Hyperplastic Germinal Centers Research Articles

Immunoglobulin G4-related lymphadenopathy with inflammatory pseudotumor-like features

Immunoglobulin (Ig) G4-related disease has been recently described. This disease affects various organs, including lymph nodes. We describe the case of a 52-year-old Japanese man with IgG4-related lymphadenopathy with inflammatory pseudotumor (IPT)-like features. Five years ago, the patient noticed a painless mass in the mandible but did not consult a doctor. Recently, he noted that the mass had increased in size and consulted an oral surgeon in the hospital. Excisional biopsy was performed for diagnosis. Histopathological examination revealed that most of the enlarged lymph node was occupied by the hyalinized tissue. A few residual lymphoid follicles with hyperplastic germinal centers and infiltration of plasma cells and eosinophils were observed. Most of the plasma cells expressed IgG4, and the ratio of IgG4-positive cells to IgG-positive cells was 57.1%. These findings were consistent with IgG4-related lymphadenopathy. In conclusion, pathologists should consider IgG4-related lymphadenopathy when diagnosing a lesion with IPT-like features.

Infectious mononucleosis lymphoadenitis showing histologic findings indistinguishable from toxoplasma lymphadenitis. A report of three cases

Lymph node lesions in infectious mononucleosis (IM) show a marked histologic diversity. We report here three cases of IM lymphadenitis with histologic findings indistinguishable from those of toxoplasmic lymphadenitis. The histologic findings of the three cases presented here showed a histologic triad of toxoplasmic lymphadenitis, including (i) numerous lymphoid follicles with hyperplastic germinal centers; (ii) small clusters or single epithelioid histiocytes; and (iii) multiple foci of monocytoid B-cells. Moreover, all three lesions contained isolated or small clusters of epithelioid histiocytes within the hyperplastic germinal centers and the periphery of lymphoid follicles, which are the most specific histologic findings of toxoplasmic lymphadenitis. However, serologic findings confirmed EBV infection in all three cases. On in situ hybridization, numerous Epstein-Barr virus (EBV)-encoded small RNA (EBER)-positive cells were demonstrated in the germinal center, as well as in interfolicular areas in all three cases. Toxoplasmosis gondii infection was excluded in at least one case, based on serologic findings. Polymerase chain reaction analysis also demonstrated that there was no T. gondii DNA in the remaining two cases. Two of our three cases showed atypical clinical presentations, including an absence of atypical lymphocytosis in peripheral blood in two cases, age more than 30 years, and an absence of systemic symptoms in one case. It appears that previous descriptions emphasize the differential diagnostic problems between IM lymphadenitis and malignant lymphomas. However, from a therapeutic perspective, it is important to discriminate IM lymphadenitis from toxoplasmic lymphadenitis particularly in patients showing atypical clinical features.

Angioimmunoblastic T-cell lymphoma with hyperplastic germinal centres: a neoplasia with origin in the outer zone of the germinal centre? Clinicopathological and immunohistochemical study of 10 cases with follicular T-cell markers

Angioimmunoblastic T-cell lymphoma with hyperplastic germinal centres: a neoplasia with origin in the outer zone of the germinal centre? Clinicopathological and immunohistochemical study of 10 cases with follicular T-cell markers

Atypical Lymphoplasmacytic and Immunoblastic Proliferation of Autoimmune Disease : Clinicopathologic and Immunohistochemical Study of 9 Cases

Atypical lymphoplasmacytic immunoblastic proliferation (ALPIB) is a rare lymphoproliferative disorder (LPD) associated with autoimmune disease (AID). To further clarify the clinicopathologic, immunohistological, and genotypic findings of ALPIB in lymph nodes associated with well-documented AIDs, 9 cases are presented. These 9 patients consisted of 4 patients with systemic lupus erythematosus, 3 patients with rheumatoid arthritis, and one case each with Sjögren's syndrome and dermatomyositis. All 9 patients were females aged from 25 to 71 years with a median age of 49 years. Four cases presented with lymphadenopathy as the initial manifestation. In 4 patients, immunosuppressive drugs were administered before the onset of lymph node lesion. However, none of the 9 patients received methotrexate therapy. The present 9 cases were characterized by : (i) prominent lymphoplasmacytic and B-immunoblastic infiltration ; (ii) absence of pronounced arborizing vascular proliferation ; (iii) absence of CD10(+) "clear cells" ; (iv) presence of hyperplastic germinal center in 7 cases ; (v) immunohistochemistry, flow cytometry, and polymerase chain reaction demonstrated a reactive nature of the T- and B-lymphocytes ; and (vi) on in situ hybridization, there were no Epstein-Barr virus -infected lymphoid cells in any of the 9 cases. Overall 5-year survival of our patients was 83%. The combination of clinical, immunophenotypic, and genotypic findings indicated that the present 9 cases can be regarded as having an essentially benign reactive process. Finally, we emphasized that ALPIB should be added to the differential diagnostic problems of atypical LPDs, particularly lymph node lesions of IgG4-related diseases.

Angioimmunoblastic T-cell lymphoma with hyperplastic germinal centres: a neoplasia with origin in the outer zone of the germinal centre? Clinicopathological and immunohistochemical study of 10 cases with follicular T-cell markers

Angioimmunoblastic T-cell lymphoma is an aggressive peripheral T-cell lymphoma whose natural history is not fully understood. Up to 17% of cases can present histologically with hyperplastic germinal centres (pattern I). The accurate recognition of Angioimmunoblastic T-cell lymphoma with pattern I remains a challenge and therefore the aim of this study is to phenotypically and morphologically characterize this variant with the use of the follicular helper T-cell (TFH) markers PD1, CXCL-13 and ICOS. Out of the 88 Angioimmunoblastic T-cell lymphoma cases reviewed, 10 showed hyperplastic follicles. Molecular probe methods for the detection of T-cell and B-cell clonality, as well as in-situ hybridization probes for EBV RNA expression, were carried out to leave no question as to the establishment of the diagnosis in each case. Of the 10 cases, all (100%) showed strong positive PD1 staining in perifollicular areas and in neoplastic cells surrounding small veins. CXCL13 and ICOS showed a similar staining pattern. By contrast, CD10 was found to only weakly label the neoplastic T cells, with only 5–10% of the target cell population staining for this marker. EBV was found in 9/10 cases. Clinically, 8/9 cases presented with stage IIIB/IVB and in 2/10 cases consecutive biopsies showed ‘progression’ from pattern I to classical Angioimmunoblastic T-cell lymphoma. In conclusion we have shown that the TFH cells markers PD1, CXCL13 and ICOS are useful adjuncts in the diagnosis of Angioimmunoblastic T-cell lymphoma with hyperplastic germinal centres. PD1 also highlighted the presence of neoplastic cells in the outer zone of lymphoid follicles, suggesting that Angioimmunoblastic T-cell lymphoma (pattern I) may originate from TFH cells in this region, in accordance with previous immunological studies. As the majority of cases in our series presented clinically with advanced stage disease, progression from pattern I to classical Angioimmunoblastic T-cell lymphoma may represent histological evolution rather than clinical progression.

Reactive lymphadenopathy in Ugandan patients and its relationship to EBV and HIV infection

In Uganda, a large number of biopsied enlarged lymph nodes is diagnosed as reactive lymphoid hyperplasia (RLH) not indicative of a specific etiologic agent. The aim of this study was to examine the spectrum of RLH in lymph node biopsies in Ugandan patients and their possible association with HIV and EBV infection. Ninety biopsies were retrieved and included in the study. The predominant RLH type was follicular, found in 45 (50.0%) of the cases. Positive staining for LMP-1 was found in six cases (6.7%), EBNA-1 in 36 cases (40.0%) and HIV1-p24 in 15 cases (16.7%), respectively. A combination of EBV and HIV positivity was found in 46 (52.2%) of the cases. EBV infection was associated with hyperplastic germinal centers (p<0.01). HIV1-p24 positive staining was associated with follicle fragmentation (p<0.01) but not hyperplastic GC (p=0.08). In conclusion, RLH in Ugandan patients is frequently associated with EBV and HIV infection. The histologic features of the lymph nodes are not specific for any individual infection, but a high number of EBV-positive cases are associated with hyperplastic GC, and follicular fragmentation is characteristic of HIV infection.

B-Cell Cutaneous Lymphoid Hyperplasia Representing Progressive Transformation of Germinal Center: A Report of 2 Cases

Cutaneous lymphoid hyperplasia (CLH) is a reactive polyclonal benign lymphoproliferative process predominantly composed of B cells or T cells, either localized or disseminated. The authors report histomorphologic, immunophenotypic, and genotypic findings of 2 cases of B-cell CLH demonstrating progressive transformation of germinal center (PTGC). Histologically, most of the lymphoid follicles were PTGCs with a few hyperplastic germinal centers. PTGC was characterized by enlarged but well-circumscribed follicles without clear demarcation of the germinal center and mantle zone, which contained a predominance of small lymphocytes and variable numbers of centrocytes, centroblasts, and immunoblasts. However, there were no centroblasts and immunoblasts resembling lymphocytic and/or histiocytic Reed-Sternberg cell variants in nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) in either lesion. These unusual CLHs should be differentiated from the primary cutaneous marginal zone B-cell lymphoma, primary cutaneous follicular lymphoma, particularly "floral variant," or NLPHL. To avoid overdiagnosis and overtreatment, immunophenotypic and genotypic studies are required along with careful morphologic examination.

血管免疫芽球性T細胞リンパ腫(AILT)の臨床病理学的検討

We retrospectively analyzed the clinical course and prognosis of 11 patients with angioimmunoblastic T-cell Lymphoma (AILT). Median patient age was 62 years old (range 39 to 85). All patients were in clinical stage III or IV. Clinical features included B symptoms, hepatosplenomegaly, skin rushes, pleural effusion, ascites and polyclonal hypergammaglobulinemia. The disease can be classified into three categories based on histological findings: 3 cases of AILT with hyperplastic germinal centers, 4 cases of typical AILT, and 4 cases of AILT with numerous clear cells. As the initial therapy, 10 patients received combination chemotherapy and only 1 patient received autologous peripheral blood stem cell transplantation. Seven patients achieved CR and 4 showed PD. The response rate was 63% and the median survival time was 20 months. One patient survived in CR for 122 months. Patients with AILT demonstrating hyperplastic germinal centers and no bone marrow infiltration were able to achieve long-term survival. The survival time of AILT demonstrated a wide range. It was thought that further consideration of the prognostic factors and stratification was required.

Tonsillar Lesions of Infectious Mononucleosis Resembling MALT Type Lymphoma. A Report of Two Cases

Infectious mononucleosis (IM) is an acute lymphoproliferative disorder that typically occurs in young patients and is usually caused by Epstein-Barr virus. We report here, two cases of tonsillar lesion of IM resembling marginal zone B-cell lymphoma mucosa-associated lymphoid tissue (MALT) type. The patients consisted of an 18-year-old Japanese woman and a 36-year-old Japanese man. Both patients presented with tonsillar mass. Histologically, in one case, the tonsil showed diffuse proliferation of medium-sized lymphocytes. The medium-sized lymphocytes had round or slightly indented nuclei with a small solitary nucleoli and abundant clear cytoplasm and somewhat resembled monocytoid B-cells. In the remaining one case, the lymphoid follicles had hyperplastic germinal centers with ill-defined borders surrounded by a sheet-like proliferation of polymorphous infiltration showing a marginal zone distribution pattern. On high-power field, the interfollicular area was diffusely infiltrated by a polymorphous infiltrate of medium-sized lymphocytes with angulated nuclei somewhat resembling centrocyte-like cells, immunoblasts, plasma cells, plasmacytoid cells and histiocytes with or without epithelioid cell feature. However, there were no CD43+ B-cells in either lesion. Moreover, the polytypic nature of the B-cells was demonstrated by immunohistochemistry or polymerase chain reaction. Although MALT type lymphoma rarely affected young adults, notably, a number of cases have been reported in the tonsil. The present two cases indicated that acute IM should be added to the differential diagnosis for MALT type lymphoma in young adults.

Clinical, biologic, and pathologic features in 157 patients with angioimmunoblastic T-cell lymphoma treated within the Groupe d'Etude des Lymphomes de l'Adulte (GELA) trials

AbstractTo evaluate the prognostic significance of clinicobiologic and pathological features in angioimmunoblastic T-cell lymphoma (AITL), 157 AITL patients were retrieved from the GELA LNH87-LNH93 randomized clinical trials. One hundred forty-seven patients received a cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)–like regimen with intensified courses in half of them. Histologically, 41 cases were classified as “rich in large cells” and 116 as “classic” (including 19 rich in epithelioid cells, 14 rich in clear cells, and 4 with hyperplastic germinal centers). Sixty-two cases were scored for CD10 and CXCL13 expression according to the abundance of positive lymphoid cells. Median age was 62 years, with 81% advanced stage, 72% B symptoms, 65% anemia, 50% hypergammaglobulinemia, and 66% elevated LDH. Overall 7-year survival was 30%. In multivariate analysis, only male sex (P = .004), mediastinal lymphadenopathy (P = .041), and anemia (P = .042) adversely affected overall survival. Increase in large cells and high level of CD10 and CXCL13 did not affect survival. Intensive regimen did not improve survival. In conclusion, AITL is a morphologically heterogeneous T-cell lymphoma commonly expressing CXCL13 and CD10 and carrying few prognostic factors. It portends a poor prognosis even when treated intensively. However, AITL is not always lethal with 30% of patients alive at 7 years.

Pitfalls of Diagnosis Based on Abnormal Flow Cytometry and [18F]Fluorodeoxyglucose Positron Emission Tomography

A 30-year-old, HIV-positive man with a previous history of an atypical nasopharyngeal Burkitt lymphoma developed fluorodeoxyglucose (FDG) avidity on a routine FDG—positron emission tomography (PET)/computed tomography scan performed 10 months after the completion of all treatment. This new FDG-avid disease was in the area of his initial disease. Flow cytometric assessment of a fine needle aspiration showed a CD10-expressing B-cell population with κ predominance. The corresponding cytology smears had large atypical lymphoid cells along with smaller lymphocytes and macrophages. Because of the patient's previous history of a CD10+, high-grade B-cell lymphoma, the cytologic and flow cytometric findings were considered highly suspicious for a B-cell lymphoma. Because the differential diagnosis included a relapsed Burkitt lymphoma versus a second, unrelated lymphoma (the former with a dismal prognosis) it was deemed prudent to obtain more tissue via an open biopsy for confirmation of diagnosis and exact subclassification. An open biopsy, however, revealed a reactive lymph node with enlarged geographic follicles; no lymphoma was demonstrable and c-Myc studies were negative. The patient remains without evidence of disease. Retrospectively, the original flow cytometric assessment was believed to likely represent sampling of hyperplastic germinal centers with significantly expanded CD10+ B cells. The FDG uptake and the κ predominance further confounded the interpretation. This case illustrates the pitfalls of standard diagnostic techniques, including PET scanning, cytology, and flow cytometry, particularly in the setting of HIV. It further underscores the importance of adequate clinical correlation and a low threshold for performing open biopsies in such patients.

Angioimmunoblastic T-Cell Lymphoma: A Clinicopathologic Study of 158 Patients Treated in GELA (Groupe d' Etude des Lymphomes de l' Adulte) Trials.

Background: Angioimmunoblastic T-cell lymphoma (AITL), the second most frequent peripheral T-cell lymphoma, is characterized by a distinct clinical presentation and a spectrum of biological and morphologic features with little available data on prognostic factors in the literature.Objective: to evaluate the prognostic significance of clinical, biological and pathological features in AITL.Methods: between 1987 and 1998, 158 AITL patients were retrieved from the GELA LNH87 and LNH93 trials. Most patients received an anthracycline based polychemotherapy. Histologically, cases were reviewed by a panel of expert hematopathologists. For each case, at least 2 hematoxylin eosin slides were available for review together with an appropriate immunohistochemical staining including CD3, CD20 and CD21/CNA42. Cases were classified as “transformed” (>10% large B and/or T cells) and “classic” (including cases rich in clear cells, rich in epithelioid cells and with hyperplastic germinal centers). 62 cases were evaluated for CD10 and CXCL13 expression and scored according to the number of positive lymphoid cells.Results: there was a slight male predominance (M/F=1.53). Median age was 62 years. 81%, 50%, 67% and 39% of patients had respectively an advanced stage, a non ambulatory PS, an IPI>2 and a PIT>2 (age>60y, PS>=2, LDH>=normal and bone marrow involvement). Anemia, positive coombs test and bone marrow involvement were observed in 65%, 33% and 47% of cases respectively. Hypergammaglobulinemia, elevated LDH levels and skin rash were observed in 15%, 66% and 44% of patients respectively. 41 cases were classified as transformed and 117 as classic including 20 epithelioid-cell rich, 14 clear-cell rich and 4 with hyperplastic germinal centers. CD10 and CXCL13 were clearly positive, in a fraction of the lymphoid infiltrate, in 71% and 73% of cases respectively. CR/CRu remission was observed in 46% of patients after induction therapy. With a median follow-up of 69 months, the 5y overall survival rate was 33%, reaching a plateau level around 6 years. Concerning PIT, patients with 0–1 factors and 3–4 factors had a 5y OS of 37% and 38% respectively. In univariate analysis, absence of CR/CRu (p<0.0001), hepatomegaly (p=0.0004), male gender (p=0.004), and anemia (p=0.05) were poor prognostic indicators for overall survival. Classic and transformed AITL were not different regarding clinical presentation, biological findings, and outcome except for a higher frequency of elevated serum LDH (p=0.0266) and b2 microglobulin levels (p=0.0456) within the transformed group. IPI and PIT were not predictive of survival.Conclusion: despite of various intensive regimens with an anthracycline based chemotherapy, AITL pursues an aggressive clinical course and carries a poor prognosis. Our large series emphasizes the morphologic heterogeneity of AITL, without any clinical impact, and further confirms the common expression of CD10 and CXCL13.

Florid monocytoid B-cell hyperplasia resembling nodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue type. A histological and immunohistochemical study of four cases

A pale ring of medium-to-large cells surrounding the follicles, namely a marginal zone distribution pattern, is the key criterion for diagnosing nodal marginal zone B-cell lymphoma (NMZBL). The tumor cells of NMZBL occasionally exhibit the morphology of monocytoid B-cells (MBC). However, this condition can be difficult to distinguish from MBC hyperplasia in reactive conditions. We describe the histopathological and immunohistochemical findings of four cases exhibiting florid MBC hyperplasia and resembling NMZBLs. The patients consisted of three males and one female (age range 48–64 years) who had asymptomatic lymphadenopathy in the head and neck area. Histologically, a pale ring surrounding more than 75% of the lymphoid follicles characterizes the lesion. The lymphoid follicles usually had hyperplastic germinal centers, and progressive transformation of germinal center was noted in two cases. The pale ring was composed of medium-to-large cells with indented or round nuclei and relatively abundant pale clear cytoplasm. Numerous plasma cells were observed in one case. The overall histomorphological findings in these four cases were similar to those of NMZBLs. However, immunohistochemical investigations demonstrated that MBCs were CD43− and bcl-2−. Moreover, immunohistochemistry, polymerase chain reaction, and flow cytometry studies demonstrated the polytypic nature of B-lymphocytes. Recognition of this unusual MBC hyperplasia in reactive lymph node lesions is important to avoid confusion with NMZBLs.

Renal Involvement in Multicentric Castleman Disease With Glomeruloid Hemangioma of Skin and Plasmacytoma

A 47-year-old man presented with fever of unknown origin, generalized weakness, edema, and renal failure. He had left-sided pleural effusion, generalized lymphadenopathy, multiple nontender cutaneous nodules, hepatomegaly, renal failure, and hypergammaglobulinemia. Axillary lymph node biopsy showed findings consistent with Castleman disease of the hyaline vascular type associated with interfollicular plasmacytosis. A renal biopsy performed in view of proteinuria and acute renal failure showed hypercellular glomeruli with capillary loop thickening and double contours consistent with membranoproliferative glomerulonephritis. Skin nodule biopsy showed a glomeruloid hemangioma characterized by dermal proliferation of capillary loops in a nodular manner resembling a glomerulus. He experienced clinical and biochemical remission with steroids. Discontinuation of steroid therapy was associated with recurrence of renal failure, reappearance of nodules, lymphadenopathy, and appearance of bony lytic lesions. Biopsy of bony lytic lesions showed plasmacytoma. The patient achieved complete remission on treatment with steroids and cyclophosphamide and is free of symptoms at the end of 40 months of follow-up. To our knowledge, this is the first case report of the occurrence of membranoproliferative glomerulonephritis, glomeruloid hemangioma of the skin, and plasmacytoma in a patient with multicentric Castleman disease without human immunodeficiency virus infection.

Histological varieties of Epstein–Barr virus-related lymph node lesion resembling autoimmune disease-like clinicopathological findings in middle-aged and elderly patients: A study of six cases

Six cases were studied to further clarify clinicopathological findings of Epstein–Barr virus (EBV)-related lymph node lesions showing autoimmune disease-like clinicopathological findings (EBVAID) in middle-aged and elderly patients. The patients, four males and two females, ranged in age from 53 to 74 years, with a median age of 62 years. Clinically, they were characterized by systemic lymphadenopathy, “B”symptoms, polyclonal hypergammaglobulinemia, elevated serum lactate dehydrogenese and a transient presence of various autoantibodies, as well as an infrequent presence of atypical lymphocytosis in peripheral blood. Two cases were associated with idiopathic thrombocytopenic purpura. The clinical course was self-limiting. Histologically, three patterns could be delineated: pattern A, follicular hyperplasia with pronounced arborizing vasculature in the expanded paracortex ( n=3); pattern B, follicular hyperplasia with pronounced interfollicular B-immunoblastic/plasma cell proliferation ( n=2); and pattern C, paracortical hyperplasia containing numerous large transformed lymphocytes ( n=1). In situ hybridization demonstrated a varying number of EBV-infected lymphocytes in the germinal center and in the interfollicular area. Polymerase chain reaction analysis demonstrated that neither clonal rearrangement of T-cell receptor gamma-chain nor immunoglobulin heavy-chain rearrangement was detected in the three cases examined. Although EBVAID appears to be rare in middle-aged and older adults, EBVAID exhibits histological variations and should be added to the differential diagnosis of various atypical or malignant lymphoproliferative disorders, in particular autoimmune-disease-associated lymphadenopathy and angioimmunoblastic T-cell lymphoma with a hyperplastic germinal center in middle-aged and elderly patients.

Pictorial Essay: Multinodular Disease

The evaluation of patients presenting with multinodular pulmonary disease provides an important clinical challenge for physicians. The differential diagnosis includes an extensive list of benign and malignant processes making the management of these cases frequently problematic. With the introduction of high-resolution CT (HRCT) scanning, the ability to assess various patterns of diffuse multinodular disease has evolved into an essential part of the diagnostic process. The purpose of this article is to develop an approach to the diagnosis of multinodular parenchymal disease using HRCT scan pattern recognition as a point of departure.

Localized lymphoid hyperplasia of the rectum resembling polypoid mucosa-associated lymphoid tissue lymphoma: A report of three cases

Histologically, benign lymphoid hyperplasia of the rectum is usually characterized by large lymphoid follicles with active germinal centers and by a narrow surrounding mantle zone and marginal zone (MZ). We report here three cases of benign lymphoid hyperplasia of the rectum associated with prominent marginal zone hyperplasia, which caused serious difficulty in the differential diagnosis from the polypoid type of mucosa-associated lymphoid tissue (MALT) lymphoma. Colonoscopy demonstrated small sessile polyps in all three cases. Histologically, the lesions were characterized by a hyperplastic germinal center and expanded MZs. The expanded MZs contained numerous monocytoid B-cells (MBC) and scattered large transformed B-cells. Initially, combined colonoscopic and histological findings strongly supported a diagnosis of polypoid MALT-type lymphoma of the rectum. However, there were neither colonized lymphoid follicles nor lymphoepithelial lesions in any of the three lesions. MBCs and large transformed B-lymphocytes were CD43- and bcl-2-. Moreover, immunohistochemical and genotypic studies proved the polytypic nature of the B-lymphocytes in all three lesions. The present cases indicated that benign lymphoid hyperplasia of the rectum should be included in the differential diagnosis for polypoid MALT-type lymphoma of the rectum.

Idiopathic multicentric Castleman's disease. A clinicopathologic and immunohistochemical study of five cases

Several lymphoproliferative disorders may be interpreted as multicentric Castleman's disease (MCD) clinicopathologically. These include HIV infection, autoimmune-disease-associated lymphadenopathy, idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia, “idiopathic MCD”, POEMS syndrome (polyneuropathy, anasarca, organomegaly, endocrinopathy, M-proteins, and skin lesions), and non-Hodgkin's lymphomas. Among these, idiopathic MCD appears to be relatively rare. We report on the clinicopathologic and immunohistologic findings of five cases of idiopathic MCD and discuss the problems regarding their differential diagnosis. Some of the characteristic clinical findings of POEMS syndrome, including hepatosplenomegaly, skin change, endocrine abnormalities and anasarca, were present in all five cases. However, during the course of disease, minimal diagnostic criteria for POEMS syndrome, i.e., monoclonal plasma cell proliferation and sensory motor neuropathys, were absent in all five cases. The serum interleukin-6 level and the vascular endothelial growth factor level were found to be elevated in two of the cases examined. Various autoantibodies were detected in three cases. However, none of them fulfilled the diagnostic criteria for any of the definite autoimmune-disease. Histologically, three lesions exhibited a mixed type of Castleman's disease, and two exhibited the hyaline-vascular type. The majority of the germinal centers were of the hyaline-vascular or epithelioid germinal type, with a few hyperplastic germinal centers. The interfollicular area was characterized by prominent vascularity. Moderate to large sheets of plasma cells were observed in three mixed type cases. The polytypic nature of B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. Immunohistochemical study demonstrated that the majority of germinal centers exhibited a tight/concentric pattern of FDC network. Few CD57-positive T-cells were observed in the hyaline-vascular and epithelioid follicles. The lack of CD57-positive T-cells appears to be related to the formation of abnormal germinal centers in the MCD.

Progressive transformation of germinal center presenting with histological features of hyaline‐vascular type of Castleman's disease

We report three cases showing progressive transformation of the germinal center (PTGC) with histological features reminiscent of the hyaline-vascular (HV) variant of Castleman's disease (CD). Each case contained a few small HV germinal centers as well as PTGC and hyperplastic germinal centers with or without follicular lysis. Moreover, some of the PTGC were penetrated by hyalinized small vessels. Our three cases also showed some of the characteristic histological findings of HV type of CD: (i) reactive lymphoid follicles with small hyaline-vascular germinal centers surrounded by small lymphocytes in a concentrated fashion; (ii) a few small foci of plasmacytoid monocytes; (iii) perivascular fibrosis; (iv) interfollicular vascularity; (v) tight/concentric pattern of the follicular dendritic cell network; and (vi) absence of CD57+ T-cells in the HV follicles. The PTGC with coexistent HV type of CD may represent a certain form of reactive follicular hyperplasia. The possibility of PTGC should be considered and excluded before diagnosing CD.

Angioimmunoblastic T‐cell lymphoma with hyperplastic germinal centres and a high content of EBV‐infected large B‐cells carrying IgH chain gene monoclonal rearrangement

HistopathologyVolume 46, Issue 4 p. 464-466 Angioimmunoblastic T-cell lymphoma with hyperplastic germinal centres and a high content of EBV-infected large B-cells carrying IgH chain gene monoclonal rearrangement F Luzzatto, F Luzzatto The first two authors equally contributed to the study.Search for more papers by this authorG Pruneri, G Pruneri The first two authors equally contributed to the study.Search for more papers by this authorE Benini, E Benini Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorM Manzotti, M Manzotti Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorD Laszlo, D Laszlo Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorG Martinelli, G Martinelli Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorG Viale, G Viale Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this author F Luzzatto, F Luzzatto The first two authors equally contributed to the study.Search for more papers by this authorG Pruneri, G Pruneri The first two authors equally contributed to the study.Search for more papers by this authorE Benini, E Benini Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorM Manzotti, M Manzotti Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorD Laszlo, D Laszlo Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorG Martinelli, G Martinelli Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this authorG Viale, G Viale Divisions of Pathology and Laboratory Medicine, and Hemato-Oncology, European Institute of Oncology and University of Milan School of Medicine, Milan, ItalySearch for more papers by this author First published: 23 March 2005 https://doi.org/10.1111/j.1365-2559.2004.01997.xCitations: 6Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume46, Issue4April 2005Pages 464-466 RelatedInformation