Anaplastic large cell lymphoma: twenty-five years of discovery

The epidemiology and targeted therapies for relapsed and refractory CD30+ lymphomas

BACKGROUND

Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL) both have consistent expression of CD30, a cytokine receptor that is expressed by activated T and B cells but is largely absent from normal tissue.

METHODS

A literature search was conducted via PubMed, Google Scholar, and UpToDate to identify relevant peer-reviewed original research or review articles on HL, sALCL, and CD30 targeted therapies.

RESULTS

These lymphomas are both more common among males, young adults and the elderly. Although many patients with HL and sALCL can achieve long-term remission after standard first-line therapy, up to a third of these patients are refractory to or relapse after initial therapy. Among these relapsed/refractory patients, many experience disease progression and/or death despite subsequent treatment, and treatment-related adverse events and mortality are not uncommon. To address the need for safer and more effective therapies for these relapsed/refractory patients, researchers have developed therapies that specifically target CD30-expressing cells. Brentuximab vedotin, an antibody-drug conjugate that selectively delivers a toxic microtubule-disrupting agent to malignant cells with CD30 expression, is the first such therapy to be approved in the US and Europe. In clinical trials, brentuximab vedotin has demonstrated efficacy and safety in patients with HL after failure of autologous stem cell transplantation (ASCT), or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates, and in patients with sALCL after failure of at least one prior multi-agent chemotherapy regimen.

CONCLUSION

HL and sALCL are both CD30+ lymphomas, and therapies like brentuximab vedotin that target cells expressing CD30 hold promise for the treatment of these diseases.

Next-generation sequencing identifies deregulation of microRNAs involved in both innate and adaptive immune response in ALK+ ALCL

Anaplastic large cell lymphoma (ALCL) is divided into two systemic diseases according to the expression of the anaplastic lymphoma kinase (ALK). We investigated the differential expression of miRNAs between ALK+ ALCL, ALK- ALCL cells and normal T-cells using next generation sequencing (NGS). In addition, a C/EBPβ-dependent miRNA profile was generated. The data were validated in primary ALCL cases. NGS identified 106 miRNAs significantly differentially expressed between ALK+ and ALK- ALCL and 228 between ALK+ ALCL and normal T-cells. We identified a signature of 56 miRNAs distinguishing ALK+ ALCL, ALK- ALCL and T-cells. The top candidates significant differentially expressed between ALK+ and ALK- ALCL included 5 upregulated miRNAs: miR-340, miR-203, miR-135b, miR-182, miR-183; and 7 downregulated: miR-196b, miR-155, miR-146a, miR-424, miR-503, miR-424*, miR-542-3p. The miR-17-92 cluster was also upregulated in ALK+ cells. Additionally, we identified a signature of 3 miRNAs significantly regulated by the transcription factor C/EBPβ, which is specifically overexpressed in ALK+ ALCL, including the miR-181 family. Of interest, miR-181a, which regulates T-cell differentiation and modulates TCR signalling strength, was significantly downregulated in ALK+ ALCL cases. In summary, our data reveal a miRNA signature linking ALK+ ALCL to a deregulated immune response and may reflect the abnormal TCR antigen expression known in ALK+ ALCL.

Advances in understanding the pathogenesis of systemic anaplastic large cell lymphomas

The currently used 2008 World Health Organization classification recognizes two types of systemic anaplastic large T cell lymphoma according to ALK protein expression in tumour cells. First, the 'anaplastic large cell lymphoma, ALK positive' (ALK(+) ALCL) that is characterized by the presence of ALK gene rearrangements and consequent ALK protein expression, and, second, the 'anaplastic large cell lymphoma, ALK negative' (ALK(-) ALCL) that is a provisional entity lacking ALK protein expression but cannot be distinguished morphologically from ALK(+) ALCL. In this review we summarize the current knowledge on the genetic lesions and biological features that underlie the pathogenesis of ALK(+) and the ALK(-) ALCL and that can lead to the use of targeted anti-cancer agents.

Anaplastic large cell lymphomas: ALK positive, ALK negative, and primary cutaneous

Anaplastic large cell lymphomas (ALCLs) comprise a group of CD30-positive non-Hodgkin lymphomas that generally are of T-cell origin and share common morphologic and phenotypic characteristics. The World Health Organization recognizes 3 entities: primary cutaneous ALCL (pcALCL), anaplastic lymphoma kinase (ALK)-positive ALCL, and, provisionally, ALK-negative ALCL. Despite overlapping pathologic features, these tumors differ in clinical behavior and genetics. pcALCL presents in the skin and, while it may involve locoregional lymph nodes, rarely disseminates. Outcomes typically are excellent. ALK-positive ALCL and ALK-negative ALCL are systemic diseases. ALK-positive ALCLs consistently have chromosomal rearrangements involving the ALK gene with varied gene partners, and generally have a favorable prognosis. ALK-negative ALCLs lack ALK rearrangements and their genetic and clinical features are more variable. A subset of ALK-negative ALCLs has rearrangements in or near the DUSP22 gene and has a favorable prognosis similar to that of ALK-positive ALCL. DUSP22 rearrangements also are seen in a subset of pcALCLs. In this review, we discuss the clinical, morphologic, phenotypic, genetic, and biological features of ALCLs.

Pathology of T-cell lymphomas: diagnosis and biomarker discovery

T-cell lymphomas are a group of predominantly rare hematologic malignancies that tend to recapitulate different stages of T-cell development, in a similar way that B-cell lymphomas do. As opposed to B-cell lymphomas, the understanding of the biology and the classification of T-cell lymphomas are somewhat rudimentary, and numerous entities are still included as 'provisional categories' in the World Health Classification of hematolopoietic malignancies. A relevant and useful classification of these disorders have been difficult to accomplish because of the rarity nature of them, the relative lack of understanding of the molecular pathogenesis, and their morphological and immunophenotypical complexity. Overall, T-cell lymphomas represent only 15 % of all non-Hodgkin lymphomas. This review is focused on addressing the current status of the categories of mature T-cell leukemias and lymphomas (nodal and extranodal) using an approach that incorporates histopathology, immunophenotype, and molecular understanding of the nature of these disorders, using the same philosophy of the most recent revised WHO classification of hematopoietic malignancies.

Hemophagocytic lymphohistiocytosis in association with primary cutaneous anaplastic large cell lymphoma

Hemophagocytic lymphohistiocytosis (HLH) has a well known association with lymphomas, especially of T cell origin. Prognosis of lymphoma associated HLH is very poor, especially in T cell lymphomas; and, therefore, early diagnosis might alter the outcome. Though association of HLH with systemic anaplastic large cell lymphoma (ALCL) is known, its occurrence in primary cutaneous ALCL (C-ALCL) is distinctly rare. We aim to describe a case of C-ALCL (anaplastic lymphoma kinase (ALK)−) in an elderly male who succumbed to the complication of associated HLH, which was possibly triggered by coexistent virus infection. We briefly present the literatures on lymphoma associated HLH and discuss the histopathological differentials of cutaneous CD30+ lymphoproliferative disorders. We do suggest that HLH may pose diagnostic challenges in the evaluation of an underlying lymphoma and hence warrants proper evaluation for the underlying etiologies and/or triggering factors.

ALK-positive cancer: still a growing entity

 Since the discovery of ALK-positive anaplastic large-cell lymphoma in 1994 many other types of tumors showing ALK expression were disclosed. They form a heterogeneous group, including lung, renal and soft tissue tumors. The biological function of ALK, its role in carcinogenesis and impact exerted on the clinical outcome have been studied by many research groups. New drugs specifically dedicated for ALK inhibition, for example, crizotinib, have been synthesized and have become a viable treatment option for ALK-positive lung adenocarcinoma, and potentially for other ALK-positive cancers. This review summarizes the current state of knowledge concerning ALK-positive neoplasms, focusing on the clinical aspects of the subject.

Breast Implant-Associated Anaplastic Large Cell Lymphoma: Report of 2 Cases and Review of the Literature

Although primary breast lymphomas are exceedingly rare, cases of breast implant-associated anaplastic large cell lymphoma (iALCL) continue to be reported. The authors describe their experience with 2 patients and review the literature. Both patients presented with periprosthetic fluid collection. Neither had evidence of systemic disease nor received systemic therapy. Both were disease free after bilateral capsulectomies and implant removal without implant replacement, and disease did not recur. During the literature review, 63 cases of iALCL (including our 2 patients) were identified. The median time from implant placement to diagnosis was 9 years. Both saline and silicone implants were associated with iALCL. Of the 26 cases for which implant surface was reported, the surface was textured in 24. Of the 58 patients with an identifiable presentation, 39 had periprosthetic fluid collection, including 7 with an associated mass; 13 had an isolated mass at presentation, including 1 with axillary adenopathy. Forty patients had capsulectomy, 7 of whom underwent implant replacement. Of the 44 patients with known treatment, 33 received chemotherapy and 23 received radiation. Of the 49 patients with known anaplastic large cell lymphoma, 15 had disease recurrence, and 4 patient deaths were reported. Of the 18 patients presenting with a mass, 11 had disease recurrence, including all 4 patients who died. This study represents the largest review of patients with iALCL described to date. Although most cases have an indolent clinical course, the variety of presentations defined as "seroma" vs "capsular involvement" emphasizes the importance of investigating a definitive method of diagnosis, management, and treatment of this disease. LEVEL OF EVIDENCE 5.

Anaplastic large cell lymphoma involving the urinary bladder: a case report and review of the literature

T cell-derived malignant lymphoma is rarely detected as a bladder neoplasm. A literature review for anaplastic large cell lymphoma (ALCL) involving urinary bladder reveals only seven previously reported cases. Here, we report a case of a 59-year-old HIV-negative man with ALK-positive ALCL. He presented an unusual clinical course with initial consideration of adult onset Still's Disease (AOSD) due to his negative results searching for malignancy and infectious diseases. He rapidly developed macrophage activation (hemophagocytic) syndrome and experienced an unusual rapid disease progression and died in 39 days after onset of symptoms. Compared to previously reported cases, the current case of ALK-1-positive ALCL is a rare case with an unusual presentation. From this case, we learned that ALCL is one malignancy that should be considered and screened in patients with suspected AOSD. Also, T-cell lymphoma associated hemophagocytic syndrome should be considered in a patient with sustained corticosteroid-resistant spike fever, high serum ferritin, and rapid exacerbation of the disease course.

Adult T-Cell Leukemia/Lymphoma

Adult T-cell leukemia/lymphoma is a rare mature CD4+ T-cell neoplasm caused by the retrovirus human T-lymphotrophic virus type 1. At present there are approximately 20 million people infected globally with this virus, and most of these individuals belong to the endemic areas in southern Japan, Africa, the Caribbean basin, and Latin America. In the United States, it is usually seen in immigrants from these endemic regions. Adult T-cell leukemia/lymphoma predominantly affects the adult population and is rare in children. Adult T-cell leukemia/lymphoma has 4 subtypes: acute, lymphomatous, chronic, and smoldering. Clinically, the first 2 variants are classified as aggressive, and the latter two are classified as indolent. Given the rare occurrence and diagnostic challenges associated with adult T-cell leukemia/lymphoma, this review will highlight its salient features to aid in recognition of this entity and perform a comprehensive diagnostic workup.

The microenvironment in T-cell lymphomas: emerging themes

Peripheral T-cell lymphomas (PTCLs) are heterogeneous and uncommon malignancies characterized by an aggressive clinical course and a mostly poor outcome with current treatment strategies. Despite novel insights into their pathobiology provided by recent genome-wide molecular studies, several entities remain poorly characterized. In addition to the neoplastic cell population, PTCLs have a microenvironment component, composed of non-tumor cells and stroma, which is quantitatively and qualitatively variable, and which may have an effect on their pathological and clinical features. The best example is provided by angioimmunoblastic T-cell lymphoma (AITL), a designation reflecting the typical vascularization and reactive immunoblastic content of the tumor tissues. In this disease, a complex network of interactions between the lymphoma cells and the microenvironment exists, presumably mediated by the neoplastic T cells with follicular helper T-cell properties. A better understanding of the crosstalk between neoplastic T or NK cells and their microenvironment may have important implications for guiding the development of novel therapies.

Anaplastic large cell lymphoma in children and adolescents

Anaplastic Large Cell Lymphoma (ALCL) is the most common mature T-cell neoplasm in children and adolescents. ALCLs comprise approximately 15% of all non-Hodgkin lymphomas (NHL) in children and adolescents and commonly present with advanced systemic disease. Dissimilar from ALCL in adults, ALCL in children is nearly universally anaplastic large cell lymphoma kinase (ALK) positive. Despite the relative rarity of the disease, a great deal of insight into the pathogenesis of ALCL has been learned by researching the essential oncogenic role of ALK. Many different treatment strategies have been utilized with similar event free survival (EFS) rates of 65-75%. This review will provide an overview of the pathology, clinical features, prognostics factors, and treatment for children and adolescents with ALK positive ALCL.

Anaplastic large cell lymphoma ALK-negative clinically mimicking alcoholic hepatitis - a review

Anaplastic large cell lymphoma (ALCL), described less than 30 years ago by Karl Lennert and Herald Stein in Kiel, West Germany, is a T-cell or null non-Hodgkin lymphoma, with distinctive morphology (hallmark cells, prominent sinus and/or perivascular growth pattern), characteristic immunophenotype (CD30+, cytotoxic granules protein+, CD3-/+) and specific genetic features as translocations involving the receptor tyrosine kinase called anaplastic lymphoma kinase (ALK) on 2p23 and variable partners genes, which results in the expression of ALK fusion protein. The absence of ALK expression is also observed and is associated with poorer prognosis that seen with ALK expression. ALK-negative ALCL is more frequent in adults, with both nodal and extra nodal clinical presentation and includes several differential diagnoses with other CD30+ lymphomas. Liver involvement by ALCL is rare and is generally seen as mass formation; the diffuse pattern of infiltration is even more unusual. The authors present a case of a 72-year-old man who presented clinical symptoms of acute hepatic failure. The patient had a long history of alcohol abuse and the diagnosis of alcoholic hepatitis was highly considered, although the serum lactic dehydrogenase (LDH) value was highly elevated. The clinical course was fulminant leading to death on the fourth day of hospitalization. Autopsy demonstrated diffuse neoplastic hepatic infiltration as well as splenic, pulmonary, bone marrow, and minor abdominal lymph nodes involvement by the tumor. Based on morphological, immunophenotypical, and immunohistochemical features, a diagnosis of ALK- negative ALCL was concluded. When there is marked elevation of LDH the possibility of lymphoma, ALCL and other types, should be the principal diagnosis to be considered.

Dual ALK and MYC rearrangements leading to an aggressive variant of anaplastic large cell lymphoma

Anaplastic lymphoma kinase (ALK) and MYC are oncogenes often dysregulated in pediatric lymphomas. NPM-ALK/t(2;5)(p23;q35) is a genetic hallmark of ALK anaplastic large cell lymphoma (ALCL). MYC gene translocations are frequently detected in high-grade B-cell lymphomas. ALKALCL cases with concurrent MYC translocation are exceedingly rare and are more aggressive and chemoresistent compared with other ALKALCL. We report a patient who presented with ALKALCL possessing coexistent MYC rearrangement, massive tumor dissemination, and early widespread relapse. This case underscores the importance of recognition of close correlation between dual ALK and MYC rearrangements and the characteristic clinical features in this unusual ALCL variant.

[Two cases of lymphoma in an implant capsule: A difficult diagnosis, an unknown pathology]

The anaplastic large cell lymphoma (ALCL) is a rare disease, its incidence in the United States is one case per 500,000 women and three for 100 million patients for breast single location. Forty-six cases have been reported in the literature. They can grow on any type of implant: expander prosthesis silicone and saline, smooth or textured envelope. Currently, the consensus process includes capsulectomy, removal of the implant, chemotherapy and radiotherapy. However, some authors classify under indolent disease, but we believe that some cases may escape any therapeutic and become very aggressive forms. It is therefore important to make an early diagnosis and start treatment urgently. Severity and suspicion of iatrogenic nature of ALCL have an obligation to inform future with implants.

Differential expression of aurora-A kinase in T-cell lymphomas

Aurora-A is a mitotic kinase implicated in oncogenesis and is known to be overexpressed in B-cell lymphomas and plasma cell myeloma. The expression of Aurora-A kinase (henceforth referred to as Aurora-A) in T-cell lymphomas is not well characterized. In this study, we assessed Aurora-A expression by immunohistochemical analysis in 100 lymphomas encompassing a variety of T-cell lymphomas as categorized in the World Health Organization classification. Aurora-A expression was highest in anaplastic large-cell lymphomas and variably expressed in other types of T-cell lymphomas. In addition, the pattern of Aurora-A expression was predominantly cytoplasmic in ALK-positive anaplastic large-cell lymphoma and was nuclear in ALK-negative anaplastic large-cell lymphoma and other T-cell lymphomas, suggesting altered biochemical mechanisms of Aurora-A nuclear transport in ALK-positive anaplastic large-cell lymphoma. Reverse transcriptase-PCR analysis showed that Aurora-A is more highly expressed in ALK-positive anaplastic large-cell lymphoma than in ALK-negative anaplastic large-cell lymphoma, and is relatively lower in peripheral T-cell lymphomas. Using western blot analysis and the DEL cell line (derived from ALK-positive anaplastic large-cell lymphoma), we showed that Aurora-A expression is decreased after treatment with either MYC or MEK inhibitors, consistent with the MYC and MAP kinase signaling pathways being involved in driving Aurora-A expression; the greatest decrease was observed after MYC inhibition. These findings provide insights into the possible importance of Aurora-A overexpression in anaplastic large-cell lymphoma pathogenesis, and also suggest that Aurora-A inhibition could be a potential therapeutic approach for patients with anaplastic large-cell lymphoma.

Non-mycosis fungoides cutaneous T-cell lymphomas: report of the 2011 Society for Hematopathology/European Association for Haematopathology workshop

Primary cutaneous T-cell lymphomas (CTCL) excluding mycosis fungoides (MF) were discussed in 2 sessions of the 2011 Society for Hematopathology/ European Association of Haematopathology Workshop, Los Angeles, CA. Session 2 focused on primary cutaneous CD30+ T-cell lymphoproliferative disorders and their differential diagnosis, including systemic CD30+ T-cell lymphoma secondarily infiltrating the skin. Interesting features like special morphologic variants and atypical phenotypes were presented. In addition, the possibility of rare ALK+ primary cutaneous lymphomas was discussed. Session 3 examined other more uncommon non-MF CTCLs, including subcutaneous panniculitis-like T-cell lymphoma, extranodal NK/T-cell lymphoma, hydroa vacciniforme-like T-cell lymphoma, and rare subtypes of primary cutaneous peripheral T-cell lymphoma, not otherwise specified. In addition, systemic T-cell lymphomas involving the skin secondarily, such as angioimmunoblastic T-cell lymphoma, were included in this session. In this report, novel findings, areas of special interest, and diagnostic challenges emerging from the cases submitted to the workshop will be highlighted. The necessity to integrate histologic, immunophenotypical, genetic, and in particular, clinical data to arrive at the correct diagnosis, and subsequently provide adequate treatment, is emphasized.

Endobronchial ALK+ anaplastic large-cell lymphoma resembling asthma in a 13-year-old girl

Anaplastic large-cell lymphoma is a rare disease in children, and endobronchial localization is extremely rare in any age group. We report the case of a 13-year-old girl with endobronchial anaplastic lymphoma kinase-positive anaplastic large-cell lymphoma presenting as asthma, and discuss the diagnostic, therapeutic, and clinical implications.

Molecular Pathology of Malignant Lymphoma

This review focuses on practical uses of molecular testing in mature B-cell and T-cell lymphomas with a focus on those lymphomas in which molecular testing is common. Clinical findings, histology, and biomarkers, as well as diagnostic and prognostic predictive value and practical applications of molecular testing for mature B- and T-cell lymphomas are presented.

Simultaneous cytomorphological and multiparameter flow cytometric analysis of ALK-positive anaplastic large cell lymphoma in children

The aim of this study was to investigate the pathological features of anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) in children and to establish the effectiveness of screening and diagnosing ALCL with multiparameter flow cytometry immunophenotyping (FCI) of lymphoid tissue samples. A total of 121 lymph node tissue specimens obtained from 121 patients with a suspected diagnosis of lymphoma were analyzed with cytomorphological and FCI analysis. Fifteen cases were diagnosed as ALK-positive ALCL based on the pathological features and immunohistochemical results. Of these, there were 3 different types, common type (10 cases), lymphohistiocytic type (4 cases) and neutrophil-rich type (1 case). Thirteen cases (10 common, 2 lymphohistiocytic and 1 neutrophil-rich type) were diagnosed as ALCL using FCI. These cases were CD30-positive and aberrantly expressed at least two T-cell antigens, including CD4 (84.6%), CD2 (76.9%), CD7 (61.5%), CD3 (53.8%) and CD5 (38.4%). Neoplastic cells accounted for only a small proportion of the total cells in FCI, with a median of 19.3% (range, 7.9-31.8%), which was significantly higher than those in the control groups (all <1.0%). The sensitivity of FCI for diagnosing ALCL in lymph node samples was 86.7% with a specificity of 100%. The majority of neoplastic cells demonstrated high light forward and high light side scatter, similar to monocytes or granulocytes in dot plots. FCI may be used as an adjunct to histopathological examination for rapid and reliable diagnosis of pediatric ALCL. Flexible gating strategies and careful analysis are required to identify neoplastic cells with FCI.

Infectious mimicry complicates diagnosis in hemophagocytic syndrome caused by anaplastic large-cell lymphoma

Hemophagocytic syndrome (HPS) arises secondary to genetic, rheumatologic, neoplastic, and infectious causes. We discuss a patient whose presentation was consistent with systemic infection but was discovered to have HPS of unknown etiology. The presenting symptoms, as well as unremarkable malignancy and rheumatologic workups, led to the pursuit of an infectious cause, but the patient was ultimately discovered to have an occult anaplastic large-cell lymphoma (ALCL). This case demonstrates the diagnostic challenges that result from infectious mimicry in the context of HPS—first, in distinguishing noninfectious HPS from the systemic inflammation that can result from a widespread infectious process, second, in the identification of the precipitating cause of HPS. While evidence of these challenges has been suggested by the limited literature on HPS and ALCL, our case illustrates the diagnostic dilemma that arises when tissue biopsy does not quickly reveal an etiology. It is important that all physicians be aware that HPS can mimic infection and be prepared to redirect the workup when an infectious etiology for HPS cannot be identified.

Antineoplastic activity of the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine in anaplastic large cell lymphoma

DNA methylation is an epigenetic mechanism establishing long-term gene silencing during development and cell commitment, which is maintained in subsequent cell generations. Aberrant DNA methylation is found at gene promoters in most cancers and can lead to silencing of tumor suppressor genes. The DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-aza-CdR) is able to reactivate genes silenced by DNA methylation and has been shown to be a very potent epigenetic drug in several hematological malignancies. In this report, we demonstrate that 5-aza-CdR exhibits high antineoplastic activity against anaplastic large cell lymphoma (ALCL), a rare CD30 positive non-Hodgkin lymphoma of T-cell origin. Low dose treatment of ALCL cell lines and xenografted tumors causes apoptosis and cell cycle arrest in vitro and in vivo. This is also reflected in genome-wide expression analyses, where genes related to apoptosis and cell death are amongst the most affected targets of 5-aza-CdR. Furthermore, we observed demethylation and re-expression of p16^INK4A after drug administration and senescence associated β-galactosidase activity. Thus, our data provide evidence that 5-aza-CdR is highly efficient against ALCL and warrants further clinical evaluation for future therapeutic use.

The heat shock protein-90 co-chaperone, Cyclophilin 40, promotes ALK-positive, anaplastic large cell lymphoma viability and its expression is regulated by the NPM-ALK oncoprotein

BACKGROUND

Anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL) is a T cell lymphoma defined by the presence of chromosomal translocations involving the ALK tyrosine kinase gene. These translocations generate fusion proteins (e.g. NPM-ALK) with constitutive tyrosine kinase activity, which activate numerous signalling pathways important for ALK+ ALCL pathogenesis. The molecular chaperone heat shock protein-90 (Hsp90) plays a critical role in allowing NPM-ALK and other signalling proteins to function in this lymphoma. Co-chaperone proteins are important for helping Hsp90 fold proteins and for directing Hsp90 to specific clients; however the importance of co-chaperone proteins in ALK+ ALCL has not been investigated. Our preliminary findings suggested that expression of the immunophilin co-chaperone, Cyclophilin 40 (Cyp40), is up-regulated in ALK+ ALCL by JunB, a transcription factor activated by NPM-ALK signalling. In this study we examined the regulation of the immunophilin family of co-chaperones by NPM-ALK and JunB, and investigated whether the immunophilin co-chaperones promote the viability of ALK+ ALCL cell lines.

METHODS

NPM-ALK and JunB were knocked-down in ALK+ ALCL cell lines with siRNA, and the effect on the expression of the three immunophilin co-chaperones: Cyp40, FK506-binding protein (FKBP) 51, and FKBP52 examined. Furthermore, the effect of knock-down of the immunophilin co-chaperones, either individually or in combination, on the viability of ALK+ ALCL cell lines and NPM-ALK levels and activity was also examined.

RESULTS

We found that NPM-ALK promoted the transcription of Cyp40 and FKBP52, but only Cyp40 transcription was promoted by JunB. We also observed reduced viability of ALK+ ALCL cell lines treated with Cyp40 siRNA, but not with siRNAs directed against FKBP52 or FKBP51. Finally, we demonstrate that the decrease in the viability of ALK+ ALCL cell lines treated with Cyp40 siRNA does not appear to be due to a decrease in NPM-ALK levels or the ability of this oncoprotein to signal.

CONCLUSIONS

This is the first study demonstrating that the expression of immunophilin family co-chaperones is promoted by an oncogenic tyrosine kinase. Moreover, this is the first report establishing an important role for Cyp40 in lymphoma.

Cutaneous manifestations of malignancy

PURPOSE OF REVIEW

Many types of cancer can cause lesions to appear on the skin. Cutaneous manifestations may be primary or secondary to an underlying malignancy. Skin lesions may appear prior to the onset of systemic malignancy or they may occur concurrently or following an established diagnosis. The purpose of this review is to educate medical providers about several types of pediatric malignancies that can present with cutaneous findings. The primary focus of this review will be cutaneous features of leukemias, lymphomas, neuroblastoma, some sarcomas, and Langerhans cell histiocytosis.

RECENT FINDINGS

A wide range of cutaneous manifestations have been reported in systemic malignancies of children. In addition to providing a description of more typical features of skin lesions associated with these conditions, this review will summarize a few recent case reports of pediatric malignancies with unusual cutaneous presentations.

SUMMARY

Systemic malignancy can present with a variety of cutaneous manifestations. Given that accurate, prompt diagnosis of malignancy can have tremendous prognostic significance, it is imperative that clinicians are familiar with features of skin lesions that may be seen in this setting.