The Pathologic Spectrum of Bone Marrow Involvement by Double- and Triple-hit Lymphomas

Introduction/Objective

B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements (double- and triple-hit lymphomas, DHL/THL) are a distinct entity due to shared biology and aggressive behavior, exhibiting poor outcomes with standard therapies. While pathologic features of DHL/THLs in primary sites have been well described, little information is available regarding the clinicopathologic features of bone marrow involvement by this entity.

Methods/Case Report

Files were searched from 2010-2020 for all DHL/THLs. Since mid-2016, all aggressive B-cell lymphomas were reflexed to DHL/THL FISH testing. Prior to that, criteria for performing FISH varied. Clinical and laboratory data were obtained through chart review. Both BM and primary diagnostic specimens were reviewed when possible.

Results (if a Case Study enter NA)

There were 46 DHL/THL cases with initial staging BM evaluations, of which 13 (28%) were positive for DHL/THL; 11 were available for review (5F:6M; 28-95 years). All patients with positive BMs were stage 3 or 4 irrespective of the BM findings. Lymphoma cytology in positive BMs was blastoid in 6, large cell in 2, and high grade, NOS in 3. The cytology in primary tissues was not significantly associated with the rate of marrow involvement. PB smears were available for 9/11 BM(+) cases; of these, 6 (66.7%) had circulating lymphoma cells in the blood, ranging from rare to greater than 40% lymphoma cells (median, 4%). Lymphoma cells with cytoplasmic vacuoles were present in 5 cases (45%). No BM infiltrates had a starry-sky appearance. Infiltration patterns included diffuse (3), diffuse and interstitial (3), and interstitial (3). One exhibited only rare, scattered lymphoma cells in the aspirate and core biopsy, and another with large cell morphology showed random focal (nodular) and focally paratrabecular infiltration. The proliferation index in the marrow infiltrates ranged from 50% to >90% (median, 65%). Flow cytometry was positive in 9 of 10 cases; the single negative study was from an outside institution

Conclusion

Our study demonstrates 28% of DHL/THLs show BM involvement at diagnosis. Notably, the peripheral blood was involved in 2/3 of cases with marrow infiltration (13% of total cases), ranging from rare circulating cells to frank leukemic involvement. Cytologically, the marrow infiltrates were predominantly blastoid or high grade NOS. Marrow infiltrates generally displayed leukemic rather than lymphomatous patterns of involvement.

Reducing IV-contaminated blood specimens in the clinical laboratory: A Quality Improvement Project

Introduction/Objective

Preanalytical errors constitute the most common errors in the laboratory, with improper specimen collection accounting for many errors. In our laboratory, we had a sentinel event related to repeated deletions of suspected IV-contaminated draws, and herein report our quality improvement project (QIP) to reduce deleted test results and IV-contaminated specimens.

Methods/Case Report

Our QIP initiated with creating a core-lab task force. Several interventions were launched: (A) policy/definition standardization, (B) nursing IV-line/cathedar in-services, (C) in-services on deleting test results and identifying IV-contamination, (D) policy updates to reflect no deletions without evidence of IV-contamination, and (E) mitigation steps requiring supervisory approval for result deletions. We measured: patient safety events (PSRs); RECOLLECTION comment usage and efficacy (disclaimer attached to results thought to be IV-contaminated, requesting recollection); and mitigation failures. Efficacy of the comment usage was measured by comparing subsequent collections to the original and determining likelihood of IV-contamination (contaminated, not contaminated, and unsure). Prior to the QIP, lab practice was to delete suspected IV-contaminated results and those requested by the care team.

Results (if a Case Study enter NA)

PSRs attributable to IV-contamination dropped from 47/mo. (time 0) to 18/mo. over an 11-month period (min-8/mo.; max-64/mo.), with the greatest decrement seen following intervention C. The RECOLLECTION comment was attached to 38 results (0.06% of total accessions) at the start and 73 results (0.12% of total accessions) at time 11 mos. and showed greatest increase in use immediately prior to interventions C and D (approximately 3-fold increase). At time 0, 54% of RECOLLECTION comments were deemed contaminated and 31% were not; at time 11mos., 74% (50/68) were contaminated and 24% (16/68) were not. Mitigation failures numbered 5/mo. initially and 1/mo. at time 11 mos.

Conclusion

With multiple educational and supervisory interventions, we demonstrate a reduction in PSRs attributable to IV-contamination collections at our hospital. Use of cautionary disclaimers was overall minimal and appropriately used.

A mysterious malady: the Malachowski-Wright-Giemsa stain to the rescue

A patient entered hospital with a puzzling absolute monocytosis. Admitting blood smears had been stained with Diff-Quik, a Romanowsky stain. When additional smears were stained using a standard Malachowski-Wright-Giemsa method, the reason for the monocytosis became abundantly clear.

Laboratory findings in CD4(+) large granular lymphocytoses

Large granular lymphocytic (LGL) leukemia is an uncommon disorder of mature T or natural killer (NK) cells. Most T-LGL proliferations are CD3(+)/CD8(+), although rare CD4(+) clonal T-LGL expansions have been reported. We report the clinicopathologic features of eight patients with aberrant CD4(+), cytotoxic T-cell lymphocytoses. Median follow-up was 29 months (range 8-100), during which all were alive without requirement for therapy. Four of eight patients had an additional malignancy; none had a history of rheumatoid arthritis, lymphadenopathy or hepatosplenomegaly. Morphologic expansions of granulated lymphocytes were evident in 6/8. All had immunophenotypically aberrant populations of CD4(+) T cells with uniform, moderate or bright CD56. Seven of eight expressed CD57, and four were CD8(partial dim +). Abnormal levels of expression of two or more T-cell antigens were seen in all cases. All tested cases were Tgamma PCR positive. Our results support that CD4(+) T-LGL lymphocytosis is a clonal disorder with clinicopathologic characteristics distinct from the more common CD8(+) variant.

Immunophenotypic analysis of hematogones (B-lymphocyte precursors) in 662 consecutive bone marrow specimens by 4-color flow cytometry

Bone marrow hematogones (B-lymphocyte precursors) may cause problems in diagnosis because of their morphologic and immunophenotypic similarities to neoplastic lymphoblasts. The purposes of this prospective, multiparametric flow cytometry study were to quantify hematogones across age groups and a spectrum of clinical conditions, to identify factors that affect the relative quantity of hematogones, and to compare their immunophenotype with that of neoplastic lymphoblasts. A total of 662 consecutive marrow specimens were analyzed for hematogones using one of two 4-color antibody combinations; hematogones were identified in 528 (79.8%). There was a significant decline in hematogones with increasing age (P <.001), but a broad range was found at all ages and many adults had a relatively high number. Specimens processed by density gradient had a higher mean percent hematogones than those processed by erythrocyte lysis (P <.001). There was a direct decline in hematogones with increasing marrow involvement with neoplastic cells. A total of 8% of the 662 specimens contained 5% or more hematogones: 24.6% of specimens from patients aged less than 16 years and 6.3% from those 16 and older (P <.000 01). Increased hematogones were observed most often in patients with lymphoma, marrow regenerative states, immune cytopenias, and acquired immunodeficiency syndrome. Hematogones always exhibited a typical complex spectrum of antigen expression that defines the normal antigenic evolution of B-cell precursors and lacked aberrant expression. In contrast, lymphoblasts in 49 cases of precursor B-ALL showed maturation arrest and exhibited 1 to 11 immunophenotypic aberrancies. Four-color flow cytometry with optimal combinations of antibodies consistently distinguishes between hematogones and neoplastic lymphoblasts.

Immunophenotypic analysis of peripheral T-cell neoplasms. A multiparameter flow cytometric approach

We retrospectively reviewed multiparameter flow cytometric analyses in 50 peripheral T-cell neoplasms (PTCNs). Results were interpreted within the context of a large cohort of nonneoplastic T-cell populations. All PTCN diagnoses were confirmed with morphologic and/or molecular analysis. Aberrant populations were defined as discrete immunophenotypic clusters exhibiting loss of or increased or diminished expression of T-cell antigens relative to internal immunophenotypically normal T-cell populations. An antigenic pattern was considered abnormal if it exceeded ranges for T-cell subsets in specific anatomic sites or was not normally encountered. Forty-six of 50 and 41 of 50 demonstrated 1 or more and 2 or more aberrations, respectively. The most common abnormally expressed antigen was CD3, followed by CD7, CD5, and CD2. Except for CD7, abnormally dim or bright antigen expression was more common than deletion. Only 3 cases were abnormal solely based on expansion of an otherwise immunophenotypically normal population; the remainder had patterns of antigen expression not seen in nonneoplastic populations. These data indicate that most PTCNs are aberrant by multiparameter flow analysis. However, results must be interpreted within the context of thorough knowledge of the immunophenotypic spectrum of nonneoplastic T cells.

Transient myeloproliferative disorder and acute myeloid leukemia in Down syndrome. An immunophenotypic analysis

Immunophenotypic analysis of transient myeloproliferative disorder (TMD) and acute myeloid leukemia (AML) using multiparameter flow cytometry might provide insight into their relationship. We retrospectively analyzed the expression of multiple lymphoid, myelomonocytic, and megakaryocytic antigens on blast proliferations in 18 patients with Down syndrome (DS; AML, 9; TMD, 9). The AMLs and TMDs shared several immunophenotypic characteristics. Blasts in all expressed CD45, CD38, and CD33; most AMLs and all TMDs were CD36+; and the majority expressed CD41 and CD61, suggesting megakaryocytic differentiation. The majority of cases were CD34+, CD14-, and CD64-. There was aberrant expression of the T-cell-associated antigen CD7 in most AMLs and TMDs. CD56 was expressed aberrantly in 5 AMLs and 7 TMDs. The major difference between the disorders was the pattern of expression of myeloid markers CD11b and CD13; each was expressed in 8 AMLs but only 2 TMDs. Blasts were HLA-DR-positive in 3 AMLs vs 7 TMDs. Blasts in TMD and AML in DS have a characteristic immunophenotype distinct from AML in other settings. The immunophenotypic similarities suggest a biologic relationship between the disorders; however, distinct immunophenotypic differences also were observed.

Clinicopathologic analysis of CD10+ and CD10- diffuse large B-cell lymphoma. Identification of a high-risk subset with coexpression of CD10 and bcl-2

We analyzed 53 cases of diffuse large B-cell lymphoma (DLBCL) to determine whether expression of CD10 is a relevant biologic parameter. Tumor morphologic features were assessed semiquantitatively. Bcl-2 protein expression was studied by immunohistochemical analysis. The presence or absence of CD10 by flow cytometry was correlated with clinical and pathologic characteristics. CD10+ (23 cases) and CD10- (30 cases) DLBCLs were indistinguishable based on age, sex, extranodal presentation, B symptoms, clinical stage, morphologic features, or bcl-2 expression. However, cases with a CD10+ phenotype showed a significantly lower rate of complete remission. Cases expressing bcl-2 showed trends toward a lower rate of complete remission and poorer overall survival. Examination of CD10 and bcl-2 interaction revealed that the prognostic effects for both of these antigens were due to a subset of CD10+ bcl-2-positive cases. Compared with cases expressing one or neither of these markers, patients with dual-positive tumors had a poorer complete response rate to initial therapy and strikingly worse overall survival. While CD10+ and CD10- DLBCLs are similar with regard to a variety of clinical and pathologic features, CD10 and bcl-2 coexpressing tumors are an extremely high-risk subset based on response to therapy and overall survival.

Precursor B-cell lymphoblastic lymphoma. A study of nine cases lacking blood and bone marrow involvement and review of the literature

We describe 9 cases of precursor B-cell lymphoblastic lymphoma (LYL) without evidence of marrow or blood involvement. Four patients had superficial nodal disease, 2 cutaneous involvement, and 1 each ovarian, retroperitoneal, or tonsillar primary tumor. Six patients had limited disease; 3 patients were stage III. Immunophenotyping revealed a terminal deoxynucleotidyl transferase (TdT)-positive, immature B-cell population with variable expression of CD10, CD20, and CD45. All patients are in complete clinical remission (median follow-up, 14 months). A literature review yielded 105 patients with a diagnosis of precursor B-cell LYL based on less than 25% marrow involvement. Of these, 64% were younger than 18 years. Skin, lymph nodes, and bone were the most common sites of disease. Mediastinal involvement was uncommon. TdT, CD19, CD79a, CD10, and HLA-DR were the most frequently expressed antigens, while CD45 and CD20 were expressed in only two thirds of the cases. Cytogenetic analysis showed additional 21q material as a recurring karyotypic abnormality. At a median follow-up of 26 months, 74% of patients were alive; the median survival was 19 months for patients dying of disease. Comparison with precursor B-cell acute lymphoblastic leukemia showed several overlapping features, although distinct differences were identified.

Large cell lymphoma transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma. A flow cytometric analysis of seven cases

We studied 7 cases of large cell transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) immunophenotyped by multiparameter flow cytometry. The 6 women and 1 man ranged in age from 45 to 91 years. All had previous or concurrent evidence of CLL/SLL. Morphologic features and sites of involvement of the diffuse large B-cell lymphoma (DLBCL) were heterogeneous; 2 cases had paraimmunoblastic morphologic features. Six DLBCLs had an immunophenotype consistent with CLL: CD19+, CD5+, CD23+, and FMC7 negative (3 cases) or very dim (2 cases); 1 case was not studied for FMC7. CD20 was dim in 3 of these, moderate to bright in 2, and variable in 1. Surface immunoglobulin was dim in 2 cases and moderate or bright in 4. Five of 6 expressed CD38. Comparison with the immunophenotypes of the previous or coexistent CLL/SLL (4 of 6 cases) revealed minor modulations in antigen expression but no major alterations. The seventh DLBCL lacked CD5 expression, but otherwise had immunophenotypic features similar to CLL. These findings indicate that DLBCL arising in CLL/SLL tends to retain a CLL immunophenotype, in contrast with de novo CD5+ large cell lymphomas that uncommonly express such a phenotype.

Prognostic significance of tumour-infiltrating T lymphocytes and T-cell subsets in de novo diffuse large B-cell lymphoma: a multiparameter flow cytometry study

Tumour-infiltrating T lymphocytes (TIL-T) have been implicated in playing a role in controlling tumour growth. We evaluated TIL-T in 55 cases of de novo diffuse large B-cell lymphoma (DLBCL) using three- or four-colour flow cytometric immunophenotyping (FCI). The percentage of TIL-T varied from 3% to 72% of total viable cellular events (mean 32 +/- 20%). The CD4:CD8 ratio varied from 0.17 to 13 (mean 2.3 +/- 2.2). Cases with >/= 20% T cells and those with CD4:CD8 ratios > or = 2.0 showed a significantly better overall survival (P = 0.017 and P = 0.034 respectively). These findings were independent of clinical stage at diagnosis. The T-cell percentage and CD4:CD8 ratio were moderately correlated (Spearman correlation coefficient = 0.47, P = 0.001) and multivariate analysis revealed that the association of the two factors with prognosis was mutually dependent. The T cells in 23 cases were studied for CD45RO. The mean percentage of total T cells expressing CD45RO was 86 +/- 10%. There was a trend towards better survival for those patients with a higher percentage of CD45RO+ T cells (P = 0.06). These results suggest that TIL-T, particularly CD4+ T cells, may play a role in the control of DLBCL, and measurement of T-cell percentage and T-cell subsets using FCI may be useful in predicting the clinical behaviour of DLBCL.

Soluble transferrin receptor (sTfR) concentration quantified using two sTfR kits: analytical and clinical performance characteristics

We compared the analytical and clinical performance characteristics of the Ramco and R&D Systems enzyme-linked immunosorbent assays (ELISAs) for quantifying serum levels of soluble transferrin receptor (sTfR). In addition, we determined both the number of samples required to determine the true individual mean sTfR concentration for a single individual and the critical difference (CD) between serial measurements that indicates a statistically significant change in sTfR concentration. sTfR concentration was determined in 127 serum samples selected retrospectively from males (n=32) and non-pregnant (n=40) and pregnant women (n=55). Intra- and inter-assay precision for both methods was good (CV values 5--10%) to excellent (CV values <5%) over a wide range of sTfR concentrations. Correlation between these methods was good (r=0.93); however, sTfR values by the R&D kit were approximately 2.9 times higher than values obtained using the Ramco kit on the same serum samples. Nevertheless, receiver-operator characteristic (ROC) curve analysis demonstrated that the diagnostic accuracy of both assays in discriminating between patients with iron-deficiency anemia (IDA) or anemia of chronic disease (ACD) was high (area-under-the-curve (AUC) values >0.95) and not significantly different (P=0.480). We determined that a minimum of 8 samples are required to determine an individual's true sTfR concentration, while a >40% difference between serial sTfR measurements would be required to indicate a statistically significant change in sTfR concentration. We concluded that both the Ramco and R&D Systems sTfR methods have similar analytical and clinical performance characteristics and were likely to be equally useful in discriminating between patients with biochemically defined IDA or ACD.

Discriminating between iron deficiency anemia and anemia of chronic disease using traditional indices of iron status vs transferrin receptor concentration

We compared the ability of soluble serum transferrin receptor (TfR) concentration, quantified using the R&D Systems (Minneapolis, MN) enzyme-linked immunosorbent TfR assay, with other, more traditional indicators of iron status (total iron binding capacity [TIBC], mean corpuscular volume [MCV], percent transferrin saturation [%TS], RBC distribution width [RDW], and serum iron concentration [SIC]) for discriminating between patients with iron deficiency anemia (IDA) or anemia of chronic disease (ACD). The TfR concentration was determined in 72 serum samples selected from men and nonpregnant women classified biochemically on the basis of ferritin concentration as having IDA (n = 41) or ACD (n = 31). By using receiver operating characteristic curve analysis, the diagnostic accuracy of the various indicators of iron status that we evaluated for discriminating between IDA and ACD decreased in the following order: TIBC > TfR > MCV > (%TS = RDW) > SIC. There was no significant difference between the diagnostic accuracy of TIBC and TfR. Thus, the routine measurement of TfR offers no advantage over TIBC for discriminating between people with biochemically defined IDA or ACD.

De novo CD5+ diffuse large B-cell lymphomas. A heterogeneous group containing an unusual form of splenic lymphoma

We reviewed our institutional experience with de novo CD5+, large B-cell lymphomas to determine whether they represent a distinct entity and are related to CD5+ small B-cell disorders. We identified 13 cases with multiparameter flow cytometry over a period of 58 months (5% of large B-cell lymphomas) in 7 females and 6 males. Three groups were identified. Group 1 (2 cases) had diffuse splenic red pulp involvement with a distinctive cordal pattern of infiltration, no other clinical evidence of mass disease, microscopic disseminated disease on further workup, and an identical immunoglobulin-negative immunophenotype. Group 2 cases (7 cases) were clinically and morphologically heterogeneous and had an immunophenotype resembling mantle cell lymphoma (FMC7-positive, CD23-). Group 3 (4 cases) had miscellaneous immunophenotypes, including one closely resembling chronic lymphocytic leukemia. Cyclin D1 was positive in only 1 of 10 evaluable cases (group 2). We conclude that CD5+ diffuse large B-cell lymphomas are heterogeneous; most cases do not seem to be related to chronic lymphocytic leukemia or mantle cell lymphoma. However, we identified a subgroup of primary splenic CD5+ large B-cell lymphoma with diffuse red pulp involvement and believe this may represent a distinct clinicopathologic entity.

Precursor B-lymphoblastic transformation of grade I follicle center lymphoma

Part of the natural history of follicle center lymphoma (FCL) is transformation to a more aggressive neoplasm, almost always a diffuse large B-cell lymphoma. We describe a rare example of a precursor B-lymphoblastic transformation of grade I FCL occurring in a 45-year-old woman 12 years after initial presentation and 3 years after successful treatment for a diffuse large cell transformation. The lymphoblastic lymphoma shared the same immunoglobulin heavy chain gene rearrangement as the FCL as assessed by polymerase chain reaction amplification and direct sequencing, as well as identical kappa light chain gene rearrangements by Southern blot analysis. The immunoglobulin heavy chain variable gene sequences of both tumors showed numerous identical base substitutions compared with germline sequences and 3 additional mutations in the lymphoblastic lymphoma not present in the low-grade FCL. These results indicate origin of the lymphoblastic process from the mature follicle center B-cell clone, rather than divergent origin of the 2 tumors from a common immature B-cell precursor.

Unusual bone marrow manifestations of parvovirus B19 infection in immunocompromised patients

Parvovirus B19 is responsible for a spectrum of disease in humans. The usual bone marrow findings in acute parvovirus infections are marked erythroid hypoplasia and occasional giant erythroblasts. Intranuclear inclusions in developing erythroid precursors are rarely described in children or adults with parvovirus infection, although abundant intranuclear inclusions are commonly observed in the placenta and other tissues in infected fetuses. In this study, 8 patients are reported in whom the first evidence of parvovirus infection was the recognition of numerous intranuclear inclusions in erythroid precursors on bone marrow biopsy sections. Six of the 8 patients had documented immunodeficiencies; 4 had acquired immune deficiency syndrome (AIDS), and 2 were on chemotherapy. Five of 7 patients were negative for immunoglobulin G (IgG) antiparvovirus antibodies, including all 4 with AIDS. Unlike the typical pattern in parvovirus infection, the bone marrow was hypercellular in most of the patients, and erythroid precursors were usually increased with the entire spectrum of normoblast maturation represented; abundant intranuclear inclusions were observed similar to the finding in fetuses. The inclusions were variably eosinophilic and compressed the chromatin against the nuclear membrane. In situ hybridization showed parvovirus B19 DNA in numerous erythroid precursors in all cases. The findings of erythroid maturation and abundant viral inclusions in these immunocompromised patients is consistent with the hypothesis that failure to produce effective IgG parvovirus neutralizing antibodies may lead to persistent infection through viral tolerance that allows erythroid development of infected cells past the pronormoblast stage. Identification of parvovirus inclusions in marrow biopsies and subsequent confirmation of infection by in situ hybridization can be important in the assessment of anemia in immunodeficient patients because serological studies for parvovirus B19 are frequently negative.

Cytoplasmic inclusions in leukocytes. An unusual manifestation of cryoglobulinemia

Cryoglobulins are circulating immunoglobulins characterized by reversible, cold-induced precipitation. A variety of laboratory abnormalities, including hypocomplementemia, elevated erythrocyte sedimentation rate, rheumatoid factor activity, pseudoleukocytosis, and pseudothrombocytosis, are associated with cryoglobulinemia. Extracellular, faintly basophilic, amorphous deposits of cryoglobulins occasionally have been described in blood smears. In the present study, smears prepared from blood collected at room temperature from 6 patients with cryoglobulinemia exhibited neutrophil and, occasionally, monocyte inclusions containing clear, light pink, or faintly basophilic amorphous material. The inclusions were absent in smears from blood collected and maintained at 37 degrees C. Ultrastructural examination revealed that the material within the leukocyte inclusions was consistent with phagocytosed immunoglobulins. The identification of characteristic cytoplasmic inclusions in leukocytes may be an important clue in the early recognition of cryoglobulinemia.

Cytomegalovirus-infected cells in routinely prepared peripheral blood films of immunosuppressed patients

We describe 4 patients identified over 5 years with large atypical cells on the feathered edge of routinely prepared peripheral blood films. Films were reviewed either as part of a blood film consultation or a bone marrow examination. The cells were 50 to 60 microns in diameter, with granular eosinophilic cytoplasmic inclusions and eccentric enlarged nuclei. Additional studies including buffy coat preparations and immunohistochemistry revealed that these were circulating cytomegalovirus (CMV)-infected cells, most likely of endothelial origin. All patients were immunocompromised (3 had HIV infection, and 1 was an organ transplant recipient) and had clinical evidence of CMV infection. The unique appearance of these cells at Wright-Giemsa staining, and their possible misidentification as malignant cells or other cells, highlights the need for pathologists to be aware of their morphologic features and possible clinical implication.

Secondary abnormalities of chromosome 6q in B-cell chronic lymphocytic leukemia: a sequential study of karyotypic instability in 51 patients

Although karyotypic abnormalities are well documented in B-cell chronic lymphocytic leukemia (B-CLL), few sequential cytogenetic studies have been done. In this study, peripheral blood lymphocytes from fifty-one patients with B-CLL were sequentially karyotyped over a mean interval of 13.8 months (range, one to 51 months). Cytogenetic clones were detected in 33/51 patients (66%) on initial study, including 17 patients with structural abnormalities of chromosome 13q14, and three patients with trisomy 12. Karyotypic evolution was documented in 22/51 patients (43%). The most common secondarily acquired chromosome aberrations were structural abnormalities of the long arm of chromosome 6 involving the region of 6q21-q24 (six patients). Four patients each had acquired structural abnormalities of 1q, 3p, 12q, and 13q. Disease progression, as measured by advance in Rai stage or death from the disease, was observed more often in the clonal evolution group than in the karyotypically stable group (11/22 vs. 5/29; P = 0.017). Patients with secondary abnormalities of 6q had a significantly decreased progression-free survival interval compared with other patients in the study (P = .023). The authors conclude that clonal karyotypic evolution is common in B-CLL, and that clonal evolution correlates with clinical disease progression. Furthermore, the poor outcomes previously attributed to CLL with 6q abnormalities may be related to the clonal acquisition of these abnormalities over time. Future studies should focus on the relevant genetic events underlying the clinical progression observed with karyotypic evolution of B-CLL.

Evaluation of CD23 expression in paraffin-embedded gastric lymphomas of mucosa-associated lymphoid tissue

The CD23 antigen is expressed in a normal subset of B lymphocytes and in some non-Hodgkin's lymphomas. Reactivity for anti-CD23 (BU38) is present in paraffin-embedded tissue in the large majority of nodal small lymphocytic lymphomas, as well as in follicular center cell lymphomas. Most studies of gastric lymphomas of mucosa-associated lymphoid tissue (MALT) reported a lack of CD23, but these studies were performed on frozen tissue. We evaluated CD23 staining in paraffin-embedded tissue in a large series of gastric MALT lymphomas, as well as in cases of chronic gastritis. We assayed 49 well-characterized gastric lymphomas (9 high-grade non-MALT and 40 MALT [20 low grade, 13 mixed low and high grade, and 7 high grade]). High-grade MALT lymphomas without a low-grade component were distinguished from high-grade non-MALT lymphomas by the presence of lymphoepithelial lesions composed of large cells. In addition, we studies nine cases of chronic gastritis containing B-cell aggregates. We used anti-CD23 (BU38) in formalin-fixed, paraffin-embedded tissue. All of our low-grade gastric MALT lymphomas lacked CD23 immunoreactivity. One of the 13 mixed low-grade and high-grade lesions showed CD23 expression in the high-grade component. All of the high-grade MALT and high-grade non-MALT lesions lacked CD23. All of the nine cases of chronic gastritis lacked CD23. CD23 highlighted residual follicular dendritic cells and gastric epithelium. We concluded that gastric MALT lymphomas lacked CD23 (BU38) in paraffin-embedded tissue, with rare exceptions. This lack of CD23 expression might represent a useful feature in small or partially crushed biopsy specimens, particularly in the differential diagnosis with follicular small cleaved cell lymphoma presenting in the gastrointestinal tract.

Follicular large cell lymphoma with immunoblastic features in a child with Wiskott-Aldrich syndrome: an unusual immunodeficiency-related neoplasm not associated with Epstein-Barr virus

Patients with Wiskott-Aldrich syndrome, a severe inherited immunodeficiency disorder, have a markedly increased risk of developing non-Hodgkin's lymphoma compared with the general population. These are uniformly diffuse aggressive B-cell neoplasms that resemble those seen in AIDS and the posttransplantation setting and also may be associated with Epstein-Barr virus. We report what to our knowledge is the first case of follicular lymphoma in a 14-year-old child with Wiskott-Aldrich syndrome. The neoplasm was composed predominantly of large cells with immunoblastic features, and it possessed light chain-restricted surface immunoglobulin, clonal immunoglobulin gene rearrangements, and a t(14;18). The tumor lacked Epstein-Barr virus sequences by in situ hybridization and Southern blot terminal repeat analysis. Interestingly, however, the tumor contained c-myc gene rearrangement.

Ruptured spleens with expanded marginal zones do not reveal occult B-cell clones

An indolent variant of splenic marginal zone lymphoma (SMZL) lacking massive splenomegaly has been described as an incidental finding in spleens removed for rupture or hypersplenism. We studied traumatically ruptured spleens with expanded marginal zones (MZs) to assess the incidence of occult monoclonal B-cell populations in this setting. Ninety-one ruptured or lacerated spleens removed from 1984 to 1995 were classified as to whether they had expanded MZs (> 12 cell layers thick). When available, paraffin-embedded, formalin-fixed tissue from cases with expanded MZs was examined for immunoglobulin heavy chain gene rearrangement by polymerase chain reaction (PCR) and stained for CD20, CD43, and kappa and lambda light chains. Splenectomies were performed for blunt (70 patients) and penetrating (7 patients) trauma, surgical misadventure (13 patients), or spontaneous rupture (1 patient). There were 58 men and 33 women in our study, ranging in age from 17 to 87 years (mean, 40 yr). Average spleen weight was 183 g (range, 44-505 g). Twenty-seven (30%) of 91 patients had expanded MZs. There were no significant differences in age, sex, spleen weight, or reason for excision between those cases with and without MZ expansion. Germinal centers varied from absent to inactive to floridly reactive. Paraffin blocks were available in 24 cases; the 20 with amplifiable DNA were polyclonal by PCR. Follow-up was available for 25 of the 27 patients with expanded MZs (range, 1-85 mo; median, 6 mo); lymphoma did not develop in anyone, although one patient's spleen was morphologically suspicious for lymphoma, showing involvement of red pulp by MZ-type B-cells; PCR revealed a polyclonal pattern. This patient's 3-year follow-up revealed no evidence of lymphoma. Traumatically ruptured spleens with expanded MZs do not seem to harbor occult B-cell clones, as detected by PCR. Although a few cases of incidentally removed spleens have been reported to contain low-stage SMZL, this seems to be an infrequent event.

Optimal procedures for detecting analytic bias using patient samples

We recently described the performance characteristics of the exponentially adjusted moving mean (EAMM), a patient-data, moving block mean procedure, which is a generalized algorithm that unifies Bull's algorithm and the classic average of normals (AON) procedure. Herein we describe the trend EAMM (TEAMM), a continuous signal analog of the EAMM procedure related to classic trend analysis. Using computer simulation, we have compared EAMM and TEAMM over a range of biases for various sample sizes (N or equivalent smoothing factor alpha) and exponential parameters (P) under conditions of equivalent false rejection (fixed on a per patient sample basis). We found optimal pairs of N and P for each level of bias by determination of minimum mean patient samples to rejection. Overall optimal algorithms were determined through calculation of undetected lost medical utility (ULMU), a novel function that quantifies the medical damage due to analytic bias. The ULMU function was calculated based on lost test specificity in a normal population. We found that optimized TEAMM was superior to optimized EAMM for all levels of analytic bias. If these observations hold true for non-Gaussian populations, TEAMM procedures are the method of choice for detecting bias using patient samples or as an event gauge to trigger use of known-value control materials.

Isolated 13q14 abnormalities and normal karyotypes are associated with typical lymphocyte morphology in B-cell chronic lymphocytic leukemia

Peripheral blood lymphocyte morphology and karyotype were correlated across the spectrum of cytogenetic abnormalities in 78 previously karyotyped cases of B-cell chronic lymphocytic leukemia (CLL). Cases were classified according to French-American-British morphologic criteria as typical CLL or CLL, mixed-cell type; the latter category was divided into CLL with a mixture of small and large cells and CLL with increased prolymphocytes (CLL/PL). Other leukemic lymphoproliferative disorders were excluded from this analysis. CLL cases with normal karyotypes were more likely to demonstrate typical morphology than those with clonal abnormalities (P = .042). In addition, all six cases containing isolated 13q14 abnormalities had typical morphology, compared with six of 16 other isolated abnormalities (P = .009), including one of seven cases of isolated trisomy 12. In contrast with the cases of isolated 13q14 changes, only seven of 17 cases with 13q14 as part of complex abnormalities had typical morphology (P = .012). Trisomy 12 was associated with mixed-cell morphology, particularly CLL/PL, consistent with previous reports. We conclude that isolated 13q14 abnormalities and normal karyotype are associated with typical CLL morphology, while other clonal abnormalities, including trisomy 12, are associated with mixed-cell morphology. These results further support the concept of distinct CLL subgroups based on karyotype. Furthermore, the association of trisomy 12 and complex abnormalities with mixed-cell morphology may have implications for clonal evolution in CLL.

Exponentially adjusted moving mean procedure for quality control. An optimized patient sample control procedure

The idea of using patient samples as the basis for control procedures elicits a continuing fascination among laboratorians, particularly in the current environment of cost restriction. Average of normals (AON) procedures, although little used, have been carefully investigated at the theoretical level. The performance characteristics of Bull's algorithm have not been thoroughly delineated, however, despite its widespread use. The authors have generalized Bull's algorithm to use variably sized batches of patient samples and a range of exponential factors. For any given batch size, there is an optimal exponential factor to maximize the overall power of error detection. The optimized exponentially adjusted moving mean (EAMM) procedure, a variant of AON and Bull's algorithm, outperforms both parent procedures. As with any AON procedure, EAMM is most useful when the ratio of population variability to analytical variability (standard deviation ratio, SDR) is low.

The pathology of the chronic lymphoid leukaemias

The chronic lymphoid leukaemias, though they all possess relatively mature lymphoid phenotypes, are a diverse group of diseases at the clinical, morphological, immunophenotypical, and biological levels. Generally accepted entities within this category include B-cell chronic lymphocytic leukaemia of classical and mixed-cell types, B-cell and T-cell prolymphocytic leukaemia, hairy-cell leukaemia and hairy-cell variant, splenic lymphoma with circulating villous lymphocytes, large granular lymphocytic leukaemia, adult T-cell leukaemia/lymphoma syndrome, and leukaemic phases of malignant lymphomas of both B-cell and T-cell types. Recent advances have helped to differentiate these diseases, allowing the development of more specific therapy and more accurate prognostication. In this article, we review the pathological aspects of these diseases.

Inflammatory pseudotumor of the pancreas

We describe a rare example of inflammatory pseudotumor of the pancreas in a 42-yr-old woman, which developed following chemotherapy for lymphoma of the uterine cervix. The patient had developed fatigue, weight loss, abdominal pain, and anemia; abdominal CT scan showed a large mass in the pancreas. Examination of the resected specimen revealed a fleshy, well-circumscribed, 7-cm mass. Histologically, there was a hypocellular to moderately hypercellular, bland spindle-cell proliferation admixed with a prominent infiltrate of lymphocytes, histiocytes, and plasma cells. The spindle cells were vimentin positive but negative for muscle markers; electron microscopy revealed only fibroblastic cells. DNA analysis revealed a diploid population with low S-phase fraction. The patient was well at 6-mo follow-up. It is important for the pathologist to be aware of the existence of this entity in unusual locations such as the pancreas so as to avoid a mistaken diagnosis of malignancy.

Appendiceal involvement as a skip lesion in ulcerative colitis

Despite the frequency of ulcerative colitis (UC), and numerous studies related to this disease, controversy remains regarding its distribution patterns. It is generally believed that UC starts in the rectum and progresses proximally in continuity to involve cecum along with appendix in 50% of all cases. However, recent endoscopic and histological studies suggest that UC can occur as a discontinuous process. Furthermore, the few existing studies specifically addressing appendiceal histology in UC are divided over whether ulcerative appendicitis (UA) may be seen without cecal involvement (i.e., as a "skip lesion"). To study the appendiceal pathology in UC, and in particular the frequency of UA as a "skip lesion," we retrospectively evaluated 39 proctocolectomy specimens containing appendices removed for UC. Six cases (17%) had obliterated appendices; appendiceal and cecal histologies of the remaining 33 cases were divided into (a) active disease, (b) quiescent disease, or (c) nonspecific or normal histology. Twenty of 39 appendices (51%) showed active disease, four (10%) had quiescent disease, and nine (23%) were either normal or nonspecifically inflamed. After exclusion of one case for inadequate cecal sampling, comparison of cecal and appendiceal histologies showed concordance in 16 cases and discordance in the remaining 16. Of these discordant cases, six had greater disease activity in the cecum and 10 had greater activity in the appendix. Of these latter 10 cases, six showed normal or nonspecific cecal histology associated with active UA. Thus, "skip lesions" of the appendix were detected in 15% of the UC specimens examined.