Ki-1 lymphomas in childhood: immunohistochemical analysis and the significance of epithelial membrane antigen (EMA) as a new marker

Establishment of a cytokine-producing anaplastic large-cell lymphoma cell line containing the t(2;5) translocation: potential role of cytokines in clinical manifestations

A permanent cell line, HSC-M1, was established from a child with advanced CD30 (Ki-1)+ anaplastic large-cell lymphoma (ALCL). Clinical features included irritability, fever, weight loss, tender lymphadenopathy, pneumonitis, neutrophilia, and bone marrow erythrophagocytosis. While HSC-M1 cells exhibited an immunophenotype characteristic of ALCL of T-cell lineage, the cell line also demonstrated features of monocyte-macrophage lineage. Cytogenetic and polymerase chain reaction (PCR) analysis of the HSC-M1 cell line and involved bone marrow demonstrated the characteristic non-random chromosomal translocation t(2:5)(p23:q35). Reverse transcriptase PCR for mRNA expression of cytokines and cytokine receptors showed that HSC-M1 cells expressed the message for multiple cytokines and their receptors. Measurement of cytokine levels in serum samples using enzyme-linked immunosorbent assays showed increased concentrations of several cytokines. The increased levels of some cytokines correlated with disease activity and clinical symptoms. Although spontaneous production by HSC-M1 cells of some of these cytokines was demonstrated, the production of others was only detectable after stimulation with exogenous CD30 ligand. With few exceptions, there was good correlation between serum cytokine levels and cytokines produced by HSC-M1 cells. These findings indicate that cytokine production is a feature of ALCL cells and that some of the clinical manifestations in ALCL may result from cytokines produced by either the malignant or accessory cells.

Primary cutaneous Ki-1(CD30) positive anaplastic large cell lymphoma in childhood

Primary cutaneous Ki-1(CD30) positive anaplastic large cell lymphoma (ALCL) is an unusual tumor in the pediatric population. However, the nodal-based form of the disease compared with other histologic subsets of childhood non-Hodgkin's lymphomas (NHL) more frequently involves skin, soft tissue, and bone. The objective of this article is to determine the histologic and immunologic characteristics of childhood primary cutaneous Ki-1(CD30) positive ALCL and its prognosis. The clinical data, histologic features and immunohistochemical profiles of skin biopsy specimens from 3 children with cutaneous Ki-1(CD30) positive lymphoma were reviewed. A literature search was performed and disclosed information on 5 childhood cases. The 3 patients with primary cutaneous Ki-1(CD30) positive ALCL all presented similarly as rapidly growing masses initially and clinically believed to be infectious/reactive processes. The diagnosis was established on the basis of histopathologic examination and immunohistochemical studies. Histologic sections revealed an extensive infiltrate of tumor cells extending throughout the entire dermis into the subcutaneous fat with frank ulceration in 1 patient. No significant epidermotropism was noted. Tumor cells exhibited striking cellular pleomorphism and a high mitotic rate with numerous atypical mitoses. Inflammatory cells were present in all patients. The tumor cells stained positively for Ki-1 antigen (CD30), epithelial membrane antigen, and for T-cell markers (UCHL-1, CD3). One of 3 cases, however, failed to stain for leukocyte common antigen (LCA). No clinically apparent adenopathy was observed in any of the patients. In all instances the patients developed recurrent disease in the skin at sites separate from the primary location. None of the patients demonstrated any involvement of lymph nodes, bone marrow, or other organ systems. All patients were treated with chemotherapy with good response. Primary cutaneous Ki-1(CD30) positive lymphoma is rare in children and is characterized by recurrences. The prognosis seems to be favorable.

Malignant histiocytosis. Histologic, cytochemical, chromosomal, and molecular data with a nosologic discussion

Although myelomonoblastic leukemia is thought to originate from a malignant transformation of the stem cell of the mononuclear phagocyte system, malignant histiocytosis (MH) is classically assumed to represent a malignant change of the terminal and fixed elements of this system. Indeed, MH is characterized by the proliferation of large, clear, pleomorphic, "histiocytic-like" HLADR and CD30+ cells resulting in a nodal and extranodal disseminated neoplasm affecting preferentially and severely children and young adults. Although there is broad agreement on the clinicopathologic presentation of this condition, there is currently quite a controversy over the T-lymphoid or histiocytic origin of the proliferative cells that results in a nosologic discussion between the anaplastic large cell lymphoma (ALCL) advocates and the MH supporters. This article has dealt mainly with this nosologic discussion and with the contributions provided by the investigations performed on MH permanent cell lines. These in vitro studies have demonstrated that the proliferation is characterized by a unique chromosomal abnormality, the 5q35bp usually associated with a t(2;5) translocation generating a fusion gene NPM/ALK and the subsequent translation of p80 protein. Although it is known that no single chromosomal abnormality is strictly restricted to a cell lineage, this 5q35bp and associated translocations seem today to represent the hallmark for this condition. In view of these chromosomal aberrations, the CD30+ ALCLs represent a heterogeneous group because 15% to 50% express the NPM/ALK fusion gene. In addition, these in vitro investigations have shown that 5q35bp proliferative cells are glass-adherent, can develop an immunodependent phagocytosis, and are able to reduce NBT and produce TNF-alpha. More significantly, they express constitutively the c-fms (the receptor of the macrophage growth factor) and, under TPA stimulation, are able to modulate the expression of this receptor and its ligand, as well as TNF-alpha and IL-1. None of these cell lines express CD3, but several express CD68 and CD71. In contrast, genomic investigations have shown the underlying existence of monoallelic and even biallelic gene rearrangements for TCR beta and IgJH. In view of these discrepancies between the genomic and phenotypic features of these cells, the histogenetic debate should remain open but must take into account these new chromosomal and molecular data.

An autopsy case of Ki-1 lymphoma associated with hepatic failure

A 62-year-old man was admitted to our hospital because of severe jaundice and fever. Physical examination demonstrated hepatosplenomegaly. The laboratory data revealed elevated serum bilirubin, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase, and the reduced hepaplastin test (Normotest). Computed tomography showed hepatosplenomegaly and swelling of the paraaortic lymph nodes. Although he was treated with antibiotics and steroids, he died of hepatic failure 22 days after admission. At autopsy, his liver weighed 1910 grams, and a histological examination of the liver revealed marked infiltration of CD30 (Ki-1) positive lymphoma cells. He was diagnosed as having non-Hodgkin lymphoma, large cell anaplastic type, Ki-1 lymphoma. We herein report our findings of this very rare case of Ki-1 lymphoma associated with hepatic failure.

Anaplastic large cell lymphoma: a distinct molecular pathologic entity: a reappraisal with special reference to p80(NPM/ALK) expression

The p80(NPM/ALK) expression activated by the t(2;5) (p23;q35) translocation recently has been shown to play an important role in the pathogenesis of anaplastic large cell lymphoma (ALCL). However, the clinicopathologic significance of identification of p80 among ALCL cases has not been completely resolved. Difficulties also exist in the histologic and immunophenotypic identification of ALCL and Hodgkin's disease (HD) as separate processes, often complicating the clinicopathologic evaluation of and therapeutic approach to these entities. In order to clarify these issues, 67 specimens of ALCL and 63 specimens of HD (31 of the nodular-sclerosing type [NS-HD] and 32 of the mixed-cellularity type [MC-HD]) were immunostained using anti-p80 antibody and other relevant markers on paraffin sections. The clinicopathologic and immunophenotypic features were reviewed on the basis of p80 reactivity. The expression of p80 was detected in 43 of 67 cases of ALCL (64%), but none of HD. The p80+ ALCL cases constituted a very homogeneous group of tumors, characterized by the occurrence in a much younger group and relatively more favorable clinical course than the p80- ALCL, which were in keeping with the data previously reported. They showed virtually the identical immunophenotypic findings of p80+, CD30+, EMA+, CD15-, bcl-2-, and Epstein-Barr virus (EBV) with T- and null-cell phenotype, and showed the distinct morphologic features, including three cases of lymphohistiocytic/small-cell variant, as follows: the indented nuclei, often termed as reniform, embryolike, and horseshoelike; multiple, irregular, but indistinct nucleoli; and few reactive cells of eosinophils and epithelioid cells. Conversely, the 24 p80- ALCL cases, in which epithelial membrane antigen (EMA) and bcl-2 positivities were 33% and 55%, respectively, were heterogeneous and could be subdivided into five different categories, namely (a) 11 cases of HD-like ALCLs, (b) six cases of p80 common ALCL, (c) three cases of secondary ALCL, (d) two cases of primary cutaneous ALCL, and (e) two cases of primary classical ALCL that lacked p80 expression. This study clearly demonstrated that the immunohistochemical detection of p80 is of a crucial importance in delineating the biologically distinct entity of "primary classical ALCL" from various diseases that show morphologic and immunohistologic overlap, including HD and HD-like ALCL.

Cytologic diagnosis of Ki-1 lymphoma in pleural and peritoneal effusions: a case report

This is a report of a case of Ki-1-positive large-cell anaplastic lymphoma in an 87-year-old man diagnosed on pleural and peritoneal fluids by cytomorphologic and immunohistochemical examination. Papanicolaou-stained smears revealed many single, large neoplastic cells containing one or two nuclei with occasional multinucleated cells having a wreath-like nuclear arrangement. The tumor cells expressed Ki-1 antigen and epithelial membrane antigen. This is the first known report of Ki-1 lymphoma diagnosed initially on cytologic examination of pleural and peritoneal fluids.

Childhood non-Hodgkin lymphomas in the United Kingdom: findings from the UK Children's Cancer Study Group

AIM

To review the presenting clinical features and the histology of cases of non-Hodgkin lymphoma (NHL) entered into the United Kingdom Children's Cancer Study Group NHL Trial.

METHODS

Sections of biopsy specimens from all cases entered into the trial were stained with Giemsa and haematoxylin and eosin. All cases were stained immunohistochemically for CD45, CD3, CD45RO, CD20, and CD30. Sections were stained with either naphthol AS-D chloroacetate esterase or KP1 (CD68) to identify granulocytic tumours. In a minority of cases, additional immunohistochemical stains were performed when necessary to establish the diagnosis. The sections were reviewed by three pathologists.

RESULTS

Of 308 cases analysed, 293 were categorised as NHL. There was only one case of low grade lymphoma in the series. Over 80% of the cases fell into the categories Burkitt lymphoma (42.2%), lymphoblastic lymphoma (27.2%) and anaplastic large cell lymphoma (15.1%). Cases of Burkitt lymphoma presented most often with abdominal tumours mainly of the ileocaecal region. Tumours of the oropharynx and nasopharynx were also common in this group. Of the 84 lymphoblastic lymphomas, 56 were of the T-cell phenotype, 12 of the B-cell phenotype and 16 of indeterminate lineage. Most of the T-lymphoblastic lymphomas showed mediastinal or pleural involvement. Infiltration of the skin and soft tissues was seen in 25% of lymphoblastic lymphoma of B or indeterminate phenotype. Forty six children were diagnosed as having anaplastic large cell lymphoma, the majority being of T or indeterminate lineage. Most patients presented with lymphadenopathy but involvement of the bones, soft tissues or skin was seen in seven patients and of the mediastinum and lungs in five.

CONCLUSION

Childhood non-Hodgkin lymphomas are almost all high grade and frequently extranodal. They fall mainly into the categories Burkitt lymphoma, lymphoblastic lymphoma and anaplastic large cell lymphoma. The separation of these subcategories can be made on the basis of morphology and immunohistochemical features. The anatomical distribution of these different categories of non-Hodgkin lymphoma is distinctive.

Ki-1 (CD30) anaplastic large-cell lymphoma in children

BACKGROUND

Ki-1 (CD30) ALCL is a rare and distinct type of high-grade NHL. A relevant feature is young age at presentation. Most reported pediatric series are retrospective analyses of heterogeneously-treated cases.

PATIENTS AND METHODS

Between 1976 and 1993, Ki-1 ALCL was diagnosed in 32 children (20 males 12 females; median age 9 years; 10.4% of childhood NHL). Before 1987, original diagnoses had been malignant histiocytosis in 14 cases, and immunoblastic NHL in 2. The treatment program for childhood T-lymphoblastic NHL, except for CNS prophylaxis, was applied in 28/32 cases. Radiotherapy to involved sites not in complete remission within 4 weeks after treatment start was used only prior to 1987.

RESULTS

In 78% of cases, Ki-1 ALCL presented in skin, bone, spleen and lung. Lymph nodes were frequently involved, often in association with periadenitis. Bone marrow and spinal fluid were negative in all cases. Eleven patients were classified as stage I/II, 21 as stage III. Fewer was present in 65% of patients. Cell phenotype was T in 21/32, and null in the remaining 11. Treatment results were evaluable in 27/32 children, all of whom achieved complete remission. Seven relapsed and 4 died of their disease. Five-year survival and progression-free survival were 84% and 72% respectively. Involvement of peripheral lymph nodes, absence of spleen, liver, lung and mediastinum involvement, and male sex were favourable indicators.

CONCLUSIONS

Ki-1 ALCL is a high-grade NHL with a relatively good prognosis when treated with multiagent intensive chemotherapy. Because of its clinical peculiarities a unique treatment approach in probably warranted.

Classification of primary cutaneous T-cell lymphomas

The term cutaneous T-cell lymphoma designates a group of neoplasms of skin homing T-cells that show considerable variation in clinical presentation, histological appearances, immunophenotype and prognosis. The disadvantages of currently available histological classification schemes are discussed and a new classification is presented. This is based on a combination of clinical, histological and immunophenotypic criteria and it recognizes distinct clinico-pathological entities within this group of diseases.

Primary gastric Ki-1 positive anaplastic large cell lymphoma: a report of two cases

Two cases with primary gastric Ki-1 positive anaplastic large cell lymphoma are presented. Morphologic features of both cases involved pleomorphism of the neoplastic cells, fibrosis and lymphatic infiltration. The neoplastic cells in both cases were positive for BerH2 (CD30), LCA(CD45), lysozyme and alpha-1-antitrypsin (alpha 1-AT). In additional case, the neoplastic cells were additionally positive for MAC387 and alpha 1-antichymotrypsin (alpha 1-ACT). The neoplastic cells in these cases were negative for L26(CD20), UCHL-1(CD45RO), DAKO CD3 and epithelial membrane antigen (EMA). According to the results of the phenotypic studies, the authors consider that the neoplastic cells have some of the features of histiocytes. Both patients at 2 and 8 years after surgery without chemotherapy are disease free. This lymphoma is well known to be frequently misdiagnosed as undifferentiated carcinoma. Although rare in occurrence, recognition of this primary lymphoma in the stomach has a significant clinical implication, as the authors consider that its prognosis might be better than undifferentiated carcinoma of the stomach.

Childhood anaplastic large cell lymphoma Ki-1/CD30: clinicopathologic features of 19 cases

The authors report their cumulative experience of 19 children with what was previously called malignant histiocytosis (MH) but is now considered a true lymphoma and termed anaplastic large cell lymphoma (ALCL). The median age at diagnosis was 10 years and 6 months (range 2 y, 11 m, to 15 y). There were 13 males and 6 females. Most cases presented with fever, wasting and enlarged, often tender, lymph nodes. Other features were: fleeting cutaneous rashes in 7 cases; spontaneous regression of lymph nodes and skin lesions were seen in 5 patients. Bone marrow involvement was present in 3 cases, pulmonary infiltrate in 5, kidneys in 2, and central nervous system in none. The morphology of lymph node involvement was consistent with so-called MH, a description originally applied to sinusoïdal infiltration by large "histiocytic" cells. The coexpression of lymphoid activation antigens Ki-1/CD 30 (18/19), epithelial membrane antigen EMA (18/19) and interleukin-2 receptor/CD 25 (10/10) was the unifying immunopathologic feature of the neoplasm. Lineage antigens were not identifiable in 8/19 instances (null phenotype), while 10/19 expressed a T-cell phenotype. None of the tumors expressed histiocytic markers. After variable, but intensive, combination chemotherapy, 15 children out of 18 evaluable achieved complete remission (CR). Among all patients, thirteen are still alive in CR (ten in first CR) with a median follow-up of 5 years. This evaluation in the pediatric age group reinforces that so-called MH is a lymphoid neoplasm, a conceptual change that could lead to improved understanding and therapy.

Spectrum of primary cutaneous CD30 (Ki-1)-positive lymphoproliferative disorders. A proposal for classification and guidelines for management and treatment

Primary cutaneous CD30 (Ki-1)-positive, large cell lymphomas (LCLs) represent a recently recognized group of cutaneous T-cell lymphomas with a favorable prognosis. The characteristic features of this cutaneous lymphoma are reviewed, differences with primary noncutaneous CD30+ LCLs emphasized, and its relation with other CD30+ cutaneous lymphoproliferative disorders, in particular lymphomatoid papulosis, is discussed. These primary cutaneous CD30+ LCLs, lymphomatoid papulosis, and related conditions represent a clinical and histologic continuum. A classification with practical guidelines for the management and treatment of patients within this spectrum of lymphoproliferative disorders is presented.

Primary cutaneous CD30-positive anaplastic large cell lymphoma. Report of 27 cases

The clinical, morphological and immunohistochemical features of 27 patients with anaplastic large cell lymphoma (ALCL) of CD30-positive type, with cutaneous lesions as the sole initial clinical manifestation, were analyzed. The neoplasm presented as solitary or multiple, usually ulcerated skin lesions, affecting predominantly elderly patients (median age: 67 years) with a male preponderance (male to female ratio of 6:1). In most patients, there was an excellent response to chemotherapy. The cardinal histological features included diffuse dermal and subcutaneous infiltration by large, anaplastic tumor cells, all or nearly all of which showed diffuse, strong membrane staining and frequently a paranuclear, dot-like reaction with the CD30 marker (Ber-H2). Epidermal ulceration, pseudo-epitheliomatous hyperplasia and dermal vascular proliferation were also observed.

Ki-1 large cell lymphoma with regressing lesions in a child

An 8-year-old boy was seen with a cutaneous Ki-1 anaplastic, large cell lymphoma with multiple lesions. Some of the lesions showed spontaneous regression. During more than seven years of disease no systemic involvement was observed, but recurrent, self-healing lesions did appear. Histopathologic examination of five lesions revealed a variety of findings, from an inflammatory infiltrate to a highly anaplastic pattern. The neoplastic cells expressed Ki-1 and leukocyte common antigens. Ultrastructurally, those cells showed ruffled indentations. The differential diagnosis includes microvillous malignant lymphoma. The patient has had a four-year follow-up without relapses.

Ki-1 lymphoma: a case report

A case of Ki-1 lymphoma of the large cell anaplastic type with weak leukocyte common antigen expression is presented. These tumors can sometimes demonstrate confusing immunophenotypes (weak or negative leukocyte common antigen, pan T, pan B, HMB 45, and S-100, and anomalous positive epithelial membrane antigen staining), and ultrastructural examination may be requested. The tumor consisted of sheets of large malignant cells with large pleomorphic nuclei, prominent nucleoli, and a high mitotic rate. Ultrastructural examination showed pleomorphic tumor cells with irregular nuclei, large nucleoli, and abundant complex cytoplasm with varied organelles.

Anaplastic large cell Ki-1 lymphoma of bone

Anaplastic large cell Ki-1 lymphoma is an uncommon type of non-Hodgkin's lymphoma that rarely presents primarily in the bone. Three such cases are reported. All patients were young and had bone pain; one had paraparesis as a complication of collapse of the thoracic vertebral body. The involvement was either monostotic or polyostotic. Radiologically, the lesions were lytic and had ill-defined borders. Histologically, the large neoplastic cells had pleomorphic bizarre nuclei, prominent nucleoli, abundant deeply amphophilic cytoplasm, and paranuclear pale hof. They were admixed with variable numbers of inflammatory cells. One case each was of T-cell, B-cell, and non-T non-B lineage. All three cases showed excellent responses to chemotherapy with or without radiation therapy. Recognizing the lymphomatous nature of this highly pleomorphic tumor is important because of its potential curability with appropriate chemotherapy.

A pathologic study of childhood lymphoma in Taiwan with special reference to peripheral T-cell lymphoma and the association with Epstein-Barr viral infection

The authors retrospectively reviewed the clinicopathologic and immunologic features of 65 consecutive cases of childhood lymphoma reported between 1980 and 1989. Southern blot hybridization was also performed in 23 cases to study their association with Epstein-Barr virus (EBV) and human T-cell leukemia virus type 1 (HTLV-1). The 65 cases included 56 non-Hodgkin's lymphoma (NHL) (86%) and 9 Hodgkin's disease (HD) (14%). The NHL could be classified into the following groups: Group I, small noncleaved cell lymphoma (20 cases); Group II, lymphoblastic lymphoma (17 cases); Group III, large cell lymphoma (17 cases); and miscellaneous (2 cases). There was no follicular lymphoma case. Immunohistochemical study on paraffin sections and/or frozen specimens in 47 cases of NHL showed that all the Group I cases belonged to B-cell neoplasm (17 of 17 cases); most of the Group II cases belonged to T-cell neoplasm (9 of 14 cases); and most of the Group III cases were peripheral T-cell lymphoma (PTL) (8 of 16 cases), including 2 cases of Ki-1 lymphoma. The majority of childhood NHL belonged to high-grade malignancy with an aggressive clinical course (median survival time, 8 months). The EBV DNA could be detected from the tumor tissues in 4 of 6 PTL, but in none of the remaining 19 cases of NHL including 6 Burkitt's type lymphomas. HTLV-1 proviral genome was not detected in all specimens examined. The authors concluded that the distribution pattern and clinicopathologic feature of childhood lymphoma in Taiwan are comparable to that in Japan and western countries. The frequent association of EBV with aggressive PTL was unique and deserves additional investigation.

Clinicopathologic study of large cell anaplastic lymphoma (Ki-1-positive large cell lymphoma) among the Japanese

The clinical, prognostic, phenotypic, and genotypic findings of 30 patients with large cell anaplastic lymphoma (Ki-1-positive large cell lymphoma) were analyzed. There were 13 male and 17 female patients (male-female ratio, 0.8) whose ages ranged from 3 to 81 years of age (mean, 28 years of age; 67% of the patients younger than 30 years of age). The 5-year survival rate was 52%; this was better than that of other types of high-grade peripheral T-cell lymphoma. Histologic examination showed distinctive morphologic features such as tumor cell pleomorphism, sinus infiltration, fibrosis, partial lymph node involvement, sparing of B-cell regions, and occasional plasma cell infiltrates. Eighty percent of the cases were of T-cell phenotype, and others expressed neither B-cell nor T-cell markers. The tumors were frequently positive for a histocompatibility antigen (HLA-DR), CD25 (the interleukin-2 receptor), and epithelial membrane antigen. Rearrangements of the T-cell receptor beta gene were observed in nine of 13 cases (69%). These findings indicated that many of the tumors had the phenotype and genotype of activated T-cells. This study also showed that large cell anaplastic lymphoma has a survival figure intermediate between Hodgkin's disease and low-grade peripheral T-cell lymphoma.

Long-term survival in Ki-1 lymphoma

Three patients with histologic and immunologic features of Ki-1-positive large cell lymphoma, who experienced long-term survival, are presented. These three patients at 2, 28, and 49 years of age had adenopathy; all cases had been initially misdiagnosed as metastatic carcinoma or malignant histiocytosis. On subsequent review, they had sinusal and diffuse growth of large pleomorphic cells that were Ber-H2 (Ki-1; CD 30) positive. One case marked as a T-cell lymphoma with UCHL1, one case expressed T-cell and B-cell markers, and one case was negative for both T-cell and B-cell markers. All patients received chemotherapy, and two received local radiation. One patient was not treated until 9 years after initial diagnosis. Two patients had several recurrences, but there has been no evidence of lymphoma in any of the three patients for 63 to 301 months; overall survival time has ranged from 14 to 25 years. These cases are the longest reported survivors with Ki-1 lymphoma; 5 years was the longest survival time previously reported. It also is noteworthy that Ber-H2 and other lymphoid-associated antigens appear to be preserved in formalin-fixed, paraffin-embedded tissues for prolonged periods. This may allow retrospective studies to evaluate the natural history of Ki-1 lymphomas, as well as their spontaneous or treatment-induced regression.

Genotype markers and proto-oncogene analysis in the CD30-positive "malignant histiocytosis" DEL cell line with t(5;6)(q35;p21)

The DEL cell line isolated from a patient who died of malignant histiocytosis exhibits a reciprocal chromosomal translocation t(5;6)(5q35;6p21). The cells were analyzed for Ig(Jh), TCR beta-gene rearrangements and proto-oncogene expression pattern, using a panel of molecularly cloned probes that included c-fms, c-myc, c-myb, c-pim, c-fos, N-myc, c-sis, c-fgr as well as the virally derived probes v-ki-ras and v-src. Consistent levels of expression of c-fms, c-myc, c-myb, c-ki-ras and c-fgr were identified in cells from several in vitro passages as well as from the heterotransplanted tumors in nude mice. Transcripts homologous to the c-fos, c-src and c-sis were not observed. Southern blot study of DNA showed that the banding pattern of the screened proto-oncogenes was not altered. Furthermore, Southern blot analysis demonstrated monoallelic immunoglobulin heavy chain (IgJh) rearrangement but a normal germ-line configuration of the kappa light chain and TCR beta-genes. These results appear to imply that a T- or B-cell origin can be eliminated and that several activated proto-oncogenes, usually expressed in immature MPS cells (c-fms) and myeloblastic cells (c-fgr), may be implicated in the proliferative activity of the DEL cell line, the stem of which may be a primitive, ancestral myelomonocytic cell.

CD30-positive large cell lymphomas ('Ki-1 lymphoma') are associated with a chromosomal translocation involving 5q35

A chromosomal translocation involving a breakpoint on the long arm of chromosome 5 at position q35 has been reported previously in 17 cases of neoplasia. In 14 of these cases the translocation involves exchange of material between chromosome 2 p23 and chromosome 5. Most cases had been diagnosed histologically as malignant histiocytosis but it was suggested recently, following the study of three cases in one of the author's laboratories, that such tumours are in reality lymphoid tumours. In the present paper we report on 12 further neoplasms with a translocation involving the 5q35 breakpoint and show that all were large cell lymphomas expressing the CD30 (Ki-1) antigen, often classifiable histologically as 'Ki-1 lymphoma'. In five cases there was evidence, based on antigen expression and/or genotypic studies, that the neoplasm was of T lymphoid derivation. These findings provide further evidence that translocations involving 5q35 are associated not with histiocytic malignancy, but with large cell lymphoid neoplasms, including typical cases of 'Ki-1 lymphoma' or 'anaplastic large cell lymphoma'. Since cell lines have been established from five of these cases it may be possible in the future to clone the breakpoint on chromosome 5 and to investigate whether there is a gene in its vicinity with oncogenic potential.

Clinicopathological study of Ki-1-positive lymphomas

We examined an antibody against Ki-1 antigen in 161 cases of malignant lymphoma, four of histiocytic sarcoma, and six of nonspecific lymphadenitis, using monoclonal antibody Ki-1, which is known to react selectively with activated lymphocytes, Reed-Sternberg cells, and Hodgkin's cells. Among them, 12 cases of malignant lymphoma demonstrated a diffuse positive cell membrane and/or cytoplasmic reaction of tumor cells and were categorized as Ki-1-positive lymphoma. Nine of these cases exhibited large cells with indented nuclei, distinct nucleoli, and abundant basophilic or amphophilic cytoplasm. Of the remaining three cases, two were of medium-sized and one of small-cell type. Immunologically, the 12 cases of malignant lymphoma demonstrated T-helper/inducer phenotype in six cases, B-cell in two case, and non-T, non-B in four cases. Tac and HLADR were positive in 9/12 and 4/5, respectively, and markers for histiocytes (lysozyme, alpha-1 anti-chymotrypsin, and OK-M1) were usually negative. Clinically, T-cell Ki-1-positive lymphoma was most likely to occur in the elderly, at extranodal sites, and had a rather poor prognosis (mean survival 35.5 months) as compared with B-cell and non-T, non-B lymphoma (7-52 months survival).

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.

Lymphoma phenotyping in formalin-fixed and paraffin wax-embedded tissues: II. Profiles of reactivity in the various tumour types

Recently, monoclonal antibodies capable of phenotyping malignant lymphomas in routinely fixed and processed tissue have become available. Some of these reagents identify lineage-restricted variants of the leucocyte common molecule, whereas others identify unique fixation-resistant epitopes on lymphoid cells, some of which are shared by non-lymphoid tissues. A new generation of antibodies recognizing 'classical' leucocyte antigens such as CD3 are also emerging. Refinements in antigen detection systems, especially for immunoglobulin recognition, combined with these new reagents promise to improve the accuracy of lymphoma diagnosis in routine histopathology. These new antibodies are reviewed, and their limitations, cross reactivities and profiles of staining in lymphoreticular disease are discussed. A strategy for their optimal use is proposed.