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

CD30/CD30 Ligand and CD40/CD40 Ligand in Malignant Lymphoid Disorders

CD30 and CD40 are members of the tumor necrosis factor (TNF) receptor family. These two receptors have pleiotropic biologic functions including induction of apoptosis and enhancing cell survival. This review will discuss the pattern of expression of these receptors in malignant lymphoid disorders and their prospective ligands. Understanding issues related to these two ligands and their receptors in lymphoid malignancies may help to improve the classification of these diseases and could open the doors for new treatment strategies.

Anaplastic large cell lymphoma: pathology, genetics, and clinical aspects

Anaplastic large cell lymphoma (ALCL) was first described in 1985 as a large-cell neoplasm with anaplastic morphology immunostained by the Ki-1 antibody, which recognizes CD30. In 1994, the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) fusion receptor tyrosine kinase was identified in a subset of patients, leading to subdivision of this disease into ALK-positive and -negative ALCL in the present World Health Organization classification. Due to variations in morphology and immunophenotype, which may sometimes be atypical for lymphoma, many differential diagnoses should be considered, including solid cancers, lymphomas, and reactive processes. CD30 and ALK are key molecules involved in the pathogenesis, diagnosis, and treatment of ALCL. In addition, signal transducer and activator of transcription 3 (STAT3)-mediated mechanisms are relevant in both types of ALCL, and fusion/mutated receptor tyrosine kinases other than ALK have been reported in ALK-negative ALCL. ALK-positive ALCL has a better prognosis than ALK-negative ALCL or other peripheral T-cell lymphomas. Patients with ALK-positive ALCL are usually treated with anthracycline-based regimens, such as combination cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) or CHOEP (CHOP plus etoposide), which provide a favorable prognosis, except in patients with multiple International Prognostic Index factors. For targeted therapies, an anti-CD30 monoclonal antibody linked to a synthetic antimitotic agent (brentuximab vedotin) and ALK inhibitors (crizotinib, alectinib, and ceritinib) are being used in clinical settings.

T-cell lymphomas, a challenging disease: types, treatments, and future

T-cell lymphomas are rare and aggressive malignancies associated with poor outcome, often because of the development of resistance in the lymphoma against chemotherapy as well as intolerance in patients to the established and toxic chemotherapy regimens. In this review article, we discuss the epidemiology, pathophysiology, current standard of care, and future treatments of common types of T-cell lymphomas, including adult T-cell leukemia/lymphoma, angioimmunoblastic T-cell lymphoma, anaplastic large-cell lymphoma, aggressive NK/T-cell lymphoma, and cutaneous T-cell lymphoma.

Anaplastic Large Cell Lymphoma of the Breast

A primary anaplastic large cell lymphoma of the breast is presented. A 19-year-old man presented with a swelling of the breast of a short duration. This was not associated with lymphadenopathy or ulceration of the skin. Biopsy of this lesion showed the presence of large, anaplastic cells with multinucleation and markedly indented, ‘embryo-like’ nuclei. The tumor cells were present within breast tissue and surrounded breast ducts. A panel of immunohistochemical markers showed these large cells to be CD30, CD3, and EMA positive. This case emphasizes the occurrence in the breast of anaplastic large cell lymphoma as a primary tumor. It should be considered in the differential diagnosis of anaplastic tumors occurring in the breast, and pertinent immunohistochemistry is recommended.

Pediatric Anaplastic Large Cell (CD30+) Lymphomas Associated With the t(2;5) (p23;q35) Chromosomal Abnormality

Translocation of genetic material from the short arm of chromosome 2 to the long arm of chromosome 5, t(2;5)(p23;q35), has been associated with so-called histiocytic malignancies, with large T-cell lymphoma in childhood and with CD30+ (Ki-1) lym phoma. In an attempt to clarify the relationship between the t(2;5)(p23;q35) abnor mality and tumors in the pediatric age group, three cases of t(2;5)(p23;q35) from the files of the Adelaide Children's Hospital were accessed and clinical and histological data were reviewed. All cases had been originally diagnosed as hematolymphoid tumors. Histologically, the tumors were anaplastic large cell lymphomas, two of pleomorphic and one of monomorphic subtype. When immunohistochemistry was performed, all three were positive for CD30, characteristic of Ki-1 lymphoma. Two were positive for epithelial membrane antigen, all were positive for at least one T-cell marker, and all were negative for histiocytic markers. The monomorphic tumor recurred on several occasions, but the worst outcome occurred in one of the pleomorphic tumors, which proved fatal within 6 months. The precise significance of the breakpoints at 2p23 and 5q35 is not known, although it is not thought to be related to the proximity of the c-fms proto-oncogene, the colony stimulating factor 1 gene, or the N- myc proto-onco gene. The uniformity of the chromosomal abnormality contrasts with the variability of tumor morphology and clinical outcome. Close follow-up evaluation of current cases will be necessary to enable further characterization of this heterogeneous group of lymphoid tumors. Int J Surg Pathol 1 (1): 43-50, 1993

ALK as a paradigm of oncogenic promiscuity: different mechanisms of activation and different fusion partners drive tumors of different lineages

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase protein implicated in a variety of hematological malignancies and solid tumors. Since the identification of the ALK gene in 1994 as the target of the t(2;5) chromosomal translocation in anaplastic large cell lymphoma, ALK has been proven a remarkably promiscuous oncogene. ALK contributes to the development of a notable assortment of tumor types from different lineages, including hematolymphoid, mesenchymal, epithelial and neural tumors, through a variety of genetic mechanisms: gene fusions, activating point mutations, and gene amplification. Recent developments led to significant diagnostic and therapeutic advances, including efficient diagnostic tests and ALK-targeting agents readily available in the clinical setting. This review addresses some therapeutic considerations of ALK-targeted agents and the biologic implications of ALK oncogenic promiscuity, but the main points discussed are: 1) the variety of mechanisms that result in activation of the ALK oncogene, with emphasis on the promiscuous partnerships demonstrated in chromosomal rearrangements; 2) the diversity of tumor types of different lineages in which ALK has been implicated as a pathogenic driver; and 3) the different diagnostic tests available to identify ALK-driven tumors, and their respective indications.

[Primary cutaneous CD30+ ALK(-) anaplastic large cell T-cell lymphoma]

Anaplastic large cell lymphomas (ALCL) are characterized by large, pleomorphic cells with a strong expression of cytokine receptor CD 30. We present a 71-year-old patient with several nodules on the right temple extending to his right ear. Based on clinical, histological and immunophenotypic criteria, the diagnosis of a primary cutaneous CD30(+) ALK(-) anaplastic large cell lymphoma was made. After local excision and adjuvant radiotherapy no relapse occurred during a follow-up period of three months.

Distribution and clinicopathologic characteristics of non-Hodgkin's lymphoma in India: a study of 935 cases using WHO classification of lymphoid neoplasms (2000)

The frequency of various subtypes of non-Hodgkin's lymphoma (NHL) differs in various regions worldwide. We studied distribution of various subtypes of NHL by using WHO classification of lymphoid neoplasms (2000), immunophenotyping and clinicopathologic characteristics of various histologic subtypes in 935 cases. B- and T-cell NHL constituted 79.3% and 18.8% of cases. Diffuse large B-cell lymphoma (DLBL) was the most common subtype (50.2%). A lower frequency of follicular lymphoma, marginal zone lymphoma and mantle cell lymphoma (MCL) was noted compared to that observed in the developed countries, whereas a lower frequency of peripheral T-cell lymphoma - not otherwise specified (PTCL-NOS) and extranodal NK/T-cell lymphoma was seen compared to that in the other Asian countries. A higher frequency of DLBL and precursor T-lymphoblastic leukemia/lymphoma was noted. Extranodal and bone marrow involvement in MCL and PTCL-NOS was less frequent. Anaplastic variant of DLBL was noted in 21.5% of all DLBLs. Null/T-cell anaplastic large cell lymphoma presented in the older age.

Primary lymphohistiocytic variant of anaplastic large cell lymphoma of the stomach

Here, we report an unusual case of gastric anaplastic large cell lymphoma (ALCL), lymphohistiocytic variant, in a 70-year-old female patient who presented with epigastric pain, tarry stool and body weight loss. Endoscopic and imaging findings revealed a Bormann type II tumor in the stomach with perigastric lymphadenopathy and multiple tumor nodules in the liver. Total gastrectomy and liver biopsy were performed. Histologically, both gastric and hepatic tumors demonstrated anaplastic large neoplastic cells scattered among numerous reactive histiocytes. Immunostaining of these tumor cells reacted positively for CD30, CD3, CD45 RO/UCHL1, and negatively for epithelial membrane antigen, CD68, lysozyme, CD15, CD79a, CD138, PAX5 and anaplastic lymphoma kinase. Both the morphologic and immunophenotypic findings supported the diagnosis of gastric ALCL of lymphohistiocytic variant with liver metastasis. This patient then received chemotherapy and was still alive after 17 months of follow-up, without evidence of residual disease.

Extra copies of chromosome 2 are a recurring aberration in ALK-negative lymphomas with anaplastic morphology

The purpose of this study was to evaluate fluorescence in situ hybridization abnormalities of the 2p23 anaplastic lymphoma kinase (ALK) gene loci in lymphomas with anaplastic morphology. We studied 24 anaplastic large cell lymphomas (ALCL) classified by World Health Organization criteria [17 primary nodal/systemic (10 ALK+, 7 ALK-), seven primary cutaneous], and 17 additional non-Hodgkin's lymphomas [one ALK+ B-lineage lymphoma, 14 ALK- diffuse large B-cell lymphomas (seven anaplastic variants, five nonanaplastic, two secondary CD30+), two follicular lymphomas]. ALK- lymphomas with anaplastic morphology showed extra nonrearranged anaplastic lymphoma kinase gene loci (P=0.004) due to trisomy 2 irrespective of the following factors: B or T/null phenotype (P=0.315), diagnostic categories of systemic or cutaneous ALCL or the above-mentioned B-cell lymphomas (P=0.131), and CD30 positivity by immunohistochemistry (P=1.000). Trisomy 2 was absent in all ALK+ lymphomas (P=0.009), which showed rearranged ALK gene loci (P<0.001). Whether trisomy 2 is a primary or secondary event that leads to ALK- lymphomas cannot be determined from this study. Its presence in secondary B-cell lymphomas suggests that trisomy 2 may be a secondary cytogenetic aberration in lymphomas in general. Further investigation of this finding is necessary to further our understanding of the heterogeneous group of ALK- lymphomas.

Establishment of a novel anaplastic large-cell lymphoma-cell line (COST) from a ‘small-cell variant’ of ALCL

Anaplastic large-cell lymphoma (ALCL) is a distinct biological and cytogenetic entity with a broad spectrum of morphological features (common type, small-cell variant and lymphohistiocytic variant). Few cell lines of ALCL are available and they all originate from primary tumors demonstrating the common type morphology (ie large-sized lymphoma cells). We established a new ALCL cell line (COST) from the peripheral blood of a patient with a small-cell variant of ALCL, at diagnosis. Cells growing in vitro and in SCID mice consisted of two populations, that is, small- and large-sized cells as seen in the patient's tumor. Both large and small malignant cells were positive for CD43/MT1 T-cell associated antigen, perforin, granzyme B and TIA-1, but negative for CD2, CD3, CD5, CD7, CD4 and CD8 antigens. Standard cytogenetic studies as well as multiplex FISH confirmed the presence of the canonical t(2;5)(p23;q35) translocation, but also revealed additional numerical and structural abnormalities. The COST cell line is the first ALCL small-cell variant cell line, and thus provides a potentially useful tool for further functional and molecular studies that should improve our understanding of the small-cell variant of ALCL, which is more frequently complicated by a leukemic phase.

Non-HTLV-1-associated primary gastric T-cell lymphomas show cytotoxic activity: clinicopathological, immunohistochemical characteristics and TIA-1 expression in 31 cases

AIMS

Most primary gastrointestinal lymphomas are of B-cell origin and T-cell origin is very rare. Recent studies have suggested that human T-cell lymphotrophic virus type 1 (HTLV-1) may be involved in the development of primary gastric T-cell lymphoma. We analysed 31 patients with primary gastric T-cell lymphoma in south-west Japan, an area endemic for HTLV-1, and determined their phenotypes, genotypes, and HTLV-1 status.

METHODS AND RESULTS

Here we present 31 cases of primary gastric T-cell lymphoma in a HTLV-1-endemic area in Japan and analyse the clinical status, histology, phenotype and virus status. The median age at onset of primary gastric T-cell lymphoma was 57 years with a gender ratio of M:F = 1.58:1. Six of the 31 primary gastric T-cell lymphoma cases had HTLV-1 proviral DNA (five males, one female), nine of the 31 cases were positive for anti-adult T cell leukaemia antibody, without examination of HTLV-1 proviral DNA (five males, four females), eight were non-HTLV-1-associated primary gastric T-cell lymphoma (four males, four females) and the other eight cases were unknown. Primary gastric T-cell lymphoma usually presented as a large ulcerated tumour at the corpus to the antrum and histologically consisted of anaplastic large cell type (n = 2), pleomorphic large cell type (n = 3), pleomorphic medium and large cell type (n = 14), pleomorphic medium cell type (n = 11), and angioimmunoblastic T-cell lymphoma type (n = 1). There were no clear macroscopic and microscopic differences between HTLV-1-associated and non-HTLV-1-associated primary gastric T-cell lymphoma. Most patients died within 2 years of diagnosis, and both types of primary gastric T-cell lymphoma (with and without HTLV-1) were associated with poor prognosis. Cytotoxic marker analysis showed that HTLV-1-associated lymphomas were negative for TIA-1, while non-HTLV-1-associated lymphomas were positive for TIA-1.

CONCLUSIONS

Our results suggest that in HTLV-1-endemic areas, patients with HTLV-1-associated primary gastric T-cell lymphoma should be managed carefully and that TIA-1 seems to be useful for identifying the aetiology of this lesion.

Molecular biology of anaplastic lymphoma kinase-positive anaplastic large-cell lymphoma

Anaplastic large-cell lymphoma (ALCL) provides an excellent example of how molecular insights into tumor pathogenesis are influencing and improving tumor classification. ALCL was described initially as a subtype of T-cell/null-cell lymphoma characterized by unusual tumor cell morphology and the expression of CD30. However, it was soon recognized that a subset of ALCLs contained chromosomal translocations involving anaplastic lymphoma kinase (ALK), a novel receptor tyrosine kinase gene. These rearrangements create chimeric genes encoding self-associating, constitutively active ALK fusion proteins that activate a number of downstream effectors, including phospholipase C-gamma, phosphoinositol 3'-kinase, RAS, and signal transducer and activator of transcription proteins, all of which seem potentially important in cellular transformation. Not all tumors classified as ALCLs have ALK rearrangements and, conversely, ALK rearrangements occur in lymphomas of widely varying morphology. Hence, only molecular markers can reliably identify ALK+ ALCL. The importance of doing so is reflected by clinical studies suggesting that ALK+ ALCLs have a significantly better prognosis than other aggressive peripheral T-cell or B-cell lymphomas, including ALK- ALCLs. The unique molecular pathogenesis of ALK+ ALCL is likely to lead to novel therapeutic approaches directed at specific inhibition of ALK or downstream effectors.

Ki-1(CD30) positive anaplastic large cell lymphoma: primary nodal disease relapsing as erythroderma

Ki-1 (CD30) positive anaplastic large cell lymphoma (ALCL) is an uncommon, high-grade non-Hodgkin's lymphoma with distinct morphologic and immunohistochemical features. Solitary or multiple ulcerated nodules typically characterize cutaneous involvement. Erythroderma is very rare. We report the first case of primary nodal ALCL in which disease relapse manifested as generalized papules, nodules, and erythroderma. This unusual case expands the spectrum of cutaneous disease associated with Ki-1 positive ALCL and highlights the need for early biopsy in patients with a history of Ki-1 positive ALCL who have skin lesions develop.

Anaplastic T large cell lymphoma diagnosed by exfoliative cytology in a post renal transplant patient

In the last two decades posttransplant lymphoproliferative disorders (PTLDs) have been recognized as a complication of organ transplantation with immunosuppression. The reported incidence of PTLDs in renal transplant patients ranges between 0.3-3% (Birkeland et al., Transplantation 1999;67:876-881). In contrast to the reported incidence of PTLDs in post bone marrow transplant, it is 1% in HLA-matched recipients and up to 20% in HLA mismatched T-cell depleted bone marrow recipients (Curtis et al., Blood 1996;94:2208-2216). In cardiac transplant recipients the reported incidence of PTLDs is between 1.8-9.8 (Mihalov et al., Clin Transplant 1996;10:248-255). PTLDs are predominately extranodal. They have varied morphologic patterns and clonality, but almost all are associated with Epstein-Barr virus (EBV). The vast majority are of B cell lineage; only about 10% are of T-cell origin. We report a T-cell anaplastic large cell lymphoma (ALCL) presenting with bilateral pleural effusion and liver involvement in a renal transplant recipient.

CD30 expression in follicular lymphoma

CONTEXT

CD30(+) anaplastic large cell lymphomas were originally described as being of T-cell, null cell, and B-cell origin. CD30, however, is not a specific marker of anaplastic large cell lymphoma and has been found to be expressed in reactive as well as neoplastic populations as a probable activation marker. In addition, CD30(+) cells have also been described in both diffuse large B-cell and follicular lymphomas (FLs), resembling the pattern seen in reactive tonsils and lymph nodes.

OBJECTIVE

We report an index case of FL with CD30 expression, which on initial touch preparations and flow cytometric immunophenotyping revealed a prominent population of CD30(+) cells with marked cellular pleomorphism (anaplasia) in a background of typical FL. Immunohistochemistry of the paraffin section for CD30 in our index case confirmed unequivocal CD30(+) pleomorphic cells in the malignant nodules in occasional clusters. This case prompted a study of additional cases of FL for pattern of immunoreactivity with CD30 on paraffin sections.

DESIGN

Twenty-two additional cases of FL (grades 1-3) were retrieved for CD30 immunoperoxidase staining as in the index case.

RESULTS

This study demonstrated 32% of the additional cases of FL had definitive CD30(+), large, pleomorphic malignant cells by paraffin immunohistochemistry. In 2 cases (9%), the pattern of immunoreactivity with CD30 showed clustering and variable staining of large cells, as our index case.

CONCLUSION

This study underscores the morphologic and immunophenotypic spectrum of FL that includes CD30 staining and cellular pleomorphism.

Peripheral T/NK-cell lymphoma: a report of the IXth Workshop of the European Association for Haematopathology

AIMS

In April 1998, The European Association for Haematopathology organized the IXth workshop on peripheral T-cell and NK-cell lymphomas and leukaemias. The workshop focused on unusual subtypes of these rare malignancies, allowing evaluation of the recently published WHO classification of neoplastic diseases of the lymphoid tissues.

METHODS AND RESULTS

One-hundred and three cases were centrally immunophenotyped and hybridized for EBER1/2 of Epstein--Barr virus. All cases were reviewed by a panel of experienced haematopathologists and classified according to the new WHO classification for lymphoid neoplasms. Three cases were considered as precursor T-cell and 95 cases as peripheral T/NK-cell lymphoma/leukaemia. Although the cases represented a selected series of unusual cases, the following conclusions could be made: (i) Most lymphomas except the hepatosplenic gamma/delta T-cell lymphomas showed a rather broad morphological spectrum, with differences both between and within individual tumours. (ii) This heterogeneity was also reflected by the immunophenotype, for instance a variable expression of CD30 was found in many enteropathy type T-cell lymphomas. (iii) Exceptions in phenotype were regularly found in almost all categories, indicating that phenotype should not be the final determining factor in classification. (iv) The great majority of T-cell lymphomas expressed the alpha/beta T-cell receptor, with the exception of all but one hepatosplenic T-cell lymphomas and a few other extranodal peripheral T cell lymphomas. (v) Malignancies of precursor cells, blastic NK-cell lymphoma/leukaemia, adult T-cell lymphoma/leukaemia and most AIL-type T-cell lymphomas did not express cytotoxic molecules such as TIA1 and granzyme-B. In contrast, all five aggressive NK/T-cell lymphomas/leukaemias, a single case of large granular lymphocyte leukaemia and 40 of 47 primary extranodal lymphoma/leukaemias expressed these molecules. In hepatosplenic gamma/delta T-cell lymphoma, five of six cases showed expression of TIA1 but not of granzyme-B. (vi) Seven tumours developed after organ-transplant, four cases being EBV-positive. No distinct phenotype could be attributed to these cases.

CONCLUSIONS

Most peripheral T/NK cell lymphomas could be categorized as distinct entities as described in the recently proposed WHO classification for lymphoid neoplasms.

Anaplastic large cell lymphoma: the shifting sands of diagnostic hematopathology

Anaplastic large cell lymphoma (ALCL) is a paradigm for the process used to define new disease entities, and provides a model that is applicable to all areas of pathology. ALCL was first recognized based on characteristic histologic features (sinusoidal invasion) and a distinctive immunophenotype (CD30+). However, neither sinusoidal invasion nor CD30-positivity proved to be entirely specific. Subsequently, a characteristic cytogenetic abnormality was identified, the t(2;5), that led to identification of the genes involved in the translocation (NPM/ALK) and insights into the pathogenesis. Generation of monoclonal antibodies to the aberrantly expressed anaplastic large cell lymphoma kinase (ALK) such as ALK-1 can be used diagnostically, and have led to improved definition of the diagnostic entity with important clinical and prognostic implications. These studies also have clarified the relationship of ALCL to Hodgkin's disease, another lymphoid malignancy associated with CD30 expression. We have learned that the ultimate histologic spectrum of ALCL is both narrower and broader than originally believed. The small cell and lymphohistiocytic variants of ALCL are ALK-positive, and are an accepted part of the disease entity, although the neoplastic cells may appear neither large nor anaplastic. Conversely, most cases of Hodgkin's-like ALCL have proved to be more closely related to true Hodgkin's disease, and are unrelated to ALCL.

T Cell and NK Cell Lymphoproliferative Disorders

This review covers the diagnosis and management of natural killer and peripheral T-cell lymphomas (PTCL). Problems with PTCL include their rarity, representing usually 10-15% of non-Hodgkin's lymphomas in the Western Hemisphere, morphologic heterogeneity, and lack of immunophenotypic markers for clonality. Additionally, their clinical behavior is variable and may not correlate with morphology.

Dr. Kinney gives a general overview of the diagnosis of PTCL and NK cell neoplasms. Emphasis will be placed on extranodal T cell and natural killer (NK) cell lymphomas such as hepatosplenic lymphoma, subcutaneous panniculitis-like lymphoma and nasal/nasal type T/NK-cell lymphoma. The use of ALK gene regulation in the classification of anaplastic large cell lymphoma is also reviewed.

Dr. Loughran describes current understanding of the pathogenesis of large granular lymphocyte (LGL) leukemia. The discussion focuses on LGL leukemia as an instructive model of dysregulated apoptosis causing both malignant and autoimmune disease. Current management options and mechanisms of therapeutic response are also described.

Dr. Greer addresses whether PTCL should be treated differently from the more common diffuse large B cell lymphomas. He discusses the therapeutic options for anaplastic large cell lymphoma (ALCL), from a conservative approach for primary cutaneous ALCL to combination chemotherapy for the highly chemosensitive ALCL expressing anaplastic lymphoma kinase. He reviews therapy options for the extranodal subtypes of PTCL by drawing from series in adults, pediatrics, dermatology, and the Far East.

CD30+ anaplastic large cell lymphoma: a review of its histopathologic, genetic, and clinical features

Anaplastic large cell lymphoma (ALCL) represents a generally recognized group of large cell lymphomas. Defining features consist of a proliferation of predominantly large lymphoid cells with strong expression of the cytokine receptor CD30 and a characteristic growth pattern. With the use of molecular and clinical criteria, 3 entities of ALCL have been identified: primary systemic anaplastic lymphoma kinase (ALK)+ ALCL, primary systemic ALK− ALCL, and primary cutaneous ALCL. ALK expression is caused by chromosomal translocations, most commonly t(2;5). ALK+ ALCL predominantly affects young male patients and, if treated with chemotherapy, has a favorable prognosis. It shows a broad morphologic spectrum, with the “common type,” the small cell variant, and the lymphohistiocytic variant being most commonly observed. The knowledge of the existence of these variants is essential in establishing a correct diagnosis. ALK− ALCL occurs in older patients, affecting both genders equally and having an unfavorable prognosis. The morphology and the immunophenotype of primary cutaneous ALCL show an overlap with that of lymphomatoid papulosis. Both diseases have an excellent prognosis, and secondary systemic dissemination is only rarely observed. The described ALCL entities usually derive from cytotoxic T cells. In contrast, large B-cell lymphomas with anaplastic morphology are believed to represent not a separate entity but a morphologic variant of diffuse large B-cell lymphoma. Malignant lymphomas with morphologic features of both Hodgkin disease and ALCL have formerly been classified as Hodgkin-like ALCL . Recent immunohistologic studies, however, suggest that ALCLs Hodgkin-like represent either cases of tumor cell–rich classic Hodgkin disease or (less commonly) ALK+ ALCL or ALK− ALCL.

Primary anaplastic large cell lymphoma of the lung: a clinicopathologic study of five patients

Primary anaplastic large-cell lymphoma is a rare malignancy in the lung. Anaplastic large-cell lymphoma characteristically involves the lymph nodes or skin, with few reports from other sites. We studied the clinical and pathologic features of five cases of anaplastic large-cell lymphoma limited to the lungs. The patients were three women and two men aged 27 to 66 years (mean, 44.6 y) The tumors ranged in size from 1.1 to 5 cm. All patients were CD 30 (Ki-1) positive and CD 15 (LeuM-1) negative. Epithelial membrane antigen immunoreactivity was seen in two patients. Epstein-Barr virus was not detected by immunohistochemistry (four patients tested) or by polymerase chain reaction studies (three patients tested). The immunophenotypes were T cell (n = 3) and null (n = 2). Gene rearrangement studies supported the immunophenotypic findings. One patient who had underlying HIV infection died of infectious complications. One patient died at 6 months. Two patients developed recurrent disease and are alive after 42 and 51 months of follow-up. The remaining patient is alive at 8 years of follow-up without evidence of disease. ALCL can mimic metastatic or primary carcinoma and should be considered in the differential diagnosis of large cell neoplasms of the lung.

Primary CD30/Ki-1 positive anaplastic large cell lymphoma of skeletal muscle with der(17)t(1;17)(q11;p11)

CD30/Ki-1 positive anaplastic large cell lymphoma (Ki-1 ALCL) frequently exhibits extranodal disease and chromosomal t(2;5)(p23;q35). An 11-year-old girl presented with an intramuscular tumor of the right upper arm. Tumors of the chest wall, left arm and leg, hepatomegaly, pleural effusion, and enlarged lymph nodes then developed. The intramuscular tumor and pleural effusion showed a diffuse infiltration of large atypical cells with abundant amphophilic cytoplasms. The tumor cells were positive for CD30, CD2, CD45RO, and p80, but were negative for other T-cell, B-cell, and myeloid cell antigens. She was diagnosed as having Ki-1 ALCL with a T-cell origin. Cytogenetic studies showed an abnormal karyotype including a der(17)t(1;17)(q11;p11). She received seven cycles of intensive chemotherapy followed by an autologous peripheral blood stem cell transplantation, and has been in complete remission for more than two years. The primary involvement of skeletal muscle is quite uncommon in ALCL, and an abnormal karyotype including t(1;17)(q11;p11) has not been reported previously. Since a high frequency of aberrations of 1p36/1q12 or 17p13.3 was detected in sarcoma cells, the presence of suppressor genes is suggestive in these sites.

Pathobiology of NPM-ALK and variant fusion genes in anaplastic large cell lymphoma and other lymphomas

Despite its clinical and histological heterogeneity, anaplastic large cell lymphoma (ALCL) is now a well-recognized clinicopathological entity accounting for 2% of all adult non-Hodgkin's lymphomas (NHL) and about 13% of pediatric NHL. Immunophenotypically, ALCL are of T cell (predominantly) or Null cell type; by definition, cases expressing B cell antigens are officially not included in this entity. The translocation (2;5)(p23;q35) is a recurring abnormality in ALCL; 46% of the ALCL patients bear this signature translocation. This translocation creates a fusion gene composed of nucleophosmin (NPM) and a novel receptor tyrosine kinase gene, named anaplastic lymphoma kinase (ALK). The NPM-ALK chimeric gene encodes a constitutively activated tyrosine kinase that has been shown to be a potent oncogene. The exact pathogenetic mechanisms leading to lymphomagenesis remain elusive; however, the synopsis of evidence obtained to date provides an outline of likely scenarios. Several t(2;5) variants have been described; in some instances, the breakpoints have been cloned and the genes forming a new fusion gene with ALK have been identified: ATIC-ALK, TFG-ALK and TPM3-ALK. Cloning the translocation breakpoint and identifying the ALK and NPM genes provided tools for screening material from patients with ALCL using various approaches at the chromosome, DNA, RNA, or protein level: positive signals in the reverse transcriptase-polymerase chain reaction (RT-PCR) and the immunostaining with anti-ALK monoclonal antibodies (McAb) serve as the most convenient tests for detection of the t(2;5) NPM-ALK since the fusion gene and ALK protein expression do not occur in normal or reactive lymphoid tissue. The wide range of NPM-ALK positivity reported in different series appears to be dependent on the inclusion and selection criteria of the ALCL cases studied. Overall, however, 43% of ALCL cases were NPM-ALK+ (83% of pediatric ALCL vs 31% of adult ALCL). Occasional non-ALCL B cell lymphomas (4%) with diffuse large cell and immunoblastic histology and Hodgkin's disease cases (3%) were NPM-ALK-, but these data are questionable. The aggregate results indicate that, in contrast to primary nodal (systemic) ALCL, the t(2;5) may be present in only 10-20% of primary cutaneous ALCL and rarely, if at all, in lymphomatoid papulosis, a potential precursor lesion; however, these 10-20% positive cases were not confirmed by anti-ALK McAb immunostaining and may represent an overestimate. Positivity for NPM-ALK is associated to various degrees with the following parameters: 44% and 45% of ALCL cases with T cell and Null cell immunophenotype, respectively, are positive, whereas only 8% of cases with a B cell immunoprofile are positive; the mean age of positive patients is significantly younger than that of negative patients; positive cases carry a better overall prognosis (but not in all studies). Recently, the homogenous category of ALK lymphoma ('ALKoma') has emerged as a distinct pathological entity within the heterogenous group of ALCL. The fact that patients with ALK lymphomas experience significantly better overall survival than ALK- ALCL demonstrates further that analysis of ALK expression has important prognostic implications. The term ALK lymphoma signifies a switch in the use of the diagnostic criteria: cases are selected on the basis of a genetic abnormality (the ALK rearrangement), instead of the review of morphological or immunophenotypical features which are clearly more prone to disagreement and controversy. Since its initial description in 1985 ALCL has become one of the best characterized lymphoma entities.

Anaplastic large cell lymphoma arising in bone: report of a case of the monomorphic variant with the t(2;5)(p23;q35) translocation

Anaplastic large cell lymphoma (ALCL) represents approximately 2% of all non-Hodgkin lymphomas according to the recent Non-Hodgkin Lymphoma Classification Project. As defined in the revised European-American classification of lymphoid neoplasms (REAL), ALCL is a neoplasm of T-cell or null-cell lineage; 20% to 60% of cases are associated with the t(2;5)(p23;q35) translocation. ALCL commonly involves nodal as well as a wide variety of extranodal sites, although primary or secondary involvement of bone is rare. We describe the case of a 71-year-old man with stage IE T-cell ALCL, monomorphic variant, arising in the left anterior fifth rib and involving adjacent soft tissue without other sites of disease. The monomorphic histologic features hindered the initial recognition of this neoplasm as ALCL. However, strong uniform CD30 antigen expression and subsequent demonstration of the t(2;5)(p23;q35) translocation and anaplastic lymphoma kinase (ALK) immunoreactivity led to the correct diagnosis. We identified only 5 reported cases of T-cell and null-cell ALCL arising in bone and only 2 of these cases involved a single bone site. All 5 previously reported cases were ALCL of the classic type. We report a case of ALCL that is unique to our knowledge. This case of monomorphic ALCL was localized to bone and tumor cells contained the t(2;5)(p23;q35) translocation.

Primary anaplastic large cell lymphoma of the adrenal gland

Primary adrenal lymphomas are rare. Most reported cases are of B-cell phenotype and follow an aggressive clinical course. We report a case of primary anaplastic large cell, CD30+ adrenal lymphoma developing in a 62-year-old woman. The patient presented with fatigue and vague right upper quadrant pressure. Computed tomography revealed bilateral adrenal masses. A right adrenalectomy was performed. Histologic evaluation showed islands of large atypical cells surrounded by eosinophilic acellular material. The tumor cells stained positive for CD45, CD45RO, CD43, and CD30. Epstein-Barr virus genome was identified in tumor cells using in situ hybridization. The patient was treated with chemotherapy and a 23-month follow-up examination showed no change in the size of the opposite adrenal gland and no other evidence of lymphoma.

Recent advances in the molecular pathogenesis of lymphomas

Most human lymphomas remain heterogeneous biologic entities in spite of recent advances in the description of their clinical presentation, cellular morphology, immunophenotype, and genotype. Elucidation of genetic alterations causing malignant transformation may explain pathogenesis, refine differential diagnosis, clarify prognosis, and provide rational basis for new therapy. During the last year the expression of anaplastic lymphoma kinase clarified presentation and provided clues toward the outcome of anaplastic large cell lymphoma; the breakpoints of t(2;5) were mapped; constitutive activation of anaplastic lymphoma kinase by a chromosomal inversion was described; transformation was shown to be independent of nuclear localization of anaplastic lymphoma kinase; and phospholipase C-gamma was identified as a molecular target for the kinase activity of anaplastic lymphoma kinase. Molecular characterization of recurrent chromosome abnormalities has identified new candidate oncogenes: bcl-9, bcl-10, PAX-5, MMSET, and c-maf. Their precise role in malignant transformation, and the frequency of their alteration in lymphoma and myeloma, is not yet defined. The expression of the antiapoptotic protein bcl-2 on aggressive lymphomas was shown to be associated with inferior disease-free survival by several investigators. This may be a target of pharmacologic reduction of bcl-2 levels. Can these advances in molecular pathogenesis improve cure rates for lymphoma? The spectacularly successful molecular modeling of inhibitors for HIV protease suggests that this may be an attainable objective.

The therapy of primary adult systemic CD30-positive anaplastic large cell lymphoma: results of 40 cases treated in a single center

The outcome of a series of adult patients, affected by primary systemic CD30-positive anaplastic large cell lymphoma (ALCL), treated with a sequential intensive therapeutic program, has been analyzed and all data available in the literature have been reviewed. Forty consecutive, unselected patients with ALCL were treated with the F-MACHOP regimen, followed by radiotherapy (RT) for residual mediastinal disease (15 cases) and by autologous stem cell transplantation (ASCT) conditioned with BAVC (29 cases). Eighty-nine percent (32/36) of the patients younger than 60 years were eligible for completing the sequential treatment. Since then, 3 patients in CR refused ASCT, 1 was excluded for cardiac toxicity and 3 progressed and died of disease. Thus, 29 have been so far submitted to the transplant procedure. CR and PR rates were 40% and 45% respectively after CHT; 52.5% and 35% after RT; 80% and 5% after ASCT, with 78% of patients transplanted in PR convertin to a CR. Actuarial overall survival is 85% at 48.5 months (93% at 66 months for the 29 transplanted patients) and disease free survival is 100% at 54 and 64 months respectively, with no relapses observed among patients who reached a CR. Considering our data and those of the literature, it can be concluded that although the role of ASCT in the therapy of ALCL must not be considered as definitive, its efficacy in converting PR into CR and in preventing relapses, suggests that a randomized trial comparing CHT alone vs CHT+ASCT should be undertaken.

Classification of cutaneous lymphoma: a critical appraisal of recent proposals

The classification of cutaneous lymphoma is a contentious issue. In this short review the merits of REAL classification and EORTC classification for cutaneous lymphoproliferative disease are examined. Points of terminological confusion between the two schemes are considered and a brief account of less common or ambiguous lymphoma types is provided.

Primary gastric T-cell lymphomas: report of two cases and a review of the literature

To understand more fully the clinicopathological features of primary gastric T-cell lymphomas (PGTL), we report two cases of PGTL and review the literature. The present cases were not associated with human T-cell leukemia virus type 1 (HTLV-1) and were at clinical stage IIE. In both cases, T-cell origin of the lymphoma cells was diagnosed immunohistochemically. The clinical courses of these two cases were different: one followed a very aggressive clinical course and the patient died 6 months after the diagnosis, whereas the other patient survived more than 2 years without adjuvant chemotherapy. Clinicopathological features of 23 patients with PGTL are summarized with regard to their differences from primary small intestinal T-cell lymphomas (PSITL) and by association with HTLV-1. The median age at onset of PGTL was 58 years. The gender ratio was male-dominant (M:F = 2.3:1). About two-thirds (10 of 17) of PGTL cases had evidence of HTLV-1 infection. The most common presenting symptom for PGTL was upper abdominal discomfort and/or pain (76%), whereas that in PSITL was weight loss (61%) and diarrhea (42%). Typical lesions for PGTL were large ulcerations at the corpus to antrum. Neoplastic cells had no typical morphological characteristics for PGTL including HTLV-1-associated cases. CD3+4+8- was the most frequently observed surface phenotype of PGTL cells. Laboratory findings at diagnosis were not informative. Most patients were treated by gastrectomy with or without chemotherapy. PGTL, excluding that with HTLV-1, showed better prognosis than PSITL, although PGTL with HTLV-1 had a poorer prognosis.

The expression of TIA-1+ cytolytic-type granules and other cytolytic lymphocyte-associated markers in CD30+ anaplastic large cell lymphomas (ALCL): correlation with morphology, immunophenotype, ultrastructure, and clinical features

Anaplastic large cell lymphomas (ALCL) are a heterogeneous group of CD30+ large cell lymphomas; the most characteristic type have a T or null cell phenotype, often express epithelial membrane antigen (EMA) and cytolytic lymphocyte markers, and often possess a nonrandom t(2;5)(p23;q35) chromosomal translocation. We studied 22 (19 T, 1 null, 2 B cell) ALCL, including four primary cutaneous ALCL (PC-ALCL), for the expression of TIA-1, the cytotoxic T lymphocyte (CTL) or natural killer (NK) cell-associated antigens CD4, CD8, betaF1, TCRdelta1, CD56, and CD57, the ALCL-associated antigens p80 and EMA, and the Hodgkin's disease-associated marker CD15 to better define the relationship of these markers to histological subtype, primary site, and patient clinical characteristics. TIA-1 expression was seen in 12 of 20 (60%) T or null cell ALCLs with a cytoplasmic, granular distribution. Ultrastructural studies showed cytotoxic-type granules (dense core, multivesicular, and intermediate types) with TIA-1 localized to granules on immunogold labeling. TIA-1 staining strongly correlated with young patient age (< or = 32 years, P < .05) and EMA expression (P < .05). Excluding the four PC-ALCL cases, TIA-1 staining also correlated with p80 expression (P < .05) in all of the T cell cases. Three CD15+ cases were TIA-1-. TIA-1 expression in T or null cell ALCL was seen in all morphological subtypes (2 of 2 small cell variant, 3 of 4 monomorphic variant, and 7 of 14 pleomorphic variant) and primary tumor sites (6 of 14 nodal, 2 of 4 primary cutaneous, 2 of 2 bone, and 2 of 2 soft tissue). TIA-1+ granules were seen in all subsets: 5 of 6 CD4+, 1 of 2 CD8+, 4 of 8 CD56+, and 1 of 2 CD57+ ALCL. Of note, 4 of 10 T or null cell ALCL expressed gammadelta T-cell receptors (TCR), whereas only 1 of 10 T or null cell ALCL was alphabeta TCR+; TCR were not detected in five cases. TIA-1 was expressed by 3 of 4 gammadelta TCR+ ALCL and 1 of 1 alphabeta TCR+ ALCL. These data support a cytotoxic lymphocyte phenotype in most T or null cell ALCL and suggest that some T cell ALCL are derived from cytolytic CD4+ T cells, gammadelta T cells, or NK-like (CD56+ or CD57+) T cells.

Characteristics and prognosis of KI-1 positive anaplastic large cell lymphoma in Asians

BACKGROUND

Ki-1 positive anaplastic large cell lymphoma is a rare type of non-Hodgkin's lymphoma (NHL), and has not been extensively described in Asian patients.

AIM

To evaluate the clinical characteristics, prognostic factors and treatment outcome of Ki-1 positive lymphoma in an Asian community.

METHODS

A retrospective analysis of all patients with CD30 antigen positive anaplastic large cell lymphoma from 1987 to 1996 in a single institution.

RESULTS

Of 218 patients with NHL, ten (5%) were identified with Ki-1 positive anaplastic large cell lymphoma. Eight were Chinese, two Indians. The male:female ratio was 1.5:1, and the median age was 32 years. Seven patients presented with B-symptoms, and five had stage III/IV disease. The majority (seven of ten) was low- or low-intermediate risk according to the International Prognostic Index (IPI). Four out of five cases immunophenotyped showed a T-cell origin. Five out of eight patients who received first-line combination chemotherapy achieved a complete remission. Two relapsed, with one being re-induced into a durable second remission. One patient with recurrent cutaneous lymphoma received solely radiotherapy and was disease-free at 20+ years from diagnosis. At analysis, two patients had died, five were disease-free at four, 27, 78, 89 months and 20 years respectively, and three were alive with disease. The IPI appears to have prognostic significance.

CONCLUSION

Incidence and clinical characteristics in our Asian patients were similar to those described in Western populations. The IPI appears to have prognostic relevance. In approximately one-third of patients, long term survival can be achieved with standard treatment.

ALK expression defines a distinct group of T/null lymphomas ("ALK lymphomas") with a wide morphological spectrum

The t(2;5)(p23;q35) translocation associated with CD30-positive anaplastic large cell lymphoma results in the production of a NPM-ALK chimeric protein, consisting of the N-terminal portion of the NPM protein joined to the entire cytoplasmic domain of the neural receptor tyrosine kinase ALK. The ALK gene products were identified in paraffm sections by using a new anti-ALK (cytoplasmic portion) monoclonal antibody (ALKc) that tends to react more strongly than a previously described ALK1 antibody with the nuclei of ALK-expressing tumor cells after microwave heating in 1 mmol/L ethylenediaminetetraacetic acid buffer, pH 8.0. The ALKc monoclonal antibody reacted selectively with 60% of anaplastic large cell lymphoma cases (60 of 100), which occurred mainly in the first three decades of life and consistently displayed a T/null phenotype. This group of ALK-positive tumors showed a wide morphological spectrum including cases with features of anaplastic large cell lymphoma "common" type (75%), "lymphohistiocytic" (10%), "small cell" (8.3%), "giant cell" (3.3%), and "Hodgkin's like" (3.3%). CD30-positive large anaplastic cells expressing the ALK protein both in the cytoplasm and nucleus represented the dominant tumor population in the common, Hodgkin's-like and giant cell types, but they were present at a smaller percentage (often with a perivascular distribution) also in cases with lymphohistiocytic and small cell features. In this study, the ALKc antibody also allowed us to identify small neoplastic cells (usually CD30 negative) with nucleus-restricted ALK positivity that were, by definition, more evident in the small cell variant but were also found in cases with lymphohistiocytic, common, and "Hodgkin's-like" features. These findings, which have not been previously emphasized, strongly suggest that the neoplastic lesion (the NPM-ALK gene) must be present both in the large anaplastic and small tumor cells, and that ALK-positive lymphomas lie on a spectrum, their position being defined by the ratio of small to large neoplastic cells. Notably, about 15% of all ALK-positive lymphomas (usually of the common or giant cell variant) showed a cytoplasm-restricted ALK positivity, which suggests that the ALK gene may have fused with a partner(s) other than NPM. From a diagnostic point of view, detection of the ALK protein was useful in distinguishing anaplastic large cell lymphoma cases of lymphohistiocytic and small cell variants from reactive conditions and other peripheral T-cell lymphoma subtypes, as well as for detecting a small number of tumor cells in lymphohemopoietic tissues. In conclusion, ALK positivity appears to define a clinicopathological entity with a T/null phenotype ("ALK lymphomas"), but one that shows a wider spectrum of morphological patterns than has been appreciated in the past.

Genomic DNA amplification and the detection of t(2;5)(p23;q35) in lymphoid neoplasms

Anaplastic large cell lymphoma (ALCL) is an intermediate grade Non-Hodgkin's lymphoma (NHL) characterized by the frequent presence of the t(2;5)(p23;q35). This translocation fuses the nucleophosmin (NPM) gene on chromosome 5q35 to a protein kinase gene (Anaplastic Lymphoma Kinase, ALK) on chromosome 2p23. In order to determine the frequency of t(2;5) we used a DNA polymerase chain reaction (PCR) amplification using genomic DNA, 5'-primers derived from the NPM gene, and 3'-primers derived from the ALK gene. The presence of amplifiable DNA in the samples was established with PCR and oligonucleotide primers designed to amplify a 3,016 bp fragment from the beta-globin locus. The t(2;5) PCR assay was established using DNA isolated from three t(2;5)-positive ALCL cell lines. Its ability to amplify genomic DNA prepared for routine molecular diagnostic use was validated using archival DNA from four ALCL tumors known to be t(2;5)-positive. Its sensitivity was established by serially diluting t(2;5)-positive DNA in normal DNA: amplicons were generated in 100% of reactions diluted 10(4)-fold (6-8 cells per tube) and in 30% of those diluted 10(5)-fold (0.6-0.8 cells per tube.) We subsequently analyzed archival genomic DNA extracted from 38 ALCL, 77 NHLs, 37 Hodgkin's lymphomas, and 9 lymphomatoid papuloses. The t(2;5) was detected in 6 ALCLs (16%, 95% confidence intervals 6%-31%), but not in any other lymphoma, or in lymphomatoid papulosis. By using the published sequence of the fourth NPM intron that is involved in t(2;5) and by sequencing the individual tumor amplicons and also the normal ALK intron that is involved in t(2;5), we established that all breakpoints involve the same introns in the ALK and NPM loci. Detailed analysis demonstrated that each translocation generates a unique breakpoint sequence, and suggested that sequence homology between the ALK and NPM intron sequences may be involved in the translocation. We conclude that genomic DNA-PCR is useful for the detection of t(2;5) that in our patient population is restricted to ALCL and is not detectable in other NHL, Hodgkin's disease, or lymphomatoid papulosis. More work is needed to determine the prognostic significance of t(2;5), and to establish the utility of the genomic DNA PCR in monitoring minimal residual disease.

Anaplastic large cell malignant lymphoma with extensive eosinophilic or neutrophilic infiltration

AIMS

We describe the clinicopathological features of eight cases of Ki-1 positive anaplastic large cell malignant lymphoma (Ki-1 ALCL) in which there was extensive infiltration by eosinophils and/or neutrophils in the absence of necrosis.

METHODS AND RESULTS

The patients comprised four males and four females with an age range of 24-74 years. Five cases had originally been diagnosed as Hodgkin's disease and one as true histiocytic lymphoma. In all cases, there was massive infiltration by eosinophils and/or neutrophils sometimes to such an extent that malignant cells were obscured. Immunohistochemical staining was performed using the monoclonal antibodies CD30, CD15, CD45, CD20, CD3, CD45RO, epithelial membrane antigen (EMA), CAM5.2, vimentin and CD68. In all cases, tumour cells were strongly positive for CD30 but negative for CD15. One case was positive for CD45 but none expressed B or T-cell markers. Five cases were positive for vimentin and two for EMA. Three of seven patients in whom adequate clinical details were available had stage III or IV disease at presentation and four exhibited B symptoms. Four patients had a peripheral neutrophilia and one a peripheral eosinophilia.

CONCLUSIONS

The study shows that an eosinophil and/or neutrophil-rich variant of Ki-1 ALCD exists, expanding the morphological spectrum of this tumour.

t(2;5) positive lymphoma with peripheral blood involvement

We report two cases of CD30 and t(2;5) positive lymphomas with peripheral blood (PB) involvement. Case one demonstrated the histological appearance of a diffuse large cell lymphoma with disease in the bone marrow (BM) and PB. Immunoperoxidase stains of the BM for CD30 proved to be of value in detecting disease. RT-PCR for the t(2;5) translocation product was positive in the PB, BM and lymph node. Case two had a typical anaplastic large cell lymphoma (ALCL) morphology, with a suboptimal BM biopsy, but abnormal circulating cells in the PB showing the presence of the NPM/ALK fusion product demonstrated by RT-PCR. The first case demonstrates that not all CD30 positive and t(2;5)-associated lymphomas have an anaplastic appearance. Routine staining for CD30 and EMA in BM biopsies is useful for pathological staging. The significance of the t(2;5) in defining a specific histological subtype is unclear. RT-PCR for the t(2;5) is a more sensitive test to detect disease in PB and BM as compared with light microscopy. The clinical significance of molecular staging for patients with ALCL using RT-PCR needs to be evaluated.

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.

Primary Anaplastic Large-Cell Lymphoma in Adults: Clinical Presentation, Immunophenotype, and Outcome

Anaplastic, CD30+, large-cell lymphoma is now a well-recognized pathologic entity that accounts for 2% to 8% of all lymphomas. Recent progress has been made in the understanding of certain biologic features found in anaplastic large-cell lymphoma, but information about its clinical behavior, in comparison to other large-cell lymphomas, is limited. The pathologic review of a large multicenter study of the treatment of aggressive lymphoma identified 146 cases of anaplastic large-cell lymphoma (ALCL) on the basis of morphology and CD30 expression. We compared initial presentation, immunophenotype, and clinical outcome of these cases with those of the 1,695 nonanaplastic diffuse large-cell lymphomas (non-ALCL) included in the same trial. Patients with ALCL were more likely to be male (P = .018) and were younger (P < .0001) than those with non-ALCL. B symptoms were more frequent in ALCL (P = .006). Skin (P < .0001) and lung (P < .05) involvement was also more frequent in ALCL, but frequency of bone marrow involvement was identical (P = .5). Tumor cell phenotype was B in 56 cases (38%), T in 49 cases (34%), and null in 33 cases (22%). Response to chemotherapy (P = .001), event-free survival (P = .006), and overall survival (P = .0004) were better for ALCL than for non-ALCL. Multivariate analyses identified anaplastic character as an independent factor that predicted a longer survival. Tumor cell phenotype did not influence event-free survival (P = .72) or overall survival (P = .83). ALCL in adults is a clinicopathologic entity which, independent of its phenotypic characteristics, has a better outcome than other diffuse large-cell lymphomas.

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.

Pathological and immunophenotypic features of adult non-Hodgkin's lymphomas by age group

To elucidate age-related differences in non-Hodgkin's lymphoma (NHL), the authors evaluated 950 consecutive, human immunodeficiency virus-negative patients (age range, 15 to 96 years) observed between July 1988 and June 1995 in the same Italian cancer institute. Patients were grouped into six age groups and cross-tabulated by Working Formulation (WF) categories and other newly recognized entities according to the Revised European American Lymphoma (REAL) classification, cell immunophenotype, and nodal or extranodal location. There was a tendency of the low-grade category to increase with increasing age (16.8% in the age group 15 to 34 years to 32.4% in the age group 65 to 74 years), although a subsequent decline was seen at age 75 years or older (23.2%). Also the intermediate-grade category was more frequent in the elderly (46.6% and 49.4% at 65 to 74 years and at 75 years or older, respectively). High-grade category showed compared with low and intermediate grade ones, a significant downward trend with age (X2 for trend = 25.31; P < .001), interrupted in only the oldest age group. The relative excess of low-grade NHL in patients older than 55 years. of age was accounted for by the high proportion of small lymphocytic lymphomas, which, however, somewhat declined at age 75 years or older. Conversely, the relative excess of high-grade NHL below age 35 years chiefly derived from the high percentage (28.4%) of CD30-positive anaplastic large cell lymphomas. B- and T-cell lymphomas accounted for 85.9% and 9.0% of all cases, respectively. B- and T- and non-B, non-T-cell and histiocytic NHL accounted for the remaining 5.1%. A highly significant trend of increase in the proportion of B-cell lymphomas with age increase was noted (X2 for trend = 21.90; P < .001); chiefly attributable to the excess of T-cell (15.1%) and undetermined phenotype (18.6%) in patients younger than 35 years of age. Extranodal location was not significantly related to age groups. Thus, the present study showed some interesting differences in NHL morphology and cell phenotype according to age, avoiding, at the same time, the arbitrariness of patients' dichotomization into elderly and nonelderly.

Is it lymphoma or lymphomatoid papulosis?

Distinguishing malignancy from premalignant conditions can be difficult. Controversy surrounds both the clinical and histologic criteria used to distinguish lymphomatoid papulosis, a benign disorder, from CD30+ anaplastic large-cell lymphoma. Three case histories illustrate important points in categorizing different lymphoproliferative disorders as benign or malignant. We emphasize a multidisciplinary approach to improve diagnosis and patient management.

Distinctive clinicopathologic features associated with regressive primary CD30 positive cutaneous lymphomas: analysis of 6 cases

A distinct group of cutaneous lymphomas has been described on the basis of CD30 antigen expression by at least 75% of the tumoral cells. When confined to the skin, these CD30 positive cutaneous lymphomas seem to be associated with a better prognosis than CD30 negative counterparts and spontaneous regression may even occur. We observed a spontaneously regressive evolution in 6 out of 9 CD30 positive primary cutaneous large cell-lymphomas diagnosed during a 5-year period. Clinicopathological data of regressive cases were analysed. The mean age of patients was 56.5 years. They were 3 males and 3 females. Skin lesions were solitary nodule or plaque measuring from 1.5 cm to 11 cm in diameter. Histologically, the lesions were classified as pleomorphic, medium and large cell (5 cases) or large cell anaplastic lymphoma (1 case) according to the updated Kiel classification. Delay for spontaneous regression varied from 1 to 6 months. Three of the 6 patients had cutaneous relapses, followed by a spontaneous regression. All patients remained disease-free with an overall median follow-up of 30 months. Histologically, some distinctive signs such as epidermal pseudo-epitheliomatous hyperplasia, epidermotropism, edema, dermal vascular hyperplasia, seemed to be more frequently associated with spontaneously regressive evolution.

T- and T/natural killer-cell lymphomas of the salivary gland: a clinicopathologic, immunohistochemical and molecular study of six cases

Primary salivary gland lymphomas are almost always of B lineage, with most being represented by low grade B-cell lymphoma of mucosa-associated lymphoid tissue. This study characterizes the rare non-B-cell lymphomas of the salivary gland based on an analysis of six cases. All patients were men, with a mean age of 53.5 years. They presented with submandibular or parotid mass, which on histological examination showed extensive interstitial infiltration by small, medium-sized, or large lymphoid cells. There was prominent invasion and expansion of the ducts and acini in five cases. Angioinvasion was evident in two cases. Three cases were of T lineage and were CD56 negative; one of these cases expressed CD30. Three cases showed an immunophenotype of CD2+ CD3(f)- CD3(p)+ CD56+, consistent with T/natural killer (NK) cell lymphoma. In situ hybridization for Epstein-Barr virus (EBV)-encoded early nuclear RNA (EBER) showed positive reaction exclusively in the three CD56+ cases. Clonal T-cell populations were shown in two CD56-negative cases by polymerase chain reaction on paraffin sections using primers for the T-cell-receptor (TCR) gamma-chain gene, but not in the other four cases (the three CD56+ cases and one CD56- case). Four patients (two CD56+ and two CD56-) died within 3 years, and two were disease free at 4 and 1.5 years, respectively. This study shows that salivary gland T- or T/NK-cell lymphomas cannot be reliably distinguished from B-cell lymphomas on morphological grounds alone, because both can show prominent lymphoepithelial lesions. It appears that T/NK-cell lymphomas, which are often extranodal in localization and strongly associated with Epstein-Barr virus (EBV), show a predilection to involve the salivary glands as well.