and pathologic features of non-Hodgkin's lymphoma of the vermiform appendix. CONCLUSION: Non-Hodgkin's lymphoma of the appendix typically manifests with acute symptoms in patients who have no prior history of lymphoma. Most patients with the disease present clinically with signs and symptoms suggestive of acute appendicitis. On CT, lymphomatous infiltration of the appendix produces markedly diffuse mural soft-tissue thickening (range of diameters, 2.5-4.0 cm; mean diameter, 3.2 cm). The vermiform morphology of the appendix is usually maintained, and aneurysmal dilatation of the lumen is sometimes seen. Stranding of the periappendiceal fat seen on CT may represent superimposed inflammation or even direct lymphomatous extension. Coexisting abdominal lymphadenopathy is not seen in all patients. Although appendiceal lymphoma is rare, the characteristic CT appearance could lead to a preoperative diagnosis.