CD2- CD4+ CD56+ hematodermic/hematolymphoid malignancy

Case for diagnosis

Blastic plasmacytoid dendritic cell tumor is a rare, highly aggressive systemic neoplasm for which effective therapies have not yet been established. We describe a 73-year-old man with multiple nodules and patches emerging on the trunk and limbs. Lesional skin biopsy revealed a plasmacytoid dendritic cell tumor with dense dermal infiltrate of tumor cells with blastoid features. No apparent systemic involvement was identified in the initial stage. The patient was treated with prednisone daily, with notorious improvement of the skin lesions, although no complete remission was obtained. During the six-month follow-up period, no disease progression was documented, but fatal systemic progression occurred after that period of time.

CD4-/CD56+/CD123+ Hematodermic Neoplasm Showing Early Liver Metastasis

Hematodermic neoplasm (HN) is a clinically aggressive neoplasm with a high incidence of cutaneous involvement and a risk of leukemic dissemination. In the recent WHO-EORTC classification, the term blastic natural killer cell lymphoma has been replaced with CD4+/CD56+ HN because of its derivation from a plasmacytoid dendritic cell precursor. Cases of HN that completely lack CD4 or CD56 expression, therefore represents a diagnostic problem. A 68-year-old Korean male was diagnosed with CD4-/CD56+ HN and treated with hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, dexamethasone) at initial treatment, and then switched to high dose methotrexate/cytarabine. His disease relapsed and resulted in death from bone and brain disease 6 months after complete clinical remission, despite diagnostic workups, including a radioisotope liver scan and ultrasound-guided fine needle aspiration biopsy. Further cytogenetic studies such as comparative genomic hybridization could elucidate the genetic mechanisms in the development and progression of lymphomas. We report an unusual case of 'CD4-/CD56+/CD123+ HN' showing early liver metastasis.

Central nervous system involvement in CD4+/CD56+ hematodermic neoplasm: a report of two cases

CD4+/CD56+ hematodermic neoplasm, formerly known as blastic NK-cell lymphoma, is an uncommon, aggressive non-Hodgkin's lymphoma with cutaneous, lymph node, and bone marrow involvement at presentation. The disease is characterized by early leukemic phase; however, central nervous system involvement is rarely reported. Herein we describe two cases of CD4+/CD56+ hematodermic neoplasm with meningeal manifestation. Microscopic analysis and flow cytometry of cerebrospinal fluid proved to be diagnostic; however, imaging studies were not informative. These observations call attention to the possibility of central nervous system involvement, which could be more common than expected previously. Authors recommend routine cerebrospinal fluid analysis and prophylactic intrathecal chemotherapy in patients with this highly aggressive disease.

Novel markers of normal and neoplastic human plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDCs) are involved in innate immunity (eg, by secreting interferons) and also give rise to CD4+CD56+ hematodermic neoplasms. We report extensive characterization of human pDCs in routine tissue samples, documenting the expression of 19 immunohistologic markers, including signaling molecules (eg, BLNK), transcription factors (eg, ICSBP/IRF8 and PU.1), and Toll-like receptors (TLR7, TLR9). Many of these molecules are expressed in other cell types (principally B cells), but the adaptor protein CD2AP was essentially restricted to pDCs, and is therefore a novel immunohistologic marker for use in tissue biopsies. We found little evidence for activation-associated morphologic or phenotypic changes in conditions where pDCs are greatly increased (eg, Kikuchi disease). Most of the molecules were retained in the majority of pDC neoplasms, and 3 (BCL11A, CD2AP, and ICSBP/IRF8) were also commonly negative in leukemia cutis (acute myeloid leukemia in the skin), a tumor that may mimic pDC neoplasia. In summary, we have documented a range of molecules (notably those associated with B cells) expressed by pDCs in tissues and peripheral blood (where pDCs were detectable in cytospins at a frequency of <1% of mononuclear cells) and also defined potential new markers (in particular CD2AP) for the diagnosis of pDC tumors.

Agranular CD4+/CD56+ Hematodermic Neoplasm: A Distinct Entity Described in the Recent World Health Organization–European Organization for Research and Treatment of Cancer Classification for Cutaneous Lymphomas

Agranular CD4+/CD56+ hematodermic neoplasm is a distinct form of lymphoma with aggressive behavior and marked predilection for cutaneous involvement. Because of CD56 positivity, natural killer cells were initially suggested as the cell of origin in this tumor. In the recent World Health Organization–European Organization for Research and Treatment of Cancer classification, the term blastic natural killer cell lymphoma has been replaced with CD4+/CD56+ hematodermic neoplasm because of its derivation from a plasmacytoid dendritic cell precursor. Clinicopathologic features, immunohistochemical features, and differential diagnosis of this rare neoplasm with emphasis on the recent World Health Organization–European Organization for Research and Treatment of Cancer classification are discussed.

The spectrum of cutaneous lymphomas in Japan: a study of 62 cases based on the World Health Organization Classification

BACKGROUND

The relative incidence of malignant lymphoma subtypes differs according to geographic location. This study investigated the epidemiology of cutaneous lymphoma subtypes in Japan and compared it with other countries.

METHODS

Sixty-two patients with cutaneous lymphoma attending the Department of Dermatology, National Hospital Organization Hokkaido Cancer Center were reviewed. The World Health Organization classification of hematopoietic and lymphoid malignancies was adopted.

RESULTS

Of the 62 patients, 31 had primary cutaneous lymphoma (PCL) and 31 had secondary cutaneous lymphoma (SCL). T- and natural killer (NK)-cell lymphoma accounted for 80% of PCL, of which, mycosis fungoides accounted for almost 35%. Of the 31 patients with secondary cutaneous lymphoma, 17 patients (54%) had T- and NK-cell lymphoma, including nine adult T-cell leukemia/lymphoma patients, and 14 patients (46%) had B-cell lymphoma, including 11 diffuse large B-cell lymphoma patients. The majority of patients with SCL and NK-cell lymphoma with primary or secondary skin lesions had a poor outcome.

CONCLUSIONS

PCL in this study showed a similar incidence to that of other institutions in Japan, while also demonstrating different frequencies from that of other countries, suggesting that the relative frequency of different PCL subtypes differ according to geographical location, similar to previous reports of systemic malignant lymphoma.

[Blastic NK-cell lymphoma]

Blastic NK (<<natural killer>>) cell lymphoma is a rare type of lymphoma, recognized as an independent entity in the new World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification for cutaneous lymphomas. Its clinical, morphological and immunophenotypical characteristics are relatively well defined. It frequently starts with extranodal involvement (primarily cutaneous), often presents with splenomegaly and pancytopenia, and initially responds well to chemotherapy, although the medium-term prognosis is usually poor. It was first considered to originate from immature NK lymphocytes, but now its origin is thought to be plasmacytoid dendritic cell precursors. We present the clinicopathological characteristics of a new case of this entity in a 78-year-old male patient.

WHO/EORTC classification of cutaneous lymphomas 2005: histological and molecular aspects

The new WHO/EORTC classification for cutaneous lymphomas comprises mature T-cell and natural killer (NK)-cell neoplasms, mature B-cell neoplasms, and immature hematopoietic malignancies. It reflects the unique features of lymphoproliferative diseases of the skin, and at the same time it is as compatible as possible with the concepts underlying the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. This article reviews the histological, phenotypical, and molecular genetic features of the various nosological entities included in this new classification. These findings always have to be interpreted in the context of the clinical features and biologic behavior.

AIM

To review the histological, phenotypical and molecular genetic features of the various nosological entities of the new WHO/EORTC classification for cutaneous lymphomas.

METHODS

Extensive review of the literature cited in Medline and own data of the authors.

RESULTS

The WHO/EORTC classification of cutaneous lymphomas comprises mature T-cell and NK-cell neoplasms, mature B-cell neoplasms and immature hematopoietic malignancies. It reflects the unique features of primary cutaneous lymphoproliferative diseases.

CONCLUSION

This classification is as much as possible compatible with the concept of the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. The histological, phenotypical and molecular genetic features always have to be interpreted in the context of the clinical features and biologic behavior.

Cutaneous tumors as the initial presentation of non-T, non-B, nonmyeloid CD4+ CD56+ hematolymphoid malignancy in an adolescent boy

We describe a 14-year-old Hispanic boy who presented with a 2-month history of enlarging plum-colored cutaneous tumors on his face, trunk, and proximal extremities. Histopathologic examination showed nodular infiltrates of malignant mononuclear cells extending from the superficial dermis to the deep subcutis. Immunohistochemical staining of the biopsy specimen and flow cytometry studies on a bone marrow aspirate revealed a CD4+, CD56+ hematolymphoid tumor that was negative for all other myeloid and lymphoid markers. Based on this information, the patient was diagnosed with the recently described, rare non-T, non-B, nonmyeloid CD4+ CD56+ hematolymphoid malignancy. To our knowledge, this is the youngest patient reported in the literature.

Fine-needle aspiration cytology of blastic natural killer-cell lymphoma (CD4+ CD56+ hematodermic neoplasm)

We describe fine-needle aspiration (FNA) cytology findings of a case of blastic natural killer (NK)-cell lymphoma. The patient was a 68-year-old man who was diagnosed with cutaneous blastic NK-cell lymphoma involving his forehead. He developed a 1.5 cm, right pre-auricular lymph node five months later. FNA cytology revealed a monomorphic population of medium-sized lymphoid cells with a dispersed single cell arrangement. The tumor cells contained eccentrically located nuclei with a plasmacytoloid appearance and moderate amount of grayish cytoplasm without azurophilic granules. The nuclei were round to oval with fine chromatin, small indistinct nucleoli, and frequent nuclear indentation. Many cells also showed elongated cytoplasm with a unique hand-mirror or ping-pong paddle-like appearance. The flow cytometry study obtained during the FNA revealed co-expression of CD4 and CD56 in the tumor cells that confirm the recurrence of a blastic NK-cell lymphoma to the pre-auricular lymph node.

Early plasmacytoid dendritic cell leukemia/lymphoma coexpressing myeloid antigenes

Early plasmacytoid dendritic cell (pDC) leukemia/lymphoma has recently been described as a CD4(+)CD56(+) lineage negative malignancy with characteristic clinical, morphologic, immunophenotypic, and biological features. We present a case of a 72-year-old man who was diagnosed with isolated skin involvement 30 months ago and received numerous chemotherapy cycles that did not prevent three relapses of the disease, the last two involving the bone marrow. The bone marrow was nearly completely infiltrated with small- to medium-sized blasts displaying a high nuclear to cytoplasmic ratio, a cytoplasm with faint basophilia lacking granulations or Auer rods. Small vacuoles surrounding the nucleus were frequently observed. Flow cytometry showed CD4(+), CD56(+), CD45(+), CD38(+), HLA-DR(+), CD33(+), CD123(+), CD2(-), cyCD3(-), CD7(-), CD10(-), CD11b(-), CD13(-), CD14(-), CD16(-), CD19(-), cyCD22(-), CD24(-), CD34(-), CD57(-), CD61(-), CD64(-), CD65(-), cyCD79a(-), CD117(-), MPO(-), and TdT(-) population. At the second bone marrow relapse, CD117 was also positive. Our patient was initially treated with acute myeloid leukemia-type chemotherapy, later he was given acute lymphoblastic leukemia-type treatment, and at the last relapse he received CHOP chemotherapy. Each treatment led to rapid response of tumor manifestations with disease-free intervals of 7 months, 9 months, and 8 months, respectively. Although patients usually have an ominous prognosis, with only 25% living more than 24 months, our patient is alive after 30+ months and has again achieved complete remission after the last chemotherapy.

CD56+ hematological neoplasms presenting in the skin: a retrospective analysis of 23 new cases and 130 cases from the literature

BACKGROUND

The aim of this study was to define prognostic parameters and guidelines for diagnosis and treatment for CD56+ hematological neoplasms with first presentation in the skin.

PATIENTS AND METHODS

The study group included 153 cases (23 new and 130 from the literature). According to the World Health Organization classification, the group included 15 nasal and 38 nasal-type natural killer (NK)/T-cell lymphomas, 63 blastic NK-cell lymphomas, 14 cutaneous CD30+ lymphoproliferations, 10 cases of myeloid leukemia, six cases of subcutaneous panniculitis-like T-cell lymphoma (SCPLTCL) and seven peripheral T-cell lymphomas, unspecified.

RESULTS

In general, these CD56+ hematological neoplasms had a poor prognosis, with only 27% of patients alive after a median follow-up of 12 months. The median survival was 13 months. Nasal and nasal-type NK/T-cell lymphomas and CD56+ SCPLTCL had the worst prognosis, with a median survival of 5, 6 and 5 months, respectively. Only nasal-type NK/T-cell lymphomas presenting with only skin lesions had a somewhat better prognosis (median survival 27 months). In blastic NK-cell lymphomas (median survival 14 months), age </=40 years, aggressive treatment with acute leukemia protocols and high TdT expression were associated with a more favorable prognosis. Striking similarities in histology, immunophenotype, clinical presentation and clinical behavior were found between blastic NK-cell lymphomas and CD56+ myeloid leukemias.

CONCLUSIONS

CD56+ hematological neoplasms presenting in the skin have a poor prognosis, except for primary cutaneous CD30+ lymphoproliferations. The striking similarities between blastic NK-cell lymphomas and CD56+ myeloid leukemias presenting in the skin provide a rationale to treat these patients with more aggressive regimens, rather than with CHOP(-like) regimens and radiotherapy, which have proven to be inadequate therapies for this neoplasm.

Subcutaneous, Blastic Natural Killer (NK), NK/T-cell, and Other Cytotoxic Lymphomas of the Skin: A Morphologic, Immunophenotypic, and Molecular Study of 50 Patients

A new group of subcutaneous, natural killer (NK), NK/T-cell, and other cytotoxic T-cell lymphomas of the skin has been recently described, and some have been included as distinct clinicopathologic entities in the classification of hematologic malignancies recently proposed by the World Health Organization. In the European Organization for Research and Treatment of Cancer classification for cutaneous lymphomas, they would be classified either as CD30- large T-cell lymphoma, small/medium pleomorphic T-cell lymphoma, or subcutaneous T-cell lymphoma. Precise clinicopathologic and prognostic features of all of them have not yet been well characterized. We studied retrospectively 81 biopsies from 50 patients with subcutaneous, blastic natural killer (NK), NK/T-cell, or other non-mycosis fungoides cytotoxic T-cell lymphomas of the skin. Clinical, morphologic, phenotypical, and genetic features and data on Epstein-Barr virus association allowed us to classify our cases according to the following 7 categories: a) subcutaneous "panniculitis-like" T-cell lymphoma (SPTCL): 10 cases (estimated 5-year survival: 80%); b) blastic NK-cell lymphoma: 12 cases (estimated 5-year survival: 0%); c) nasal-type extranodal NK/T-cell lymphoma: 5 patients (estimated 5-year survival: 0%); d) epidermotropic CD8+ T-cell lymphoma: 5 cases (estimated 5-year survival: 0%); e) cutaneous gamma/delta T-cell lymphoma: 8 cases (estimated 5-year survival: 0%); f) cutaneous alpha/beta pleomorphic T-cell lymphoma: 8 cases (estimated 5-year survival: 0%); and g) cutaneous medium/large pleomorphic T-cell lymphoma, not otherwise specified: 2 cases. Our study shows that these cutaneous lymphomas can be classified according to precise diagnostic categories. With the exception of SPTCL, analysis of follow-up data from our patients showed that these groups of lymphomas are characterized by an aggressive course, regardless of the diagnostic category.

Leucémie aleucémique non T non B CD4+ CD56+ (2 cas)

INTRODUCTION

Non T non B CD4+ CD56+ leukemia is often revealed by cutaneous lesions. We report 2 patients with this disorder who had characteristic anatomoclinical findings.

CASE REPORTS

An 81 year-old female and a 75 year-old man presented with erythematous macules which increased in number and progressed to infiltrated plaques and nodules. The lesions became ecchymotic, but the patients remained in good general condition and blood count as well as bone marrow examination were unremarkable. A cutaneous biopsy revealed a lymphomatous mononuclear cell infiltrate. The cells expressed CD4 and CD56, but not CD3. The cutaneous lesions preceded for 10 and 9 months respectively the appearance of overt leukemia and medullar involvement. At this stage, the patients deceased rapidly from their leukemia.

DISCUSSION

This is an original anatomoclinical syndrome. The histopathologist must pay attention to the unusual CD4+ and CD3- immunophenotype and search for CD56 expression. The malignant cell responsible for this type of leukemia is now individualized and corresponds to a type II dendritic cell precursor.

Characteristics of cutaneous lymphomas in Korea

The clinicopathologic characteristics of malignant lymphomas vary according to geography. The aim of this study was to determine the relative frequency of cutaneous lymphomas and to examine the clinical relevance of the WHO classification in Korean cases of cutaneous lymphoma. The Korean Dermatopathology Research Group conducted a clinicopathologic review of a nationwide collection of 80 cutaneous lymphomas, diagnosed at 23 institutes over a recent 3-year period. The clinical records, haematoxylin & eosin-stained slides and immunohistochemical stains from 80 patients with malignant lymphomas of the skin were reviewed. In our study, the most frequent cutaneous lymphoma was mycosis fungoides. Compared with Western countries, Korea had higher rates of NK/T cell lymphoma and subcutaneous panniculitis-like T-cell lymphoma and a much lower rate of B-cell lymphoma. The occurrence rates for various subtypes of malignant lymphoma in Korea are distinct from those in Western countries. The EORTC classification is not fully appropriate in dealing with Korean cases of cutaneous lymphoma, because NK/T cell lymphoma is not included in the EORTC classification for cutaneous lymphoma.

Plasmacytoid dendritic cells: from the plasmacytoid T-cell to type 2 dendritic cells CD4+CD56+ malignancies

Recent identification of CD4(+)CD56(+) malignancies as pathological counterparts of the precursors of type 2 dendritic cells (DC2) has shed new light on a leukocyte lineage that long remained elusive. This review retraces how knowledge evolved, through careful examination and analysis of both normal lymphoid tissue and rare proliferative diseases, from plasmacytoid T cells to plasmacytoid dendritic cells (pDC) and then DC2. The functions of these cells and their key role at the crossroads of innate and cognitive immunity are also discussed. The major characteristics of DC2 malignancies are summarized and compared to natural killer cell (NK) lymphomas, another type of proliferative disease sharing the expression of CD56.

What is CD4+CD56+ malignancy and how should it be treated?

CD4+CD56+ malignancy is a rare neoplasm with a typical clinical pattern, an aggressive course and high early relapse rate despite good initial response to chemotherapy. In this review, the impact of different therapeutic approaches on clinical outcome has been studied. We evaluated 91 published cases and our own six patients in terms of clinical features, immunophenotype/cytogenetics and treatment outcome. Treatment was divided into four groups: (A) chemotherapy less intensive than CHOP; (B) CHOP and CHOP-like regimens; (C) therapy for acute leukemia; (D) allogeneic/autologous stem cell transplantation. The median overall survival was only 13 months for all patients. Patients with skin-restricted disease showed no difference in the overall survival from patients with advanced disease (17 and 12 months, respectively). Age >/=60 years was a negative prognostic factor. Age-adjusted analysis revealed improved survival after high-dose chemo/radiotherapy followed by allogeneic stem cell transplantation when performed in first complete remission. This therapeutic approach should be recommended for eligible patients with CD4+CD56+ malignancy. For older patients the best treatment option is still unknown.

'Agranular CD4+ CD56+ hematodermic neoplasm' (blastic NK-cell lymphoma) originates from a population of CD56+ precursor cells related to plasmacytoid monocytes

In 1999, we reported seven cases of an unusual hematologic malignancy with primary cutaneous presentation that appeared as a distinct clinicopathologic entity characterized by medium-sized tumor cells with a peculiar CD3- CD4+ CD56+ CD43+ HLA-DR+ cell surface phenotype. Because the origin of tumor cells was not clear and they exhibited a nonlineage-specific phenotype, we hypothesized that such tumors likely originated from hematologic-myeloid precursor cells and were tentatively assigned the designation "agranular CD4+ CD56+ hematodermic neoplasms." In the present study we report 14 cases (seven already reported and seven additional cases) of these tumors, and simultaneously we present now a rare population of cells that we have identified in the peripheral blood of healthy volunteers treated with Flt3 ligand. These cells express all the characteristic markers of CD4+ CD56+ hematodermic neoplasms. This population appears to be related to plasmacytoid monocytes because they also expressed CD68 and bright levels of CD123. To confirm the relationship between these normal cells and CD4+ CD56+ hematodermic neoplasms, we conducted an extensive comparative phenotypic study. Results show that these two cell types are indeed related because they share many phenotypic features, including the presence of CD4, CD56, CD43, CD68, and HLA-DR and the absence of other T, B, NK, or myelomonocytic markers. More importantly, we found that the bright expression of CD123 by immunohistochemistry is a distinctive characteristic of CD4+ CD56+ hematodermic neoplasms because all (n = 14) cases expressed this marker, whereas only two specimens in a control panel comprising 30 samples of related tumors expressed comparable levels of CD123. We therefore propose that oncogenic transformation of NCAM-expressing plasmacytoid monocyte-like cells may lead to "agranular CD4+ CD56+ hematodermic neoplasm."