Physiology and pathophysiology of dendritic cells

Fine-Needle Cytological Characteristics of Carcinoma Breast with Medullary or Medullary-like Features Masquerading as Dendritic Reticulum Cell Sarcoma: An Attempt to Explore the Reasons for Erroneous Cytologic Interpretation

Background:

Infiltration of tumors by dendritic reticulum cells (DRC) reflects the host immune defense mechanism. We observed three breast carcinomas cases with dense tumor-infiltrating DRC and lymphocytes in fine-needle aspiration (FNA) smears, leading to cytodiagnosis or differential diagnosis of dendritic reticulum cell sarcoma (DRCS). An attempt was made to find out the reason behind such an erroneous interpretation.

Materials and Methods:

Between 2009 and 2014, two cases were diagnosed as DRCS of the female breast by FNA cytology and in one case possibility of DRCS was considered along with medullary breast carcinoma (MBC). We compare and contrast the cytomorphological features of these three cases with those of nine cytologically diagnosed MBC.

Results:

Cases diagnosed as DRCS or MBC showed singly dispersed tumor cells, nuclear pleomorphism, bare nuclei, prominent nucleoli, and presence of lymphocytes. There was no significant difference between the two groups for discohesive clusters, syncytial clusters, plasma cells, neutrophils, foamy histiocytes, and necrosis. However, there was significant difference for presence of cohesive clusters (0% DRCS and 100% MBC, P = 0.00485), severe degree (+++) of pleomorphism (100% DRCS vs. 11.1% MBC, P = 0.01818), +++ DRC (P = 0.04697), and DRC with ++ to +++ enlarged nuclei (P = 0.03333), and pleomorphic nuclei (P = 0.00833). Two of the three cytologically diagnosed DRCS cases proved to be MBC or MBC-like and one as invasive ductal carcinoma. Six of nine cytologically diagnosed MBC cases with histology proved to be invasive breast carcinomas.

Conclusion:

Criteria for cytodiagnosis MBC need a fresh look. Cases with numerous dendritic cells possibly represent MBC.

Trichostatin A Shows Transient Protection from Chronic Alcohol-Induced Reactive Oxygen Species (ROS) Production in Human Monocyte-Derived Dendritic Cells

OBJECTIVE

The objective of this study was to understand whether histone deacetylase (HDACs) inhibitor Trichostatin A or TSA can block and/or reverse chronic alcohol exposure-induced ROS in human monocyte-derived dendritic cells (MDDCs). Additionally, since nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a known regulator of antioxidant responses, we studied the effects of alcohol and TSA on ROS production and modulation of Nrf2 by MDDCs.

METHODS

Intra-cellular, extra-cellular, and total ROS levels were measured in MDDCs treated chronically with alcohol (0.1 and 0.2 % EtOH) using 2',7'-dichlorofluorescin diacetate (DCF-DA) followed by detection of ROS in microplate reader and imaging flow cytometer. Nrf2 expression was analyzed by qRT- PCR and western blot. In addition, NFE2L2 (Nrf2), class I HDAC genes HDAC1, HDAC2, and histone acetyltransferase genes KAT5 were analyzed in silico using the GeneMania prediction server.

RESULTS

Our results confirmed alcohol's ability to increase intracellular ROS levels in MDDCs within minutes of treatment. Our findings have also demonstrated, for the first time, that TSA has a transient protective effect on MDDCs treated chronically with alcohol since the ability of TSA to reduce intracellular ROS levels is only detected up to 15 minutes post-chronic alcohol treatment with no significant protective effects by 10 hours. In addition, chronic alcohol treatment was able to increase the expression of the antioxidant regulator Nrf2 in a dose dependent manner, and the effect of the higher amount of alcohol (0.2%) on Nrf2 gene expression was significantly enhanced by TSA.

CONCLUSION

This study demonstrates that TSA has a transient protective effect against ROS induced by chronic alcohol exposure of human MDDCs and chronic long-term exposure of MDDCs with alcohol and TSA induces cellular toxicity. It also highlights imaging flow cytometry as a novel tool to detect intracellular ROS levels. Overall, the effect of TSA might be mediated through Nrf2; however, further studies are needed to fully understand the molecular mechanisms.

A decreased peritumoral CD1a+ cell number predicts a worse prognosis in oral squamous cell carcinoma

AIMS

Dendritic cells (DCs) are known to play a central role in the regulation of both innate and adaptive immunological responses, including antitumour immunity. The aim of this study was to evaluate the prognostic impact of intratumoral and peritumoral DCs in oral squamous cell carcinoma (OSCC) affecting the tongue and floor of the mouth.

METHODS AND RESULTS

Immunohistochemistry for CD1a and CD83 was performed in 53 patients with OSCC in the tongue and floor of the mouth. The markers were evaluated by automated examination in intratumoral and peritumoral compartments, and the results were expressed as density of cells/mm² . Correlations between these data and clinicopathological and survival outcomes were investigated. Depletion of peritumoral CD1a+ cells was associated with lymph node metastasis (P = 0.05), whereas depletion of peritumoral CD83+ cells was correlated with smoking history (P = 0.04), lymph node metastasis (P = 0.015), and extracapsular spread of lymph nodes (P = 0.018). Peritumoral CD1a+ was correlated with recurrence (P = 0.007) and overall survival (P = 0.03). The results of the survival analysis with the Cox proportional hazard model showed that depletion of peritumoral CD1a+ cells is an independent factor associated with overall survival and disease-free survival.

CONCLUSION

Our results suggest that depletion of peritumoral CD1a+ cells is a strong independent prognostic factor, predicting a higher recurrence rates and worse survival outcomes.

A Rare Case of Interdigitating Dendritic Cell Sarcoma of the Rectum: Review of Histopathology and Management Strategy

Interdigitating dendritic cell sarcoma (IDCS) is a rare neoplasm arising from a subclass of dendritic cells, known for their role in mediating various immunological functions, including T-cell mediated immunity. Although existing literature on IDCS is limited to scattered reports, extranodal manifestation in the gastrointestinal tract, and in particular, the rectum is extremely rare. To our knowledge, we report only the second case of IDCS arising in the rectum in a young 20-year-old man, successfully managed surgically and with a good oncological outcome. Existing literature on the incidence, pathophysiology and treatment strategies is also examined.

Solitary Fibrous Tumor of Soft Tissue Clinically Simulating a Chemodectoma

We present a case of a 48-year-old woman with a solitary fibrous tumor localized in the carotid bifurcation clinically simulating a chemodectoma. The tumor was composed of spindle cells with abundant intercellular collagen. These spindle cells were positive for CD34 and negative for chromogranin, S-100 protein, NSE, GFAP, and cytokeratin. This is the first solitary fibrous tumor reported in this location, in the English literature.

Role of abnormal Langerhans cells in oral epithelial dysplasia and oral squamous cell carcinoma: A pilot study

BACKGROUND

The oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), although initiated by tobacco carcinogens, their progression is due to inability of Langerhans cells (LCs) to detect these abnormal cells and promote lymphocytes to destroy these cells. We assessed and quantified the tumor associated LCs and inflammation in OED and OSCC to understand their role.

MATERIALS AND METHODS

Fifty-five microscopic sections were assessed (27 OED and 28 OSCC). The LCs were detected using S-100 immunohistochemical marker. The number of tumor associated LCs were counted. The presence of abnormal appearing large cells and its relation to histopathologic grade and inflammation was assessed.

RESULTS

Significant increase in the LC count was observed in OSCC when compared to dysplasia. Large, abnormal appearing cells were observed in dysplasia and carcinomas however, these were more pronounced in moderate dysplasia and poorly-differentiated carcinomas. The presence of these abnormal appearing cells was associated with decrease in lymphocytic infiltrate.

CONCLUSION

The present study indicates more LC are recruited into the carcinoma. These accumulated nonfunctional LC in the tumor tissue are indicative of aggressive tumor with potential malignant transformation.

Cytomorphometry of canine cutaneous histiocytoma

A morphometric analysis of tumoral Langerhans cells and activated macrophages was conducted using canine cutaneous tumors (65 cases of canine cutaneous histiocytoma and 7 cases of pyogranuloma). The histiocytic origin of the tumor cells was confirmed using immunohistochemistry. The parameters of the morphometric analysis included cellular and nuclear size and shape and the nuclear:cytoplasmic ratio; the variability of these features was calculated separately for each tumor. The canine cutaneous histiocytoma group was divided into four stages of regression depending on the intensity of the lymphocytic infiltration. Statistical analysis revealed that the anisocytosis, anisokaryosis and cellular pleomorphism of tumoral Langerhans cells increased, while the cellular circularity and nuclear:cytoplasmic ratio decreased with tumor regression. Activated macrophages of the pyogranuloma were significantly larger, and had larger nuclei, than tumoral Langerhans cells. Furthermore, these activated macrophages showed greater anisocytosis and anisokaryosis and a lower nuclear:cytoplasmic ratio than tumoral Langerhans cells in the first stages of tumor regression. These results indicate that tumoral Langerhans cells undergo morphologic changes during the regression of canine cutaneous histiocytoma, reflecting their maturation and differentiation. Morphometry can be a useful method for distinguishing activated macrophages from tumoral Langerhans cells.

Does adjunctive chemotherapy reduce remission rates compared to cortisone alone in unifocal or multifocal histiocytosis of bone?

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disorder that can affect almost any organ, including bone. Treatment options include local corticosteroid infiltration in isolated bone lesions and oral corticosteroids and chemotherapy in multifocal bone lesions. Several studies show local corticosteroid injection in unifocal bone lesions heal in more than 75% of patients with minimal side effects. Therefore, it is unclear whether chemotherapy adds materially to the healing rate.

QUESTIONS/PURPOSES

We therefore compared overall survival, remission rate, and recurrence rate in patients with bone LCH treated with chemotherapy and corticosteroids or corticosteroids alone.

METHODS

We retrospectively reviewed the records of 198 patients with LCH since 1950. Median age at diagnosis was 5 years, male-to-female ratio was 1.33, and the most frequent symptom was local pain (95%). We recorded the disease presentation, demographics, treatment, and clinical evolution of each patient. Minimum followup was 4 months (median, 24 months; range, 4-360 months).

RESULTS

The survival rate of the systemic disease group was 76.5% (65 of 85) while the survival rate in the unifocal and multifocal bone involvement groups was 100% at a median 5-year followup. All patients with unifocal bone involvement and 40 of 43 (93%) with multifocal bone involvement had complete remission. One of 30 patients with multifocal bone involvement treated with chemotherapy and oral corticosteroids did not achieve remission whereas two of six receiving only corticosteroids did not achieve remission.

CONCLUSIONS

Our observations suggest intralesional corticosteroid injection without adjunctive chemotherapy achieves remission in unifocal bone LCH but may not do so in multifocal single-system bone involvement. Larger series would be required to confirm this observation.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Role of dendritic cells in progression and clinical outcome of colon cancer

PURPOSE

The dendritic cells (DCs) are key players in the initiation and regulation of immune responses including antitumor immunity. In the current study, we aimed to elucidate the role of different subtypes of DCs infiltrating the tumor stroma and invasive margin for tumor progression and survival of patients with colon cancer.

METHODS

The presence of immature (CD1a- and S100 protein+) and mature (CD83- and HLA-DR+) DCs was evaluated by immunohistochemistry in tissue samples from 145 patients with colon cancer. Patients were dichotomized according to the number of DCs in the tumor stroma and invasive margin, and clinical, histological, and survival data were compared between the two groups of patients.

RESULTS

The number of the mature CD83+ DCs in the tumor stroma and in the invasive margin significantly correlated with the tumor stage: the lower level of infiltration was found in patients that have advanced tumor stage. The frequency of distant metastases was higher in patients who had lower numbers of immature CD1a+ DCs in tumor stroma and of CD83+ DCs in invasive margin. Patients showing a relatively high number of S100+ DCs in the tumor stroma and HLA-DR+ DCs in the invasive margin had a longer overall survival (p < 0.05). Patients with lower CD83+ DCs infiltration in invasive margin had worse prognosis after surgical therapy compared with those with higher CD83+ DCs infiltration (p = 0.0397).

CONCLUSIONS

Our results demonstrate that the infiltration of colon cancer with DCs is related with tumor progression and patient prognosis, suggesting a central role for DCs in controlling local antitumor immunity.

Dendritic cells in the pathogenesis and treatment of human diseases: a Janus Bifrons?

Dendritic cells (DCs) represent the bridging cell compartment between a variety of nonself antigens (i.e., microbial, cancer and vaccine antigens) and adaptive immunity, orchestrating the quality and potency of downstream immune responses. Because of the central role of DCs in the generation and regulation of immunity, the modulation of DC function in order to shape immune responses is gaining momentum. In this respect, recent advances in understanding DC biology, as well as the required molecular signals for induction of T-cell immunity, have spurred many experimental strategies to use DCs for therapeutic immunological approaches for infections and cancer. However, when DCs lose control over such 'protective' responses - by alterations in their number, phenotype and/or function - undesired effects leading to allergy and autoimmune clinical manifestations may occur. Novel therapeutic approaches have been designed and currently evaluated in order to address DCs and silence these immunopathological processes. In this article we present recent concepts of DC biology and some medical implications in view of therapeutic opportunities.

Langerhans cell histiocytosis of bone in children: a clinicopathologic study of 108 cases

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease that is characterized by abnormal proliferation of pathological Langerhans cells (LCs). In this study, a total of 108 pediatric patients with LCH of bone were evaluated retrospectively for illustrating the clinicopathologic features of this disease, with a goal of improving the diagnosis, treatment, and prognosis.

METHODS

A retrospective study was based on the clinical records and pathological data of 108 patients (13 days to 12 years of age) with LCH of bone from a single hospital. Hematoxylin-eosin stain and immunohistochemical stain were applied. The follow-up was conducted to June 2008.

RESULTS

The peak age of the patients ranged between 3 years and 6 years (80.6%, 87/108), and male gender predominated. The most common clinical presentation was local pain, and the imaging findings commonly showed an isolated lytic lesion in the bone. Of the 108 patients, 79 (73.1%) had single bone involvement, 27 (25.0%) had multi-bone involvement (with or without related skin involvement), and 2 (1.8%) had multisystem involvement. Histologically, all the lesions revealed abnormal proliferation of pathological Langerhans cells along with an admixture of eosinophils, lymphocytes, and other inflammatory cells. The LCs have similar shape and are positive for cluster of differentiation 1a (CD1a) (100.0%, 60/60), S100 (90.0%, 54/60), CD68 (41.7%, 25/60), lysozyme (Lys) (40.0%, 24/60), and macrophage antigen compound (MAC) 387 (30.0%, 18/60); cytokeratin (CK) and epithelial membrane antigen (EMA) were negative. The overall survival rate was 98.0% at a median follow-up of 5 years.

CONCLUSIONS

LCH of bone in children is predominant in males and usually shows as an isolated lytic lesion. Histologically, the lesions reveal abnormal proliferation of pathological Langerhans cells, admixed with various types of inflammatory cells. The patients have a good prognosis, except those with multi-system involvement.

Histiocytic disorders of the lung

Histiocytic proliferations involving the lung span a broad spectrum. Some proliferations are primary; others represent a histiocytic response secondary to conditions in which there may be isolated lung involvement or the lung may be involved as part of a systemic process. Primary histiocytic lung disorders, particularly those of uncertain histogenesis are a heterogeneous and intriguing group of disorders. Although they have been the focus of attention by clinicians and pathologists alike, much is unknown about their etiopathogenesis. Owing to this uncertainty, our understanding of these processes is in a state of flux, and is likely to change as more information is brought to light. This review will focus on pulmonary histiocytic proliferations of uncertain histogenesis. Other histiocytic lesions will be dealt with in brief.

Development of an effective method for dendritic cell immunotherapy of mouse melanoma

Dendritic cell (DC) immunotherapy is a strong candidate for the treatment of incurable cancers especially malignant melanoma. Nevertheless, the proper guideline of DC immunotherapy does not exist. The absence of the guideline is also an obstacle to clinical trials of DC immunotherapy. So we conducted this study in order to develop an effective DC preparation method for immunotherapy in mouse malignant melanoma. Mouse bone marrow-derived DC were stimulated with tumour antigen alone or tumour antigen plus a cocktail (anti-CD40 antibody +TNF-alpha+ IL-1beta) for 8, 24 or 48 h and the characteristics of these DC, such as surface molecules (CD40, CD80, CD86, MHC class II, CCR7), cytokines(IL-12, IFN-gamma, and IL-10), DC-induced T cell proliferation in vitro, and the production of IFN-gamma by those cells, were evaluated. Mice with melanoma were then treated with DC stimulated with tumour antigen alone and tumour antigen plus cocktail for 8 or 48 h. The tumour size and survival rate of these mice were then evaluated. (1) Beneficial clinical effects such as a reduction of tumour size and an increased survival rate were best observed in the group treated with DC stimulated for 8 h with tumour antigen plus cocktail. (2) The single prominent characteristic of DC stimulated for 8 h with tumour antigen plus cocktail was an elevated IL-12 secretion. The cytokine IL-12 was not secreted by other DC. Consequently, proper production of IL-12 was found to be an important requirement for DC used in immunotherapy of mouse melanoma.

Lymphomatoid papulosis with CD1a+ dendritic cell hyperplasia, mimicking Langerhans cell histiocytosis

Although CD1a+ dendritic cells (DC) in cutaneous T-cell lymphomas (CTCL) have been well documented, the presence of large numbers of DC within lymphoid infiltrates can pose a diagnostic difficulty. We present a case of a 70-year-old man with a 3-year history of recurrent red papules and plaques on the extremities and trunk that was referred to our institution, with the diagnosis of Langerhans cell histiocytosis. Skin biopsies showed a wedge-shaped cellular infiltrate in the superficial and deep dermis consisting of two cell populations. Most prominent were clusters of epithelioid cells with grooved nuclei and abundant eosinophilic cytoplasm, which stained with antibodies to CD1a and S-100. A second, less prominent population of atypical lymphocytes, some with enlarged, hyperchromatic and convoluted nuclei, were intermixed. The latter were positive for CD30, CD3 and CD5 and negative for CD20, CD34, CD68, ALK-1 and TdT. T-cell receptor gene rearrangement studies confirmed a clonal T-cell population, which with the clinical history was consistent with the diagnosis of lymphomatoid papulosis. While previous studies have shown an increased density of dermal DC in CTCL, we believe that this represents the first report of an unusually florid DC proliferation mimicking Langerhans cell histiocytosis and masking a lymphoproliferative disorder.

Histiocytic lesions and proliferations in the lung

Pulmonary lesions encountered by the pathologist in which histiocytes are the dominant finding histologically are reviewed. Lesions discussed include neoplasms of histiocytes and nonneoplastic processes. The nonneoplastic processes are divided into those that present as nodular histiocytic proliferations in the lung, those that present as diffuse proliferations of histiocytes in the lung, and those with a mixed pattern. Entities discussed include pulmonary Langerhans' cell histiocytosis, pneumonoconioses, infections, diffuse panbronchiolitis, crystal storing histiocytosis, respiratory bronchiolitis, alveolar hemorrhage, eosinophilic pneumonia, obstructive pneumonia, exogenous lipoid pneumonia, some drug reactions, and some metabolic/storage diseases. Entities of uncertain histogenesis, including Rosai-Dorfman disease and Erdheim-Chester disease, are also discussed. Qualitative features of the histiocytes are addressed, including the presence of foreign dust, hemosiderin, foamy change, and histiocytes showing features of Langerhans' cells.

Larger numbers of immature dendritic cells augment an anti-tumor effect against established murine melanoma cells

The dendritic cell (DC) is a potentially promising tool for cancer immunotherapy. To date, however, DC-based immunotherapy has not yielded data with which firm conclusions can be drawn. In the present study, we tested the dose-dependant enhancement of the anti-tumor effect induced by DCs. When large numbers of DCs were used, tumor growth was suppressed up to 41% when compared to control mice. Survival of the animals was prolonged to 54 days compared to the 33-day survival the control mice. The delayed-type hypersensitivity (DTH) response induced was 26-fold higher than in the controls. Larger numbers of DCs also led to higher expansion of IFN-gamma-secreting-CD8(+) T cells. Furthermore, the secretion of IL-12p70 and IFN-gamma by spleen cells were enhanced in proportion to the dosage. However, the level of IL-4 secreted from spleen cells was negligible compared to the level of IFN-gamma that was released. These results indicate that DCs induce Th1-dominant immune response and that more DCs could lead to better immunological results, a finding which was consistent with our therapeutic results.

Graft rejection and hyperacute graft-versus-host disease in stem cell transplantation from non-inherited maternal antigen complementary HLA-mismatched siblings

Human leukocyte antigen (HLA)-mismatched stem cell transplantation from non-inherited maternal antigen (NIMA)-complementary donors is known to produce stable engraftment without inducing severe graft-versus-host disease (GVHD). We treated two patients with acute myeloid leukemia (AML) and one patient with severe aplastic anemia (SAA) with HLA-mismatched stem cell transplantation (SCT) from NIMA-complementary donors (NIMA-mismatched SCT). The presence of donor and recipient-derived blood cells in the peripheral blood of recipient (donor microchimerism) and donor was documented respectively by amplifying NIMA-derived DNA in two of the three patients. Graft rejection occurred in the SAA patient who was conditioned with a fludarabine-based regimen. Grade III and grade IV acute GVHD developed in patients with AML on day 8 and day 11 respectively, and became a direct cause of death in one patient. The findings suggest that intensive conditioning and immunosuppression after stem cell transplantation are needed in NIMA-mismatched SCT even if donor and recipient microchimerisms is detectable in the donor and recipient before SCT.

Enhanced antitumor effect of dendritic cell based immunotherapy after intratumoral injection of radionuclide Ho-166 against B16 melanoma

Internal radiotherapy with the intratumoral injection of the beta-emitting radionuclide, Holmium (Ho)-166, into B16 melanoma resulted in a reduction in size and growth rate; however, complete remission was not always achieved. Therefore, additional dendritic cell (DC) therapy was investigated to determine whether it could improve therapeutic results. Malignant melanoma was induced in mice by inoculating B16F10 cell line subcutaneously. Fifty-four mice were divided into four groups: (1) non-treated (group I, n = 11), (2) treated with Ho-166 (group II, n = 16), (3) treated with immature DCs (group III, n = 8), and (4) treated with immature DCs after Ho-166 injection (group IV, n = 19). Changes in tumor size, survival rates, and immunologic profiles were observed. Nineteen days after Ho-166 or PBS injection, mean tumor sizes in the four groups were 6044 +/- 1046, 1658 +/- 523, 3871 +/- 921, and 444 +/- 167 mm(3), respectively. We observed a significant decrease in tumor size (P < 0.05) and an increase in survival in group IV. When the B16F10 cell line was reinjected into the contralateral backs of survivors, much slower growth was observed in group IV (P < 0.05). Both tumor-specific CTL and natural killer cell activities and the infiltration of inflammatory cells into tumor tissues were found to be elevated in group IV. In addition, strong immune responses as determined by in vitro T cell proliferation, ELISA and ELISPOT assay were induced in group IV. Our results suggest that a combination of internal radiotherapy using Ho-166 and immature DCs could be used either to treat unresectable melanoma or as an adjuvant therapy after surgery.

Morphological observation of tumor infiltrating immunocytes in human rectal cancer

AIM: To investigate the morphological characterization of tumor infiltrating dendritic cells (TIDCs) and tumor infiltrating lymphocytes (TILs) in human rectal cancer.

METHODS: Light and electron microscopy as well as immunohistochemistry were used to observe the distributive and morphological changes of TIDCs and TILs.

RESULTS: TIDCs were mainly located in tumor-surrounding tissue. The number of TIDCs in the earlier stage was higher than that in the later stage (P < 0.01). TILs were mainly seen in adjacent tissue of cancers and tumor-surrounding tissue. There were more TILs in the earlier stage than that in the later stage (P <0.01). Under electron microscope, TIDCs were irregular in shape and exhibited many dendritic protrusions. It isn’t obvious that cancer cells perforated the basement membrane and TILs were arranged along the basement membrane in the earlier stage. In the later stage, it is explicit that cancer cells perforated the basement membrane and surrounded by TILs. There were contacts among TIDCs, TILs and tumor cell. One TIDCs contacted one or several TILs which clustered around TIDCs. Glycogen granules were seen between TIDCs and TILs.

CONCLUSION: The number of TIDCs and TILs is related with tumor progression There exist close relationships among TIDCs, TILs and tumor cell.

Relationship between HIV viral load and Langerhans cells of the cervical epithelium

AIM

To determine the relationship between the density of cervical mucosa Langerhans cells, cervical histology, and HIV viral load.

METHODS

Eighty-four HIV-infected and 17 women at high risk for HIV had cervical biopsies assessed for squamous intraepithelial lesions and Langerhans cell density. Langerhans cells were identified using the S-100 immunohistochemical stain and were counted manually. Polymerase chain reaction assays were used to detect cervical human papillomavirus (HPV)-DNA. T-cell subsets were determined using immunofluorescent flow cytometry. Plasma HIV RNA levels were measured using a nucleic acid sequence-based amplification technique. The associations between cervical Langerhans cell density, cervical histology, CD4 counts, HIV viral loads, HPV-DNA detection, and smoking status were assessed using multivariate statistical models.

RESULTS

In multivariate analysis among women infected with HIV, the mean Langerhans cell density per high-powered field was 4.00 among women with no detectable plasma HIV-RNA, and 1.92 among those with detectable HIV-RNA (P = 0.01). The mean cervical Langerhans cell density was increased in women with high-grade squamous intraepithelial lesions compared with those with low-grade squamous intraepithelial lesions and normal/metaplastic histology (3.87 vs 2.11; P = 0.05). Neither HPV-DNA detection, smoking status, nor CD4 count was significantly associated with Langerhans cell density.

CONCLUSIONS

The decrease in cervical Langerhans cell density in women with detectable HIV-RNA suggests an impaired mucosal immune response to local infections, such as HPV. Conversely, HPV infection resulting in high-grade dysplasia might be associated with an enhanced local immune response.

Therapeutic potential of dendritic-based vaccines

Involving a delicate balance of cell types, the interaction between the immune system and disease or abnormality in the human body is complex. Moreover, the mere presence of antigen and immune cells is necessary, yet insufficient to elicit immune reactivity. In order to elicit an immune response, an antigen in some form must be processed and presented to the immune system. Arguably, the most efficient antigen-presenting cell, the dendritic cell (DC), is the centre of intense investigation. The elicitation or cessation of an immune response is not a simple matter. The body must be able either to up-regulate (e.g., in the case of infectious disease) or down-regulate (e.g., in the case of transplantation) immunity to antigens located anywhere in the body. This sentinel role is capably filled via the distribution of Langerhans cells in the epidermis of the skin, and the migration of DCs throughout the lymphatic and circulatory systems. DCs are potent, as well as efficient: small numbers of cells and low levels of antigen still induce clinically relevant immunity. Lastly, they are capable of tolerance induction to self components by helping to delete self-reactive thymocytes and generating anergy in committed T-cells. Since DCs both initiate and modulate immunity, they are a component of a vast array of vaccines. This review highlights some of the intriguing basic research involving the development of DC-based therapeutics. Furthermore, whenever an area of study has progressed to human treatment, recent and on-going clinical trials are discussed.

Interdigitating dendritic cell tumor with breast and cervical lymph-node involvement: a case report and review of the literature

Interdigitating dendritic cell tumor (IDCT) is an extremely rare malignancy. It occurs primarily in lymph nodes, but extranodal involvement has also been reported. A 38-year-old woman with IDCT with breast and cervical lymph-node involvement is reported in this paper. To our knowledge, this is the first case of IDCT originating from the breast. In the breast and lymph node, the tumor displayed diffuse sheets, fascicles and storiform growth pattern. It was composed of oval to spindle cells with pale to eosinophilic cytoplasm, ill-defined cell outlines, oval nuclei with vesicular chromatin and prominent eosinophilic nucleoli. Mitotic activity was three per ten high-power fields. The neoplastic cells were intermingled with small mature lymphocytes and plasma cells. Immunohistochemical studies showed that the tumor cells were strongly and diffusely positive for vimentin, CD68, S-100 protein, CD45/leukocyte common antigen and fascin and focally positive for lysozyme, alpha-1 antitrypsin and CD4. Ki-67 labeling index was 10%. The patient was treated with combined therapeutic approaches, including surgery, radiotherapy and chemotherapy. IDCT has the potential for an aggressive clinical course. However, 32 months after the initial diagnosis, the patient is still alive and being followed with a stable tumor burden.

Follicular dendritic cell sarcoma of the pharyngeal region: Histologic, cytologic, immunohistochemical, and ultrastructural study of three cases

Follicular dendritic cell sarcoma is a tumor of recent description and characterization; it is often underdiagnosed because it is easily confused with other entities. Three cases of follicular dendritic cell sarcoma are described in the present article. The first occurred in the parapharyngeal space in a 29-year-old woman who developed multiple recurrences over the span of 10 years. The second was located in the left tonsil in a 48-year-old man, and the third case developed in the parapharyngeal space in a 26-year-old man. All cases were positive for CD21 and CD35 and ultrastructurally they displayed a morphologic spectrum. The first case featured spindle cells with interdigitated long cell processes joined by well-developed desmosomes. In the other two cases there were round to ovoid cells with interwoven processes connected by occasional desmosomes. Including these three cases, a total of 20 follicular dendritic cell sarcoma of the pharyngeal region have been reported to date. The clinical behavior of these tumors is similar to other low-grade sarcomas.

Interdigitating dendritic cell sarcoma: a report of four paediatric cases and review of the literature

AIMS

To report a series of four paediatric cases of interdigitating dendritic cell sarcoma (IDCS) and add to the known extranodal sites of occurrence for this tumour. Neoplasms derived from interdigitating dendritic cells are rare, with only 33 cases being reported in the literature (Medline search). These tumours usually occur in lymph nodes in the adult population.

METHODS AND RESULTS

The patients were a 10-year-old girl with a large soft tissue mass bulging into the left chest, a 12-year-old girl with a right paraspinal mass, a 21-month-old boy with generalized lymphadenopathy and hepatosplenomegaly and a 6-year-old girl with a large bladder mass. Paraffin blocks and haematoxylin and eosin slides were available in all cases. In addition, immunohistochemistry and electron microscopy were performed. A diagnosis of IDCS was made in all cases.

CONCLUSION

The diagnosis of IDCS can rarely be entertained on clinical information alone. Microscopically, there is a wide spectrum of features. Thus, immunohistochemistry and electron microscopy are crucial in making the diagnosis. The differential diagnosis includes inflammatory pseudotumour, follicular dendritic cell sarcoma, true histiocytic lymphoma, malignant Langerhans cell histiocytosis, anaplastic large-cell lymphoma, melanoma, and a range of sarcomas. IDCS displays aggressive behaviour and approximately half of the patients die of the disease.

Tumor antigens and antigen-presenting capacity in breast cancer

AIMS

Cancer cells frequently express antigens capable of being recognized by the host immune system; however, any resultant immune response is often ineffective. This may be related in part to tumor-induced defects in antigen presentation. We screened for dendritic cell infiltration, tumor MHC II expression and associated lymphocytic reaction in the context of three established breast tumor antigens.

METHODS

Forty primary breast tumors were evaluated by immunohistochemical techniques for expression of her2/neu, p53, and MUC1 and MHC class II molecules. Twenty-five samples were further analyzed for p53 mutations by PCR-SSCP analysis and DNA sequencing. The phenotype of tumor-infiltrating inflammatory cells was evaluated using the following markers: CD1a, MHC Class II, CD3, CD45, and CD45RO.

RESULTS

Tumors with p53 mutations and overexpression, but not her2/neu or MUC1 overexpressing tumors, more frequently harbored marked CD1a+ dendritic cell infiltrates. An overall correlation between CD1a+ cell infiltrates and HLA class II expression on tumor cells (p = 0.0008) was also observed and these tumors had greater CD45RO+ lymphocytic infiltrates.

CONCLUSIONS

In breast cancer, p53 mutations may present a more visible signal to the immune system and hence provide a better target for immunotherapy. Infiltrating CD1a positive cells are associated with a more dense tumor lymphocytic infiltrate and tumor cell expression of MHC II molecules.

Multiple lung nodules in a woman with a history of melanoma

A 61-year-old Caucasian female presented with a 6-week history of dry persistent cough. She had no shortness of breath, chest pain, fever, chills, or weight loss. She had been diagnosed with melanoma on the left thigh 6 months earlier. It was a spindle cell variant, Clark's grade III, with maximal thickness of 0.5 mm. At the time of diagnosis of melanoma, there was no evidence of metastasis on chest radiographs or computed tomography (CT) of the abdomen and pelvis. Treatment of her melanoma was limited to surgical excision with no subsequent radiation or chemotherapy. Other significant past medical history included hypertension, hypothyroidism, and bilateral breast augmentation. She had a 40 pack-year history of smoking.

Function of CD80 and CD86 on monocyte- and stem cell-derived dendritic cells

Dendritic cells (DCs) consist of a heterogeneous population of hematopoietic cells characterized by their unique dendritic morphology, their efficient antigen-presenting capability to activate naïve CD4+ and CD8+ T cells, as well as their lack of lineage-specific markers. Functional properties comparing umbilical cord blood monocyte-derived and umbilical cord blood stem cell-derived DCs have not yet been investigated. Human umbilical cord blood CD14+ monocytes and CD34+ stem cells were induced to differentiate into dendritic cells using 100 ng/mL granulocyte-macrophage colony-stimulating factor (GM-CSF), 25 ng/mL interleukin (II)-4, 2.5 ng/mL tumor necrosis factor alpha (TNF-alpha) and 100 ng/mL GM-CSF, 25 ng/mL stem cell factor, and 2.5 ng/mL TNF-alpha, respectively. Differentiated dendritic cells were CD80+, CD86+, CD83+, CD54+, CD1a+, CD11b+, CD11c+, HLA-DR+, CD34-, CD3-, CD19-, CD14-, and CD16-. Reverse transcription polymerase chain reaction revealed that differentiating monocytes initially expressed CD86 mRNA while CD80 mRNA appeared on Day 2. Differentiating stem cells expressed both CD80 and CD86 mRNA on Day 2 of culture. Mixed lymphocyte reaction was employed to evaluate the two types of lineage-derived DCs. Monoclonal antibodies (mabs) to CD80 and CD86 were employed to assess their costimulatory roles. CD14 and CD34 derived DCs prior to the functional assay were stimulated for 18 h with 0.1 and 1.0 mg/mL Escherichia coli lipopolyssacharide, respectively. A decrease in stimulation as depicted by decreased T-cell activation was significant with mabs to both CD80 and CD86 on monocyte-derived DCs while only mabs to CD86 induced decreased T-cell activation by stem cell-derived DCs. The varied functional role of CD80 and CD86 costimulatory molecules is associated with DC differentiation from distinct cord blood-isolated hematopoietic lineages. These studies demonstrate that DC association with distinct hematopoietic lineages is of relevance in transplantation and vaccine therapies.

Evaluation of Myeloid and Lymphoid Dendritic Cells in Peritoneal Fluid in Women with Non-malignant Ovarian Tumors

PROBLEM

Identification of myeloid and lymphoid dendritic cells (DCs) in peritoneal fluid (PF) and peripheral blood (PB) of patients with ovarian pathology.

METHOD OF STUDY

PF and PB were collected from 60 patients who underwent laparoscopy because of non-malignant ovarian tumors. Mononuclear cells were separated by gradient centrifugation. The cell surface antigens were determined by flow cytometry using monoclonal antibodies.

RESULTS

Both myeloid and lymphoid DCs were detected in PF and PB of women with ovarian tumors. The percentage of myeloid DCs was significantly higher in PF than in PB. The concentration of PF myeloid DCs was the highest (P < 0.05) in patients with dermoid cysts (0.67 x 10(6)/mL PF) in comparison with the other studied groups, excluding patients with normal pelvis.

CONCLUSIONS

Domination of myeloid and not lymphoid cells in PF may support the hypothesis that local PF immune disturbances may play a role in some non-malignant ovarian pathology.

Costimulatory function of umbilical cord blood CD14+ and CD34+ derived dendritic cells

Dendritic cells (DCs) consist of a heterogeneous population of hematopoietic cells characterized by their unique dendritic morphology, their efficient antigen-presenting capability to activate naive CD4(+) and CD8(+) T cells, and their lack of lineage specific markers. Functional properties comparing umbilical cord blood monocyte-derived and umbilical cord blood stem cell-derived DCs have not yet been investigated. CD14(+) monocytes and CD34(+) stem cells were isolated from human umbilical cord blood and were induced to differentiate into dendritic cells using 100 ng/mL granulocyte-macrophage colony stimulating factor (GM-CSF), 25 ng/mL IL-4, 2.5 ng/mL tumor necrosis factor-alpha (TNF-alpha), 100 ng/mL GM-CSF, 25 ng/mL stem cell factor, and 2.5 ng/mL TNF-alpha, respectively. Flow cytometric analysis revealed that the 14-day-old dendritic cells were CD80(+), CD86(+), CD83(+), CD54(+), CD1a(+), CD11b(+), CD11c(+), HLA-DR(+), CD34(-), CD3(-), CD19(-), CD14(-), and CD16(-). Reverse transcription polymerase chain reaction was employed to detect expression of mRNA for CD80 and CD86. Differentiating monocytes initially expressed CD86 while CD80 appeared on day 2. Differentiating stem cells expressed CD80 and CD86 on day 2 of culture. The surface expression of CD80 and CD86 was studied over the course of differentiation. Mixed lymphocyte reaction was employed to evaluate the two types of lineage-derived DCs. Prior to the functional assay, CD14(+) and CD34(+) derived DCs were stimulated for 18 h with 0.1 mg/mL and 1.0 mg/mL E. coli lipopolyssacharide, respectively. Monoclonal antibodies (mabs) to CD80 and CD86 were employed to assess their costimulatory roles. A decrease of stimulation as depicted by decreased T cell activation was significant with mabs to both CD80 and CD86 on monocyte-derived DCs while only mabs to CD86 induced decreased T cell activation by stem cell-derived DCs. The varied functional role of CD80 and CD86 costimulatory molecules is associated with DC differentiation from distinct cord blood isolated hematopoietic lineages. These studies demonstrate that DC association with distinct hematopoietic lineages is of relevance in transplantation and vaccine therapies.

The clinical implications of mixed lymphocyte reaction with leukemic cells

To evaluate the clinical implications of a mixed lymphocyte reaction between leukemic cells and lymphocytes from HLA-matched sibling donors, we attempted to generate donor-derived, graft-versus-leukemia-effective cells and to define their characteristics. We studied 8 patients with chronic myelogenous leukemia (CML), including 5 patients in the chronic phase (CP), 3 patients in the accelerated phase (AP), and 2 patients with acute myelogenous leukemia (AML) in their first complete remission. Cells from these patients were used as stimulators in a mixed lymphocyte reaction.The effects of natural killer (NK) cells and cytotoxic T-lymphocytes (CTLs) were separated by observing tests for cytotoxicity to target cells, including K562 cells, the patient's leukemic cells, and phytohemagglutinin (PHA) blasts. Donor-derived antileukemic CTLs againstthe patient's own leukemic cells are productive in vitro. The efficacy of generating CTLs against leukemic target cells was (in decreasing order) AML, CML-CP, and CML-AP. Cytotoxic activity against leukemic targets was prominent in 4 cases--2 CML-CP and the 2 AML cases. On the contrary, the 3 cases of CML-AP showed low CTL activity. In cases showing 1 positive result among 3 targets (K562 cells, the patient's leukemic cells, and PHA blasts), the relapse rate was significantly lower (P = .022) on follow-up (median, 33 months; 7-40 months) after hematopoietic stem cell transplantation. By a combined analysis of the cytotoxicity effects for all 3 target cells, we were able to demonstrate a correlation between leukemic relapse and the variable degree of the cytotoxicity test results. Although the total sample numbers for this study were low, we speculate that these results may come from differences in the individual characteristics of the leukemic cells that are in line with their clinical disease status.

Langerhans cell histiocytosis in a patient with systemic lupus erythematosus: a clonal disease responding to treatment with cladribine, and cyclophosphamide

Langerhans cell histiocytosis (LCH) is a rare neoplastic disease of specific dendritic cells which belong to the monocyte-macrophage system. The association of LCH with autoimmune disease is extremely rare and to our knowledge its coexistence with systemic lupus erythematosus (SLE) has not been described so far. We report a case of LCH affecting liver, spleen and abdomen lymph nodes, which developed in an adult female six years after diagnosis of SLE treated for a long time with prednisone. Histology showed infiltration of characteristic Langerhans cells with folded, grooved or lobulated nuclei with fine chromatin. In the background there were eosinophils, lymphocytes and CD-68-positive histiocytes. The neoplastic cells were S100p-immunopositive, but stained negatively for CD1a--probably as the result of overfixation of consulted material. CD-68 was present mostly in macrophages. Ultrastructurally, the tumour cells presented structures consistent with Birbeck granules. Clonal origin of neoplastic cells was shown using the HUMARA-PCR assay. The disease was refractory to treatment with high doses of prednisone and vincristine but complete response was achieved after treatment with caldribine combined with cyclophosphamide.

Novel membrane-bound GM-CSF vaccines for the treatment of cancer: generation and evaluation of mbGM-CSF mouse B16F10 melanoma cell vaccine

Cancer vaccines composed of tumor cells engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) are currently being clinically evaluated. To enhance the immunogenicity of GM-CSF-secreting tumor cell vaccines, a novel approach expressing GM-CSF as a membrane-bound form (mbGM-CSF) on the tumor cell surface was investigated. The intent was to enhance antigen presentation by increasing interactions between the tumor cell lines in the vaccine and GM-CSF receptor positive antigen presenting cells (APC), notably the patient's Langerhans cells residing within the intradermal injection site. B16.F10 cells engineered to express either membrane-bound or secreted GM-CSF were compared in the B16.F10 mouse melanoma model. We observed that mbGM-CSF on the tumor cell surface retarded growth and induced protective immunity to subsequent wild-type tumor challenge more effectively than tumor cells secreting GM-CSF. Vaccination with irradiated mbGM-CSF B16.F10 also provided strong protection from wild-type tumor challenge, improved therapeutic effects against established tumors, and retarded lung metastases. These results demonstrate that mbGM-CSF B16.F10 cells can induce strong systemic immunity that protects against and therapeutically treats B16.F10 melanoma more effectively than analogous vaccines containing only secreted GM-CSF. These data warrant further development and clinical testing of mbGM-CSF tumor cell vaccines.

Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases

Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with 'malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer-Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.

CD1a-positive cells in odontogenic cysts

Langerhans cells (LC) are bone marrow-derived cells that have a CD1a-positive immunophenotype and are an important portion of the cell-mediated immune response. The aim of this study was an immunohistochemical evaluation of CD1a positive cells in different types of oral cysts. Fifty-five cysts were studied: 18 odontogenic keratocysts (OKC), of which five were orthokeratotic and 13 parakeratotic; 19 radicular cysts; and 18 dentigerous cysts. Positive LC was 80% for orthokeratotic OKC, 33% for parakeratotic OKC, approximately 35% for radicular cysts, and approximately 20% for dentigerous cysts. The results show that OKC with well-differentiated epithelial linings presented a greater number of LC than the other cysts. However, when the cyst wall was inflamed there were no differences in LC expression in the different types of cysts. The data confirm that LC distribution seems to be associated with the degree of differentiation of the epithelia.

Local immune response in squamous cell carcinoma of the uterine cervix

The role of Langerhans cells as antigen-presenting cells was examined in cervical carcinomas. Frozen samples were obtained from 34 women with stage Ib and II cervical carcinomas. Langerhans cells (CD1), T lymphocytes (CD4 and CD8), B lymphocytes (CD22), and natural killer (CD57, NK) cells were all quantitatively assessed in cervical carcinomas using immunohistochemical methods. These results were related to the MHC class I and II expression on the tumor cells. The majority of Langerhans cells were distributed among cancer cells and they were positively correlated with CD4+, NK and B cells in cervical carcinomas. This is suggestive of the presence of local immune response. The numbers of Langerhans, CD4+, CD8+ and NK cells did not significantly correlate with age at operation, lymph node metastases or depth of cervical wall invasion. The downregulation of MHC class I expression found in 8 (24%) carcinomas was not associated with the decrease in the number of immunologic cells. The upregulation of MHC class II expression found in 26 (76%) carcinomas was significantly associated with the increase in the number of Langerhans cells (p < 0.007). However, the association between the upregulation of MHC-II expression and CD4+ cells did not reach statistical significance (p < 0.07). This is probably due to a small case in this study. MHC-II-restricted immunity may partly contribute to the local immune response in stages Ib and II squamous cell carcinoma of the uterine cervix.

Evaluation of cellular tumour rejection mechanisms in the peritumoral bladder wall after bacillus Calmette-Guérin treatment

OBJECTIVE

To compare the immunological status of normal and peritumoral bladder walls, and to characterize immunocompetent cells before and during intravesical instillations of bacillus Calmette-Guérin (BCG).

PATIENTS AND METHODS

Twenty-three patients with superficial urothelial bladder carcinoma (stages pTa to pT1, grades 1-3) were treated with six weekly instillations of 150 mg of BCG (Pasteur strain). Biopsies of cystoscopically normal bladder wall were taken before, 3 weeks and 3 months after BCG instillation. The controls comprised bladder biopsy specimens from 13 brain-dead ventilated kidney donors. Local infiltrating cell types, i.e. lymphocyte infiltrates (CD4, CD8, CD20, CD3, interleukin-2-receptor-positive, natural killer, gammadelta), macrophages and dendritic cells, adhesion and costimulatory molecules (ICAM-1 and B7-BB1) and major histocompatibility complex (MHC) class I and class II antigens were assessed using semi-quantitative immunohistochemical analysis.

RESULTS

Before BCG the peritumoral bladder wall had fewer macrophages than control bladder wall. BCG treatment restored normal numbers of macrophages and enhanced T helper lymphocytes, B lymphocytes, natural killer cells, activated lymphocytes, dendritic cells, normal MHC class I, adhesion (ICAM-1) and costimulatory (B7-BB1) expression. The enhancement of these immunological variables was transient, with a return to baseline 3 months after BCG instillation.

CONCLUSIONS

These results support the concept that there is a host-immune escape associated with bladder cancer. BCG therapy may temporarily restore impaired tumour rejection mechanisms in the peritumoral bladder wall, suggesting a need for maintenance therapy after the first course of BCG.

Interdigitating dendritic cell sarcoma. A report of four cases and review of the literature

To better define the clinical and pathologic features of interdigitating dendritic cell sarcoma (IDCS), we report 4 cases, including the first reported in the tonsil. There were 2 male and 2 female patients (mean age, 70 years). Sites of tumor included 1 case each in the right cervical lymph node, left axillary lymph node, right tonsil, and right inguinal lymph node. Histologically, all showed diffuse effacement of the lymphoid tissue by pleomorphic round to spindled cells with convoluted nuclei and abundant eosinophilic cytoplasm. All were immunoreactive for S-100, CD68, lysozyme, and vimentin. CD45 was positive in 3 cases and CD1a in 1 case. Fascin was positive in 3 cases. Other immunostains, including CD3, CD20, CD21, CD30, actin, cytokeratin, and HMB-45, were negative. Ultrastructurally, the tumor cells were elongated and showed indented nuclei, variable numbers of lysosomes, and interdigitating cytoplasmic processes. Follow-up was available for all cases. One patient died of widespread disease 2 months after diagnosis. One was alive with metastatic lung disease at 12 months. Two patients were disease free at 5 and 9 months.

Lymphatic microvessel density as a novel prognostic factor in early-stage invasive cervical cancer

Few data on the influence of lymphatic microvessel density (MVD) on survival in cancer are available since until recently there was no reliable immunohistological marker for lymphatic endothelium. Using an antibody staining podoplanin, a novel marker for lymphatic endothelium, lymphatic MVD in tissue samples of 85 patients with cervical cancer classification pT1b treated by radical hysterectomy was investigated. Survival was determined using univariate and multivariate analyses. Lymphatic MVD was also compared to MVD assessed by immunostaining against factor VIII-related antigen, which is considered a marker for blood vessels. Patients with >5 lymphatic microvessels/0.25 mm(2) field had significantly better overall survival (mean 91.8 months) than those with < or =5 lymphatic microvessels/field in univariate analysis (mean 113 months) (p = 0.0105, log-rank test). In multivariate analysis, lymphatic node involvement (p =0.0183), vessel infiltration (p =0.0158) and lymphatic MVD (p =0.0269) remained independent prognostic factors. No correlation between lymphatic MVD and various clinical and histopathological parameters was observed. Correlation between lymphatic MVD and MVD assessed by immunostaining against factor VIII was only weak (p = 0.004, r = 0.312, Spearman's coefficient of correlation). Our results suggest that increased lymphatic MVD is associated with favorable prognosis in early-stage cervical cancer.