Primary platelet-derived growth factor-producing,spindle-shaped diffuse large B-cell lymphoma of the skull: a case report and literature review

A 39-year-old woman with a right frontal mass underwent a cranial bone tumor biopsy. Histopathologic examination of hematoxylin and eosin–stained slides showed spindle-shaped tumor cells in a storiform pattern, appearing somewhat like a sarcoma. However, the tumor cells were CD20-positive by immunohistochemical staining. Therefore, a diagnosis of spindle-shaped diffuse large B-cell lymphoma (Sp-DLBCL) was made. There have been at least 35 cases of Sp-DLBCL documented in the literature, and most were of the germinal center type, while the present case is the first report of a vimentin-positive primary Sp-DLBCL of the skull. The DLBCL in this case was immunohistochemically stained for six representative cytokines that might give rise to fibrosis, due to the evidence of fibroblastic proliferation. The DLBCL cells were positive for platelet-derived growth factor (PDGF), and some cells were also positive for tumor necrosis factor (TNF) α. Based on these findings, it was inferred that the PDGF and TNFα produced by DLBCL cells induced fibroblastic proliferation. The resultant conspicuous fibrosis caused interfibrous impingement on the DLBCL cells, which deformed them into a spindle shape. The present case is the first reported case of a PDGF-producing Sp-DLBCL.     

纵隔芯针活检的病理诊断

目的 提高纵隔芯针穿刺组织的诊断准确性并做出具体分类。方法 用光镜、免疫组织化学抗生物素蛋白-生物素复合物法(ABC法)回顾性观察65例纵隔穿刺组织的形态和免疫组织化学表型,利用聚合酶链反应(PCR)检测部分非霍奇金淋巴瘤的基因重排状况,并随访。结果 本组标本镜下主要由不同比例的上皮样细胞、淋巴样细胞和纤维组织组成,包括21例淋巴瘤、20例肺癌、14例胸腺瘤、4例胸腺癌、3例精原细胞瘤、1例慢性炎症。2例因穿刺组织过少,无法诊断。本组淋巴瘤依不同类型可表达CD20、CD3、末端脱氧核苷酸转移酶(TDT)、CD30、D15或上皮膜抗原(EMA);除3例肺小细胞癌细胞角蛋白(CK)阴性外,17例肺癌均表达CK;10例肺和1例胸腺小细胞癌突触素、嗜铬粒素A(CgA)、神经元特异性烯醇化酶(NSE)均阳性,CD5阴性;3例肺腺癌甲状腺转录因子阳性,CD5阴性;14例胸腺瘤CK、CD3或CD20可阳性;3例胸腺癌表达CK和CD5;3例精原细胞瘤胎盘碱性磷酸酶阳性、CK阴性。5例淋巴母细胞性淋巴瘤T细胞型的T细胞受体B链的编码基因存在重排,3例大B细胞淋巴瘤和1例大细胞间变B细胞淋巴瘤存在免疫球蛋白重链编码基因的重排。结论 纵隔穿刺组织的镜下诊断需结合临床和影像资料,选择适当的免疫组织化学套餐,才能提高确诊率,并可对有疑问的非霍奇金淋巴瘤病例进行克隆性分析。     

Cytodiagnosis of primary thyroid lymphoma with histologic correlation: A case report

Primary thyroid lymphoma is a very rare disease. Here, we present a case of primary diffuse large B-cell lymphoma (DLBCL) in a 48-year-old female involving thyroid gland. The patient had thyroid swelling for 15 years which rapidly increased during last 5 months. Fine needle aspiration cytology revealed monomorphic large cells arranged discretely. The cells have high nuclear-cytoplasmic ratio with prominent single to multiple nucleoli. Aggregates of thyroid follicular cells were absent in the smears. A cytodiagnosis of DLBCL was made and a differential diagnosis of lymphocytic thyroiditis was also included. Subsequent histologic examination revealed a high-grade non-Hodgkin lymphoma (NHL). Immunohistochemistry showed the tumor cells expressing CD45, CD20, BCl-6, and tumor cells were negative for cytokeratin, epithelial membrane antigen, CD3, CD5, and CD30. Proliferative index (Ki-67) was very high (70%). Thus, a final diagnosis of NHL of DLBCL subtype was established. The patient was treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristin, prednisone) and radiotherapy. The patient is under one-year follow-up which is uneventful.     

Composite diffuse large B-cell lymphoma and CD20-positive peripheral T-cell lymphoma

Composite lymphoma is defined as two or more distinct types of lymphoma in a single anatomical site. Among various combinations, composite B-cell and T-cell non-Hodgkin's lymphomas (CBTL) are very infrequent. Herein we describe a 66-year-old female with CBTL presenting with lymphadenopathy, multiple bone lesions and an epidural tumor. Light microscopic examination of a biopsied cervical node revealed a dual population of lymphoid cells: sheets of large cells admixed with medium-sized cells. The large cells expressed B-cell markers and showed immunoglobulin light chain restriction, consistent with diffuse large B-cell lymphoma (DLBCL). The medium-sized cells were positive for CD20 as well as T-cell markers. Because polymerase chain reaction amplification showed monoclonal rearrangement of the T-cell receptor β chain gene, this population was compatible with peripheral T-cell lymphoma not otherwise specified (PTCL-NOS). We therefore made a diagnosis of composite DLBCL and CD20-positive PTCL-NOS. Complete remission was achieved after six cycles of R-CHOP regimen (rituximab, doxorubicin, vincristine, cyclophosphamide and prednisolone). This is the first report of CD20-positive PTCL-NOS associated with composite lymphoma. Moreover, a literature review of composite DLBCL and PTCL-NOS indicates that this rare clinical entity may be featured by efficacy of systemic chemotherapy in spite of prevalent extranodal lesions.     

B细胞特异性激活蛋白Pax-5在淋巴瘤组织中的表达

目的探讨B细胞特异性激活蛋白(BSAP)／Pax-5在淋巴瘤的表达情况及应用价值。方法按2001年WHO关于淋巴造血组织肿瘤分类标准收集102例弥漫性大B细胞淋巴瘤(DLBCL)、3例滤泡型淋巴瘤(FL)、3例黏膜相关淋巴组织结外边缘区B细胞淋巴瘤(MALT淋巴瘤)、1例结节性淋巴细胞为主型的霍奇金淋巴瘤(NLPHL)、10例间变性大细胞淋巴瘤(ALCL)和10例浆细胞瘤,用免疫组织化学LSAB法同步检测比较BSAP与CD20的表达情况。结果102例DLBCL全部表达CD20,100例表达BSAP,3例FL、3例MALT淋巴瘤和1例NLPHL BSAP和CD20全部阳性表达,10例ALCL、10例浆细胞瘤BSAP和CD20全部阴性表达。BSAP与CD20的表达差异无统计学意义。结论。BSAP/Pax-5是一种新的B细胞标记,阳性信号定位于细胞核,抗BSAP抗体在常规外科病理诊断工作中的应用价值有限。     

Rare case of biphasic tumor of the breast with prominent CD34-positive spindle cells

We report an unusual case of biphasic tumor of the breast with prominent CD34-positive spindle cells. A 53-year-old woman presented with a mass in her right breast. Following an incisional biopsy, a partial mastectomy was done. Histologically, the tumor was a biphasic variant of a malignant spindle cell tumor of the breast. The lack of a leaf-like structure, together with the apparent myoid features of the spindle-shaped tumor cells, made it difficult to distinguish from malignant phyllodes tumor and from myoepithelial carcinoma. Immunohistochemistry revealed the spindle-shaped tumor cells to be myofibroblastic, but not myoepithelial in nature, ultimately categorizing this tumor as a malignant phyllodes tumor with prominent myofibroblastic differentiation.     

Pancreatic acinar cell carcinoma with pleomorphic and spindle cells: An autopsy-proven case

Pancreatic acinar cell carcinomas are glandular and have amphophilic/eosinophilic cytoplasm, presenting acinar, solid, and trabecular structures. Unusual histological features of acinar cell carcinoma are known, such as oncocytic, pleomorphic, spindle, and clear cell variants, but their clinical significance has not been well described. A man in his 70s was referred to our hospital because of elevated serum pancreatic enzymes. Contrast-enhanced abdominal computed tomography revealed slight swelling of the pancreatic head and suspension of the main pancreatic duct in the pancreatic body. He died only 14 days after admission. Gross findings at autopsy showed an ill-defined tumor located in the pancreatic head, involving the gastric and duodenal walls. Peritoneal dissemination, liver metastases, and lymph node metastases were also observed. Microscopically, tumor cells had moderate-to-severe nuclear atypia and amphophilic cytoplasm showing pleomorphism, and diffusely proliferated in solid pattern without lumina, were admixed with spindle cells. Immunohistochemically, tumor cells including pleomorphic and spindle cells were positive for B-cell lymphoma/leukemia 10 and trypsin. Consequently, the diagnosis was pancreatic acinar cell carcinoma with pleomorphic and spindle cells. We encountered a rare variant of pancreatic acinar cell carcinoma with pleomorphic and spindle cells. Clinically, our case showed rapid progression.     

Pitfalls in the diagnosis of hepatic epithelioid hemangioendothelioma by FNA and needle core biopsy

Epithelioid hemangioendothelioma (EHE) of the liver is an extremely rare tumor that masquerades as an epithelial neoplasm and poses significant diagnostic pitfalls for the cytopathologist. This report describes a 64‐year‐old woman whom on computerized tomography was found to have multiple peripherally calcified hypodense lesions throughout the liver and an ipsilateral adrenal mass. Fine needle aspiration and needle cores biopsies of the largest liver lesion showed epithelioid cells and spindle cells in fibrous stroma. The epithelioid cells had round or oval, hyperchromatic nuclei with smooth nuclear contours, delicate cytoplasm and indistinct cytoplasmic borders. Rare cells had intracellular vascular lumen containing fragmented or intact red blood cells. The cells were individually dispersed or arranged in nests and vague tubular arrays. No mitotic figures or necrosis were seen. An immunohistochemical profile demonstrated diffuse CD31 and focal CD 34 and nuclear Fli‐1 immunoexpression and low Ki‐67 proliferative activity (1%) within lesional cells confirming the diagnosis of EHE. The differential diagnosis of EHE which includes cholangiocarcinoma, hepatocellular carcinoma, metastatic carcinoma and melanoma is discussed. Diagn. Cytopathol. 2014;42:516–520. © 2013 Wiley Periodicals, Inc.     

Clear cell variant of diffuse large B-cell lymphoma: a case report and review of the literature

Diffuse large B cell lymphoma (DLBCL) is a diffuse proliferation of large neoplastic B lymphoid cells with nuclear size equal to or exceeding that of normal macrophage nuclei. The DLBCL morphological variants are centroblastic, immunoblastic, T-cell- and histiocyte-rich, anaplastic, plasmablastic, anaplastic lymphoma kinase-positive, and primary mediastinal large B-cell lymphoma (PMBCL). These histopathologically-recognized morphological variants respond differently to treatment and have distinct prognoses. We report a case of a 43-year-old patient who presented pain in the lower abdomen that had begun four months prior. Ultrasound-guided biopsy revealed epithelial cell features and a partial alveolar growth pattern. We discovered large diffuse areas comprising large cells with slightly irregular nuclei and very clear cytoplasm. These features were similar to those of clear cell carcinoma in renal tissue, suggesting the possibility of an epithelial neoplasm. To test this possibility, immunohistochemistry for cluster designation markers was performed, but the diffuse areas were found to be positive only for CD45. Additional immunohistochemistry was performed, and the diffuse areas were found to be positive for CD20, CD79a, P53, and Mum-1. Based on these characteristics, a diagnosis of a clear cell variant of DLBCL was made, and the patient was treated with chemotherapy. Precise histological diagnosis is crucial for clinical management and ultimately for patient survival. There has been one additional report of a case of clear cell DLBCL, in outside the mediastinum. The features we identified can be used to define a new subtype of DLBCL. The expression of P53 and Mum-1 suggest a poor prognosis.     

Composite T lymphoblastic leukemia/lymphoma and diffuse large B-cell lymphoma: case report

This report concerns a unique case of a composite lymphoma composed of T-lymphoblastic leukemia/lymphoma (T-LBL) and diffuse large B-cell lymphoma (DLBCL) in a 72-year-old woman with generalized lymphadenopathy, splenomegaly and ascites. Laboratory findings showed increased lactate dehydrogenase and soluble interleukin-2 receptor. The biopsy specimen showed replacement of the normal architecture of the lymph nodes by a tumor containing a dual cell population composed of large lymphocytes and medium-sized lymphocytes. Sheets of large lymphocytes often were punctuated by clusters of medium-sized lymphocytes. Flow cytometry and immunohistochemical analysis showed a composite lymphoma with both T-LBL and DLBCL. The T-LBL expressed CD1a, CD3, CD4, CD8, and terminal deoxynucleotidyl transferase. The DLBCL expressed CD19 and CD20, CD23, bcl-2, bcl-6, MUM1 and immunoglobulin κ light chain. Polymerase chain reaction detected a monoclonal pattern of T-cell receptor γ and immunoglobulin heavy chain rearrangements in the same specimen. She received eight cycles of R-CHOP (rituximab+cyclophosphamide, doxorubicin, vincristine, prednisone) therapy and achieved complete remission. She has shown no signs of recurrence 20 months after the diagnosis. We describe here a very unusual and, to the best of our knowledge, an as yet never reported case of a primary composite lymphoma of T-LBL and DLBCL.     

The stromal cell marker SPARC predicts for survival in patients with diffuse large B-cell lymphoma treated with rituximab

The cellular composition of the tumor microenvironment may affect survival in diffuse large B-cell lymphoma (DLBCL). We performed immunostains for 2 stromal cell markers, CD68 and SPARC (secreted protein, acidic and rich in cysteine), in 262 patients with DLBCL treated with rituximab and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like therapies. Patients with any SPARC+ cells in the microenvironment had a significantly longer overall survival, and patients with high SPARC positivity in the microenvironment also had a significantly longer event-free survival. Survival differences were mainly due to the prognostic effect of SPARC+ cells in activated B-cell (ABC)-type DLBCL, with no effect found in the germinal center B-cell-type DLBCL. Of clinical features examined, only the number of extranodal sites was significantly associated with SPARC expression. Multivariate analysis revealed that SPARC expression predicted patient survival independent of the International Prognostic Index or tumor cell of origin. SPARC expression in the microenvironment of DLBCL can be used for prognostic purposes, determining a subgroup of patients with ABC DLBCL who have significantly longer survival. More aggressive chemotherapy protocols should be considered for patients with ABC DLBCL without SPARC+ stromal cells. CD68 expression by cells in the microenvironment did not predict survival.     

Primary diffuse large B-cell lymphoma of the ethmoid sinus

Malignant lymphoma of the ethmoid sinus is very rare. A case of diffuse large B-cell lymphoma (DLBCL) of the left ethmoid sinus is presented here. A 79-year-old Japanese man was consulted to our hospital because of head ache and disturbance of left eye movement. Nasal endoscopy revealed a tumor, and imaging modalities including CT and MRI detected a tumor in the left ethmoid sinus. The tumor was invasive into left eye and left nose. A biopsy was performed via the nasal cavity. The biopsy revealed a diffuse proliferation of atypical lymphocytes. The atypical lymphocytes were large and had enlarged hyperchromatic nuclei. Mitotic figures were scattered. Hodgkin's cells were absent. Follicular structures were not seen. Immunohistochemically, the tumor cells were negative for cytokeratins (AE1/2, polyclonal, KL-1, and CAM5.2, Dako) and epithelial membrane antigen, CD3, CD15, CD30, CD45RO, and TdT. In contrast, the tumor cells were positive for CD20, CD45, CD79α, and p53. KI-67 labeling was 100%. Light chain restriction was present; there were numerous λ-chain-positive cells, while κ-chain-positive cells were scant. The pathological diagnosis was DLBCL of the left ethmoid sinus. Imaging of the whole body revealed no tumors and lymphadenopathy other than the ethmoid DLBCL. The patient was treated with chemoradiation, and is now alive 3 months after the presentation. In conclusion, a very rare case of DLBCL of the ethmoid sinus was reported.     

Frequency and diagnostic patterns of lymphomas in liver biopsies with respect to the WHO classification

The recent World Health Organization (WHO) classification of hematopoietic and lymphoid tissue tumors represents the first worldwide consensus classification of these malignancies. However, the applicability of this classification to a representative number of hepatic lymphomas in liver biopsy specimens has not yet been investigated. The frequency and infiltration pattern of a series of 205 liver biopsies with lymphoma manifestations was analyzed with the aid of immunohistochemical and molecular pathological analyses. Diffuse large B-cell lymphoma (DLBCL) was by far the most frequent entity, comprising 45% of the cases analyzed. Using a previously published immunohistochemical algorithm, 35% of 80 DLBCL were assigned to a germinal center B-cell-like (GCB) and 65% to a non-GCB group. Most B-cell lymphoma entities involving the liver revealed a characteristic infiltration pattern. Diagnostically challenging entities were T-cell-rich B-cell lymphomas, anaplastic large cell lymphomas and peripheral T-cell lymphomas, which frequently required additional molecular clonality assessment. Overall, the percentage of T-cell lymphomas in the liver (12%) was higher as compared to other extranodal sites except for the skin and the small intestine. This study provides relevant data on the distribution of hepatic lymphomas and demonstrates the applicability of the WHO classification proposing a diagnostic algorithm for liver biopsies.     

CD14 and CD169 expression in human lymph nodes and spleen: specific expansion of CD14+CD169- monocyte-derived cells in diffuse large B-cell lymphomas

The mononuclear phagocyte system of human lymphoid tissue comprises macrophages and dendritic cells (DCs). The heterogeneity of the non-DC mononuclear phagocyte population in human lymphoid tissue has been little addressed. Here, we studied the expression of 2 monocyte-derived markers, CD14 and CD169 (sialoadhesin), in reactive human lymphoid tissue as well as in a series of 51 B-cell lymphomas by immunohistochemistry on paraffin-embedded tissue. We confirmed that lymph node sinusoidal monocyte-derived cells were the only population staining for CD169. Although most sinusoidal histiocytes also expressed CD14, monocyte-derived cells with phagocytosis such as erythrophagocytosis, anthracosis, or tingible bodies macrophage lacked CD14 and CD169. Among B-cell lymphomas, splenic marginal zone lymphoma was the only one associated with an expansion of the CD14(+)CD169(+) cells in the cords. With respect to nodal B-cell lymphomas, CD14(+) cells were rare among B-chronic lymphocytic leukemia, follicular lymphoma (FL), mantle cell lymphoma (MCL). However, strikingly, we found a strong expansion of CD14(+)CD169(-) cells in numerous diffuse large B-cell lymphomas (DLBCLs), except in cases associated with numerous mitoses, apoptotic bodies, and tingible bodies macrophages. When cultivated in granulocyte/macrophage colony stimulating factor/interleukin 4, DLBCL purified CD14(+) cells differentiate into plasmacytoid cells, expressing DC-specific intercellular adhesion molecule 3-grabbing nonintegrin, suggesting dendritic cell differentiation potential. Our observation fits well with the lymph node and host response cluster signatures described in the gene profiling signatures of DLBCL. However, the role of this CD14(+) population that may constitute a microenvironment-related marker of this subgroup of DLBCL remains to be determined.     

Anaplastic lymphoma kinase-positive diffuse large B-cell lymphoma with a complex karyotype and cryptic 3' ALK gene insertion to chromosome 4 q22-24

Anaplastic lymphoma kinase (ALK)-positive diffuse large B-cell lymphoma (DLBCL) is a rare tumor that is frequently associated with t(2;17)(p23;q23), a translocation fusing the ALK gene at 2p23 to the clathrin heavy chain gene (CLTC) at 17q23. Here, we report a unique case of ALK-positive DLBCL with plasmablastic morphology and focal cytoplasmic granular ALK stain in an HIV-negative 33-year-old man. By conventional karyotyping, the lymphoma cells were near-tetraploid and included 4 structurally normal copies each of chromosomes 2 and 17. Fluorescence in situ hybridization revealed an apparently normal, intact ALK gene on each of the 4 chromosome 2 homologs plus a cytogenetically cryptic ALK gene insertion into 2 of the 4 chromosome 4 homologs at band 4q22-24. The lymphoma cells expressed CD138, lambda light chain, focal and weak CD30, and exhibited aberrant T-cell antigens, including perforin. This case indicates that ALK-positive DLBCL is more heterogeneous at the cytogenetic/molecular level than previously recognized.     

浆细胞肿瘤病理形态的多样性

目的 观察浆细胞肿瘤的病理形态学特点,探讨其组织结构和细胞形态的类型及其鉴别诊断.方法应用HE、免疫组织化学(EliVision法),对46例浆细胞肿瘤的组织形态学及免疫表型进行研究.结果 46例浆细胞肿瘤中,有40例组织结构以弥漫分布为主,3例呈巢状结构而似神经内分泌肿瘤,3例出现硬化的纤维性背景.淀粉样物质沉积、钙化骨化及"血湖"样结构在部分病例中有可能会非常突出而掩盖了肿瘤性浆细胞的特点.细胞形态上,30例由较成熟和欠成熟的浆样细胞组成而较易辨认.6例由类似免疫母细胞的浆母细胞组成.4例肿瘤细胞较小,似小淋巴细胞.2例瘤细胞胞质透亮似透明细胞或印戒细胞.另各有1例分别由异型性明显的间变型细胞、组织细胞样细胞及梭形细胞构成.最后1例细胞形态多样,可出现分叶核、单核及多核型细胞.免疫表型上93.1%(27/29)的病例表达CD79a而仅有5.1%(2/39)的病例表达CD20,87.1%(27/31)的病例表达CD38和83.3%(25/30)表达CD138,96.8%(30/31)的病例表达MUM-1.38例呈免疫球蛋白轻链限制性表达,其中表达λ链27例,表达κ链11例.结论浆细胞肿瘤除了常见的组织形态外,还可出现不典型或少见的组织结构和细胞形态,诊断时应注意与其他类型淋巴瘤如小淋巴细胞淋巴瘤及间变性大细胞淋巴瘤、低分化癌、透明细胞或印戒细胞癌、间叶性肉瘤等进行鉴别,免疫组织化学是必不可少的.     

Composite recurrent hodgkin lymphoma and diffuse large B-cell lymphoma: one clone, two faces

We describe a composite lymphoma with recurrent Hodgkin lymphoma and diffuse large B-cell lymphoma components manifesting as a single, perforated small intestinal tumor in a 56-year-old man with a history of classical Hodgkin lymphoma and recent relapse in the bone marrow. The resected mass had 2 morphologically and immunophenotypically distinct components; 1 showed a pleomorphic cellular infiltrate with fibrosis and contained numerous, large Hodgkin/Reed-Sternberg-like cells and variants. The tumor cells were CD30+ and focally positive for CD15 but CD20-, CD79a-, and PAX-5-. In situ hybridization for Epstein-Barr virus (EBV) was strongly positive in the large pleomorphic tumor cells. The adjacent component displayed sheets of relatively uniform, large lymphoid cells with typical morphologic features of diffuse large cell lymphoma. The tumor cells showed uniform expression of tested B-cell antigens, absence of CD30 or CD15, and complete absence of EBV-encoded RNA. Separate molecular studies with immunoglobulin heavy and k light chain gene rearrangements clearly demonstrated an identical rearrangement pattern, indicating derivation from the same clone, which was confirmed by direct DNA sequencing analysis. Such distinctly different morphology, immunophenotype, and EBV status in different components within a clonally related single tumor mass is striking.     

De novo CD5 positive diffuse large B-cell lymphomas with bone marrow involvement in Korean

In CD5 positive (CD5+) mature B-cell lymphomas, newly recognized CD5+ diffuse large B-cell lymphoma (DLBCL) has been characterized by aggressive features. We studied twenty-five cases with CD5+ lymphomas involving bone marrow. Eleven cases were diagnosed as chronic lymphocytic leukemia, six cases were diagnosed as mantle cell lymphoma (MCL), and three cases with morphologic characteristics of MCL and without both the cyclin D1 expression and IGH/CCND1 rearrangement were unclassifiable. The remaining five cases, showing large to medium-sized lymphoid cells with prominent nucleoli and a moderate amount of cytoplasm, were diagnosed as DLBCL. Five DLBCL cases were positive for CD5, CD20, surface immunoglobulin, but negative for CD23. Patients with CD5+ DLBCL showed a high age of onset (median, 68 yr) and two patients expired one month after the diagnosis. Since CD5+ DLBCL forms a distinct subgroup of DLBCL, a study of CD5 expression in DLBCL would be helpful to predict prognosis and to determine future therapeutic strategy. To the best of our knowledge, this is the first report on de novo CD5+ DLBCL in Koreans.     

Composite mantle cell and diffuse large B-cell lymphoma: report of two cases

Composite lymphomas are rare and involve the concurrent evolution of 2 distinct lymphoma types within a single organ or tissue. This study describes 2 cases of composite mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL), which has not previously been reported. Each case demonstrated distinct populations of CD20 positive small and large atypical B cells. In both cases, only the small lymphocytes were positive for CD5 and cyclin D1, and fluorescence in situ hybridization (FISH) showed a t(11;14) translocation in the small lymphocytes but not in the large cells. Molecular studies for B-cell clonality showed a possible clonal relationship between the 2 components in one case but not the other. This study describes in detail the morphology, immunophenotype, FISH, and molecular analysis of both components in each case. To the authors' knowledge, this represents the first report of juxtaposition of MCL with DLBCL that does not represent transformation of the mantle cell component.     

Patterns of liver infiltration in lymphoproliferative disease

Aims:  Liver involvement is a common finding in patients suffering from lymphoproliferative disease, and histopathological patterns of infiltration vary according to lymphoma subtype. Data correlating the form of liver involvement with distinct lymphoma subtypes is, however, scarce. The aim was to review 89 liver biopsies diagnosed with lymphoma infiltration and evaluate the infiltration patterns.
Methods and results:  In equivocal cases, additional immunohistochemical and molecular pathology analyses were performed to differentiate between neoplastic and reactive cell infiltrates and to classify the lymphoma subtypes. Diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukaemia (CLL), Hodgkin's lymphoma (HL) and Burkitt lymphoma (BL) were the most prevalent subtypes in our series, which included 14 different lymphoma entities in total. Whereas DLBCL and BL predominantly demonstrated tumour nodules deranging the normal hepatic architecture, CLL and HL mostly showed infiltration of the portal fields. Interestingly, distinct lymphoma entities, particularly marginal zone B-cell lymphomas (MZL) and HL, commonly revealed lympho-epithelial lesions of bile ducts, which were observed in 10% of all investigated cases. Four cases, initially interpreted as T-cell lymphomas, proved to be reactive T-cell lesions.
Conclusions:  Distinct lymphoma subtypes show characteristic patterns of liver infiltration. Additional molecular analyses can support diagnosis by verification of clonality or detection of characteristic genetic aberrations.