T-immunoblastic lymphoma mimicking B-immunoblastic lymphoma

A T-cell immunoblastic lymphoma having plasmacytoid features that mimic B-cell immunoblastic lymphoma, is described. The lesion was composed of sheets of pleomorphic plasmacytoid cells that displayed a helper T-cell immunophenotype (Leu-1+, Leu-3+, Leu-4+, Leu-5+, Leu-9-, Leu-2-). Ultrastructural features were consistent with a T-cell lymphoma. Flow cytometric analysis revealed that the cells were DNA triploid and had a high proliferative activity. Although the histology of immunoblastic lymphomas alone may suggest either a T- or B-cell phenotype, immunophenotyping is essential in making this distinction.     

肝脾γδT和αβT细胞淋巴瘤

从 1990年Ｆａｒｃｅｔ等描述了 2例肝脾γδＴ细胞淋巴瘤以来 ,人们渐渐认识到肝脾γδＴ细胞淋巴瘤是一个独立的淋巴瘤亚类 ,1994年它被ＲＥＡＬ分类确认为一个临时的淋巴瘤亚类[1] ;而在新的ＷＨＯ血液和淋巴组织肿瘤分类中它被确认为一个独立的疾病[1] 。它有典型的临床病理特征 ,包括多为青年男子发病 ,有Ｂ症状 (发热、夜汗、体重减轻 ) ,肝脾肿大 ,没有淋巴结病 ,重度贫血 ,明显的血小板减少症。患者多在诊断后 1年内死亡。组织学上 ,主要为小到中等大小的肿瘤细胞浸润脾脏的脾索和脾窦 ,以及肝窦 ,骨髓血窦等。特征性的免疫表型为Ｃ…     

Mantle cell lymphoma disguised as marginal zone lymphoma

We report a case of mantle cell lymphoma histologically indistinguishable from marginal zone lymphoma. An 83-year-old man presented with a 9.0-cm, slowly enlarging axillary mass. Microscopically, the neoplastic process was largely interfollicular, surrounding residual follicular centers, some of which had discernible small lymphocyte mantles. Overall, the morphologic pattern was highly suggestive of marginal zone lymphoma. However, flow cytometric and immunohistochemical results, including cyclin D1 positivity, revealed an immunophenotype that fit with mantle cell lymphoma. The differential diagnosis of mantle cell lymphoma is broad, and it is well known that mantle cell lymphoma can assume a number of histologic appearances, including, infrequently, that of more indolent B-cell non-Hodgkin lymphomas. Although not pathognomonic, cyclin D1 positivity is highly specific for mantle cell lymphoma and is key in distinguishing these clinically dissimilar malignant lymphomas. In recent years, detection of cyclin D1 has expanded the recognizable histologic spectrum of mantle cell lymphoma.     

Extranodal lymphoma

Lymphomas arising in extranodal sites are intriguing. The types of lymphomas encountered vary widely from one extranodal site to another. For many types of extranodal lymphomas, there are distinctive clinicopathologic features, sometimes including association with an underlying immunodeficiency syndrome, autoimmune disease, infection, or other immunologic disorder, or a predilection to affect patients of certain ethnic origins. Presented below is a review of lymphomas that are encountered most often in extranodal sites.     

Mediastinal lymphoma

Malignant lymphoma may involve the mediastinum as a component of disseminated disease or as a primary lesion. The most common types of primary mediastinal lymphomas (ML) are Hodgkin's disease (HD, usually of the nodular sclerosis type), large cell lymphoma (often associated with sclerosis), and lymphoblastic lymphoma (frequently seen in conjunction with acute lymphoblastic leukemia). The characteristic clinical, morphologic, and immunophenotypic features of these three neoplasms are reviewed. ML must be distinguished from Castleman's disease, an enigmatic lymphoid proliferation that frequently involves the mediastinum.     

Discordant lymphoma: MALT lymphoma of the stomach and follicular lymphoma of the parotid gland

More than one histological type of malignant lymphoma can occur simultaneously in an individual. The entity is classified as either composite or discordant lymphoma. Both types of lymphoma, particularly discordant lymphoma comprised of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue lymphoma (MALT-L) and follicular lymphoma (FL), are rare. We report a case of discordant lymphoma comprising MALT-L in the stomach and FL in the parotid gland. The patient was a 50-year-old Japanese woman who visited the University Hospital of Showa (Tokyo, Japan) because a barium study showed erosive gastric lesions. A gastro-intestinal endoscopy was performed 2 months after the barium study, which showed irregular erosions throughout the stomach body. A gastric biopsy showed MALT-L, and Helicobacter pylori (H. pylori) infection was confirmed. The patient had noticed a painless and elastic hard tumor mass of about 2 cm in diameter in the area of the left parotid gland 6 months before the barium study. We removed the parotid gland tumor and diagnosed it as FL 6 months after the barium study. We were able to diagnose the MALT-L and FL by morphological, immunohistochemical and molecular analyses of paraffin-embedded sections. This appears to be the first reported case of MALT-L and FL occurring together as a discordant lymphoma.     

Gastrointestinal lymphoma

The gastrointestinal tract is the commonest site for primary extranodal malignant lymphoma. Despite this, gastrointestinal lymphomas are rare and present diagnostic and conceptual challenges. Principal among these are the differential diagnoses of malignant lymphoma and carcinoma and malignant lymphoma and pseudolymphoma, especially in the stomach; the nature of Mediterranean lymphoma and of the lymphoma complicating celiac disease; and the conceptual basis for differentiation of follicular centre cell lymphomas in the intestine.     

皮肤淋巴瘤

1.病例简介:患者男,56岁.无明显诱因背部肿物7年,进行性生长缓慢,不痛,无明显临床症状于2006年5月20日入院.体检:左背部见一隆起型肿物,直径约3 cm,高起皮面1 cm,皮色淡红,隆起处皮面光滑,皮纹消失,压痛不明显;全身其他部位皮肤未见病灶;全身浅表淋巴结未触及明显肿大,B超示内脏器官未见异常.     

Extranodal mantle cell lymphoma mimicking marginal zone cell lymphoma

AIM: We report a case of mantle cell lymphoma masquerading as a marginal zone cell lymphoma. METHODS AND RESULTS: In the initial manifestation in the palatine tonsils, the neoplastic cells were found to grow exclusively within the marginal zones of secondary follicles which showed a preserved mantle zone. The few immunostains performed showed a B-cell phenotype including an immunoglobulin light chain restriction. The extranodal manifestation, the growth pattern, and the immunophenotype led to the diagnosis of an extranodal marginal zone B-cell non-Hodgkin's lymphoma (NHL). The specimen from the relapse occurring 8 months later exhibited diffuse monomorphous cells co-expressing B-cell antigens and CD5, CD43 and cyclin D1, leading to the diagnosis of mantle cell lymphoma. Re-investigation of the initial biopsy revealed that the neoplastic cells within the marginal zones had a mantle cell lymphoma immunophenotype expressing cyclin D1, the immunoglobulin heavy chains IgD and IgM and partly CD5. Both lesions harboured identical clonal immunoglobulin gene rearrangements proving that they represented different manifestations of the same lymphoma. CONCLUSION: This case emphasizes the importance of broad immunohistological investigation of B-cell NHLs involving the marginal zone.     

Pyothorax-associated lymphoma: a lymphoma developing in chronic inflammation

Pyothorax-associated lymphoma (PAL) is a non-Hodgkin lymphoma of exclusively B-cell phenotype developing in the pleural cavity of patients after more than 20-year history of pyothorax resulting from an artificial pneumothorax for the treatment of pulmonary tuberculosis or tuberculous pleuritis. The most common symptoms on admission are chest pain and fever. Serum neuron-specific enolase level suggesting a diagnosis of small cell lung cancer is occasionally elevated. Histologically PAL usually shows a diffuse proliferation of large cells of B-cell type (diffuse large B-cell lymphoma [DLBL]). In PAL cells, representative B-cell markers other than CD20 are frequently negative with aberrant expression of T-cell markers such as CD2. A gene expression profile of PAL is distinct from nodal DLBL in its higher expression level of interferon-inducible genes. PAL is strongly associated with Epstein-Barr virus (EBV) infection with expression of EBV latent genes such as EBNA-2, LMP-1, together with EBNA-1. Taken together, PAL is a distinct entity both in its clinicopathologic presentation as well as its gene expression profile. Use of an artificial pneumothorax, EBV infection, and cytokines and reactive oxygen species produced in longstanding pyothorax might be important factors for PAL development.     

Peripheral T-cell lymphoma mimicking marginal zone B-cell lymphoma.

Peripheral T-cell lymphoma (PTCL) may assume a variety of histologic and cytologic appearances. We describe eight cases of PTCL morphologically simulating marginal zone B-cell lymphoma. We reviewed PTCL cases diagnosed in our institution between 1990 and 2000 and selected eight cases for study based on the following criteria: small-cell morphology with abundant, clear cytoplasm and either marginal zone involvement by the neoplastic infiltrate in lymph node biopsies or lymphoepithelial lesions in extranodal biopsies. Histologic features and ancillary studies were reviewed. Patients included six women and two men with a median age of 53 years (range, 35 to 74 years). Six patients were diagnosed with primary nodal PTCL, and two presented with primary extranodal disease. The original diagnosis was PTCL in only four cases; three cases were diagnosed as atypical lymphoid infiltrate, and one case as benign lymphoepithelial lesion. Lymph node biopsies revealed partial effacement of the architecture with residual follicles surrounded by the neoplastic small cells. Extranodal sites included hard palate, tongue, tonsil, and submandibular glands; all but one case demonstrated lymphoepithelial lesions. Monoclonality was demonstrated in six of eight cases (rearrangement of T-cell receptor gene), and three of eight had an aberrant T-cell population by flow cytometry. The differential diagnosis of atypical lymphoid infiltrates with morphologic features of marginal zone B-cell lymphoma should include PTCL. This uncommon morphological mimicry should be recognized, because PTCL is an aggressive disease regardless of morphology and should be treated accordingly.