Absence of anaplastic lymphoma kinase (ALK) and Epstein–Barr virus gene products in primary cutaneous anaplastic large cell lymphoma and lymphomatoid papulosis

Primary cutaneous anaplastic large cell lymphoma

Primary cutaneous anaplastic large cell lymphoma (PC-ALCL) is a CD30+ lymphoproliferative disorder (LPD) of the skin with a relatively good prognosis in the absence of high-stage disease. CD30+ LPDs comprise approximately 25%-30% of primary cutaneous lymphomas and as a group represent the second most common clonal T-cell neoplasm of the skin behind mycosis fungoides. Diagnosis of PC-ALCL relies strongly on clinicopathologic correlation given the potential morphologic, clinical and molecular overlap with the other cutaneous CD30+ LPD, lymphomatoid papulosis, and more aggressive hematolymphoid neoplasms.

Cutaneous CD30 lymphoproliferative disorders and similar conditions: a clinical and pathologic prospective on a complex issue

We elaborate on the diagnosis of CD30 positive cutaneous lymphoproliferative conditions including the various clinical and pathological presentations, our understanding of its pathomechanisms and prognostic implications. The most common reactive conditions that can simulate CD30 lymphoproliferative conditions, including arthropod bite reactions, various viral infections, pityriasis lichenoides and lymphocytic papules in myelodysplastic syndrome, are discussed in detail.

Differential expression of TRAF1 aids in the distinction of cutaneous CD30-positive lymphoproliferations

Lymphomatoid papulosis (LyP), primary cutaneous anaplastic large T-cell lymphoma (cALCL), and cutaneous infiltrates of systemic anaplastic large cell lymphoma (sALCL) are CD30-positive lymphoproliferative disorders of the skin that overlap clinically, histopathologically, immunophenotypically, and genetically but differ considerably in their prognosis. In particular, lesions of LyP regress spontaneously, whereas those of cALCL and sALCL persist and may progress and spread to extracutaneous sites. In contrast to patients with cALCL, LyP patients do not benefit from an aggressive radio- and/or chemotherapeutic approach. We generated a novel tumor necrosis factor receptor (TNFR)-associated factor 1 (TRAF1) antibody that recognizes a formalin-resistant epitope (Ber-TRAF1A) and investigated the expression of TRAF1, an intracellular component of TNFR signaling, in LyP and ALCL. We could show a strong TRAF1 expression in the tumor cells of most LyP cases (42/49, 84%). In contrast, tumor cells of primary and secondary cALCL revealed TRAF1 expression in only a few cases (3/41, 7%) as shown for sALCL without skin manifestation. The data indicate that TRAF1 expression reliably distinguishes LyP from primary or secondary cALCL. This might be of crucial diagnostic importance and has a strong impact on the treatment decision for patients with cALCL and LyP.

Management of multifocal primary cutaneous CD30 anaplastic large cell lymphoma

Primary cutaneous CD30(+) anaplastic large cell lymphoma in adults is rare, but the prognosis is generally excellent. Skin lesions may be localized or, less commonly, multifocal. Although not extensively reported, multifocal primary cutaneous anaplastic large cell lymphoma tends to relapse after systemic chemotherapy and is generally considered more prone to progress to extracutaneous involvement than the localized disease. We report the case of a 21-year-old woman with primary cutaneous CD30(+) anaplastic large cell lymphoma manifesting as widespread papules and nodules. Despite remaining localized to the skin, the disease relapsed after multiple chemotherapy regimens and autologous stem-cell transplantation. Treatment with an experimental anti-CD30 monoclonal antibody was successful. Review of this case and similar cases illustrates that traditional combination chemotherapy may not be best. Newer treatments, including anti-CD30 monoclonal antibodies, show promise. However, further study is needed to develop optimal therapeutic strategies.

Lymphomatoid papulosis from childhood with anaplastic large-cell lymphoma of the small bowel

Lymphomatoid papulosis (LyP) is a lymphoproliferative disorder that exists on a spectrum of diseases with cutaneous CD30+ anaplastic large-cell lymphoma (ALCL). Multiple treatment options are available, although none are curative. The typical age of onset for LyP is in the third and fourth decades, but it has been seen occasionally in children. Lymphomatoid papulosis is associated with primary cutaneous ALCL and other lymphoproliferative malignancies, but is rarely associated with extranodal systemic ALCL. A 43-year-old man developed lymphomatoid papulosis lesions at 3 years of age, which persisted into adulthood, and he later developed ALCL of the duodenum. Treatment with standard CHOP (cyclophosphamide/doxorubicin/vincristine/prednisolone) chemotherapy resulted in complete remission of his gastrointestinal lymphoma and temporary improvement of his skin lesions. However, the LyP relapsed and proved refractory to psoralen plus ultraviolet-A phototherapy, and was only temporarily and partially responsive to bexarotene and denileukin diftitox.

ALK-negative systemic anaplastic large cell lymphoma: differential diagnostic and prognostic aspects--a review

Anaplastic large cell lymphoma (ALCL) can be divided into two major groups. The first is a spectrum of CD30+ T-cell lymphoproliferative disorders including primary cutaneous ALCL and lymphomatoid papulosis, usually affecting older patients but characterized by an excellent prognosis. The second is systemic nodal ALCL, which on the basis of genetic and immunophenotypic features combined with clinical parameters can be divided into two subgroups: anaplastic lymphoma kinase (ALK)-positive and ALK-negative systemic ALCL. ALK expression, usually the result of a t(2;5) translocation, correlates with the expression of other markers such as EMA and a cytotoxic phenotype, and is strongly related to younger age groups, lower international prognostic index (IPI) risk groups, and a good prognosis. ALK-negative ALCL, however, shows a more heterogeneous immunophenotype and clinical behaviour, and prognostic parameters are needed to determine treatment strategies in individual patients. Besides clinical parameters included in the IPI, recent studies have pointed out several biological prognosticators of potential value, such as the percentage of tumour-infiltrating activated cytotoxic T-lymphocytes. The expression of proteins involved in the execution or regulation of apoptosis, such as activated caspase 3, Bcl-2, and PI9, was also found to be strongly related to clinical outcome. These studies indicate that inhibition of the apoptosis cascade in particular is an important mechanism that can explain the poor clinical outcome in therapy refractory ALCL. Functional studies are required to investigate whether disruption of one or more of the apoptosis pathways is the major factor in the fatal outcome of the disease and whether apoptosis resistance based on inhibition of one pathway can be overcome by activating another pathway that is still intact.

A case of lymphomatoid papulosis with prominent myxoid change resembling a mesenchymal neoplasm

Lymphomatoid papulosis is a chronic recurrent eruption of self-regressing papules and nodules. Histologically this disorder is characterized by large atypical lymphoid cells resembling Reed-Sternberg (RS) cells that are set in a background of a mixed inflammatory infiltrate. Depending on the architecture of the infiltrate and the percentage of atypical cells, the histologic appearance is subclassified as type A, B, or C. The different histologic patterns do not seem to correlate with distinct clinical appearances. We report a case of lymphomatoid papulosis with unusual histologic features affecting a 14-year-old girl. The presence of anaplastic cells in a background of myxoid stroma closely resembled a sarcoma on histologic examination.

Initial spontaneous remission of posttransplantation Epstein Barr virus-related B-cell lymphoproliferative disorder of the skin in a renal transplant recipient: case report and review of the literature on cutaneous B-cell posttransplantation lymphoproliferative disease

Primary cutaneous posttransplantation B-cell lymphoproliferative disorder is rare. The few previously reported patients were all treated with surgery, radiotherapy, or lowering of immunosuppression. We describe a 65-year-old woman presenting with an intermammary skin ulcer 21 years after renal transplantation, proving on biopsy to be an Epstein Barr virus (EBV)-related posttransplantation B-cell lymphoproliferative disorder. A few weeks later, the skin ulcer showed complete clinical regression. Hematologic staging evaluation showed no evidence of extracutaneous involvement. Despite continuation of immunosuppression, the patient stayed free of disease until 18 months after initial diagnosis, when she developed a progressive hemiparesis and died of acute myocardial infarction. At autopsy, a recurrent B-cell posttransplantation lymphoproliferative disorder in the left side of the thalamus region (measuring 1 x 0.8 cm) was established. The long interval between the primary cutaneous lesion and the localized brain recurrence supports primary skin posttransplantation lymphoproliferative disorder, especially because the patient was not treated for her posttransplantation lymphoproliferative disorder. Review of the literature on primary cutaneous posttransplantation B-cell lymphoproliferative disorder and this case gives the impression that cutaneous posttransplantation B-cell lymphoproliferative disorders of B-cell lineage behave in a more benign manner than identical lesions arising extracutaneously. Because of the rare occurrence of posttransplantation B-cell lymphoproliferative disorder primarily involving the skin, extracutaneous origin should be excluded. If B-cell lineage can be established, EBV is present, alterations in oncogenes or tumor suppressor genes associated with malignant lymphoma are absent, and bcl-6 gene mutation associated with progression is absent, initially aggressive treatment might be avoided. However, long-term clinical follow-up with prolonged maintenance therapy (reduction of immunosuppression or antiviral therapy) for prevention of recurrent posttransplantation lymphoproliferative disorder seems indicated, as is demonstrated by the case reported in the current study.

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.

Peripheral T-cell lymphoma

Peripheral (post-thymic) T-cell lymphoma consists of a wide spectrum of disorders with marked differences in biology and behavior. Proper classification is pivotal for evaluating treatment results, and most studies performed a decade ago lump together different disease entities and cannot be interpreted. With improved use of immunophenotyping and molecular methods for these disorders, their exact nature is better defined in the Revised European-American Lymphoma and subsequent World Health Organization (WHO) classifications. The WHO classification of post- thymic T/natural killer (NK)-cell lymphoma consists of 15 entities, including about 30% that are unclassified cases. A wide range in incidence exists between different populations, but it is likely to be lower than previously estimated. Certain entities, like nasal/nasal-type T/NK-cell lymphoma and human T-cell leukemia/lymphoma virus 1, are much more prevalent in certain racial groups and show exquisite viral association. In these entities as a group, prognosis and treatment seem inferior to those of their B-cell counterparts, but treatment must be tailored to the exact pathologic diagnosis and prognostic index. Aggressive combination chemotherapy appears to be curative for certain entities (eg, anaplastic lymphoma kinase-positive), whereas purine analogues may be useful for low-grade entities. The role of autologous and allogeneic stem cell transplantation is still poorly defined. Specific antibody-based therapy is also on the horizon.

Cutaneous T-cell lymphoma developing in a patient on cyclosporin therapy

The use of cyclosporin in the transplant setting is associated with a small but significantly increased risk of the development of lymphoproliferative disorders. These are predominantly but not always related to Epstein-Barr virus (EBV) infection. We report a cutaneous CD30(+) T-cell lymphoma in a patient with atopic eczema during low-dose cyclosporin monotherapy. There was no evidence of EBV DNA transcripts in the tumor tissue as assessed by in situ hybridization. The tumors resolved when cyclosporin therapy was stopped and have not recurred. There are a few reports of primary cutaneous lymphoma in transplant patients. This is the first report to our knowledge of cutaneous lymphoma in a patient treated with low-dose cyclosporin monotherapy. Although this finding may be coincidental, we believe this case highlights the small lymphoproliferative risk associated with cyclosporin.

Fascin expression in CD30-positive cutaneous lymphoproliferative disorders

BACKGROUND

CD30-positive cutaneous lymphoproliferative disorders (LPD) represent a spectrum of diseases ranging from low-grade (lymphomatoid papulosis; LyP) to high-grade (pleomorphic and anaplastic large-cell lymphoma; PTL, ALCL) with overlapping morphologic and immunophenotypic features. The common phenotypic hallmark is the expression of CD30-antigen by the tumor cells which morphologically resemble Reed-Sternberg cells. Although LyP is a non-fatal recurring disorder, it is associated with systemic lymphomas including Hodgkin's lymphoma (HL), mycosis fungoides (MF) and ALCL in 5-20% of the cases. Currently there is no marker to predict the development of systemic lymphomas in patients with LyP. Fascin, an actin bundling protein, has recently been shown to be a unique marker found in almost 100% of classical HL.

METHODS

Because of the association of LyP with HL, fascin expression was analyzed by immunohistochemistry in LyP (n = 45), cutaneous CD30+ ALCL (n = 17) and pleomorphic T-cell lymphoma (n = 9) (PTL) and LyP associated with systemic lymphomas (7 HL, 2 ALCL, 1 MF), with the intent to determine if fascin expression can predict disease progression.

RESULTS

Fascin was expressed by tumor cells in 11/45 (24%) cases of LyP, 11/17 (64%) cases of ALCL, 7/9 (77%) cases of PTL and 6/10 (60%) cases of LyP associated with systemic lymphomas. Fascin expression in LyP was significantly less frequent than in ALCL (p < 0.001) and also than in LyP associated with lymphomas (p < 0.05). There was no significant difference of fascin expression within the histological subtypes of LyP. We found no evidence of ALK expression nor of Epstein-Barr virus expression in any case either by in situ hybridization or immunohistochemistry in the LyP cases associated with HL.

CONCLUSIONS

This is the first study to demonstrate that fascin is expressed in cutaneous CD30+ LPD and that it is a candidate marker of disease progression in LyP.

Proteins encoded by genes involved in chromosomal alterations in lymphoma and leukemia: clinical value of their detection by immunocytochemistry

Acquired chromosomal anomalies (most commonly translocations) in lymphoma and leukemia usually result in either activation of a quiescent gene (by means of immunoglobulin or T-cell-receptor promotors) and expression of an intact protein product, or creation of a fusion gene encoding a chimeric protein. This review summarizes current immunocytochemical studies of these 2 categories of oncogenic protein, with emphasis on the clinical relevance of their detection in diagnostic samples. Among the quiescent genes activated by rearrangement, expression of cyclin D1 (due to rearrangement of the CCND1 [BCL-1] gene) is a near-specific marker of t(11;14) in mantle cell lymphoma; BCL-2 expression distinguishes follicular lymphoma cells from their nonneoplastic counterparts in reactive germinal centers and appears to be an independent prognostic marker in diffuse large cell lymphoma; and TAL-1 (SCL) expression identifies T-cell acute lymphoblastic neoplasms in which this gene is activated. The protein products of other genes activated by chromosomal rearrangement have a role as markers of either lineage (eg, PAX-5 [B-cell-specific activator protein] for B cells, including B-lymphoblastic neoplasms), or maturation stage (eg, BCL-6 for germinal-center and activated B cells and MUM-1/IRF4 for plasma cells). Currently, no hybrid protein encoded by fusion genes is reliably detectable by antibodies recognizing unique junctional epitopes (ie, epitopes absent from the wild-type constituent proteins). Nevertheless, staining for promyelocytic leukemia (PML) protein will detect acute PML with t(15;17) because the microspeckled nuclear labeling pattern for PML-RARalpha is highly distinctive. Similarly, antibodies to the anaplastic lymphoma kinase (ALK) tyrosine kinase are valuable (because wild-type ALK is not found in normal lymphoid tissue) in detecting neoplasms (CD30-positive large T-cell lymphomas) with t(2;5) or its variants. Thus, immunocytochemical detection of the products of many rearranged genes in lymphoma and leukemia can be clinically informative and provide information on cellular and subcellular protein expression that cannot be inferred from studies based on messenger RNA.

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.

ALK expression in extranodal anaplastic large cell lymphoma favours systemic disease with (primary) nodal involvement and a good prognosis and occurs before dissemination

AIMS

In anaplastic large cell lymphoma (ALCL), the site of origin has been described as an important prognostic factor. Recently, a fusion protein containing anaplastic lymphoma kinase (ALK) was described in systemic nodal ALCL, and shown to be associated with a good prognosis. The aims of this study were to investigate whether the presence of ALK protein differs between ALCL of different sites of origin; to determine whether ALK expression occurs before dissemination to other sites; and, finally, to investigate whether the site of origin remains a prognostic parameter in ALK negative ALCL.

METHODS

ALK expression, as detected by immunohistochemistry using the monoclonal antibodies ALK1 and ALKc, was studied in 85 ALCLs from different sites of origin. In 22 patients, ALK expression was studied in multiple biopsies from different sites (including 13 skin, 16 lymph node, and nine other). Overall survival time was analysed using the Kaplan Meier method.

RESULTS

ALK expression was found in 20 of 51 systemic ALCLs with (primary) nodal involvement. No ALK expression was found in 15 primary cutaneous, 14 gastrointestinal, and five nasal ALCLs. Multiple and subsequent biopsies of patients showed ALK expression to be identical to that seen in the primary diagnostic biopsy. Kaplan Meier survival curves showed that in ALK negative ALCLs originating from different sites, primary cutaneous cases are associated with an excellent overall survival, whereas the other cases show a comparable five years survival of less than 40%.

CONCLUSIONS

If present, ALK expression favours systemic ALCL with (primary) nodal involvement, and can be used in differentiating between extranodal involvement of systemic (nodal) ALCL and primary extranodal ALCL. ALK is expressed consistently in multiple biopsies of a given patient, indicating that the chromosomal abnormality leading to aberrant ALK expression occurs before dissemination to other sites. Finally, in ALK negative non-cutaneous ALCLs, different sites of origin show comparable poor survival.