Lymphoblastic lymphoma/leukemia with convoluted nuclei: the question of its relation to the T-cell lineage studied in 13 patients

Primary Mediastinal Nodal and Extranodal Non-Hodgkin Lymphomas: Current Concepts, Historical Evolution, and Useful Diagnostic Approach: Part 2

Primary mediastinal non-Hodgkin lymphomas (PM-NHLs) represent ∼5% of all non-Hodgkin lymphomas (NHLs) and comprise lymphomas of B-cell and T-cell origin. PM-NHLs are defined as involvement of mediastinal lymph nodes, thymus, and/or mediastinal organs (heart, lung, pleura, pericardium) by NHL without evidence of systemic disease at presentation. The clinical scenario is variable and depends on the lymphoma subtype. The radiologic presentation is also variable ranging from a mediastinal mass with or without superior vena cava syndrome, a pleural or a cardiac mass associated with effusion, or as an effusion only. The diagnosis of PM-NHLs can only be established by microscopic evaluation, and therefore, general pathologists should be aware of these tumors and familiar with their diagnostic approach. The most common anterior mediastinal NHLs (90% to 95%) are primary mediastinal (PM) large B-cell lymphoma and T-lymphoblastic lymphoma. Thymic marginal zone lymphoma and mediastinal gray zone lymphoma are very rare. The remainder PM-NHLs involving middle or posterior mediastinum include diffuse large B-cell lymphoma (DLBCL) and rare cases of T-cell lymphoma, including anaplastic large cell lymphoma and breast implant-associated anaplastic large cell lymphoma extending to the anterior mediastinum. Primary pleural and cardiac NHLs are mostly DLBCLs. Other rare subtypes of PM-NHLs include DLBCL associated with chronic inflammation/pyothorax-associated lymphoma, fibrin-associated DLBCL (both Epstein-Barr virus positive), and pleural and/or pericardial primary effusion lymphoma (human herpesvirus-8 positive/Epstein-Barr virus positive). We review the historical aspects, epidemiology, clinicoradiologic features, histopathology, immunohistochemistry, differential diagnosis, and relevant cytogenetic and molecular features of the remaining mediastinal B-cell lymphomas, including primary thymic marginal zone lymphoma of the mucosa-associated lymphoid tissue type, other PM small B-cell lymphomas, PM plasmacytoma, and the most relevant PM T-cell lymphomas.

Lymphomas of the mediastinum

The purpose of this clinicopathologic overview is to describe the types of lymphomas that present in the mediastinum. A comparison of the frequency of the different subtypes of lymphoma that are found in children and adults is provided. In general, immunohistochemistry and immunophenotyping studies are essential to the laboratory workup of neoplasms presenting in the mediastinum. An assessment of proliferative index in lymphoma is most helpful to determine tumor aggressiveness and patient prognosis. Electron microscopy is most helpful in the differential diagnosis of mediastinal neoplasms, where lymphomas may be distinguished from nonlymphomatous neoplasms using key ultrastructural features. The role of electron microscopy in the subclassification of lymphomas is mostly academic, with a few exceptions. The varied ultrastructural appearance of Hodgkin's cells and of different subtypes of non-Hodgkin's lymphoma is illustrated, using cases from our patient files. An ultrastructural study of lacunar cells in Hodgkin's disease provides evidence that the formation of lacunae may have a structural and/or physiologic basis. Mummified cells showing some of the features of a physiologic form of cell death, called apoptosis, are also described.

Multiple myeloma associated with multilobated plasma cell nuclei

Ten cases of multiple myeloma are reported in which there were a large number of plasma cells with excessively convoluted or lobulated nuclei. These cases represent 3% of the 297 evaluable multiple myeloma patients treated at our institution over a 22-year period. All 10 had intermediate or advanced stage disease at the time of diagnosis, and all have died after a mean survival of 19.5 months. Ultrastructural features of 2 cases are described. When found in abundance, such cells can cause difficulty in establishing a morphologic diagnosis of multiple myeloma because of their resemblance to other cell types. Therefore, it may be necessary to perform immunoperoxidase staining and/or electron microscopy to confirm the plasmacytic identity of these cells. The findings add further support to the contention that the presence of excessive nuclear convolutions is not a completely reliable indication of T-cell, as opposed to B-cell, lineage.

High frequency of plasminogen activator secretion by malignant human lymphoid cell lines of T-cell type origin

Diffuse defibrination is rarely observed in acute lymphoblastic leukemia (ALL). Clinical and immunologic data suggest that it is more likely to occur in T cell derived ALL. The current investigation involved the secretion of plasminogen activators (PA) of tissue type (t-PA) or urokinase type (U-PA) by testing supernatants of 21 permanent human leukemic cell lines originating from various hematopoietic lineages and one induced lymphoblastoid cell line. (LCL) The amount of PA in each supernatant was determined by biologic and immunoenzymologic assays. The correspondence with the expected molecular weight (MW) according to the PA type was checked by zymography. PA secretion of U-PA type was observed in the three myeloid cell lines. Except for the normal LCL, no B-lymphoid lineage related cell lines of various levels of differentiation displayed PA secretion, whereas PA activity was observed in the supernatant of six of nine malignant T-cell lines. The T-leukemic cell lines CCRF CEM, KE 37, HUT 78, and HUT 102 released U-PA-like activity. Peer released t-PA-like activity and CCRF-HSB2 supernatant showed both types of PA activity. These findings are discussed in view of the natural history of these diseases and the stage of differentiation of the cell lines.

Non epidermotropic cutaneous lymphoma ending in leukemia. A case of adult T cell lymphoma (ATL) in France?

A case of uncommon non Hodgkin malignant lymphoma with initial skin involvement is reported. The pathological pattern does not come under standard classifications. An aspect of non epidermotropic diffuse pleomorphic lymphoma is observed. In an immunological cell membrane study, the T-cell lineage of the malignant proliferation exhibited a very unusual pattern including the presence of the E rosette receptor and the expression of HLA-DR monomorphic determinant. This type of T cell malignant lymphoma can probably be included in the group of adult T cell leukemia/lymphoma (ATL) which is endemic in South Western Japan and occasionally observed in Western countries. The emergence of such cases in these countries raises important epidemiological questions.

B-cell lymphomas morphologically resembling T-cell lymphomas

Seven cases of B-cell lymphoma that morphologically resembled T-cell lymphoma are described. These cases are of four morphologic types: atypical poorly differentiated lymphocytic lymphoma (PDLL) with convoluted nuclei, "Lennert's" lymphoma, mixed lymphocytic-"histiocytic" lymphoma with large variation in size of abnormal cells, and "histiocytic" lymphoma with large multilobed nuclei. These cases add further support to the belief that morphologic criteria alone are not sufficient for accurate immunologic classification of the malignant lymphomas since they may represent a distinct clinicopathologic entity.

Phenotypic and ultrastructural characterization of a medullary thymocyte acute lymphoblastic leukemia with cellular procoagulant activity

The phenotypic and ultrastructural characterization of the blast cells from a T-cell acute lymphoblastic leukemia (T-ALL) that was associated with disseminated intravascular coagulation (DIC) is described. The bone marrow blasts were considered to represent neoplastic medullary thymocytes and were acid phosphatase (+), terminal deoxynucleotidyl transferase (-), acid alpha-naphthyl acetate esterase (-), E-rosette (+) at 4 degrees C and 37 degrees C, Fc- and C3-receptor (-), and cALLA-, Ia-, 9.6+, OKT3+, OKT4+, OKT6+/-, OKT8+, OKT10+. On transmission electron microscopic study, the predominant cell was 6 micron in diameter and possessed an irregular nucleus, moderate-sized nucleolus, marginated heterochromatin, abundant Golgi elements and granules, and prominent intermediate filaments. The cells were analyzed with normal and factor-deficient human plasmas and contained significant amounts of tissue factor-like procoagulant activity. This is the first report of a well-characterized medullary thymocyte T-ALL in which DIC was an accompanying feature, and the first demonstration of tissue factor-like procoagulant activity in acute lymphoblastic leukemia. In view of thrombohemorrhagic phenomena observed in association with other medullary thymocyte leukemias, these findings suggest that tissue factor-like procoagulant activity may be a characteristic of medullary thymocyte-derived lymphoid leukemias.

Primary leptomeningeal presentation of T-cell lymphoma. Report of a patient and review of the literature

Although secondary leptomeningeal lymphoma is relatively common, primary leptomeningeal lymphoma is rare. We report a patient with the extremely unusual clinical and pathologic presentation of a primary T-cell lymphoma of the leptomeninges. Diagnosis was established by morphologic and immunologic studies of cerebrospinal fluid (CSF) and brain biopsy. The leptomeningeal lymphoma responded well to intrathecal chemotherapy and irradiation but the patient has severe residual motor paralysis. The clinical and pathological features of primary and secondary central nervous system (CNS) lymphoma are reviewed in reference to this most unusual patient.

Tubular complexes of endoplasmic reticulum in lymphoblastic lymphoma: case report

Distinctive intracytoplasmic tubular complexes have been identified occasionally by electron microscopy in a wide variety of hematologic and nonhematologic disorders. The mechanism of induction and significance of these tubular complexes are unknown. Tubular complexes were identified in the majority of bone marrow lymphoma-leukemia cells in a patient with documented lymphoblastic lymphoma in lymph node. These complexes varied in size but in general ranged from 800--1500 nm, and consisted of masses of nonparallel, twisted, smooth, 40-nm tubules. Continuity with adjacent endoplasmic reticulum was evident in some of the complexes. Cytochemical characteristics of the malignant cells included strong, focal, paranuclear acid phosphatase reactivity and strong, stippled nuclear terminal deoxynucleotidyl transferase positivity. Flow cytometric analysis showed a DNA-RNA content pattern consistent with acute lymphoblastic leukemia and typical of T-cell lymphoma. This represents the first report of such tubular complexes in a presumed T-cell malignancy.

Lysosomal localisation of parallel tubular arrays in chronic lymphocytic leukaemia of T cell origin: an ultrastructural cytochemical study

An ultrastructural cytochemical study of lysosomal acid phosphatase was performed on leukemic cells in a case of chronic lymphocytic leukaemia of T cell origin (T-CLL). The cells showed inclusion bodies known as parallel tubular arrays, which often lay within acid phosphatase-positive, membrane-bound spaces. This suggests their lysosomal location.