Leu-6-expressing cells in lymph nodes: dendritic cells phenotypically similar to interdigitating cells

Braf mutation in interdigitating dendritic cell sarcoma: a case report and review of the literature

Interdigitating dendritic cell sarcoma is an extremely rare tumor. The diagnosis is difficult and is based on clinical, pathological and immunohistochemical evaluation. Differential diagnosis includes melanoma, mesenchymal and hematological malignancies. The mainstay of treatment is surgery for limited disease and different chemotherapy combinations have been tested for advanced disease. No evidence from prospective trials is currently available. We report the case of a 59 year-old male patient who experienced axillary lymphadenopathy with initial diagnosis of large-cell lung cancer on tumor biopsy. He underwent surgical resection with radical intent. Pathological diagnosis of interdigitating dendritic cell sarcoma was obtained on surgical samples. Nine months after radical surgery, he experienced systemic recurrence of disease and underwent chemotherapy with epirubicin and ifosfamide for 4 courses. During chemotherapy, he developed brain disease progression and underwent whole-brain radiotherapy. Systemic progression was then observed and molecular characterization was performed. B-RAF evaluation resulted positive for V600E mutation and the patient was treated with Vemurafenib according to molecular findings. He thus obtained initial clinical benefit but eventually died of brain hemorrhage. In conclusion, we report a case of B-RAF mutation detected in an interdigitating dendritic cell sarcoma patient treated with targeted therapy. B-RAF pathway could have a role in pathogenesis and evolution of this rare disease and could open new perspectives of treatment.

Successful treatment of disseminated interdigitating dendritic cell sarcoma with adriamycin, bleomycin, vinblastine, and dacarbazine chemotherapy

Interdigitating dendritic cell sarcoma (IDCS) is a very rare and aggressive neoplasm that arises from antigen presenting cells. IDCS usually involves lymph nodes; however, extra-nodal involvement has also been reported. Because a consistent standard therapy for IDCS has not been established to date, we report a case of the successful treatment of disseminated IDCS using ABVD chemotherapy (doxorubicin, bleomycin, vinblastine, and dacarbazine). A 64-year-old man was diagnosed with IDCS on the basis of immunohistochemical findings of a biopsy specimen of the inferior nasal concha. Immunohistochemical staining showed a positive reaction for CD68, leukocyte common antigen, and S-100 protein, but a negative reaction for CD34, CD1a, and CD21. Imaging studies showed cervical and axillary lymphadenopathies, subcutaneous nodules, and a soft tissue lesion in the nasal cavity. Treatment with the ABVD regimen resulted in complete remission after 8 cycles of chemotherapy.

Dendritic cell neoplasms: an overview

Dendritic cell neoplasms are rare tumors that are being recognized with increasing frequency. They were previously classified as lymphomas, sarcomas, or histiocytic neoplasms. The World Health Organization (WHO) classifies dendritic cell neoplasms into five groups: Langerhans' cell histiocytosis, Langerhans' cell sarcoma, Interdigitating dendritic cell sarcoma/tumor, Follicular dendritic cell sarcoma/tumor, and Dendritic cell sarcoma, not specified otherwise (Jaffe, World Health Organization classification of tumors 2001; 273-289). Recently, Pileri et al. provided a comprehensive immunohistochemical classification of histiocytic and dendritic cell tumors (Pileri et al., Histopathology 2002;59:161-167). In this article, a concise overview regarding the pathological, clinical, and therapeutic aspects of follicular dendritic, interdigitating dendritic, and Langerhans' cell tumors is presented.

Clinical implication of dermatopathic lymphadenopathy among Japanese: a report of 19 cases

To clarify the clinicopathologic and immunohistochemical features of dermatopathic lymphadenopathy not associated with mycosis fungoides among Japanese, 19 patients were studied. Seventy-four percent of the patients were more than 50 years old (median; 63 years, mean 61 years). Systemic symptoms such as fever were recorded in 68% and multicentric lymphadenopathy was noted in 83% of patients. An association of autoimmune disease or positivity of autoantibodies was recorded in 6 patients. Five patients showed cutaneous hypersensitivity reactions to a drug. Histologically, in addition to the dermatopathic lymphadenopathy, numerous immunoblasts were observed in 2 cases and sheet-like proliferation of mature plasma cells in 3 cases. Various atypical or malignant lymphoproliferative disorders exhibiting immunologic abnormalities such as angioimmunoblastic T-cell lymphoma or autoimmune disease-associated lymphadenopathy frequently occur in middle-aged and elderly patients. At least some of the patients with dermatopathic lymphadenopathy should be clinicopathologically differentiated from these lymphoproliferative disorders.

Interdigitating dendritic cell sarcoma: a rare malignancy responsive to ABVD chemotherapy

Interdigitating dendritic cell sarcoma (IDCS) is an aggressive neoplasm of which fewer than 25 cases have been reported in the world literature. This malignancy is difficult to diagnose because of its rarity, and because of the subtle histopathologic features that distinguish IDCS from similar tumors arising from reticular cells. To date, there exists no consensus on a standard chemotherapeutic regimen for IDCS. Patients with this malignancy have been treated with chemotherapy regimens used against non-Hodgkin's lymphomas. Responses to these regimens have been variable, but mostly unsuccessful. In this article we describe a case of IDCS occurring in a 44 year old female who presented with abdominal pain and inguinal adenopathy. Staging of the tumor with CT scan, PET scan, and bone marrow biopsy demonstrated inguinal and abdominal lymphadenopathies, a large mass encasing the small bowel, and extensive liver infiltration. Morphologic and cytochemical analysis of biopsies from the abdominal mass and inguinal node were consistent with a diagnosis of IDCS, and immunohistochemical stains of the lymph node were positive for CLA, Kp-1, S-100, while negative for CD1a, CD3, CD20, CKER, and HMB45. Treatment of this patient with ABVD chemotherapy resulted in rapid clinical improvement with a marked decrease in tumor burden after two cycles of ABVD, and a complete response after six cycles of therapy.

The morphology, immunophenotype and distribution of paracortical dendritic leucocytes in lymph nodes regional to cutaneous melanoma

Our aim was to identify and delineate alterations in the distribution and immunophenotype of the lymphocytes and paracortical dendritic leucocytes (interdigitating dendritic cells; IDCs) in lymph nodes regional to tumours. Using immunocytochemistry and computer-assisted image analysis we examined 65 lymph nodes excised from 47 patients with malignant melanoma. Twenty-nine patients had American Joint Committee on Cancer (AJCC) stage II melanoma (no tumour spread beyond the primary site) and 18 had AJCC stage III disease (metastases in the regional nodes). There were significant differences in the frequency, morphology, immunophenotype and anatomical distribution of the IDCs and in the complexity of their dendritic processes in different areas within individual lymph nodes. We conclude that morphological and phenotypical variations in IDCs correlate with differing levels of antigen presentation. Downregulation of antigen presentation in lymph nodes regional to tumours is most probably mediated by tumour products. Differences in IDC distribution and characteristics in lymph nodes from different anatomical sites must be considered in interpreting studies of nodal morphology and function.

Reticulum cell neoplasms of lymph nodes: a clinicopathologic study of 11 cases with recognition of a new subtype derived from fibroblastic reticular cells

Lymph nodes contain nonlymphoid accessory cells including follicular dendritic cells (FDCs), interdigitating dendritic cells (IDCs) and fibroblastic reticular cells (FBRCs). Neoplasms derived from FDCs are uncommon, and those of IDC origin are even more rare. We report the clinicopathologic features of 11 reticulum cell neoplasms, including 2 of FBRC origin. There were seven male patients and four female patients ranging in age from 13 to 73 years. All cases involved lymph nodes (cervical or supraclavicular-6 cases), (abdominal--2 cases), epitrochlear (1 case); two had more than one site of involvement (cervical lymph node and mediastinum--1 case, cervical and abdominal lymph nodes--1 case). One case of FDC tumor had concomitant Castleman's disease, plasma cell variant. Each neoplasm showed similar histology with oval-to-spindle-shaped cells in a storiform or fascicular pattern. Based on immunophenotypic findings, the neoplasms were classified as FDC (five cases), IDC (two cases), FBRC (three cases), and reticulum cell neoplasm, not otherwise specified (one case). The FDC tumors showed immunoreactivity for CD21 or CD35, vimentin, and CD68. The IDC tumors showed strong positivity for S-100 protein and variable positivity for CD68 and CD1a. The cases derived from FBRCs were positive for vimentin, desmin, and smooth-muscle actin. The neoplasm classified as reticulum cell neoplasm, not otherwise specified had similar morphologic features but showed only equivocal positivity for CD68 and vimentin. Follow-up was available for 9 of 11 (82%) cases with a mean of 3.5 years. Four of five patients with FDC tumors were alive with disease when last seen; the fifth is alive and well with no evidence of disease at 4-year follow-up. One patient with IDC tumor had a recurrence in a different nodal site. Two patients with FBRC tumor were disease free at follow-up of 2 years and 8 years, respectively. The patient with reticulum cell neoplasm, not otherwise specified, was alive and disease free 8 years after diagnosis.

Langerhans cell histiocytosis research. Past, present, and future

This article reviews the various investigative events that led to the endorsement of the term Langerhans cell histiocytosis for the various clinicopathologic conditions previously called Hand-Schüller-Christian disease, Abt-Letterer-Siwe disease, eosinophilic granuloma of bone, and histiocytosis X. The different denominations reflect the changing conceptual approaches to the so-called reticuloendothelial system and the successive acquisition of new ultrastructural and immunocytochemical data.

Langerhans'-cell histiocytosis (histiocytosis X)--a clonal proliferative disease

BACKGROUND

The lesions of Langerhans'-cell histiocytosis (histiocytosis X), a proliferative histiocytic disorder of unknown cause, contain histiocytes similar in phenotype to dendritic Langerhans' cells. The disease ranges in severity from a fatal leukemia-like disorder to an isolated lytic lesion of bone. Intermediate forms of the disease are usually characterized by multiorgan involvement, diabetes insipidus, and a chronic course.

METHODS

To determine whether Langerhans' histiocytosis is a polyclonal reactive disease or a clonal disorder, we used X-linked polymorphic DNA probes (HUMARA, PGK, M27 beta[DXS255], and HPRT) to assess clonality in lesional tissues and control leukocytes from 10 female patients with various forms of the disease. Lymphoid clonality was also assessed by analysis of rearrangements at immunoglobulin and T-cell-receptor gene loci.

RESULTS

The HUMARA assay detected clonal cells in the lesions of 9 of the 10 patients: 3 patients had acute disseminated disease, 3 had unifocal disease, and 3 had intermediate forms. The percentage of clonal cells closely approximated the percentage of CD1a-positive histiocytes in each lesion. Clonality was also confirmed in two of nine cases with the PGK or M27 beta probe. Extreme constitutional lyonization precluded assessment of clonality in the 10th case. Lymphoid clonality was ruled out in all cases.

CONCLUSIONS

The detection of clonal histiocytes in all forms of Langerhans'-cell histiocytosis indicates that this disease is probably a clonal neoplastic disorder with highly variable biologic behavior. Thus, genetic mutations that promote clonal expansion of Langerhans' cells or their precursors may now be identified.

Interdigitating cell sarcoma: a morphologic and immunologic study of lymph node lesions in four cases

Interdigitating cell sarcoma is an extremely rare tumor. Its presentation and histologic appearance has varied among the reported cases. In this study, the authors investigated four cases of the hematolymphoid malignancy arising within lymph nodes, which were considered to be of interdigitating cell origin. All patients presented in the 6th to 8th decade of life with peripheral lymphadenopathy, and had a relatively indolent clinical course, without bone marrow or skin involvement. Carcinomas were observed as a second neoplasm in two of four patients. Distinctive morphologic features are proliferation of histiocyte-like cells with nuclear pleomorphism and occasionally multinucleated, paracortical distribution sparing of B-cell regions, fibrosis, sinus infiltration, and a prominent eosinophil/plasma cell infiltrates. The combination of light microscopic, fine structural, and immunohistochemical features suggested that these tumors derive from interdigitating cells; these tumor cells expressed CD68 (KP1), S-100 protein and HLA-DR, but lack CD21 (1F8), desmosomes and Birbeck granules. The diagnosis of interdigitating cell sarcoma should be considered on any pleomorphic tumor with the features described in this report.

Immunohistochemical detection of CD1A antigen in formalin-fixed and paraffin-embedded tissue sections with monoclonal antibody 010

The immunoreactivity of a CD1a monoclonal antibody (MAb), denoted 010, was investigated by means of the streptavidin-biotin-peroxidase method in formalin-fixed and paraffin-embedded tissues from 47 cases. The samples comprised reactive lymphoid proliferations of skin, tonsil, and lymph node including dermatopathic lymphadenopathy and Langerhans' cell histiocytosis, Hodgkin's and non-Hodgkin's lymphomas, and thymomas. Interdigitating and dermal dendritic cells, veiled cells, Langerhans' cells, and also cortical thymocytes and their neoplastic counterparts displayed immunostaining with MAb 010 in paraffin sections. These results are identical to previous ones reported for other CD1a MAbs in fresh or frozen specimens. The findings suggest that the binding site of 010 is a fixation-resistant epitope of CD1a antigen which has not been previously identified.

Precursor Langerhans cell histiocytosis. An unusual histiocytic proliferation in a patient with persistent non-Hodgkin lymphoma and terminal acute monocytic leukemia

BACKGROUND

Langerhans cell precursors are considered to be identical to their mature counterparts except for the lack of Birbeck granules. Proliferations composed of such histiocytes appear to be uncommon.

METHODS

Standard immunophenotypic, molecular genetic, and DNA content studies were used to characterize various hematopoietic disorders, including a proliferation of precursor Langerhans cells, which arose sequentially in a patient.

RESULTS

The patient studied initially had a low-grade, B-cell, non-Hodgkin lymphoma and subsequently had an unusual histiocytic proliferation (precursor Langerhans cell histiocytosis) in cutaneous and lymph node sites. The patient eventually died of acute myelogenous leukemia (FAB, M5).

CONCLUSIONS

A larger series is required to determine the significance of the precursor Langerhans cell phenotype, particularly with respect to the development of acute myelogenous leukemia.

Syndrome of severe skin disease, eosinophilia, and dermatopathic lymphadenopathy in patients with HTLV-II complicating human immunodeficiency virus infection

Two intravenous drug users dually infected with human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type II (HTLV-II) developed an unusual severe dermatitis characterized by progressive brawny induration, fissuring, and ulceration of the skin, with an associated CD8 cell infiltration in one patient. Both patients had persistent eosinophilia. Lymph node biopsy revealed dermatopathic lymphadenopathy, an unusual pathologic finding in HIV-1 infection but one seen in association with mycosis fungoides and other skin disorders. Two new isolates of HTLV-II virus were established from these patients and were identified as HTLV-II by Southern blotting. This type of skin disease and lymph node pathology has not been found in other intravenous drug users who have been infected with HIV-1 alone or in patients in other risk groups for HIV-1 infection. HTLV-II may play a role in this unique new disease pattern in patients infected with HIV-1.

Sinus histiocytosis with massive lymphadenopathy: a spectrum of disease associated with immune dysfunction

A detailed immunologic study of three cases of sinus histiocytosis with massive lymphadenopathy (SHML) was performed to better characterize this rare disorder. One patient had prominent cervical lymphadenopathy that regressed spontaneously, whereas the other two patients had persistent cervical lymphadenopathy and recurrent infections. The first patient was otherwise healthy and had normal immunologic studies. One of the latter patients had a relative increase in blood B cells, a decreased level of serum immunoglobulin A (IgA), decreased blood lymphocyte mitogenic responses to multiple mitogens (37-42% of controls), and cutaneous anergy. The other patient with persistent disease also had a relative increase in blood B cells, polyclonal hypergammaglobulinemia, and circulating immune complexes, as well as decreased blood T cells and markedly decreased blood lymphocyte responses to mitogens (12-37% of controls). Immunohistochemical stains of the lymph nodes of the three patients revealed a characteristic phenotype for the sinus histiocytes: S-100 protein, 3/3; CD14 (Leu M3) 3/3; CD11c (Leu M5), 1/1; CD71 (OKT9), 3/3; CD4 (Leu 3a), 2/3; CD1a (OKT6), 1/3; alpha-1-antitrypsin, 3/3; alpha-1-antichymotrypsin, 3/3; CD35 (C3b), 1/1; CD11b (Mo1), 0/3; CD15 (Leu M1), 0/3; HLA-DR, 0/3; and lysozyme, 0/3. This phenotype suggests that the cells of SHML have features of both the Langerhans/interdigitating cell and mononuclear phagocyte lineages. Emperipolesis by the histiocytes of B cells, T cells, and natural killer cells was demonstrated by a double-staining technique. Our findings indicate that patients with SHML may have a variably expressed immunodeficiency that predisposes them to recurrent infections.

Langerhans cell histiocytosis of the female genital tract

Langerhans cell histiocytosis (LCH) of the female genital tract is rare. Four new cases are reported, and there is a review of the 38 cases in the literature. This disease may involve the vulva, vagina, cervix, endometrium, and ovary. Four distinct patient groups, segregated on the basis of initial presentation and subsequent anatomic extent of disease, were categorized as follows: (1) "pure" genital LCH, (2) genital LCH with subsequent multi-organ involvement, (3) oral or cutaneous LCH with subsequent genital and multi-organ involvement, and (4) diabetes insipidus with subsequent genital and multi-organ disease. Although involvement of the genital tract can occur at any age, it is most common in young adulthood. Clinically, LCH may mimic either primary neoplasia or various inflammatory lesions; the major pathologic differential diagnosis is venereal and other inflammatory diseases. The pure genital form may have a distinct nosologic position in the spectrum of LCH similar to the "pure," self-limited cutaneous histiocytosis seen in infants. There is no correlation between histologic findings and the outcome of the genital lesions. There is also no correlation between clinical presentation and/or the extent of involvement and outcome of genital lesions; complete regression, partial improvement, persistent lesions, and recurrences were seen in all four groups of patients. The treatment of genital LCH is not well defined and is highly individualized. Therapy has included surgery, radiation, topical corticosteroids, topical nitrogen mustard, systemic chemotherapy, and combination therapy; mixed results were obtained with all treatment modalities. Although no modality has been shown to yield a superior outcome, complete surgical excision is advocated as initial therapy.

Eosinophilic granuloma of the cavernous sinus and orbital apex in an HIV-positive patient

A 35-year-old HIV-positive woman with painful ophthalmoplegia, sensory loss extending to all branches of the trigeminal nerve, and progressive optic neuropathy was found to have eosinophilic granuloma of the cavernous sinus, superior orbital fissure, and orbital apex. There was no radiologic evidence of a lytic bone lesion within the skull or orbit and clinical evidence suggested a primary intracranial origin for this lesion. This is the first case of a cavernous sinus syndrome caused by eosinophilic granuloma and the first time HIV infection is reported in association with histiocytosis-X.

S-100 protein-positive dendritic cells in colorectal adenocarcinomas. Distribution and relation to the clinical prognosis

Dendritic cells (DC) in 121 colorectal adenocarcinomas were investigated immunohistochemically, using anti-S-100 protein antibody. S-100(+)DC were recognized among the malignant cells and/or around the tumor and differed in distribution either from lysozyme-positive macrophages or from neuron-specific enolase-positive neural tissue. Patients with many S-100(+)DC (more than 30 cells per 10 high-power fields) in the tumor survived longer than did those with few such cells (less than 30 cells), most often with no metastases (P less than 0.001). The grade of S-100(+)DC infiltration was related to both density of lymphocytic infiltration in the primary tumor and the degree of paracortical hyperplasia in the regional lymph nodes (P less than 0.05). Dendritic cells, therefore, as antigen-presenting cells, conceivably mediate cell immunity in a tumor with lymphoid infiltration and in the regional lymph nodes. The number of S-100(+) DC in the primary colorectal carcinomas represents one aspect of such a series of antitumor immunoreaction, in vivo.

S-100 protein-positive dendritic cells in colorectal adenocarcinomas. Distribution and relation to the clinical prognosis

Dendritic cells (DC) in 121 colorectal adenocarcinomas were investigated immunohistochemically, using anti-S-100 protein antibody. S-100(+)DC were recognized among the malignant cells and/or around the tumor and differed in distribution either from lysozyme-positive macrophages or from neuron-specific enolase-positive neural tissue. Patients with many S-100(+)DC (more than 30 cells per 10 high-power fields) in the tumor survived longer than did those with few such cells (less than 30 cells), most often with no metastases (P less than 0.001). The grade of S-100(+)DC infiltration was related to both density of lymphocytic infiltration in the primary tumor and the degree of paracortical hyperplasia in the regional lymph nodes (P less than 0.05). Dendritic cells, therefore, as antigen-presenting cells, conceivably mediate cell immunity in a tumor with lymphoid infiltration and in the regional lymph nodes. The number of S-100(+) DC in the primary colorectal carcinomas represents one aspect of such a series of antitumor immunoreaction, in vivo.

Immunohistological analysis of human fetal lymph nodes

A panel of monoclonal antibodies directed against various lymphoid and non-lymphoid cell subsets was used to study the lymph nodes of human fetuses of 16-40 weeks. B cells were of intermediate size and were present at all ages in primitive follicles and in the outer cortex. The fetal B-cell immunophenotype is indicative of an intermediate stage of development, just preceding the differentiation to mature B cell. Forty to sixty per cent Leu1+ B cells were observed in the follicles until the end of the second trimester. At all stages, T cells showed an immunophenotype similar to type III thymocytes, different from adult peripheral T cells, with a marked predominance of CD4+ T cells. Leu7+ NK cells were generally absent. OKIa+ interdigitating reticulum cells were present in T-cell areas. Some axillary lymph nodes showed strongly CD1+ dendritic cells, probably Langerhans' cells. Macrophages and granulocytes were present in varying numbers. Altogether, our results indicate that fetal lymph nodes are quite well differentiated at an early fetal age, although T and B cells do not (yet) show adult immunophenotypes. The expression of the CD38 antigen may be a main marker related to the immaturity of fetal T and B cells.

Immunophenotypic characterization of mononuclear phagocytes and dendritic cells in lymphoid organs of the rhesus monkey

Mononuclear phagocytes and dendritic cells are potent antigen-presenting cells that localize to distinct microenvironmental compartments in many different organs. These cells are particularly plentiful in spleen and lymph node. Recently, these cells have been identified and immunophenotypically characterized in human tissue sections using monoclonal antibodies. However, similar studies in animal species, particularly those representing models of human diseases, have yet to be completely performed. We have evaluated 18 monoclonal reagents raised against human determinants for their reactivity with macrophages and dendritic cells in lymphoid organs of rhesus monkeys. Six of the 18 (EBM11, 25F9, Mol, R4/23, To5, and SK9) produced labeling patterns in rhesus monkey lymphoid tissue that paralleled the staining patterns described for human tissues. Seven others (KB90, FMC17, Mo3, PHM3, PHM2, G16/1, and 27E10) stained varying subsets of specific cells types in these simian tissues. These reagents are requisite for the future study in an experimental animal of the afferent immune response in both normal and disease states.

A simple guide to the terminology and application of leucocyte monoclonal antibodies

This review aims to provide a simple guide and quick reference to the terminology and diagnostic applications of leucocyte monoclonal antibodies. The differentiation cluster terminology, where applicable, is used throughout.

Immunohistological analysis of Rosai-Dorfman histiocytosis. A disease of S-100 + CD1-histiocytes

Five cases of Rosai-Dorfman histiocytosis (RDH) (also called Sinus Histiocytosis with Massive Lymphoadenopathy; SHML) have been studied by immunohistochemical methods with heteroantisera and monoclonal antibodies. One case was also studied by Southern blot hybridization analysis with DNA probes specific for T cell receptor beta chain and immunoglobulin heavy chain. Immunophenotyping of large histiocytes, characteristic of RDH, evidenced the presence of S-100 protein and the absence of CD1 and other markers usually found in histiocytes and macrophages. DNA hybridization study showed the absence of clonal T or B lymphoid populations.