Fluorescence immunophenotypic and interphase cytogenetic characterization of nodal lymphoplasmacytic lymphoma

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

Is lymphoplasmacytic lymphoma/immunocytoma a distinct entity? A clinicopathologic study of 20 cases

Lymphoplasmacytic lymphoma/immunocytoma (LLI) was defined initially as a small B-cell lymphoma with plasmacytoid or plasmacytic features. Because other types of small B-cell lymphoma, particularly marginal zone B-cell lymphoma may exhibit plasmacytic differentiation, the revised European-American lymphoma classification and World Health Organization has defined LLI more narrowly to exclude other small B-cell lymphomas. The goal of this study was to reevaluate LLI as a clinicopathologic entity. Twenty cases were selected from 43 previously diagnosed as "small lymphocytic lymphoma, plasmacytoid" or "immunocytoma" from 1985 to 1998. Cases fulfilling the criteria for B-cell small lymphocytic lymphoma, follicular lymphoma, marginal zone B-cell lymphoma, or other types of B-cell lymphoma were excluded. The histopathology and immunoreactivity for CD20, CD79a, CD3, CD43, CD23, CD5, kappa, lambda, and immunoglobulins (Ig's) M, G, and A were reviewed, in addition to available clinical findings. There were 13 men and seven women, with a mean age of 69 years. Five patients had documented Waldenstr?m's macroglobulinemia (WM). Three architectural patterns were observed. Pattern A (seven of 20) showed open sinuses, small follicles, and hemosiderosis; pattern B (four of 20) showed hyperplastic follicles; and pattern C (nine of 20) showed diffuse effacement. Epithelioid histiocytes were prominent in patterns B and C but absent in A. Cytologically, six of 20 were polymorphous with 10% to 40% transformed cells; 14 of 20 were lymphoplasmacytic. Five cases showed minor foci of monocytoid B cells. One case showed a composite histology of LLI and small lymphocytic lymphoma. Amyloid was present in two cases. All cases were CD20 and/or CD79a immunoreactive, with two of 20 positive for CD43. Twelve cases were kappa monoclonal and eight cases were lambda monoclonal. Twelve of 17 cases that could be evaluated were positive for IgM and five were positive for IgG. All cases were negative for CD5 and CD23 with the exception of the one case with a composite histology. Eleven of 20 patients with available follow-up died of disease (median, 48 months), and eight of 20 are alive with disease at a follow-up of 6 months to 2 years. LLI does appear to represent a distinct clinicopathologic entity even though it shows morphologic heterogeneity and overlapping features with marginal zone B-cell lymphoma and small lymphocytic lymphoma. Recognition of LLI is important because the overall prognosis may be worse than for other types of small B-cell lymphomas.     

Lymphoma of the ocular adnexa: A study of 353 cases

We studied the cases of 353 patients with lymphoma involving the ocular adnexa diagnosed at the Massachusetts General Hospital between 1974 and 2005. The patients included 153 males and 200 females, aged 7 to 95 years, with a mean age of 64 years. In 277 cases, there was no known history of lymphoma. Seventy-six patients had a history of lymphoma, with the ocular adnexa being involved at relapse or with progression of the previously diagnosed lymphoma. The patients had marginal zone lymphoma (182 cases), follicular lymphoma (80 cases), mantle cell lymphoma (18 cases), small lymphocytic lymphoma/chronic lymphocytic leukemia (13 cases), lymphoplasmacytic lymphoma (4 cases), splenic marginal zone lymphoma (2 cases), low-grade B cell, not subclassified (19 cases), precursor B lymphoblastic lymphoma (3 cases), diffuse large B-cell lymphoma (26 cases), and 1 case each of high-grade B-cell lymphoma, not subclassified, peripheral T-cell lymphoma, unspecified type, extranodal NK/T-cell lymphoma, nasal type, and Hodgkin lymphoma, nodular sclerosis type. Almost all marginal zone lymphoma patients (168 of 182, 92%) had primary ocular adnexal lymphoma. Fourteen marginal zone lymphoma patients (8%) had a prior history of lymphoma, usually arising in another extranodal site. Twenty-five of 80 (31%) follicular lymphoma patients had a prior history of lymphoma, usually arising in lymph nodes. Patients with mantle cell lymphoma, chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, and splenic marginal zone lymphoma almost always had a prior history of lymphoma or were known to have widespread disease at the time of diagnosis of ocular adnexal lymphoma. A subset of the diffuse large B-cell lymphomas were associated with large destructive masses involving adjacent structures such as paranasal sinuses, raising the possibility that they may have arisen from one of the adjacent structures and involved the ocular adnexa by direct extension. The relatively high proportion of low-grade lymphoma, not subclassified, highlights the difficulty that may arise in distinguishing different types of low-grade lymphoma, particularly when biopsies are small and artifactually distorted. Ocular adnexal lymphoma is primarily a disease of older adults, with a slight female preponderance. Most lymphomas are low-grade B-cell lymphomas, with marginal zone lymphoma being by far the most common type. Marginal zone lymphoma typically involves the ocular adnexa primarily, whereas other types of low-grade B-cell lymphoma often involve the ocular adnexa secondarily. High-grade B-cell lymphomas only occasionally involve the ocular adnexa, and T-cell lymphoma, NK-cell lymphoma, and Hodgkin lymphoma are only rarely encountered in this site.     

Gamma heavy-chain disease: defining the spectrum of associated lymphoproliferative disorders through analysis of 13 cases

Gamma heavy-chain disease (gHCD) is defined as a lymphoplasmacytic neoplasm that produces an abnormally truncated immunoglobulin gamma heavy-chain protein that lacks associated light chains. There is scant information in the literature regarding the morphologic findings in this rare disorder, but cases have often been reported to resemble lymphoplasmacytic lymphoma (LPL). To clarify the spectrum of lymphoproliferative disorders that may be associated with gHCD, this study reports the clinical, morphologic, and phenotypic findings in 13 cases of gHCD involving lymph nodes (n=7), spleen (n=2), bone marrow (n=8), or other extranodal tissue biopsies (n=3). Clinically, patients showed a female predominance (85%) with frequent occurrence of autoimmune disease (69%). Histologically, 8 cases (61%) contained a morphologically similar neoplasm of small lymphocytes, plasmacytoid lymphocytes, and plasma cells that was difficult to classify with certainty, whereas the remaining 5 cases (39%) showed the typical features of one of several other well-defined entities in the 2008 WHO classification. This report demonstrates that gHCD is associated with a variety of underlying lymphoproliferative disorders but most often shows features that overlap with cases previously reported as "vaguely nodular, polymorphous" LPL. These findings also provide practical guidance for the routine evaluation of small B-cell neoplasms with plasmacytic differentiation that could represent a heavy-chain disease and give suggestions for an improved approach to the WHO classification of gHCD.     

Pulmonary lymphoma of mucosa-associated lymphoid tissue type followed as a long-standing indeterminate lesion in immunoglobulin M-type paraproteinemia

An 82-year-old woman with monoclonal immunoglobulin (Ig) M-type paraproteinemia had a large opacity in the right lung field. The abnormal shadow on roentgenogram had persisted for more than 6 years since the initial diagnosis of paraproteinemia, which had been diagnosed as Waldenström’s macroglobulinemia (WM). Computed tomography revealed the lesion as a pulmonary tumor which was finally diagnosed as a marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) after surgical removal. MALT lymphoma constitutes the majority of primary pulmonary lymphomas and is often associated with monoclonal IgM-type paraproteinemia as well as WM, a distinctive lymphoproliferative disorder. Pulmonary MALT lymphoma should frequently be suspected in case of an indeterminate pulmonary tumor with IgM-type paraproteinemia.     

Pulmonary lymphoma of mucosa-associated lymphoid tissue type followed as a long-standing indeterminate lesion in immunoglobulin M-type paraproteinemia

An 82-year-old woman with monoclonal immunoglobulin (Ig) M-type paraproteinemia had a large opacity in the right lung field. The abnormal shadow on roentgenogram had persisted for more than 6 years since the initial diagnosis of paraproteinemia, which had been diagnosed as Waldenstr?m’s macroglobulinemia (WM). Computed tomography revealed the lesion as a pulmonary tumor which was finally diagnosed as a marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) after surgical removal. MALT lymphoma constitutes the majority of primary pulmonary lymphomas and is often associated with monoclonal IgM-type paraproteinemia as well as WM, a distinctive lymphoproliferative disorder. Pulmonary MALT lymphoma should frequently be suspected in case of an indeterminate pulmonary tumor with IgM-type paraproteinemia.     

Waldenström's macroglobulinemia and large B-cell central nervous system lymphoma: a case report

BACKGROUND: Waldenstr?m's macroglobulinemia is a low-grade B-cell lymphoma characterized by monoclonal synthesis and secretion of IgM antibodies [3]. The classic symptoms of WM result from blood hyperviscosity. Neurologic symptoms, such as fatigue, dizziness, and blurred vision, are common. The metastatic spread to the CNS, which rarely has been reported, can occur either diffusely or in the form of a mass lesion. CASE DESCRIPTION: We present the case of a 73-year-old woman with intracerebral large B-cell lymphoma and concurrent WM. CONCLUSION: This case illustrates the importance of histopathologic diagnosis by brain biopsy despite an existing diagnosis of systemic neoplasm.     

Splenic marginal zone lymphoma with or without plasmacytic differentiation

We report a series of 31 cases of splenic marginal zone lymphomas with an enlarged spleen and a multimicronodular macroscopic pattern. Two groups, A and B, were distinguished based on the presence (A) or absence (B) of a lymphoplasmacytic component with monoclonal immunoglobulin expression in the cytoplasm. There were no differences between the groups as far as age, sex, spleen weight, and progression. The only difference was the presence in group A of a monoclonal serum component and autoimmune disorders, particularly autoimmune hemolytic anemia. In most cases in which a liver and/or bone marrow biopsy was performed, lymphomatous infiltration was detected. Seven cases had a seric monoclonal IgM of 5 g/L or more and liver or bone marrow infiltration, corresponding to the definition of Waldenstrom's macroglobulinemia. Lymphoma cells had a monocytoid, centrocytoid and, in group A, lymphoplasmacytic morphology. The lymphomatous cells were positive for CD20, CD45 RA, and bcl-2. They expressed IgD in 9 cases, partially in 6, and were negative for IgD in 9 of the 24 cases studied. Progression seems to be slow, with a long survival. Three patients presented with transformation into a large B-cell lymphoma, which was responsible for death in two patients.     

Primary mediastinal lymphoma; a clinicopathologic case series

Treatment for primary mediastinal lymphoma generally involves chemotherapy and radiotherapy, and treatment regimens depend on histologic subtypes of lymphoma. The histologic subtype of lymphoma is mostly determined by computed tomography (CT)-guided core-needle biopsy or surgical procedures, including thoracotomy, thoracoscopy and mediastinoscopy. We describe the clinicopathologic features and diagnostic procedures of 8 cases of primary mediastinal lymphoma. The male-to-female ratio was 1:1, and median age at diagnosis was 27 years. The median size of the primary mediastinal tumor on CT was 8.5 cm. Five patients were diagnosed by CT-guided core-needle biopsy, 1 by open biopsy and 2 by surgery. Three patients were diagnosed with nodular sclerosis Hodgkin lymphoma, 3 with mediastinal diffuse large B-cell lymphoma, 1 with precursor T-lymphoblastic leukemia/lymphoma and 1 with thymic extranodal marginal zone B-cell lymphoma. According to their histological subtypes, 5 patients were treated with chemoradiotherapy, 2 patients with chemotherapy and 1 patient of thymic extranodal marginal zone B-cell lymphoma with surgery alone. All patients survived in the median follow-up of 34.5 months. Appropriate biopsy procedure should be performed in patients with suspected mediastinal lymphoma.     

Bone marrow biopsy involvement by non-Hodgkin's lymphoma: frequency of lymphoma types, patterns, blood involvement, and discordance with other sites in 450 specimens

To evaluate the features of bone trephine biopsy involvement by non-Hodgkin lymphoma, 450 specimens were evaluated for percentage of marrow involvement, pattern of involvement, presence of germinal centers or follicular structures, and discordance with other involved sites. A subset of 197 cases was evaluated for evidence of concurrent peripheral blood involvement. Follicular grade 1 lymphoma (30.4%) was the most common type to involve the marrow, followed by diffuse large B-cell lymphoma (16.0%), mantle cell lymphoma (9.3%), low-grade B-cell lymphoma, not otherwise specified (8.7%), lymphoplasmacytic lymphoma (8.4%), follicular grade 2 lymphoma (7.1%), and mature T- and NK-cell lymphomas (6.4%). A mixed pattern of infiltration was most common, followed by paratrabecular, nodular, diffuse, and interstitial patterns. Greater than 90% of follicular lymphomas had at least a focal paratrabecular infiltration pattern, but this pattern was also seen with other lymphoma types. Interstitial disease infiltration tended to correlate with lymphoplasmacytic lymphoma but was also not specific. The presence of germinal centers or follicular structures was associated with follicular lymphoma in 88% of cases. Discordance between the bone marrow morphology and other tissue sites was observed in 24.9% of cases and was most often seen with follicular or diffuse large B-cell lymphoma. Peripheral blood involvement by lymphoma was observed in 29% of cases, found in all disease groups except for follicular grade 3 lymphoma. This study highlights the frequency of different lymphoma patterns in the marrow, limitations of primary lymphoma classification on biopsy material alone, and the relative frequency of marrow discordance and peripheral blood involvement by marrow lymphoma.     

Low-grade T-cell lymphoma of the kidney and Waldenström's macroglobulinemia in a patient presenting with renal failure

Renal failure is rarely the presenting manifestation of non-Hodgkin's lymphoma. We describe the unusual case of a patient who presented with uremia due to lymphomatous infiltration of the kidney by a low-grade T-cell lymphoma. The diagnosis of lymphoma was made by renal biopsy. Extrarenal nodular or extra-nodular involvement could not be detected. However, simultaneously, a lymphoplasmacytic lymphoma was found on bone marrow biopsy associated with IgM paraproteinemia. To our knowledge, this is the first report of a renal T-cell lymphoma associated with Waldenstr?m's macroglobulinemia.     

Epstein-Barr virus-positive B-cell lymphoproliferative disorders arising in immunodeficient patients previously treated with fludarabine for low-grade B-cell neoplasms

We describe five patients with treated low-grade B-cell neoplasms who subsequently developed Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disorders (BLPDs). The low-grade B-cell neoplasms were B-cell chronic lymphocytic leukemia in four patients and splenic marginal zone lymphoma in one patient. All patients had received treatment with fludarabine for the low-grade B-cell neoplasm, and three had also received Campath-1H. The EBV-BLPDs arose 2-12 months after completion of fludarabine therapy and morphologically resembled the EBV-BLPDs that occur in the setting of iatrogenic immunodeficiency. Molecular genetic studies showed that these lesions were clonally distinct from the low-grade B-cell neoplasm in three of four cases assessed. Two patients did not receive therapy for the EBV-BLPD. The lesions regressed spontaneously in both patients but recurred in one. One patient underwent surgical excision and remains without evidence of the EBV-BLPD. One patient received aggressive multiagent chemotherapy with a complete response initially, but the EBV-BLPD recurred after 12 months. One patient received antiviral therapy and responded completely but died 2 months later of an opportunistic infection. We conclude that patients with low-grade B-cell neoplasms treated with fludarabine, possibly in combination with other immune suppressive agents, may subsequently develop EBV-BLPDs that morphologically resemble other iatrogenic immunodeficiency-associated BLPDs. Most are clonally distinct from the underlying low-grade B-cell neoplasm. A subset of these lesions may regress without systemic therapy.     

B-cell Non-Hodgkin Lymphomas with Plasmacytic Differentiation

B-cell non-Hodgkin lymphomas with plasmacytic differentiation are a diverse group of entities with extremely variable morphologic features. Diagnostic challenges can arise in differentiating lymphoplasmacytic lymphoma from marginal zone lymphoma and other low-grade B-cell lymphomas. In addition, plasmablastic lymphomas can be difficult to distinguish from diffuse large B-cell lymphoma or other high-grade lymphomas. Judicious use of immunohistochemical studies and molecular testing can assist in appropriate classification.     

Non-Hodgkin Lymphoma of the Breast: Clinical and Radiologic Presentations

Abstract: We reviewed the clinical presentations, radiologic findings, and histopathologic findings in 18 women with 21 non-Hodgkin lymphomas involving the breast. Eight patients had primary breast lymphoma, 10 had secondary involvement. Three had bilateral lesions. Thirteen lymphomas (62%) presented as palpable breast masses, and one (5%) as a palpable axillary mass with ipsilateral breast peau ?orange. Seven (33%) were clinically occult and detected on routine mammography. Masses ranged from well-circumscribed to ill-defined mammographically, and were all hypoechoic at sonography. Histopathologic diagnoses included diffuse large B-cell lymphoma in six patients (33%), follicle center lymphoma in five patients (28%), small lymphocytic lymphoma in three patients (17%), nodal marginal zone B-cell lymphoma in two patients (11%), high-grade B-cell, Burkitt-like lymphoma in one patient (5.5%), and Burkitt's lymphoma in one patient (5.5%). The radiologic appearance of breast lymphoma is nonspecific, possessing no pathognomonic or distinguishing features. No correlation was noted between radiologic appearance and histopathologic subtype.?     

SHP-1 expression by malignant small B-cell lymphomas reflects the maturation stage of their normal B-cell counterparts.

SHP-1 is a protein phosphotyrosine phosphatase that plays an important role in modulating intracellular signaling, which regulates cell activation, proliferation, differentiation, and migration. It is a negative regulator of signal transduction induced by a number of cell receptors. Our immunohistochemical examination of paraffin-embedded reactive lymph nodes and lymphoid tissues revealed that B lymphocytes in follicle germinal centers do not express SHP-1. A weak staining of the B cells in the germinal center light zones was detected when an ultrasensitive amplification system was used. In contrast, normal B cells in mantle and marginal zones as well as interfollicular B lymphocytes and plasma cells displayed strong immunoreactivity. This pattern of SHP-1 expression was repeated in small B-cell lymphomas. All cases of mantle cell lymphoma (12 of 12), marginal zone lymphoma (10 of 10), and chronic lymphocytic leukemia/small lymphocytic lymphoma (13 of 13) expressed SHP-1 protein. However, only 1 of 30 cases of grade 1 follicle center cell lymphoma expressed SHP-1. Our observations highlight the biologic functions of SHP-1 and demonstrate that the SHP-1 expression pattern by small B-cell lymphomas reflects the maturation stage of their normal cell counterparts. These results indicate that determination of SHP-1 expression may help in the differential diagnosis of small B-cell lymphomas.     

Practicality of molecular studies to evaluate small lymphocytic proliferations in endoscopic gastric biopsies.

Fifteen endoscopic gastric biopsies (GBx) from 12 patients with small lymphocytic infiltrates morphologically raising a differential of indeterminate lymphocytic infiltrate versus mucosa-associated lymphoid tissue (MALT) lymphoma were analyzed genotypically after frozen-section identification of the abnormal lymphocytic infiltrate. Frozen-section immunoperoxidase immunophenotyping was equivocal in each case. All patients had abdominal pain attributable to superficial gastric ulceration, most often antral, without peripheral lymphadenopathy or hepatosplenomegaly. Rearrangement of the immunoglobulin heavy-chain gene (JH-R, seven patients) or kappa light-chain gene (JK-R, eight patients), was found in eight GBx from eight (seven stage IAE; one stage IBE) of 12 patients, establishing, in conjunction with the histologic features, a diagnosis of low-grade B-cell lymphoma. This diagnosis had not been tenable on multiple prior GBx, ranging from one to five per patient, over intervals of 1 month to 6.5 years (median 4.5 months). The T-cell receptor beta-chain gene retained germline configuration in all cases. Insufficient DNA for molecular studies was extracted from the GBx of two patients, one with JK-R (JH-G) on subsequent GBx and one without further GBx. One patient had two GBx, each demonstrating a single additional band in HindIII digests hybridized with the JH probe. No rearrangements were detected in either the BamHI or the EcoRI digests. Uninvolved tissue from this patient was not available for the exclusion of restriction fragment length polymorphism. Three GBx (two patients) showed germline JH genes (JH-G). One had a partial gastrectomy (histology: MALT lymphoma) in 1981 followed by GBx in 1983 (histologically benign) and in 1990 (JH-G), and negative esophagogastroduodenoscopy (EGD) in 1991 without biopsy. The other patient (two GBx with JH-G) had multiple subsequent abnormal EGD, but no biopsies since December 18, 1990. Adequate DNA for gene rearrangement studies can be extracted from GBx samples weighing as little as 20 mg. The two samples with insufficient DNA weighed 1 and 16 mg, respectively. Practically speaking, the remainder of a frozen block from a single GBx is adequate, thus allowing the screening of multiple endoscopic GBx by sequential frozen sections to determine which one contains the most extensive lymphocytic infiltrate for molecular study. Consistent results are obtained on samples weighing 40 to 60 mg. This method is a suitable alternative to kappa/lambda frozen-section immunoperoxidase immunostaining, which can be uninterpretable on endoscopic biopsies or small biopsies from other sites.     

Cast nephropathy in a case of Waldenström's macroglobulinemia

Waldenstr?m's macroglobulinemia is a low-grade lymphoplasmacytic lymphoma characterized by a circulating monoclonal IgM. The clinical manifestations are due to deposition of IgM in liver, spleen, and/or lymph nodes. Related symptoms include anemia and complications of the hyperviscosity syndrome. Renal involvement in classical cases of Waldenstr?m's macroglobulinemia is rare, and the pathological hallmark finding in the renal biopsy specimen is a thrombotic microangiopathy. We report the case of a 73-year-old female with the diagnosis of pernicious anemia for 2 years before she presented with acute renal failure. A renal biopsy performed suggested the diagnosis of myeloma cast nephropathy. However, bone marrow biopsy specimens and hematological studies did not support this diagnosis. Serum and urinary protein electrophoresis revealed a monoclonal lambda subtype IgM. Ultrasound imaging showed an enlarged spleen. The diagnosis of cast nephropathy in a patient with Waldenstr?m's macroglobulinemia was made. She underwent treatment with fludarabine and plasmapheresis/hemodialysis with dramatic improvement of her renal function.     

Characterization of CXCL13+ neoplastic t cells in cutaneous lesions of angioimmunoblastic T-cell lymphoma (AITL)

Skin manifestations of angioimmunoblastic T-cell lymphoma (AITL) are frequent, sometimes as first manifestations of the disease. In the absence of a specific marker for neoplastic cells, diagnosis of AITL in skin biopsies is often difficult. CD10 and CXCL13 have been recently recognized as characteristic markers of AITL, but have not been yet investigated in the skin. We analyzed 15 skin biopsies from 8 patients with AITL having skin manifestations and compared them to 14 skin biopsies from patients with various cutaneous lymphocytic infiltrates. A few CD10 lymphocytes were found in only 2 samples of the AITL group, the identification of which was hampered by the presence of a dermal CD10 cell population with dendritic features. By contrast, CXCL13 lymphoid cells were identified in most AITL cutaneous biopsies (n=12, 80%), whereas, absent in all samples from control cases. Among 12 biopsies with CXCL13 cells, cutaneous involvement by AITL was suspected in only 5 on the basis of light microscopy and classic immunophenotyping. In another case, a diagnosis of cutaneous marginal zone B-cell lymphoma had been proposed. In conclusion, this study shows that neoplastic AITL CXCL13 T cells localize in the skin and that accurate diagnosis of AITL lesions can be done in skin specimens using CXCL13 immunostaining on paraffin-embedded tissues.     

Renal involvement in Waldenström’s macroglobulinemia: case report and review of literature

Waldenström’s macroglobulinemia (WM) is a rare lymphoid neoplasia, accounting for 2% of all hematological malignancies. Renal complications occur rather rarely compared to multiple myeloma. The most common renal manifestations are mild proteinuria and microhematuria. We describe a case of MW presenting with acute renal failure and NS. A 67-year-old man was referred to our hospital for sudden onset nephrotic syndrome. Electrophoresis revealed a monoclonal component in the gamma region, which was classified as an IgM k. During hospitalization, acute kidney injury developed, with creatinine up to 5?mg/dL, despite adequate hydration and alkalinization. A kidney biopsy was performed, showing minimal change disease (MCD) with interstitial and capsular lymphoid infiltrates of B-Lymphocytes CD20+. B-lymphocytes infiltration suggested the possibility of renal localization of lymphoproliferative disorder. So, bone marrow histology was performed, revealing lymphoplasmacytic lymphoma (WM). The patient was treated with bortezomib, desamethasone, and rituximab, with partial recovery of renal function (creatinine 1.5?mg/dL) and complete remission of proteinuria after 8-month follow-up. The remission of NS in our patient with rituximab seems to emphasize the pathogenetic role of B cells in MCD, although a coincident effect of immunosuppression on both the underlying renal disease and the hematologic disease cannot be excluded.     

Aberrant expression of the dendritic cell marker TNFAIP2 by the malignant cells of Hodgkin lymphoma and primary mediastinal large B-cell lymphoma distinguishes these tumor types from morphologically and phenotypically similar lymphomas

Tumor necrosis factor-α-inducible protein-2 (TNFAIP2) is a protein upregulated in cultured cells treated with tumor necrosis factor α (TNF), but its expression in normal and neoplastic tissues remains largely unknown. Here, we use standard immunohistochemical techniques to demonstrate that TNFAIP2 is normally expressed by follicular dendritic cells, interdigitating dendritic cells, and macrophages but not by lymphoid cells in secondary lymphoid tissues. Consistent with this expression pattern, we found strong TNFAIP2 staining of tumor cells in 4 of 4 cases (100%) of follicular dendritic cell sarcoma and in 3 of 3 cases (100%) of histiocytic sarcoma. Although TNFAIP2 is not expressed by the small and intermediate-sized neoplastic B cells comprising follicular lymphoma, small lymphocytic lymphoma, mantle cell lymphoma, or marginal zone lymphoma, we observed strong TNFAIP2 staining of the large, neoplastic cells in 31 of 31 cases (100%) of classical Hodgkin lymphoma, in 12 of 12 cases (100%) of nodular lymphocyte-predominant Hodgkin lymphoma, and in 27 of 31 cases (87%) of primary mediastinal (thymic) large B-cell lymphoma. In contrast, TNFAIP2 was expressed by malignant cells in only 2 of 45 cases (4%) of diffuse large B-cell lymphoma, not otherwise specified, in 2 of 18 cases (11%) of Burkitt lymphoma, and in 1 of 19 cases (5%) of anaplastic large cell lymphoma. Further analysis indicates that TNFAIP2, as a single diagnostic marker, is more sensitive (sensitivity=87%) and specific (specificity=96%) than TRAF1, nuclear cRel, or CD23 for distinguishing the malignant B cells of primary mediastinal (thymic) large B-cell lymphoma from those of its morphologic and immunophenotypic mimic, diffuse large B-cell lymphoma, not otherwise specified. Thus, TNFAIP2 may serve as a useful new marker of dendritic and histiocytic sarcomas, the aberrant expression of which in the malignant cells of classical Hodgkin lymphoma and primary mediastinal (thymic) large B-cell lymphoma serves to distinguish these tumors from other large cell lymphomas in routine clinical practice.