PD-L1 expression and CD8-positive T cells are associated with favorable survival in HER2-positive invasive breast cancer

Programmed cell death 1 (PD-1) and its ligand (PD-L1) are key physiologic suppressors of the cytotoxic immune reaction. However, to date, the combination of PD1/PD-L1 expression and tumor-infiltrating lymphocytes (TILs) and antigen-presenting cells has been only minimally reported in breast carcinoma, in particular in relation to HER2-positive cases. The goal of this study was to evaluate both cellular tumoral immune reaction and PD-L1/PD1 distribution in HER2-positive cases, as well as any associations with clinical outcome using conventional chemotherapy combined with HER2 blocking. Multicolor immunohistochemical multiplex assays simultaneously demonstrating PD1, PD-L1, and CD8 or PD-L1, CD3, and CD163 were performed on tissue microarrays (TMA) representing 216 pretreatment cases of HER2-positive invasive breast carcinoma. PD-L1 expression was identified in 38 cases (18%), including 12 cases (6%) with PD-L1 labeling of tumor cells and 26 cases (12%) with PD-L1 labeling of immune cells only. Ten of 12 cases with PD-L1 staining of tumor cells showed staining of associated immune cells as well. With this assay method, PD1 was detectable in many fewer cases (6 cases or 3%). PD-L1 expression was positively associated with high Nottingham grade, negative ER and PR, the absence of lymph node metastasis, and high levels of CD8⁺ cells. The overall survival by univariate analysis was positively associated with lower tumor stage, the absence of lymph node metastasis, PD-L1 expression, and high levels of CD8⁺ cells. Therefore, our data suggest cytotoxic immune reaction mediated by CD8-positive T cells and PD-L1 expression may predict a better outcome in patients with HER2-positive breast carcinoma managed with conventional chemotherapy and HER2-blocking therapy. These findings recommend clinical trials utilizing checkpoint blocking immunotherapy in some form for HER2-positive breast cancer.

Interpathologist Diagnostic Agreement for Non-Small Cell Lung Carcinomas Using Current and Recent Classifications

CONTEXT.—

Measurement of interpathologist diagnostic agreement (IPDA) should allow pathologists to improve current diagnostic criteria and disease classifications.

OBJECTIVES.—

To determine how IPDA for pathologists' diagnoses of non-small cell lung carcinoma (NSCLC) is affected by the addition of a set of mucin and immunohistochemical (IHC) stains to hematoxylin-eosin (H&E) alone, by recent NSCLC reclassifications, by simplification of these classifications, and by pathologists' practice location, pulmonary pathology expertise, practice duration, and lung carcinoma case exposure.

DESIGN.—

We used a Web-based survey to present core images of 54 NSCLC cases to 22 practicing pathologists for diagnosis, initially as H&E only, then as H&E plus mucin and 4 IHC stains. Each case was diagnosed according to published 2004, 2011, and 2015 NSCLC classifications. Cohen's kappa was calculated for the 231 pathologist pairs as a measure of IPDA.

RESULTS.—

Twenty-two pathologists diagnosed 54 NSCLC cases by using 4 published classifications. IPDA is significantly higher for H&E/mucin/IHC diagnoses than for H&E-only diagnoses. IPDA for H&E/mucin/IHC diagnoses is highest with the 2015 classification. IPDA is estimated higher after collapse of stated diagnoses into subhead or dichotomized classes. IPDA for H&E/mucin/IHC diagnoses with the 2015 World Health Organization classification is similar for community and academic pathologists, and is higher when pathologists have pulmonary pathology expertise, have more than 6 years of practice experience, or diagnose more than 100 new lung carcinoma cases per year.

CONCLUSIONS.—

Higher IPDA is associated with use of mucin and IHC stains, with the 2015 NSCLC classification, and with pathologists' pulmonary pathology expertise, practice duration, and frequency of lung carcinoma cases.

Evaluation of Immune Reaction and PD-L1 Expression Using Multiplex Immunohistochemistry in HER2-Positive Breast Cancer: The Association With Response to Anti-HER2 Neoadjuvant Therapy

BACKGROUND

Immune reaction with tumor-infiltrating lymphocytes (TILs) has been extensively investigated in breast cancer. Programmed cell death 1 and its ligand (PD-L1) are key physiologic suppressors of cytotoxic immune reaction. However, the combination of TILs with PD-L1 expression has not been well studied in breast cancer.

PATIENTS AND METHODS

A multi-color immunohistochemical multiplex assay simultaneously detecting PD-L1, CD8, and CD163 was performed on biopsy whole sections from 123 HER2-positive (HER2⁺) breast cancers, including 64 treated with anti-HER2 neoadjuvant therapy and subsequent resection.

RESULTS

PD-L1 expression was identified in 88 cases (72%) including 21 (17%) in tumor cells and 67 (55%) in immune cells. PD-L1 expression was positively associated with high Nottingham grade, high nuclear grade, and a high level of CD8⁺ and CD163⁺ cells. Among the 64 patients who received neoadjuvant therapy, 39 had pathologic complete remission (pCR) and 25 had incomplete response. Multivariate analysis showed progesterone receptor negativity, HER2/chromosome 17 centromere (CEN17) ratio and intratumoral CD8⁺ cells were significantly associated with pCR. Furthermore, all patients with intratumoral CD8⁺ cells but no PD-L1 expression achieved pCR.

CONCLUSION

Our data have shown that examination of intratumoral CD8⁺ cells together with PD-L1 expression proves useful in predicting response to anti-HER2 targeted therapy in patients with HER2⁺ breast cancer.

A novel highly differentially expressed gene in wheat endosperm associated with bread quality

Analysis of gene expression in developing wheat seeds was used to identify a gene, wheat bread making (wbm), with highly differential expression (~1000 fold) in the starchy endosperm of genotypes varying in bread making quality. Several alleles differing in the 5’-upstream region (promoter) of this gene were identified, with one present only in genotypes with high levels of wbm expression. RNA-Seq analysis revealed low or no wbm expression in most genotypes but high expression (0.2-0.4% of total gene expression) in genotypes that had good bread loaf volume. The wbm gene is predicted to encode a mature protein of 48 amino acids (including four cysteine residues) not previously identified in association with wheat quality, possibly because of its small size and low frequency in the wheat gene pool. Genotypes with high wbm expression all had good bread making quality but not always good physical dough qualities. The predicted protein was sulphur rich suggesting the possibility of a contribution to bread loaf volume by supporting the crossing linking of proteins in gluten. Improved understanding of the molecular basis of differences in bread making quality may allow more rapid development of high performing genotypes with acceptable end-use properties and facilitate increased wheat production.

The utility of BRAF V600E mutation-specific antibody VE1 for the diagnosis of hairy cell leukemia

OBJECTIVES

BRAF V600E mutation is characteristic of hairy cell leukemia (HCL). A V600E mutation-specific antibody, VE1, has been recently developed. We studied the diagnostic utility of this antibody in HCL and compared it with other B-cell neoplasms.

METHODS

VE1 activity was assessed using immunohistochemistry in 90 mature B-cell neoplasms, including HCL (n = 17), HCL variant (n = 6), chronic lymphocytic leukemia (CLL) (n = 20), and 47 other B-cell lymphomas. Most (87/90) specimens were formalin-fixed, paraffin-embedded bone marrow (BM) biopsy specimens decalcified in either hydrochloric acid or formic acid.

RESULTS

VE1 was positive in 15 (88%) cases of HCL and two (10%) cases of CLL and was negative in all other tumors assessed. The VE1-positive HCL cases showed uniform staining in all tumor cells, but intensity was variable. The two VE1-negative HCL cases had BRAF V600 mutations proven by molecular analysis. The two CLL cases positive with VE1 showed an atypical staining pattern with expression in a minority of lymphoma cells. Immunohistochemistry using the VE1 antibody had a sensitivity of 88% and a specificity of 97% for HCL.

CONCLUSIONS

VE1 immunohistochemistry is a useful and convenient surrogate for detecting BRAF V600E mutation in BM biopsy specimens decalcified with hydrochloric or formic acid-based solutions.

Varying chromosome composition of 56-chromosome wheat x Thinopyrum intermedium partial amphiploids

Thinopyrum intermedium (2n = 42) is a source of many potentially useful genes for wheat improvement. Many partial amphiploids have been produced between Th. intermedium and Triticum aestivum that are fertile and stable. These partial amphiploids all have 56 chromosomes, including seven pairs of chromosomes from Th. intermedium. To explore the genomic composition of these lines, meiotic analysis was conducted on 32 hybrid combinations between eight different partial amphiploids. All but two of the chosen parents were distinguishable on the basis of perenniality, head morphology, and reactions to leaf, stripe, and stem rusts and to barley yellow dwarf virus. Chromosome pairing in the hybrids clearly indicated that all but two of the partial amphiploids differed in their composition of Thinopyrum chromosomes. The differences varied from one to five chromosomes. This confirms molecular evidence that the extra genome of the octoploid partial amphiploids is a variable synthetic genome combining chromosomes of the three Thinopyrum genomes E, J, and X. Though the extra synthetic genomes vary widely between different octoploids, they are nevertheless stable once formed. It is argued that the failure to establish these octoploid amphiploids as a new crop is a consequence of their differing chromosome complements, which makes it impractical to interbreed them.

The use of cell culture for subchromosomal introgressions of barley yellow dwarf virus resistance from Thinopyrum intermedium to wheat

Barley yellow dwarf virus (BYDV) resistance has been transferred to wheat from a group 7 chromosome of Thinopyrum (Agropyron) intermedium. The source of the resistance gene was the L1 disomic addition line, which carries the 7Ai-1 chromosome. The resistance locus is on the long arm of this chromosome. BYDV resistant recombinant lines were identified after three or more generations of selection against a group 7 Th. intermedium short arm marker (red coleoptile) and selection for the presence of BYDV resistance. One recombinant line produced by ph. mutant induced homoeologous pairing and 14 recombinant lines induced by cell culture have been identified. Resistance in seven of the cell culture induced recombinants has been inherited via pollen according to Mendelian segregation ratios for up to eight generations. Meiotic analysis of heterozygotes indicates that the alien chromatin in the cell culture induced recombinants is small enough to allow regular meiotic behaviour. The ph-induced recombinant was less regular in meiosis. A probe, pEleAcc2, originally isolated from Th. elongatum and that hybridizes to dispersed repeated DNA sequences, was utilised to detect Th. intermedium chromatin, which confers resistance to BYDV, in wheat backgrounds. Quantification of these hybridization signals indicated that the translocations involved a portion of alien chromatin that was smaller than the complete long arm of 7Ai-1. Restriction fragment length polymorphism analysis confirmed the loss of the short arm of 7Ai-1 and indicated the retention of segments of the long arm of 7Ai-1. Two 7Ai-1L DNA markers always assorted with the BYDV resistance. A third 7Ai-IL DNA marker was also present in seven of eight recombinants. In all recombinants except TC7, the 7Ai-1L markers replaced the 7DL markers. None of the wheat group 7 markers was missing from TC7. It is concluded that all the resistant lines are the result of recombination with wheat chromosome 7D, except line TC7, which is the result of recombination with an unidentified nongroup 7 chromosome.

Validation of interobserver agreement in lung cancer assessment: hematoxylin-eosin diagnostic reproducibility for non-small cell lung cancer: the 2004 World Health Organization classification and therapeutically relevant subsets

CONTEXT

Precise subtype diagnosis of non-small cell lung carcinoma is increasingly relevant, based on the availability of subtype-specific therapies, such as bevacizumab and pemetrexed, and based on the subtype-specific prevalence of activating epidermal growth factor receptor mutations.

OBJECTIVES

To establish a baseline measure of interobserver reproducibility for non-small cell lung carcinoma diagnoses with hematoxylin-eosin for the current 2004 World Health Organization classification, to estimate interobserver reproducibility for the therapeutically relevant squamous/nonsquamous subsets, and to examine characteristics that improve interobserver reproducibility.

DESIGN

Primary, resected lung cancer specimens were converted to digital (virtual) slides. Based on a single hematoxylin-eosin virtual slide, pathologists were asked to assign a diagnosis using the 2004 World Health Organization classification. Kappa statistics were calculated for each pathologist-pair for each slide and were summarized by classification scheme, pulmonary pathology expertise, diagnostic confidence, and neoplastic grade.

RESULTS

The 12 pulmonary pathology experts and the 12 community pathologists each independently diagnosed 48 to 96 single hematoxylin-eosin digital slides derived from 96 cases of non-small cell lung carcinoma resection. Overall agreement improved with simplification from the comprehensive 44 World Health Organization diagnoses (κ  =  0.25) to their 10 major header subtypes (κ  =  0.48) and improved again with simplification into the therapeutically relevant squamous/nonsquamous dichotomy (κ  =  0.55). Multivariate analysis showed that higher diagnostic agreement was associated with better differentiation, better slide quality, higher diagnostic confidence, similar years of pathology experience, and pulmonary pathology expertise.

CONCLUSIONS

These data define the baseline diagnostic agreement for hematoxylin-eosin diagnosis of non-small cell lung carcinoma, allowing future studies to test for improved diagnostic agreement with reflex ancillary tests.

Co-occurrence of Langerhans cell histiocytosis and Rosai-Dorfman disease: possible relationship of two histiocytic disorders in rare cases

Rosai-Dorfman disease and Langerhans cell histiocytosis are both disorders of accessory immune cells. Two cases have been previously reported of concurrent Langerhans cell histiocytosis and Rosai-Dorfman disease. In this report, we characterize the findings and selected molecular studies in nine additional cases. Histology was reviewed. Immunohistochemical stains were performed on all cases in which slides or blocks were available. A combination of CD1a, S-100, CD3, CD20, langerin, CD68, CD163, CD21, CD35 and CD123 immunohistochemical stains were performed. High-resolution array comparative genomic hybridization was performed on six samples from five cases. In these cases, seven were female and two male, with an average age of 25 years (15 months-59 years). A majority of the cases were identified in lymph node. Areas of Langerhans cell histiocytosis had a typical appearance with the existence of bland 'coffee-bean' nuclei, clear cytoplasm and associated eosinophils. The immunophenotype was typical, including expression of CD1a, S100, CD68 and langerin. In areas of Rosai-Dorfman disease, there was emperipolesis seen in all cases. Cells were intermediate-large in size with large round nuclei and ample clear or pale cytoplasm. The lesional cells were positive for S100, CD68, CD163, without expression of langerin or CD1a. Array comparative genomic hybridization showed gains and/or losses in four of the six samples. One case showed no gains or losses and one additional case showed gains and losses in the Langerhans cell histiocytosis, while no abnormalities were discovered in the Rosai-Dorfman disease component. These findings are comparable to those seen in previous studies of Langerhans cell histiocytosis. We report the clinical and pathologic findings of the combination of Langerhans cell histiocytosis and Rosai-Dorfman disease. Furthermore, we suggest on the basis of evidence from our cases that, when simultaneous, the two entities may be pathophysiologically related.

Altered aquaporin 9 expression and localization in human hepatocellular carcinoma

BACKGROUND

In addition to the biochemical components secreted in bile, aquaporin (AQP) water channels exist in hepatocyte membranes to form conduits for water movement between the sinusoid and the bile canaliculus. The aim of the current study was to analyse AQP 9 expression and localization in human hepatocellular carcinoma (HCC) and non-tumourigenic liver (NTL) tissue from patients undergoing hepatic resection.

METHODS

Archived tissue from 17 patients was sectioned and analysis performed using an antibody raised against AQP 9. Slides were blind-scored to determine AQP 9 distribution within HCC and NTL tissue.

RESULTS

Aquaporin 9 was predominantly expressed in the membranes of hepatocytes and demonstrated zonal distribution relative to hepatic sinusoid structure in normal liver. In HCC arising in the absence of cirrhosis AQP 9 remained membrane-localized with zonal distribution in the majority of NTL. By contrast, AQP 9 expression was significantly decreased in the HCC mass vs. pair-matched NTL. In HCC in the presence of cirrhosis, NTL was characterized by extensive AQP 9 staining in the membrane in the absence of zonal distribution and AQP 9 staining in NTL was significantly greater than that observed in the tumour mass.

CONCLUSIONS

These data demonstrate that human HCC is characterized by altered AQP 9 expression and AQP 9 localization in the NTL mass is dependent on underlying liver pathology. Given the central role of AQPs in normal liver function and the potential role of AQPs during transformation and progression, these data may prove valuable in future diagnostic and/or therapeutic strategies.

Castleman disease of the hyaline-vascular type confined to the kidney

The case is a 38-year-old man in whom a solitary subcapsular left renal cortical mass was successfully resected. Comorbidities included a benign epididymal cyst and a history of nephrolithiasis. Computed tomographic imaging demonstrated a 1.8-cm enhancing mass in the anterior midregion of the kidney. An open partial nephrectomy was performed, and histopathologic examination established a diagnosis of the hyaline-vascular type of Castleman disease (CD). The patient had an uneventful postoperative course and has experienced no local or metastatic recurrence in the 10 months since surgery. CD localized in the kidney is an exceptionally rare occurrence but should be included in the complete differential diagnosis of solitary renal cortical mass lesions.

Gastrointestinal lymphoproliferative disorders

Malignant lymphomas can be first detected in some patients in endoscopic biopsies of the gastrointestinal (GI) tract. However, their recognition and accurate classification often pose problems for the pathologist for several reasons. First, the small sampling size limits pattern recognition and the number of ancillary studies which can be performed. Second, the immune system of the GI tract is capable of intense hyperplastic responses which may mimic lymphoma. Third, in a fashion similar to cutaneous lesions, those in the alimentary tract may be visualized and biopsied at a very early phase in their development when differentiation into neoplasia may be incomplete. Some forms of immune response actually pass through a poorly defined transition into lymphoma. Examples of such 'dysplasia' of the gut immune system include Helicobacter gastritis, coeliac disease and multicentric lymphoid hyperplasia associated with underlying immunodeficiency. With ever increasing endoscopic scrutiny of the gut by gastroenterologists, it is not surprising that the frequency of these indeterminate cases seems to be growing. In combination with careful clinical correlation and conventional microscopic analysis, selective immunohistochemical studies currently constitute the most powerful ancillary method in the pathologist's effort to recognize and classify GI lymphomas accurately.

Ki67 staining pattern as a diagnostic tool in the evaluation of lymphoproliferative disorders

AIMS

To evaluate a group of lymphoid proliferations using only Ki67-stained slides to determine the value of the pattern of proliferating cells in diagnosis. Ki67 immunohistochemistry allows evaluation of the distribution of proliferating cells in addition to simply determining the proliferation rate of cells.

METHODS AND RESULTS

Three observers, using a Ki67-stained slide only, studied 149 cases from five diagnostic groupings: follicular hyperplasia, mixed pattern hyperplasia, localized Castleman's disease, follicular lymphoma and marginal zone lymphoma. The sensitivity for benign lesions varied from 94% to 97% among the three observers. Follicular lymphomas were recognized as neoplastic with a sensitivity of 96% and 100% by two of the observers. Marginal zone lymphoma was recognized as neoplastic in 67-73% of cases.

CONCLUSIONS

The Ki67 stain alone is a powerful tool for distinguishing benign from malignant proliferations within the selected groups. Nuances and pitfalls in the interpretation of Ki67 staining pattern are discussed.

Brief communication: severe hepatotoxicity of telithromycin: three case reports and literature review

BACKGROUND

Telithromycin is a ketolide antibiotic approved by the U.S. Food and Drug Administration for acute bacterial infections causing sinusitis, bronchitis, and community-acquired pneumonia.

OBJECTIVE

To describe 3 cases of severe hepatotoxicity in patients receiving telithromycin.

DESIGN

Case reports.

SETTING

A tertiary care medical center.

PATIENTS

3 previously healthy patients who had recently taken telithromycin and took no other prescription medications.

MEASUREMENTS

Serologic, histologic, and liver function tests.

RESULTS

Within a few days of receiving telithromycin, the patients presented with acute hepatitis. All had jaundice and markedly abnormal results on liver function tests. Results of viral serologic tests were negative. One patient spontaneously recovered, 1 required orthotopic liver transplantation, and 1 died. Histologic examination in the latter 2 patients showed massive hepatic necrosis.

LIMITATIONS

Two patients had some history of alcohol use. The frequency of severe telithromycin-related hepatotoxicity cannot be established with case reports.

CONCLUSIONS

Telithromycin can cause severe hepatotoxicity. Caution is advised in prescribing this drug pending additional postmarketing surveillance data.

Langerhans Cell Sarcoma

Proliferations of Langerhans cells can be histologically divided into cytologically benign Langerhans cell proliferations, which include the clinical syndromes of Langerhans cell histiocytosis, and cytologically malignant Langerhans cell sarcoma. We report a Langerhans cell sarcoma in a 33-year-old male that arose on the posterior thigh with subsequent regional lymph node involvement. Conventional microscopic, immunohistochemical, and ultrastructural analysis confirmed Langerhans cell differentiation. Aberrant CD31 expression, similar to that described previously in Langerhans cell histiocytosis, was prominent in this tumor, possibly enhancing its migratory capabilities.

Acute panmyelosis with myelofibrosis: an entity distinct from acute megakaryoblastic leukemia

The WHO criteria for diagnosing acute panmyelosis with myelofibrosis are somewhat distinct from those for acute megakaryoblastic leukemia. However, clinical and hematopathologic findings partially overlap. This has raised questions as to whether these are indeed separate, definable entities. To determine the potential importance of bone marrow biopsy supplemented by immunohistochemistry in distinguishing between these two conditions, we studied 17 bone marrow biopsies of well-characterized cases of acute panmyelosis with myelofibrosis (six cases) and acute megakaryoblastic leukemia (11 cases). We compared blast frequency, reticulin content, CD34 expression, and the degree of megakaryocytic differentiation of the blast cells in these two conditions. Our results demonstrate important differences. Acute panmyelosis with myelofibrosis is characterized by a multilineage myeloid proliferation with a less numerous population of blasts than acute megakaryoblastic leukemia (P<0.01). In the former condition, blasts are always positive with CD34, while in acute megakaryoblastic leukemia they express CD34 in 60% of the cases. The blasts in acute panmyelosis with myelofibrosis only rarely express megakaryocytic antigens. By contrast, acute megakaryoblastic leukemia has a significantly higher proportion of blasts expressing megakaryocytic antigens (P<0.01 with CD42b). Our results confirm that histology supplemented by immunohistochemistry permits the distinction of these conditions in routinely processed bone marrow biopsies.

Human herpesvirus-6-associated acute lymphadenitis in immunocompetent adults

In contrast to other causes of herpetic lymphadenitis, the histological features associated with human herpesvirus-6 (HHV-6) infection have remained elusive since its discovery in 1986. We describe the histologic and phenotypic changes associated with acute HHV-6 lymphadenitis in two immunocompetent adults who presented with fever, fatigue, generalized lymphadenopathy, and elevated liver enzymes. Serologic tests for human immunodeficiency virus, acute Epstein-Barr virus, and cytomegalovirus infection were negative. Lymph node biopsies were consistent with viral lymphadenitis. Intranuclear and cytoplasmic inclusions were identified in CD4-positive T lymphocytes in expanded paracortical areas. Immunohistochemical staining with monoclonal antibody to the HHV-6 gp60/110 kDa envelope glycoprotein showed that the inclusions were positive for viral antigen. Electron microscopy demonstrated numerous viral particles in the cytoplasm and nucleus, characteristic of Herpesviridae family. Clustering of viral particles was observed, which has previously been reported only in infected tissue culture cells. PCR followed by sequencing of DNA extracted from the lymph nodes identified the virus as HHV-6, type B. This is the first report that documents distinctive histologic features of HHV-6 lymphadenitis and demonstrates that the cells harboring the virus in vivo are CD4-positive T lymphocytes.

Recommendations for the reporting of lymphoid neoplasms: a report from the Association of Directors of Anatomic and Surgical Pathology

In this report, the Association of Directors of Anatomic and Surgical Pathology (ADASP) provides guidelines for the reporting of lymphoid neoplasms. The World Health Organization Classification of Tumors of the Haematopoietic and Lymphoid Tissues is the preferred international standard for diagnostic criteria (disease definition) and nomenclature. Ancillary studies are often required, and the Association recommends that immunophenotypic and genotypic information be integrated into the final report, to the extent possible.

Clinicopathologic analysis of follicular lymphoma occurring in children

Follicular lymphoma is a rare lymphoid malignancy in pediatric patients and consequently remains poorly characterized, particularly with respect to its immunophenotype and molecular pathogenesis. A total of 23 pediatric patients with follicular lymphoma were identified, with a median age of 11 years and a male-to-female ratio of 2.3:1. Of the 19 patients for whom presenting clinical features were available, 15 patients had stage I, 1 had stage II, and 3 had stage III or IV disease. All tumors had a follicular architecture, and 74% of cases had grade 2 or 3 histologic features. All patients expressed CD20 and bcl-6, and 80% were positive for CD10. Bcl-2 expression was detected in only 5 of 16 cases. Consistent with this finding, bcl-2 gene rearrangements were detected in only 2 of 16 cases by polymerase chain reaction. These patients were treated primarily with cyclophosphamide, doxorubicin, vincristine, and prednisone-based chemotherapy; 4 patients also received involved-field irradiation. Of the 13 patients with available clinical follow-up, all but 2 achieved durable clinical remission. Importantly, all 4 patients with tumors diffusely positive for bcl-2 either presented with stage III/IV disease or had disease refractory to therapy, whereas patients with bcl-2-negative tumors uniformly had stage I disease, achieved complete remission, and experienced no relapses. These findings indicate that, in contrast to adult follicular lymphomas, dysregulated bcl-2 expression does not play a significant pathogenetic role in most pediatric follicular lymphomas. However, bcl-2 expression in pediatric follicular lymphoma identifies a subset of patients in whom disease is often disseminated at clinical presentation and is more refractory to combination chemotherapy.

Primary endometrial T-cell lymphoma. A case report

Primary lymphomas of the female genital tract are rare. Most involve the cervix rather than the uterine corpus. All of those previously reported have been B-cell lymphomas, with the exception of 1 case report of an endometrial T-cell lymphoma in a Japanese woman. We report the case of a white woman from the United States with a diffuse large cell lymphoma of the endometrium, characterized as a peripheral T-cell type on the basis of immunophenotypic and molecular probe studies. Staging evaluation revealed tumor limited to the endometrium (stage IE). The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and lymph node dissection and received 6 cycles of combination chemotherapy, after which she remained free of disease at last follow-up of 36 months. Unusual features of this lymphoma case are discussed, with emphasis on differential diagnosis and speculation on histogenesis. This case illustrates that, while most peripheral T-cell lymphomas are widely disseminated at presentation, those limited to a single extranodal site may have a favorable outcome akin to that associated with high-grade extranodal B-cell lymphomas of early stage.

Epstein-Barr virus-positive primary gastrointestinal Hodgkin's disease: association with inflammatory bowel disease and immunosuppression

Inflammatory bowel disease (IBD) is associated with an increased risk of lymphoma, which is usually extraintestinal but sometimes may involve the diseased bowel itself. Most lymphomas described in this setting are of non-Hodgkin's type, but rare cases of Hodgkin's disease (HD) have been reported. We describe the clinicopathologic and molecular features of four patients with primary gastrointestinal HD. Three patients had preexistent Crohn's disease (CD), for which two of them had received immunosuppressive therapy. The fourth patient had a longstanding history of diverticulitis and myasthenia gravis and was receiving immunosuppressive therapy for the latter. Multifocal involvement of the bowel by HD was noted in all four cases. Disease was staged as IVA in one patient, IIIB in one patient, and IE in one patient, and the fourth patient died in the postoperative period before further workup. Two patients received chemotherapy, one of whom was dead at 9 months, whereas the other has no evidence of disease at 25 months' follow-up. The patient with IE disease did not receive any therapy because only a few microscopic foci of disease were present and is also without any evidence of disease at 17 months. The Reed-Sternberg (RS) cells in all four cases expressed CD30, CD15, EBER-1, and LMP-1; two of four were focally CD20-positive. VJ-polymerase chain reaction for immunoglobulin heavy chain (IgH) rearrangement showed a polyclonal pattern in all four cases. In two cases, laser capture microdissection was used to isolate individual RS and Hodgkin's cells, which contained rearranged immunoglobulin genes, confirming a B-cell genotype. Whereas one case showed a dominant clonal band present in all isolates, cells from the patient with stage IE disease clearly showed a polyclonal population of RS cells. Our findings indicate that HD arising in the setting of IBD or chronic inflammation is the result of an Epstein-Barr virus-driven lymphoproliferation, analogous to that found in other immunodeficient states. Disordered immunoregulation inherent to CD and immunosuppressive therapy for the latter may contribute to its development. The finding of polyclonal RS cells in a patient with early stage disease and apparent cure by surgical resection versus monoclonal RS cells in the patient with disseminated disease suggests that HD in the setting of immunodeficiency also may show molecular progression, in a manner similar to that occurring in conventional B-cell lymphoproliferative disorders arising in the same setting.

New malignant diseases after allogeneic marrow transplantation for childhood acute leukemia

PURPOSE

To determine the incidence of and risk factors for second malignancies after allogeneic bone marrow transplantation (BMT) for childhood leukemia.

PATIENTS AND METHODS

We studied a cohort of 3, 182 children diagnosed with acute leukemia before the age of 17 years who received allogeneic BMT between 1964 and 1992 at 235 centers. Observed second cancers were compared with expected cancers in an age- and sex-matched general population. Risks factors were evaluated using Poisson regression.

RESULTS

Twenty-five solid tumors and 20 posttransplant lymphoproliferative disorders (PTLDs) were observed compared with 1.0 case expected (P <.001). Cumulative risk of solid cancers increased sharply to 11.0% (95% confidence interval, 2.3% to 19.8%) at 15 years and was highest among children at ages younger than 5 years at transplantation. Thyroid and brain cancers (n = 14) accounted for most of the strong age trend; many of these patients received cranial irradiation before BMT. Multivariate analyses showed increased solid tumor risks associated with high-dose total-body irradiation (relative risk [RR] = 3.1) and younger age at transplantation (RR = 3.7), whereas chronic graft-versus-host disease was associated with a decreased risk (RR = 0.2). Risk factors for PTLD included chronic graft-versus-host disease (RR = 6.5), unrelated or HLA-disparate related donor (RR = 7. 5), T-cell-depleted graft (RR = 4.8), and antithymocyte globulin therapy (RR = 3.1).

CONCLUSION

Long-term survivors of BMT for childhood leukemia have an increased risk of solid cancers and PTLDs, related to both transplant therapy and treatment given before BMT. Transplant recipients, especially those given radiation, should be monitored closely for second cancers.

Risk of lymphoproliferative disorders after bone marrow transplantation: a multi-institutional study

We evaluated 18,014 patients who underwent allogeneic bone marrow transplantation (BMT) at 235 centers worldwide to examine the incidence of and risk factors for posttransplant lymphoproliferative disorders (PTLD). PTLD developed in 78 recipients, with 64 cases occurring less than 1 year after transplantation. The cumulative incidence of PTLD was 1.0% +/- 0.3% at 10 years. Incidence was highest 1 to 5 months posttransplant (120 cases/10,000 patients/yr) followed by a steep decline to less than 5/10,000/yr among >/=1-year survivors. In multivariate analyses, risk of early-onset PTLD (<1 year) was strongly associated (P <.0001) with unrelated or human leukocyte antigen (HLA) mismatched related donor (relative risk [RR] = 4.1), T-cell depletion of donor marrow (RR = 12.7), and use of antithymocyte globulin (RR = 6.4) or anti-CD3 monoclonal antibody (RR = 43.2) for prophylaxis or treatment of acute graft-versus-host disease (GVHD). There was a weaker association with the occurrence of acute GVHD grades II to IV (RR = 1.9, P =.02) and with conditioning regimens that included radiation (RR = 2.9, P =.02). Methods of T-cell depletion that selectively targeted T cells or T plus natural killer (NK) cells were associated with markedly higher risks of PTLD than methods that removed both T and B cells, such as the CAMPATH-1 monoclonal antibody or elutriation (P =.009). The only risk factor identified for late-onset PTLD was extensive chronic GVHD (RR = 4.0, P =.01). Rates of PTLD among patients with 2 or >/=3 major risk factors were 8.0% +/- 2.9% and 22% +/- 17.9%, respectively. We conclude that factors associated with altered immunity and T-cell regulatory mechanisms are predictors of both early- and late-onset PTLD.

Microscopic mimicry of lymphomas: diagnostic pitfalls

A common, critical challenge for the pathologist is the distinction between lymphoma and lymphoma simulators. Ancillary studies are effective in making this distinction and should be used in descending order of their likely reliability according to the particular differential diagnostic consideration at hand. Clinical case information is essential to avoid misinterpretation. Lymphoma simulators can be grouped into several major categories: nonlymphoid neoplasms, usually high-grade, simulating high-grade lymphomas; chronic lymphoid hyperplasias simulating low-grade lymphomas; and acute lymphoid hyperplasias simulating high-grade lymphomas.

MALT lymphomas in 1997. Where do we stand?

Steady advances in our scientific understanding of primary extranodal mucosa-associated lymphoid tissue-type lymphomas have been achieved during the past 14 years, leading to their inclusion within the International Lymphoma Study Group (revised European-American classification of lymphoid neoplasms, known as REAL) classification as extranodal B-marginal zone lymphomas. Although most cases conform to prototype criteria, exceptional cases, such as those discussed at the Fourth Slide Workshop of the Society for Hematopathology on Extranodal Hematopoietic/Lymphoid Disorders, September 11-13, 1997, raise issues relating to microscopic, immunophenotypic, and clinical behavioral limits for diagnostic criteria. Furthermore, questions about therapeutic management have only begun to be addressed.

Translocations of 11q13 in mantle cell lymphoma fail to disrupt the S mu bp-2 gene

We recently cloned a gene whose protein product binds to the Epstein-Barr virus BZLF1 gene promoter. The same gene has been previously cloned by another group who named it S mu bp-2 because its protein product binds to the S mu motif of the immunoglobulin heavy chain gene where it is postulated to function in immunoglobulin class switching. In the current study, we confirm that the S mu bp-2 gene is located on chromosome 11q13, a locus known to be altered by translocation in 50-70% of mantle cell lymphomas. We used Southern blot analysis to determine whether the S mu bp-2 gene was structurally rearranged in any of 25 mantle cell lymphomas. We found no evidence of rearrangement in any of these lymphomas including 18 that were proven to contain t(11;14) by cytogenetic analysis. These data suggest that structural alteration of the S mu bp-2 gene is not an underlying mechanism of tumorigenesis in mantle cell lymphomas.

Multiple myeloma with hairy cell-like features

Hairy cell leukemia (HCL) and multiple myeloma (MM) are well-described disease entities with characteristic clinical and pathologic features. We describe two patients initially treated for MM in whom atypical clinical and morphologic features subsequently developed that raised the possibility of HCL. Although the cytologic appearance and immunophenotype were not diagnostic of HCL, these cases challenge the criteria used to diagnose MM, HCL, and other recently described villous neoplasms.

Clinicopathological factors relating malignant lymphoma with Sjögren's syndrome

This study was undertaken to summarize the current status of the clinicopathologic factors related to non-Hodgkin's lymphoma (NHL) development in patients with Sjögren's syndrome (SS). Through a MEDLINE search, pertinent articles on SS, monoclonality, and NHL were found and reviewed. Malignant lymphoma description was based on the International Lymphoma Study Group classification. Patients with SS are known to have an increased risk for developing B-cell NHL (B-NHL). However, such a complication occurs in less than 10% of patients, being reported mainly in those with primary SS. Extranodal low-grade B-NHL are observed most frequently. Persistent enlargement of parotid glands, adenopathy, monoclonal gammopathy, and cross-reactive idiotypes are all signs suggesting possible lymphoma evolution. Although monoclonality does not mean malignancy unequivocally, it is considered to be a precursor for NHL development in SS. Factors implicated into lymphomagenesis in SS include dysregulation in the mechanisms leading to apoptosis, hyperstimulation of B-1 cells, and an infectious agent. Polyclonal lymphoproliferation characterizing SS might in some instances transform into monoclonal, and then to malignancy. Further studies on the mechanism whereby NHL develops in SS are warranted.

Inflammatory pseudotumors of lymph node origin show macrophage- derived spindle cells and lymphocyte-derived cytokine transcripts without evidence of T-cell receptor gene rearrangements. Implications for pathogenesis and classification as an idiopathic retroperitoneal fibrosis-like sclerosing immune reaction

Sclerosing pseudotumorous immune reactions of the retroperitoneum have been shown to consist of HLA-DR-positive spindle-shaped fibroblasts and macrophages that resemble fibroblasts, and in some instances they contain clonal populations of T lymphocytes not found in granulation tissue, keloids, nodular fasciitis, or fibromatoses. In patients who are iatrogenically immunosuppressed, circulating monocytes may be induced in vitro to transform into spindle-shaped macrophages, and secrete collagen after stimulation by conditioning medium from activated T lymphocytes. The authors investigated a series of five inflammatory pseudotumors (IPT) of lymph node origin for identification of spindle-shaped macrophages, T-cell receptor gene rearrangements, and lymphocyte-derived cytokine mRNA production. All cases of IPT demonstrated spindle-shaped macrophages resembling fibroblasts or myofibroblasts characterized by vimentin, CD45 (LCA), CD68 (KP1) or HAM-56, and HLA-DR(LN3) immunoreactivity and demonstrated production of procollagen-alpha1 (I) mRNA by in situ hybridization. Clonal T-cell receptor chain gene rearrangements were undetectable by polymerase chain reaction. Strong specific lymphocyte-derived interleukin-1beta and interleukin-6 mRNA cytokine transcripts were identified. Although all patients with IPT were managed with steroids and nonsteroidal anti-inflammatory medication, some had treatment-refractory disease. Because all-trans retinoic acid has been demonstrated to inhibit the in vitro transformation of monocytes into collagen-producing spindle-shaped macrophages ("neofibroblasts"), it may be of benefit for patients with IPT.

Epstein-Barr virus and lymphoproliferation in methotrexate-treated rheumatoid arthritis

Generalized lymphadenopathy developed in a 60-year-old female receiving methotrexate and prednisone for treatment of rheumatoid arthritis. Histologic examination of an enlarged right axillary lymph node revealed effacement of normal architecture by a polymorphic population of lymphocytes. The recognition that the patient was medically immunosuppressed and the similarity of lymph node histology to that of a polymorphic post-transplantation lymphoid proliferation led to suspicion that the adenopathy might represent an immunosuppression-related lymphoid proliferation. This possibility was supported by regression of the adenopathy on discontinuation of methotrexate, despite continued corticosteroid therapy, which is an outcome reminiscent of the remissions observed with reduction of immunosuppressive therapy in post-transplantation lymphoproliferative disorders. Subsequent ancillary laboratory studies of lymph node tissue included genetic probe analysis, which revealed a monoclonal population of B-lymphocytes containing clonal Epstein-Barr virus DNA. In situ hybridization studies performed on lymph node tissue revealed expression of Epstein-Barr virus-encoded RNA 1 transcripts, and immunohistochemical studies revealed expression of Epstein-Barr virus latent membrane protein 1. These ancillary studies confirmed the similarity to post-transplantation lymphoproliferative disorder. Although immunosuppression-related lymphoproliferative disorders share features with malignant lymphoma, the possibility of resolution in situations in which immunosuppression can be reversed provides a distinction from true malignancy and is of profound importance in therapeutic decision making.

Leukemia following low-dose total body irradiation and chemotherapy for non-Hodgkin's lymphoma

PURPOSE

Low-dose total body irradiation (TBI) is used to treat non-Hodgkin's lymphoma (NHL) and several other malignancies. Large volumes of bone marrow and other tissue receive considerable exposure, but few studies have quantified late carcinogenic sequelae.

PATIENTS AND METHODS

A cohort of 61 2-year survivors of NHL treated initially with low-dose TBI was monitored for second cancer occurrence. Data on primary and subsequent therapy were collected, and cumulative dose of radiation to active bone marrow (ABM) (median, 5.2 Gy) was reconstructed.

RESULTS

Thirteen second primary cancers occurred. Four patients developed acute nonlymphocytic leukemia (ANLL), which represents a relative risk (RR) of 117 (95% confidence interval [CI], 31.5 to 300) compared with population rates. A fifth patient was diagnosed with myelodysplastic syndrome (MDS). All five patients with secondary hematologic malignancies subsequently received salvage treatment, with either alkylating agents alone (n = 1) or combined modality therapy (CMT) (n = 4). Overall, eight solid tumors were observed (RR = 2.0; 95% CI, 0.9 to 4.0). The 15-year cumulative risks of all second cancers and secondary ANLL were 37% and 17%, respectively.

CONCLUSIONS

Despite the small number of subjects, a considerable risk of leukemia was observed among patients treated with low-dose TBI in combination with CMT including alkylating agents. Based on these results, approximately eight to nine excess ANLLs might be expected to occur among 100 NHL patients treated with low-dose TBI and salvage treatment and followed-up for 15 years.

Epstein-Barr virus is detected in undifferentiated nasopharyngeal carcinoma but not in lymphoepithelioma-like carcinoma of the urinary bladder

The Epstein-Barr virus (EBV) is associated with nasopharyngeal carcinoma (NPC) and with lymphoepithelioma-like carcinomas developing in certain anatomic sites. In this study, an in situ hybridization was used to identify EBV-encoded ribonucleic acid (RNA) (EBER1) transcripts in 32 of 45 cases of NPC but not in any of the 11 lymphoepithelioma-like carcinomas developing in the urinary bladder. EBER1 was most commonly detected in those NPCs having undifferentiated or nonkeratinizing squamous histology rather than the keratinizing squamous cell subtype of NPC. The EBV-encoded latent membrane protein 1 (LMP1) was expressed focally in only seven of 21 EBER1-positive NPCs by an immunohistochemical technique. These findings imply that EBER1 hybridization is more sensitive than LMP1 immunohistochemistry on paraffin sections in detecting carcinoma-associated virus. Previous in vitro studies have suggested that LMP1 expression might be a function of differentiation, but this study of naturally infected NPCs showed no strong correlation between LMP1 positivity and degree of tumor differentiation, albeit a limited spectrum of differentiation that could be examined. In two cases in which frozen tissue was available, the NPCs were monoclonal with respect to viral DNA structure, implying that the virus was present before malignant transformation. Unlike NPCs, the lymphoepithelioma-like carcinomas of the bladder were uniformly EBV negative, lending further evidence to the growing body of literature linking EBV with lymphoepithelial carcinomas of foregut-derived tissues but not with similar-appearing tumors developing in other anatomic sites.