Immunoblastic sarcoma: morphologic criteria and the distinction of B and T cell types

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.

Anaplastic large cell Ki-1 lymphoma. Delineation of two morphological types

This report describes 16 cases of the recently recognized anaplastic large cell Ki-1 lymphoma. The disease showed a male:female ratio of 2.2:1 and a bimodal age distribution with peaks in the third and eighth decades. The clinical presentation was highly variable, with lymph node, skin, bone and gastrointestinal tract being the most commonly affected sites. The lymph nodes usually showed subtotal or sinusoidal involvement, and parenchymal fibrosis was common. The large neoplastic cells were almost invariably admixed with many reactive small lymphocytes, histiocytes and/or neutrophils. Two cytological types could be delineated: type I (pale cell, four cases) consisted of large polygonal cells with distinct pink-staining cell membrane and pale cytoplasm and pleomorphic nuclei showing marked chromatin clearing; and type II (basophilic cell, 12 cases) consisted of round or oval cells with basophilic cytoplasm and/or paranuclear pale hof, pleomorphic nuclei often reniform or lobulated and with frequent multinucleated wreath-like and Reed-Sternberg-like cells. Immunohistochemical studies showed that nine cases (56.3%) exhibited a T-cell phenotype, three cases (18.8%) each exhibited a B-cell or null-cell phenotype, while one case exhibited both T- and B-cell markers. Cutaneous involvement at presentation was associated with a favourable outcome, and spontaneous regression was common. For patients with non-cutaneous presentation, the prognosis was relatively good for young patients treated with aggressive chemotherapy, but was grave for old patients.

Mitoses in non-Hodgkin's lymphomas. Frequency and prognostic relevance

The frequency of mitoses was investigated in 279 lymph node biopsies from untreated patients with non-Hodgkin's lymphomas. The data were correlated with histological subtypes and survival time. It could be shown that the frequency of mitoses increases parallel to the amount of large tumor cells, except for lymphoblastic varieties. The proliferative activity was not influenced by a plasmacytoid differentiation. The nodules of follicular centroblastic centrocytic lymphomas revealed more mitoses than did the diffuse lymphomas of a similar grade of malignancy which shows that the growth pattern must be considered when the frequency of mitoses is interpreted. Immuno- and centroblastic lymphomas exhibited no marked differences with regard to mitotic activity. If all lymphomas are subdivided into three groups according to the mitotic grade alone, three survival curves are obtained that differ significantly from each other. It is concluded, therefore, that the mitotic activity of malignant lymphomas is a useful prognostic parameter that, until now, has received unduly limited attention.

Retroperitoneal mass presentations of B-immunoblastic sarcoma

A clinicopathologic analysis of nine patients with B-immunoblastic sarcoma (B-IBS) presenting as a bulky lymph node-based retroperitoneal mass is reported. The histologic and immunologic findings, similar to those reported in B-IBS presenting in various other nodal and extranodal sites, support the recognition of this aggressive large cell non-Hodgkin's lymphoma (NHL) as a distinct pathologic entity. The patients, with a mean age of 60.5 years, presented for evaluation of abdominal pain and a palpable abdominal mass. Four patients were Stage II or IIE, one Stage III, and four Stage IV; eight of nine had B symptoms. Chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin [CHOP-B] or cyclophosphamide, doxorubicin, vincristine, methotrexate with leucovorin rescue, cytarabine [ACOMLA]) yielded significant palliation in five patients (mean survival, 12.3 months); three untreated patients and one receiving radiation treatment (XRT) died within 1 month from diagnosis. There was a striking predilection for pleuropulmonary involvement in disseminating disease. The initial blood lymphocyte count correlated significantly with survival (correlation coefficient, 0.84). The one durable complete remission (CR) was obtained in a patient who received substantial surgical debulking before chemotherapy.

Primary lymphomas of the nasal cavity and paranasal sinuses

Extranodal lymphomas which present in the nasal cavity and/or the paranasal sinuses are rare. Thirty-eight patients with disease that was clinically limited to the head and neck (Ann Arbor Stages IE-IIE) were admitted between 1947 and 1983. Twenty-eight patients were treated with radiotherapy alone and 10 received combination chemotherapy in addition. The overall 5-year survival figure was 56%. The corresponding result for Stage IE was 67%. No patient with Stage IIE disease survived 5 years. Extent of the extranodal disease also influenced results for Stage IE patients who were treated with radiotherapy only. When the extranodal disease was staged using the American Joint Committee TNM system, the 5-year disease-free survival for T1 and T2 patients was 78% as compared with 19% for patients with T3 and T4 disease. The addition of combination chemotherapy improved results for patients with T3 and T4 lesions.

Heterogeneity of response and survival in diffuse histiocytic lymphoma after BACOP therapy (bleomycin, doxorubicin, cyclophosphamide, vincristine, prednisone)

Diffuse 'histiocytic' lymphoma (DHL) is heterogeneous pathologically, consisting of four subtypes within Lukes-Collins; large-cleaved (LC), large non-cleaved (LNC), immunoblastic sarcoma of B cells (B-IBS), and immunoblastic sarcoma of T-cells (T-IBS). This heterogeneity is also recognized in the Cooperative Working Formulation on non-Hodgkin's lymphoma. Prior studies have suggested clinical heterogeneity of DHL as well, although conclusions were hampered by small numbers, and lack of therapeutic uniformity. We treated 57 patients with advanced DHL, using BACOP: 22 LNC, 16 T-IBS, 13 B-IBS, six LC. Complete remission rate for LNC was 64 per cent (14/22); B-IBS was 54 per cent (7/13); LC was 33 per cent (2/6); T-IBS was 25 per cent (4/16). (p = 0.10). Median survival for LNC was 27.8 months, B-IBS was 25.9, LC was 14, T-IBS was 12.0. The survival was significantly shorter for T-IBS patients when compared to the others (p = 0.01). By multi-variate analysis, histologic subtype (p = 0.02), age (p = 0.03), and stage (p = 0.06) were significant and independent prognostic variables in predicting survival. We conclude that LNC may respond the most favourably to BACOP, whereas alternative regimens appear necessary for patients with T-IBS.

Immunoblastic sarcoma of B-cells in a 24-month-old child. Report of a case

Immunoblastic sarcoma is a malignancy of transformed lymphocytes with a high association of occurrence in patients with immune disorders. The youngest previously reported case occurred in a 6-year-old child with immunoblastic lymphadenopathy. The authors report the finding of immunoblastic sarcoma of B-cells in a previously healthy 24-month-old boy. This represents the youngest reported patient with this lymphoma.

Nuclear morphologic and morphometric analyses of large noncleaved cell and immunoblastic non-Hodgkin's lymphomas

Both morphologically and immunologically, non-Hodgkin's lymphoma (NHL) of the large cell type has been shown to be a heterogeneous category. However, the homogeneity of the nuclear parameters, particularly size and condensed chromatin organization, used to classify this subtype of NHL has not been investigated. In fact, objective morphologic techniques have not been systematically applied to verify the segregation of NHL on the basis of nuclear parameters, a concept common to all current classification systems. In this study morphometric image analysis was used to compare the nuclei in 20 specimens from NHLs of the large cell type with those in mantle zone and germinal center lymphocytes from lymph nodes with reactive hyperplasia. Results of the assessment of mean nuclear area in large cell lymphomas revealed that this class is also heterogeneous, with some of the specimens having a nuclear size in the upper range of that for normal small lymphocytes. In addition, in only a few of these specimens was the mean nuclear area within the range of that for fully transformed germinal center lymphocytes. The majority of large cell lymphomas have a nuclear size more characteristic of partially transformed lymphocytes in germinal centers. In addition to indicating inconsistencies in the current diagnostic criteria used in NHL classifications, the results indicate reasons for interobserver variations in clinicopathologic trials; the validity of nuclear size as a prognostic indicator and the biologic basis for classifying NHL as a reflection of normal lymphocyte transformation are also questioned. In terms of patient management, the classifications of NHL currently used require objective reappraisal.

Undifferentiated thyroid tumors of diffuse small cell type. Histological and immunohistochemical evidence for their lymphomatous nature

A histological review of 72 undifferentiated thyroid tumors was performed in order to discover small cell anaplastic carcinomas and Non-Hodgkin lymphomas. Cases suspected to be lymphoma were examined for the presence of Ig and keratin and lectins with a PAP-procedure. Among the 72 cases, 68 (94,5%) were anaplastic carcinomas of various types. Four cases (5,5%) were diffuse small cell tumors, which had previously been regarded as anaplastic carcinomas. All four could be identified as Non-Hodgkin lymphomas by histology, immunohistochemistry, repeat biopsy or autopsy. The findings suggest that the majority of small cell anaplastic thyroid tumors are lymphomas and that true anaplastic small cell carcinoma of the thyroid must be extremely rare. Its diagnosis requires electronmicroscopy and/or immunohistochemistry to demonstrate the epithelial nature of tumor cells.

Non-Hodgkin's lymphoma of the tonsil. A clinicopathologic study of 65 cases

Sixty-five patients presenting to M. D. Anderson Hospital and Tumor Institute with Stages IE and IIE primary tonsillar lymphoma between 1954 and 1981 were reviewed. All cases were non-Hodgkin's lymphomas, with the majority being diffuse large cell lymphoma (85%). Initial therapy was radiotherapy alone in 54 patients, radiotherapy combined with chemotherapy in 8 patients, and chemotherapy alone in 3 patients. Stage was the most important prognostic factor, with 86% and 41% 5-year survivals for Stages IE and IIE, respectively (P = 0.006). Lymphangiography was crucial in staging patients with clinically positive cervical lymph nodes because 94% of clinically staged IIE patients developed recurrent disease, in comparison with only 50% of lymphangiogram-staged IIE patients. The incidence of large cell lymphoma was so high as to preclude analysis of survival by histologic type. From this limited series, radiotherapy alone would appear to be sufficient initial therapy for Stage IE patients, whereas Stage IIE patients probably benefit from the addition of prophylactic chemotherapy. Relapses were most common in nonirradiated lymph-node-bearing areas, with the majority presenting in the first 2 years following initial therapy. The salvage of relapsing patients has been disappointing, with the best hope residing in combination chemotherapy.