弥漫性大B细胞淋巴瘤继发嗅神经母细胞瘤1例报道并文献复习

目的 探讨1例弥漫大B细胞淋巴瘤患者化疗-放射治疗后继发嗅神经母细胞瘤临床及病理学特点.方法 回顾性分析1例弥漫大B细胞淋巴瘤放化疗后继发嗅神经母细胞瘤患者的临床资料,对其肿瘤进行形态学观察、免疫组化染色,并随访患者.结果 患者右侧咽部异物感半个月,查体发现扁桃体肿大,活检明确诊断为弥漫大B细胞淋巴瘤(非生发中心型),行6个疗程CHOP化疗34天22次局部放疗,10年后发现右筛窦占位,术后明确诊断为嗅神经母细胞瘤,随访2个月,死于双肺转移.结论 弥漫大B细胞淋巴瘤化疗-放疗后继发嗅神经母细胞瘤诊断明确,继发肿瘤预后较差.     

原发淋巴结套细胞淋巴瘤临床病理分析

目的：探讨原发淋巴结套细胞淋巴瘤（MCL）的临床病理与免疫组化特点。方法：收集6例淋巴结MCL,免疫组化ABC法确定肿瘤细胞特征,使用的抗体有CD45、CD20、CD79、CD45RO、CD30、CD68、TdT、CD43、CD5、cyclinD1、c-myc,IgD,IgM等。结果：光镜可将MCL分为4种亚型：套区型1例,结节型1例,弥漫型2例,母细胞化型2例。肿瘤细胞表达全B细胞标记,IgD CD43 ,cyclinD1(5/6),CD5(4/6) 。结论：MCL是一种具有特殊免疫表型的B细胞淋巴瘤,不同的组织学构型其预后可能不同,临床应与其它类型B细胞淋巴瘤鉴别,如淋巴结边缘区B细胞淋巴瘤（MZL）,滤泡性淋巴瘤（FL）及CLL／SLL等鉴别。     

富于PD-1阳性T细胞的滤泡间弥漫大B细胞淋巴瘤1例临床病理分析

目的探讨富于PD-1阳性T细胞的滤泡间弥漫大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)的临床病理学和免疫表型特征及鉴别诊断。方法应用HE和免疫组化染色、EBER原位杂交及基因克隆性重排技术检测1例罕见的富于PD-1阳性T细胞的滤泡间DLBCL,并复习相关文献。结果镜下见淋巴结内增生的淋巴滤泡散在分布,滤泡间区增宽明显伴多形性细胞浸润,包括异型的中心母细胞和免疫母细胞样大细胞、小淋巴样细胞、嗜酸性粒细胞和组织细胞。免疫表型:滤泡间区异型大细胞CD20、PAX5、MUM1一致强阳性表达,CD3、CD5、CD10、BCL-6、CD30和CD15均阴性,背景小淋巴样细胞多为PD-1阳性的T细胞。此外,EBER原位杂交阴性,免疫球蛋白基因重排示B细胞单克隆性增生,T细胞受体基因未见单克隆性重排。结论滤泡间DLBCL,特别是伴有PD-1阳性的T细胞背景,其诊断具有挑战性。认识DLBCL这一罕见生长方式很重要,需与包括反应性免疫母细胞增生性疾病、血管免疫母细胞性T细胞淋巴瘤、滤泡间霍奇金淋巴瘤和其它富于PD-1阳性T细胞的大B细胞淋巴瘤等类似病变鉴别。     

滤泡性淋巴瘤的发病机制

滤泡性淋巴瘤（follicular lymphoma,FL）起源于滤泡生发中心细胞,是一类西方国家较常见的恶性淋巴瘤,发病构成约占成人恶性淋巴瘤的20％,我国也不少见。FL主要以淋巴结肿大为首发症状,病程进展缓慢,而且治疗后易复发,典型病例病程长,呈慢性经过,平均生存期为8～10年,部分患者随病情进展,可转化为弥漫性大细胞性淋巴瘤（DLBCL）。形态学上,FL是由滤泡中心细胞和中心母细胞构成的至少有一个滤泡结构的B细胞淋巴瘤。     

肾脏原发性淋巴瘤临床病理分析

目的 :对肾脏原发性淋巴瘤的临床病理特点、组织学起源、诊断及鉴别诊断等进行初步探讨。方法 :对 1例手术切除的肾脏原发性淋巴瘤标本做HE染色和S P免疫组化染色 ,光镜观察。结果 :左肾脏上极见一 7 5cm× 6cm× 4cm界限不清的肿块。镜下见在肾实质内有弥漫大片淋巴瘤细胞浸润。瘤细胞核呈略不规则形 ,染色质呈凝块状。免疫表型肿瘤细胞表达LCA、L2 6、IgA弥漫阳性。病理诊断为弥漫小核裂细胞型。 结论 :肾脏原发性淋巴瘤甚为罕见。结合文献 ,其主要诊断依据为 :①肾脏内有弥漫大片形态一致的淋巴瘤细胞浸润 ;②肿瘤主要位于肾脏实质内 ,肾包膜及其周围脂肪组织内亦可见瘤细胞浸润 ;③患者浅表淋巴结不肿大 ,CT检查未见胸、腹腔内有肿大的淋巴结 ;④骨髓穿刺涂片和活检未见异常细胞。⑤发现肾脏淋巴瘤至少 3月后未发现其它部位的淋巴瘤。发生于肾脏的淋巴瘤应与肾脏的肉瘤样癌、Wilm瘤、慢性炎症等相鉴别。其主要治疗方法为肾切除加化疗和 (或 )放疗。     

累及鼻咽、胸膜的睾丸原发性非霍奇金淋巴瘤2例并文献复习

目的 分析睾丸原发性非霍奇金淋巴瘤(PNHL)的临床特点及病理特征，探讨复发部位对预后的影响及可能的转移方式。方法 对2例睾丸PNHL进行HE及免疫组化染色，结合文献对其临床病理特征及随访资料进行分析。结果 患者年龄为82岁、67岁，均为单侧睾丸肿大伴有疼痛，免疫表型瘤细胞表达CD45、CD45RA、CD20，病理诊断为弥漫大B细胞性淋巴瘤，中心母细胞性，临床Ⅰ期。病例1单纯患侧睾丸切除术后第5个月出现鼻咽部复发，病例2双侧睾丸切除术后化疗于第6个月先后出现腹膜后淋巴结、肝、肾、肺累及，第10个月出现胸水，第16个月死亡。结论 睾丸PNHL有很高的结外复发倾向，预后差。     

小B细胞恶性淋巴瘤形态学和免疫组织化学研究

目的：探讨各种小B细胞恶性淋巴瘤的形态学、免疫表型特征及其鉴别诊断。方法：对15例小淋巴细胞性淋巴瘤（SLL）、3例淋巴浆细胞性淋巴瘤（LPL）、36例滤泡性淋巴瘤（FL）、25例套细胞淋巴瘤（MCL）、7例淋巴结边缘区B细胞淋巴瘤（MZL）和30例黏膜相关淋巴细胞型结外边缘区B细胞淋巴瘤（MALT－MZL）的石蜡切片进行HE形态学观察和CD5、CD10、CD23和cyclinD1等抗体的免疫组织化学分析。结果：各种小B细胞恶性淋巴瘤在组成细胞和组织结构上各具特征；免疫表型：SLL表达CD5（82％）和CD23（80％），FL表达CD10（87％），MCL表达cyclinD1（84％）和CD5（80％），MZL／MALT－MZL和LPL均不表达CD5、CD10、CD23和cyclinD1。结论：各种小B细胞恶性淋巴瘤均是独立疾病，各具形态学和免疫表型特征，结合HE形态学观察和CD5、CD10、CD23、cyclinD1等免疫组化分析有助于正确诊断和鉴别诊断。     

青年滤泡性淋巴瘤伴骨髓浸润1例并文献复习

目的 探讨青年滤泡性淋巴瘤(follicular lymphoma,FL)的临床病理特征.方法 对1例伴骨髓浸润的FL临床特征、组织学及免疫表型进行观察,并结合文献探讨其病理形态及鉴别诊断.结果 患者全身浅表淋巴结肿大,组织学显示淋巴结结构大部分破坏.免疫组化标记肿瘤细胞膜CD20弥漫阳性.骨髓内见表达CD20的淋巴细胞结节.结论 FL是一种对放、化疗均敏感的恶性肿瘤,确诊依赖于病理学形态及免疫表型检查,各年龄段均可发病,骨髓累及与临床分期、治疗及预后密切相关.     

唾腺Warthin瘤淋巴成分恶变1例

患者,男,63岁。间歇发热1月余,抗炎治疗无效。查体:心肺及骨髓穿刺阴性。左颌下淋巴结肿大。活检病理诊断为左颌下淋巴结腺淋巴瘤,淋巴成分恶变为恶性淋巴瘤。免疫标记属IgM/k表型,电镜观察符合B淋巴细胞起源,形态属大裂细胞性。讨论唾腺Warthin瘤,又称腺淋巴瘤和淋巴乳头状囊腺瘤,起源于唾腺导管或腮腺周围淋巴结内的异位唾腺     

原发性乳腺恶性淋巴瘤临床病理分析

目的：探讨原发性乳腺恶性淋巴瘤的临床病理、免疫组织化学及预后特征。方法：对8例原发性乳腺恶性淋巴瘤的临床资料、术前诊断、病理形态、免疫组织化学及预后进行分析。结果：8例原发性乳腺恶性淋巴瘤患者均为女性,发病年龄34－65岁,平均年龄46．4岁。左乳4例,右乳3例,双侧乳腺发病1例。7例患者为临床IE期,1例为ⅡE期。5例为弥漫大B细胞淋巴瘤,其中4例为中心母细胞形态,1例为免疫母细胞形态;3例为黏膜相关淋巴组织型边缘区淋巴瘤。8例均为白细胞共同抗原（LCA）、CD20、CD45RA阳性;CD43、CD45RO、CD5、CD10均阴性,3例雌、孕激素受体均阴性。治疗大多采用综合治疗,术后6例随访8－108个月未见复发。结论：原发性乳腺淋巴瘤少见,术前诊断较难。组织学类型主要为弥漫大B细胞淋巴瘤和黏膜相关淋巴组织淋巴瘤,经综合治疗后,原发性乳腺淋巴瘤的预后较好。     

B-chronic lymphocytic leukemia showed triple transformation,to diffuse large B cell,CD20-negative,and T-cell neoplasm during ofatumumab treatment: a case report

Background

Chronic lymphocytic leukemia (CLL) is a mature lymphoid neoplasm currently categorized as an indolent type of malignant lymphoma. CLL progresses slowly over years, but it eventually transforms to a more aggressive lymphoma such as the diffuse large B-cell (DLBCL) type, also known as Richter’s syndrome.

Case presentation

We treated a 69-year-old Japanese male who was histologically diagnosed with Richter’s syndrome after 6 years of CLL. His lymphadenopathy had systemically progressed for years, with lymphocyte counts of less than 10,000 cells/μL and a disease status of Rai classification stage I and Binet classification B. He had high fever and hepatosplenomegaly upon Richter’s transformation. The patient was treated with ofatumumab for refractory CLL, which relieved his febrile lymphadenopathy. He received a total of 11 ofatumumab courses and achieved partial remission. On the day of the 12th course of ofatumumab, his disease relapsed with febrile lymphadenopathy. Computed tomography revealed multiple liver masses and systemic lymphadenopathy, while a liver biopsy confirmed T-cell lymphoma. Concomitantly, CD20-lacking CLL cells were detected in his peripheral blood and bone marrow, and pathological examination of his left cervical lymph node biopsy showed CD20-positive DLBCL. The final diagnosis was three different types of lymphoma pathologies: (1) CD20-positive DLBCL of the lymph nodes, (2) CD20-lacking CLL of the peripheral blood and bone marrow, and (3) peripheral T-cell lymphoma (PTCL) of the liver. He received intravenous and oral dexamethasone therapy as palliative care. He died because of the rapid progression of abdominal masses 2 months after the diagnosis of triple transformation CLL. An autopsy revealed aggressive PTCL with aggressive systemic involvement of the liver, spleen, gall bladder, pericardium, bone marrow, and mediastinal–paraaortic–intraceliac lymph nodes. T-cell receptor study of an autopsy specimen supported the diagnosis of PTCL that spread to the intraceliac organs and lymph nodes. We concluded that his pathogenicity progressed to a mixture of triple lymphoma as a result of double malignant transformations, which included PTCL from CLL, CD20-negative CLL, and CD20-positive DLBCL by Richter’s transformation.

Conclusions

Our case provides information on the biology of CLL, to transform from a low-grade chemosensitive status to a malignant chemoresistant status.

     

Mantle cell lymphoma with a unique pattern of CD5 expression: a case report with review of the literatures

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin’s lymphoma characterized by chromosomal translocation t(11;14)(q13;q32), positive CD5, and nuclear cyclin D1 overexpression with unfavorable prognosis. We report herein a case of MCL in a 73-year-old male diagnosed with diffuse large B-cell lymphoma (ileal tumor) at another hospital, who subsequently relapsed with CD5-negative MCL. At the 1st relapse, he developed neck lymph node swelling, of which biopsy showed proliferation of atypical large pleomorphic cells with CD5-negativity by both immunohistochemistry and flow cytometry. At the 2nd relapse, he again developed an ileal tumor, of which biopsy showed positivity for CD5, CD20, and cyclin D1. In MCL, CD5-negative expression has sometimes been reported as having pleomorphic and blastoid variants. The present case was also histologically the pleomorphic type, but the CD5 expression changed from negative at the onset and the 1st relapse to positive at the 2nd relapse. This is a rare and interesting case because of the different expression of CD5 at all stage. This phenomenon made the diagnosis of MCL difficult.     

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.     

Spotlight on Rituximab in Chronic Lymphocytic Leukemia, Low-Grade or Follicular Lymphoma, and Diffuse Large B-Cell Lymphoma

Rituximab (MabThera®, Rituxan®) is a chimeric mouse anti-human CD20 monoclonal antibody. This article reviews the use of intravenous rituximab in the treatment of chronic lymphocytic leukemia (CLL), low-grade or follicular lymphoma, and diffuse large B-cell lymphoma. The addition of rituximab to fludarabine plus cyclophosphamide significantly prolonged progression-free survival both in previously untreated patients with CLL and in those with relapsed or refractory CLL, according to the results of two randomized, open-label, multicenter trials. In patients with previously untreated advanced follicular lymphoma, the addition of rituximab to chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]; cyclophosphamide, vincristine, and prednisone [CVP]; mitoxantrone, chlorambucil, and prednisolone; or cyclophosphamide, doxorubicin, etoposide, and prednisolone) was generally associated with better outcomes than chemotherapy alone in randomized, multicenter trials. In a similarly designed trial, progression-free survival was significantly longer in previously untreated patients with follicular lymphoma, other indolent lymphomas, or mantle-cell lymphoma who received rituximab plus bendamustine than in those receiving rituximab plus CHOP. Monotherapy with rituximab also demonstrated efficacy in patients with relapsed or refractory low-grade or follicular lymphoma, according to the results of noncomparative trials. In terms of maintenance therapy, progression-free survival was significantly prolonged with rituximab maintenance therapy versus observation alone in patients with advanced indolent lymphoma who had not progressed following first-line therapy with CVP and in patients with relapsed or refractory follicular lymphoma who had responded to CHOP (with or without rituximab), according to the results of randomized, open-label, multicenter trials. In four randomized, open-label, multicenter trials in younger or elderly patients with previously untreated diffuse large B-cell lymphoma, event-free survival, failure-free survival, progression-free survival, and overall survival were generally improved to a significant extent by the addition of rituximab to CHOP or CHOP-like chemotherapy. Intravenous rituximab was generally well tolerated in patients with CLL, low-grade or follicular lymphoma, or diffuse large B-cell lymphoma, both as monotherapy and when administered in combination with chemotherapy. Infusion reactions were one of the most commonly occurring adverse events in patients receiving intravenous rituximab. The results of pharmacoeconomic modeling analyses demonstrated that rituximab appears to be cost effective in patients with previously untreated follicular lymphoma, in patients with follicular lymphoma receiving rituximab maintenance therapy following treatment for relapsed or refractory disease, and in patients with previously untreated diffuse large B-cell lymphoma. In conclusion, rituximab remains a valuable therapy in patients with CLL, low-grade or follicular lymphoma, and diffuse large B-cell lymphoma and, in a variety of treatment settings, represents the standard of care.     

Primary sacral non-germinal center type diffuse large B-cell lymphoma with MYC translocation: a case report and a review of the literature

An 85-year-old man presented with pain and numbness in the left buttock, and physical examination revealed an approximately 7 cm mass extending from the first to the third sacral vertebrae; biopsy of the mass led to the diagnosis of CD10-negative, BCL6-weakly positive, MUM1-positive, non-germinal center (non-GC) type diffuse large B-cell lymphoma (DLBCL). Furthermore, serological testing showed negative results for Epstein-Barr virus (EBV) infection, and fluorescence in situ hybridization (FISH) revealed a MYC translocation. Radiographs showed no remarkable osteolytic bone destruction, and the patient was staged with Stage IAE. After 8 cycles of rituximab therapy and 6 cycles of CHOP therapy, complete remission has been maintained until now, approximately 1 year after the treatment. Primary sacral lymphoma is very rare, with only 6 reported cases, including the present one. A review of the reported cases revealed that the disease predominantly affects elderly men, is usually non-GC-type DLBCL and stage IAE, measures approximately 2-7 cm in diameter in general, and does not show early recurrence after chemotherapy or chemoradiotherapy. There is no report in the literature yet of primary sacral DLBCL with MYC translocation, and this is the first case report. On the other hand, 35 cases of CD10-negative DLBCL with MYC translocation, including the present one, have been reported, and a review of the reported cases showed that the disease predominantly affects Asians, middle-aged or elderly men, shows positivity for either BCL6 or MUM1 and negativity for EBV, and has a high international prognostic index and poor prognosis.     

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.     

The unexpected evolution of a case of diffuse large B-cell non-Hodgkin lymphoma

The diffuse large B-cell lymphoma (DLBCL) represents the most common type of aggressive non-Hodgkin's lymphoma with a heterogeneous morphology, biology and clinical presentation. Gene expression profiling studies identified three distinct molecular subtypes of DLCBL arisen from B-cells at different stages of differentiation: germinal center B-cell-like (GCB) DLBCL, activated B-cell-like (ABC) DLBCL, primary mediastinal B-cell lymphoma (PMBL). The most relevant oncogenic pathways in diffuse large B-cell lymphoma are: deregulated B-cell receptor/proliferation signaling, BCL6 and NF-kB constitutive expression, defects in apoptosis and neoangiogenesis. The treatment of DLBCL has been completely modified in the last ten years by combination of anti-CD20 monoclonal antibody (rituximab) and CHOP chemotherapy, which is now the first line therapy. In the last years, there have been reported several cases of progressive multifocal leukoencephalopathy (PML) at patients with rheumatoid arthritis treated with rituximab. Progressive multifocal leukoencephalopathy is possible as an adverse reaction to rituximab at patients treated with R-CHOP for diffuse large B-cell lymphoma.     

Follicle center lymphoma and Warthin tumor involving the same anatomic site. Report of two cases and review of the literature

We report 2 cases of follicle center non-Hodgkin lymphoma (NHL) and Warthin tumor involving the same site. Case 1 is a 68-year-old woman with Warthin tumor and grade 1 follicular NHL involving a periparotid lymph node. She had localized NHL and was treated with radiation therapy; dissemination developed 54 months later. Case 2 is a 55-year-old man with a 17-year history of a parotid mass with gradual enlargement during the last 5 years. Surgical excision revealed Warthin tumor and grade 1 follicular NHL involving the right parotid gland and surrounding lymph nodes. Immunohistochemical studies supported the diagnosis of NHL in both cases; the neoplasms were positive for CD20 and BCL-2 and negative for CD3. Polymerase chain reaction analysis done on paraffinembedded tissue of case 1 revealed monoclonal immunoglobulin heavy chain gene rearrangement and bcl-2/JH fusion DNA sequences diagnostic of the t(14;18)(q32;q21). The small size of the Warthin tumor in case 1, clearly arising in lymph node, supports the hypothesis that Warthin tumor arises from heterotopic salivary gland ducts within lymph nodes. The localized NHL in both patients suggests that the NHL initially arose in the lymph node involved by Warthin tumor, and, thus, the Warthin tumor may have provided a source of long-term antigenic stimulation from which a monoclonal B-cell population subsequently arose.     

Peripheral T-cell lymphoma arising from an intraglandular lymph node in the parotid gland: a case report and literature review

T/NK-cell lymphoma of the salivary gland is rare. A 58-year-old man complained of a tumor mass in the left parotid gland region and he was diagnosed to have a left parotid tumor. The tumor was subsequently resected, revealing a diffuse growth pattern of medium to large sized atypical cells. The tumor was surrounded by fibrous connective tissue in the form of a capsule, and those were positive for CD3, CD4, CD5 and CD30, but negative for Bcl2, CD8, CD10, CD15, CD20, CD25, CD56, CD79a, CD246, EMA, granzyme B, TdT and TIA-1. There was no molecular evidence of Epstein-Barr virus (EBV) infection. It was diagnosed as peripheral T-cell lymphoma (PTCL) arising from an intraglandular lymph node in the parotid gland. In conclusion, Only 17 cases of primary T/NK-cell lymphoma of the salivary glands have been recorded until now, and the characteristics of these are not clear yet. Additional study is needed.     

Nodular lymphocyte predominant Hodgkin lymphoma and diffuse large B-cell lymphoma: a study of six cases concurrently involving the same site

Cotta C V, Coleman J F, Li S & Hsi E D
(2011) Histopathology  59 , 1194–1203
Nodular lymphocyte predominant Hodgkin lymphoma and diffuse large B‐cell lymphoma: a study of six cases concurrently involving the same site Aims: Nodular lymphocyte‐predominant Hodgkin lymphoma (NLPHL) is a slowly progressing neoplasm with a favourable prognosis. However, in a minority of cases (3–12%) it progresses to a clonally related diffuse large B‐cell lymphoma (DLBCL), diagnosed between 6 months and 24 years after NLPHL. This study investigated six cases of NLPHL and DLBCL at the same location. Methods and results: The patients were five men and one woman. In four cases, the site was an axillary lymph node, and in two it was inguinal. In all cases, NLPHL areas had typical morphological and immunophenotypic features. DLBCL involvement was multifocal, diffuse, and characterized by large centroblastic and anaplastic cells. Immunohistochemical studies showed DLBCL cells to be positive for CD20, CD45, and BCL6. In one case, DLBCL cells were positive for BCL2, and in two cases they were positive for MUM‐1. There were no networks of follicular dendritic cells (FDC) associated with DLBCL. Rosettes of PD‐1‐positive and CD57‐positive cells surrounding malignant cells in NLPHL were absent in DLBCL. All the cases were negative for Epstein–Barr virus. No translocations involving MYC were identified in DLBCL. Treatment and outcome were known in four cases. All of these patients were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP), and this was followed by clinical remission (CR). Conclusions: In adequately sampled tumors, DLBCL can be associated with NLPHL at diagnosis. Diffuse architecture, loss of FDC networks, sometimes immunophenotype shift are characteristics of DLBCL associated with NLPHL. Treatment with R‐CHOP usually leads to CR.