IMMUNOHISTOCHEMICAL ANALYSES OF PHOSPHATASES IN CHILDHOOD B-CELL LYMPHOMA: Lower Expression of PTEN and HePTP and Higher Number of Positive Cells for Nuclear SHP2 in B-Cell Lymphoma Cases Compared to Controls

Although many pediatric B-cell lymphoma patients are being cured today, much is still unknown about the pathogenesis of this disease. Protein tyrosine phosphatases are involved in the control of survival, growth, and differentiation of cells. The authors have analyzed 26 pediatric B-cell lymphoma cases for the expression of a panel of phosphatases and report a statistically significant lower expression intensity of PTEN and HePTP and higher nuclear SHP2 expression in B-cell lymphoma cases compared to lymphoid tissue. Knowledge about the expression of key regulatory proteins in pediatric B-cell lymphomas is necessary for revealing the complex molecular background of this disease.     

Lymphoma,a great imitator in neurology

The title “great imitator” refers to conditions which can cause varied manifestations and mimic many diseases. Lymphoma is worthy of this title. We describe three cases of lymphoma in which lymphoma mimicked other diseases causing neurological dysfunction, specifically sarcoidosis, vasculitis and infection respectively. Case 1 was a 66-year-old man with subacute progressive diplopia and gait disturbance and investigations revealing a supratentorial para-falcine soft tissue lesion, mid-thoracic cord enhancement and right axillary mass and an elevated serum ACE. Right axillary mass core biopsy was diagnostic of Burkitt lymphoma. Case 2 was a 50-year-old man with several weeks of constitutional symptoms and development of lower limb weakness and numbness, urinary retention and confusion while in hospital. MRI brain demonstrated multi-territory cerebral infarcts. Intravascular lymphoma was diagnosed on random skin biopsy. Case 3 was a 65-year-old man with several weeks of headache and diplopia on a background of previously treated Burkitt lymphoma. CSF analysis showed a lymphocytic pleocytosis and markedly low glucose with cytologic analysis negative for malignancy. Investigations for an infective cause were negative. FDG-PET demonstrated marked, disseminated spinal and cranial leptomeningeal disease and a multi-focal, intra-dural relapse of Burkitt lymphoma was diagnosed. The varied manifestations in our cases demonstrate the ability for lymphoma to mimic infective, inflammatory, granulomatous (including sarcoidosis) and neoplastic aetiologies. An elevated serum ACE appears insufficiently diagnostic to confirm sarcoidosis and tissue for histological examination should be sought whenever possible. When the diagnosis is uncertain, the possibility of this great imitator should be considered, especially for multi-focal disease.     

10例HIV/AIDS相关Burkitt淋巴瘤(BL)临床病理和免疫表型分析

 目的  探讨HIV/AIDS相关Burkitt淋巴瘤(Burkitt lymphoma,BL)的临床病理学形态、免疫表型特点、诊断及其鉴别诊断。方法  按照WHO(2008)造血与淋巴组织肿瘤病理学分类,应用HE染色、免疫组化EnVision法染色、荧光原位杂交(fluorescence in situ hybridization,FISH)及原位杂交并结合临床资料对2010年8月至2013年3月收集的10例HIV/AIDS相关BL进行综合分析。结果  10例患者中活检腋下肿块4例、颈部肿块3例、腹股沟肿块1例、腹部手术切除肿物2例。免疫组化染色瘤细胞均显示IgM、CD20、CD19、CD79a、CD10、Bcl 6阳性,CD5、CD21、CD30、EMA、Bcl 2、CD3、ALK-1、TdT阴性,Ki67增殖指数均＞90%,1例表达CD38及MUM-1,3例c-myc阳性,1例LMP-1阳性,突变型p53阳性表达5例。原位杂交EBER 示3例阳性;FISH示C-MYC基因断裂重组8例t(8;14)(q24;q32)。病理诊断:经典型BL 9例,浆细胞样分化BL 1例。结论  HIV-BL为高度恶性淋巴瘤,预后较差,光镜下易与弥漫大B细胞淋巴瘤和淋巴母细胞性淋巴瘤/白血病等相混淆,结合典型病理表现、免疫组化和FISH技术有助于临床病理诊断及其鉴别诊断。     

Low incidence of MYC/BCL2 double‐hit in Burkitt lymphoma

Translocations involving MYC are highly characteristic for Burkitt lymphoma (BL). BCL2 expression has also been found previously in about 10 to 20% of BL cases, and BCL2 translocation is a major mechanism for the deregulation of BCL2 expression in non‐Hodgkin lymphomas. However, we know little about the incidence of MYC/BCL2 double‐hit (DH) in BL. We examined BL cases to determine how frequently they contained BCL2 translocations in combination with MYC translocations using fluorescence in situ hybridization. We also determined the effect of BCL2 expression on clinical outcomes of BL. BCL2 translocations were detected in 3.5% (2/57 cases) of the cases, and BCL2 expression was detected in 33%. Two cases with BCL2 translocation also showed BCL2 expression. The incidence of BCL2 expression was significantly higher in patients 16 years of age and older (46%) than in patients under 16 years of age (6%). Among patients 16 years of age and older, we did not detect significant differences in overall survival with respect to BCL2 expression status. In conclusion, BCL2 translocation is a rare cytogenetic abnormality in BL, and BL probably accounts for only a small fraction of MYC/BCL2 DH lymphomas. BCL2 expression in BL is probably not associated with BCL2 translocations.     

Burkitt Lymphoma — Subtypes,Pathogenesis, and Treatment Strategies

Burkitt's lymphoma (BL) is a rare and highly aggressive Non-Hodgkin lymphoma (NHL) with a germinal center phenotype, a nearly universal myc oncogene translocation to an enhancer element and a proliferation index greater than 95%.¹ Bcl-2 is not expressed as opposed to double-hit or triple-hit lymphoma. Genetic mutations and aberrancy involving the phosphatidylcholine 3-kinase and cyclin-dependent kinase pathways are also involved.2, 3, 4, 5 Rarely patients present with stage I disease and others are considered as high risk if greater than stage I or with elevated LDH or masses greater than 10 cm.