S-100 protein-positive Langerhans cells in various human lung cancers, especially in peripheral adenocarcinomas

Calcifying epithelial odontogenic tumour with clear langerhans cells: a novel variant, report of a case and review of the literature

Clear cell calcifying epithelial odontogenic tumour (CCEOT) is a rare variant of calcifying epithelial odontogenic tumor (CEOT). While it is not surprising to find clear cells in odontogenic lesions, the exact nature of the clear cells in CCEOT has not been elucidated. Herein, we report a case of peripheral CCEOT of anterior mandible in a 37 year old black female. Histologically, the tumour consisted of cords and small nests of clear cells surrounded by dense deposits of amyloid and basophilic calcifications. The cells possessed abundant clear cytoplasm and eccentrically located indented nuclei. Admixed with the clear cells were eosinophilic cuboidal to polyhedral cells. The clear cells were PAS negative and immunoreactive for S100 protein, CD1a and Langerin. The clear cells were negative for MNF-116, SMA, Desmin and CK-19. It is therefore recommended to recognize two variants of CCEOT, namely, CEOT with clear cell change and CEOT with clear Langerhans cells (LC). We further suggest that the contradictory term "non-calcifying variant of calcifying epithelial odontogenic tumour with LC" to be abandoned, as the current case clearly indicates that LC could be seen in CEOT irrespective of the presence or absence of calcifications.

Deciphering the message broadcast by tumor-infiltrating dendritic cells

Human dendritic cells (DCs) infiltrate solid tumors, but this infiltration occurs in favorable and unfavorable disease prognoses. The statistical inference is that tumor-infiltrating DCs (TIDCs) play no conclusive role in predicting disease progression. This is remarkable because DCs are highly specialized antigen-presenting cells linking innate and adaptive immunity. DCs either boost the immune system (enhancing immunity) or dampen it (leading to tolerance). This dual effect explains the dual outcomes of cancer progression. The reverse functional characteristics of DCs depend on their maturation status. This review elaborates on the markers used to detect DCs in tumors. In many cases, the identification of DCs in human cancers relies on staining for S-100 and CD1a. These two markers are mainly expressed by Langerhans cells, which are one of several functionally different DC subsets. The activation status of DCs is based on the expression of CD83, DC-SIGN, and DC-LAMP, which are nonspecific markers of DC maturation. The detection of TIDCs has not kept pace with the increased knowledge about the identification of DC subsets and their maturation status. Therefore, it is difficult to draw a conclusion about the performance of DCs in tumors. We suggest a novel selection of markers to distinguish human DC subsets and maturation states. The use of these biomarkers will be of pivotal importance to scrutinize the prognostic significance of TIDCs.

Tumor microenvironment is multifaceted

Cancer initiation, progression, and invasion occur in a complex and dynamic microenvironment which depends on the hosts and sites where tumors develop. Tumors arising in mucosal tissues may progress in an inflammatory context linked to local viral and/or bacterial infections. At the opposite, tumors developing in immunoprivileged sites are protected from microorganisms and grow in an immunosuppressive environment. In the present review, we summarize and present our recent data on the influence of infectious context and immune cell infiltration organization in human Non-Small Cell Lung Cancers (NSCLC) progression. We show that stimulation of tumor cells by TLR for viral ssRNA, such as TLR7/8, or bacteria, such as TLR4, promotes cell survival and induces chemoresistance. On the opposite, stimulation by TLR3, receptor for double-stranded viral RNA, decreases tumor cell viability and induces chemosensitivity in some lung tumor cell lines. Since fresh lung tumor cells exhibit a gene expression profile characteristic of TLR-stimulated lung tumor cell lines, we suspect that viral and bacterial influence may not only act on the host immune system but also directly on tumor growth and sensitivity to chemotherapy. The stroma of NSCLC contains tertiary lymphoid structures (or Tumor-induced Bronchus-Associated Lymphoid Tissues (Ti-BALT)) with mature DC, follicular DC, and T and B cells. Two subsets of immature DC, Langerhans cells (LC) and interstitial DC (intDC), were detected in the tumor nests and the stroma, respectively. Here, we show that the densities of the three DC subsets, mature DC, LC, and intDC, are highly predictive of disease-specific survival in a series of 74 early-stage NSCLC patients. We hypothesize that the mature DC may derive from local activation and migration of the immature DC--and especially LC which contact the tumor cells--to the tertiary lymphoid structures, after sampling and processing of the tumor antigens. In view of the prominent role of DC in the immune response, we suggest that the microenvironment of early-stage NSCLC may allow the in situ activation of the adaptive response. Finally, we find that the eyes or brain of mice with growing B cell lymphoma are infiltrated with T cells and that the cytokines produced ex vivo by the tumoral tissues have an impaired Th1 cytokine profile. Our work illustrates that the host and external tumor microenvironments are multifaceted and strongly influence tumor progression and anti-tumor immune responses.

Prognostic value of S-100 immunostaining in tumour cells of non-small cell lung cancer

S-100 protein expression is present in various malignant tissues, yet its prognostic relevance is debatable. The aim was to assess in non-small cell lung cancer (NSCLC) patients' prognostic value of S-100 protein considered alone or in relation with other variables. Tumour samples taken from 86 NSCLC patients during resection were assayed for S-100 protein expression with the use of polyclonal DAKO ZO311 antibody. S-100 expression was found in 32 cases (37%). Positive staining was not correlated with clinical characteristics including age, sex, pathology type of tumour, stage and cigarette smoking. There was a tendency for simultaneous expression of S-100 and P53 protein (p=0.06). A median survival rate for the entire group was 2.3 years (95% CI, 0.9-3.6 years). The median and 5-year survival of patients with positive staining for S-100 protein was 1.5 years and 25%, respectively, compared with 3.0 years and 35%, respectively, in the S-100 negative group (p=0.17). In the final model of a multivariate analysis, S-100 protein expression in tumour cells was associated with significantly decreased survival (p=0.005). S-100 protein expression in tumour cells seems to be an independent predictor of poor prognosis in NSCLC patients.

A rare case of coexistence of pulmonary adenocarcinoma with Langerhans' cell histiocytosis

We report a rare case of coexisting pulmonary adenocarcinoma and Langerhans' cell histiocytosis (LCH) in a 78-year-old woman who did not smoke. During follow-up of diabetes mellitus, she had complained of chest pain and was found to have a nodular lesion in S9 of the left lower lobe, which was resected surgically. No abnormal laboratory findings were obtained. Before surgical resection, needle biopsy specimens confirmed the existence of adenocarcinoma. The resected tumor in the left lower lobe was 3.0 x 1.8 x 3.0 cm, and histologically both acinar and bronchioloalveolar cell subtypes of adenocarcinoma were found in cancer foci. In addition to pulmonary adenocarcinoma, Langerhans' cell proliferation associated with marked eosinophil infiltration was incidentally found in a small nodule, approximately 3 x 2 mm in size in the subpleural region. The Langerhans' cells contained interdigitated nuclei, exhibiting rather clear nucleoplasm and cytoplasm; they were positive for S-100 protein, CD1a, and also CD4. Massive eosinophil infiltration was found around the focus of Langerhans' cell proliferation. This nodule appeared to be LCH. The adenocarcinoma and LCH were adjacent, and cancer cells were infiltrated only in the peripheral parts of LCH. The coexistence of adenocarcinoma and LCH appeared to be incidental. The association of adenocarcinoma and LCH is rare, and only several reports of it can be found in the English literature.

Compartment specific expression of dendritic cell markers in human glomerulonephritis

Macrophages and dendritic cells are heterogenous and highly plastic bone marrow-derived cells that play major roles in renal diseases. We characterized these cells using immunohistochemistry in 55 renal biopsies from control patients or patients with glomerulonephritis as an initial step towards postulating specific roles for these cells in kidney disease. In proliferative glomerulonephritis numerous CD68 positive (pan monocyte, macrophage and dendritic marker) cells were found in both glomeruli and the tubulointerstitial space, however, a myeloid dendritic cell marker (DC-SIGN) was identified only in the tubulointerstitium. A significant number of plasmacytoid dendritic cells (identified as BDCA-2 positive cells) were seen at sites of interstitial inflammation, including follicular aggregates of inflammatory cells. Langerin positive cells (a marker of Langerhans' cells) were detectable but rare. The area of either CD68 or DC-SIGN positive interstitial cells correlated with serum creatinine. Low levels of DC-SIGN, DC-LAMP and MHC class II mRNA were present in the tubulointerstitial space in controls and increased only in that region in proliferative glomerulonephritis. We demonstrate that the CD68 positive cells infiltrating the glomerulus lack dendritic cell markers (reflecting macrophages), whereas in the tubulointerstitial space the majority of CD68 positive cells are also DC-SIGN positive (reflecting myeloid dendritic cells). Their number correlated with serum creatinine, which further emphasizes the significance of interstitial DCs in progressive glomerular diseases.

Malignant triton tumor of the nasal cavity

BACKGROUND

Malignant triton tumor is usually an aggressive sarcoma consisting of a malignant schwannoma with rhabdomyoblastic differentiation. However, malignant triton tumor of the nasal cavity is very rare.

METHODS

A case report of a 38-year-old woman with polypoid mass, which bled easily in the right nasal cavity, and nasal obstruction is presented with a review of the literature pertaining to this unusual case.

RESULTS

The malignant triton tumor was treated with wide surgical excision followed by radiation therapy. Histopathological diagnosis of the malignant triton tumor was made on the surgical specimen. The patient's postoperative course was unremarkable, and follow-up at 5 years reveals no evidence of disease.

CONCLUSIONS

A malignant triton tumor in the nasal cavity is a rare disease. Head and neck surgeons should recognize the possibility of malignant triton tumor occurring in the nasal cavity.

Extremely high Langerhans cell infiltration contributes to the favourable prognosis of HPV-infected squamous cell carcinoma and adenocarcinoma of the lung

AIMS

The infiltration of Langerhans cells in adenocarcinomas and squamous cell carcinomas of the lung was examined in relation to prognostic implications and human papillomavirus (HPV) infection.

METHODS AND RESULTS

Samples from 62 adenocarcinoma and 59 squamous cell carcinoma patients in 1995-97, the prognosis of which had been followed up, were used. The Langerhans cells were demonstrated immunohistochemically using anti S100a and CD1 antibodies. Human papillomavirus (HPV) infection was examined by polymerase chain reaction (PCR) and nonisotopic in-situ hybridization (NISH) methods. Statistical analysis was carried out using the Kaplan-Meier method (Wilcoxon analysis) and multiple regression analysis. HPV infection was demonstrated in 12 cases (19.4%) of adenocarcinoma. The HPV-infected adenocarcinomas had abundant faintly eosinophilic cytoplasm, and were immunohistochemically positive for the surfactant apoprotein A. In the 59 cases of squamous cell carcinomas 19 were of the well differentiated form, and 29 and 11 were moderately and poorly differentiated cases, respectively. HPV was detected in 29 cases (49.2%) (13 well and 16 moderately differentiated cases). In all HPV-infected adenocarcinoma and squamous cell carcinoma cases, extremely large numbers of Langerhans cells (more than 100 per high-power field) were demonstrated in the tumour nests. In contrast, in the non-HPV-infected adenocarcinomas and squamous cell carcinomas, only a few (less than about 10 per high-power field) Langerhans cells were observed. The squamous cell carcinoma cases with high Langerhans cell infiltration, which were also infected with HPV, showed a significantly good prognosis (P = 0.007). The adenocarcinoma cases with high Langerhans cell infiltration tended to have a better prognosis than the cases with low Langerhans cell infiltration, but the difference was not statistically significant. The low number of highly infiltrated cases was insufficient for an adequate statistical analysis. Furthermore, there was no significant correlation between either Langerhans cell infiltration and smoking, or HPV infection and smoking, in either squamous cell carcinoma or adenocarcinoma cases.

CONCLUSIONS

It was considered that the extremely high Langerhans cell infiltration in the tumours was caused by HPV infection. The extremely large number of Langerhans cells in the tumours contributes to the favourable prognosis for HPV-infected lung cancer.

Prognostic implication of human papillomavirus infection in squamous cell carcinoma of the lung

On the subtropical island of Okinawa, squamous cell carcinoma (SCC), particularly the well-differentiated form, is the most frequent type of lung cancer, while this form is relatively rare on the Japanese mainland and in other countries. Furthermore, in Okinawa, in 1993, 80% of SCC cases of the lung were found to be infected with human papillomavirus (HPV). We studied the prognosis of SCC of the lung with HPV infection (n = 25) and compared it with non-HPV-infected SCC (n = 16). Using the Kaplan-Meier method (Wilcoxon analysis), the prognosis of HPV-infected cases was found to be better than that of the non-infected cases. In the virus-infected cases, apoptosis and infiltration of a large number of Langerhans cells were demonstrated. In addition to these findings, the virus-infected tumors were demonstrated to be histologically well-differentiated, perhaps contributing to the favorable prognosis. However, among the virus-infected cases, the type 16 virus-infected cases showed a poorer prognosis, compared to those infected with other HPV types. p53 gene mutation was also examined, and was considered to be an unfavorable prognostic factor, as reported elsewhere. However, in Okinawa, HPV-positive cases with p53 mutations showed a slightly better prognosis than did non-viral infected cases with p53 mutations. The TNM staging system was also useful for categorizing the virus-infected cases. The prognosis of stage III (A and B) cases was poor. All of our present cases received surgical treatment. Chemotherapy and radiation therapy were not performed. Such treatment, however, might be effective, because virus-infected uterine cervical carcinomas have been routinely treated with chemotherapy and radiation. Furthermore, if the immunological basis of increased Langerhans cell infiltration in HPV-infected cases is elucidated, a clinical trial with immunotherapy may be favorable for the clinical outcome.

Mucin-producing adenocarcinoma of the lung, with special reference to goblet cell type adenocarcinoma: immunohistochemical observation and Ki-ras gene mutation

To clarify its biological nature, 10 samples of goblet cell-type adenocarcinoma of the lung were collected and compared with 10 other pulmonary mucin-producing adenocarcinomas with respect to immunohistochemical features and the presence of Ki-ras gene mutation in codons 12 and 13. Goblet cell-type adenocarcinomas lacked immunoreactivity for surfactant apoprotein and S-100 protein-positive Langerhans cells, which was in marked contrast to other mucin-producing adenocarcinomas. In addition, the mucin gene products, MUC-1 and MUC-2 glycoproteins were immunohistochemically stained. The results showed that MUC-1 glycoprotein is frequently expressed by mucin-producing adenocarcinomas except the goblet cell-type. Ki-ras gene mutation was detected in 12 of 20 (60%) mucin-producing adenocarcinomas. These mutations were exclusively found in codon 12 and G to A transitions were the most frequent type of alteration in the Ki-ras gene. In goblet cell-type adenocarcinomas, the frequency of Ki-ras gene mutation was 80% consisting of G to A transitions and G to T transversions in six and two tumors, respectively. Therefore, goblet cell-type adenocarcinomas differed from other mucin-producing adenocarcinomas in terms of immunohistochemical and molecular biological features, suggesting that goblet cell-type adenocarcinomas are distinctly different from other subtypes of adenocarcinomas.

Role of cytokines in distribution and differentiation of dendritic cell/Langerhans' cell lineage in human primary carcinomas of the lung

The possibility that production of some cytokines in the carcinoma microenvironment is associated with the presence and differentiation of cells belonging to the dendritic cell (DC)/Langerhans' cell (LC) lineage was investigated. Immunohistochemical examination showed the presence of intraepithelial LCs (CD1a- and S100-positive cells) in 6 of 10 squamous cell carcinomas and in 8 of 10 adenocarcinomas. Langerhans' cells were mainly located close to lymphoid aggregates. In situ hybridization performed in four cases (three LC positive and one LC negative) of squamous cell carcinoma and in five cases (four LC positive and one LC negative) of adenocarcinoma showed that some mononuclear cells in the interstitium displayed hybridization with granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF alpha), and interleukin 1-beta (IL1 beta) cDNA probes. Only in LC-positive carcinomas did epithelial cells close to lymphoid aggregates display small amounts of GM-CSF and TNF alpha mRNA expression. Immunohistochemical analysis performed in the 20 cases of lung carcinoma showed that epithelial cells in tumors with lymphoid aggregates and LCs were immunoreactive with antihuman GM-CSF monoclonal antibody. Specimens negative for GM-CSF contained very few LCs. Northern blot analysis was used to investigate GM-CSF, TNF alpha, IL1 alpha, and IL1 beta mRNA expression in six human lung carcinoma cell lines. A constitutive expression of TNF alpha mRNA was found in all of them, whereas only three showed a low constitutive expression of GM-CSF mRNA. In the latter three cell lines treatment with phytohemagglutinin (PHA)-stimulated peripheral blood lymphocyte (PBL) supernatant (PHA-SUP) upregulated GM-CSF mRNA expression and induced that of IL1 alpha mRNA. Carcinomatous epithelial cells producing small amounts of cytokines could promote the recruitment of cells of DC/LC lineage. Subcellular factors produced by reactive lymphocytes and/or macrophages may influence the production of GM-CSF and IL1 alpha by various epithelia. Up-regulation of this production could favor the arrival and differentiation of DCs and activate LC functions.

Surface phenotype and functions of tumor-infiltrating dendritic cells: CD8 expression by a cell subpopulation

Although the function and significance of tumor-infiltrating dendritic cells (TIDC) in the immune response to tumor have never been clearly demonstrated, their location suggests that they play a critical role in the presentation of tumor antigen to specific T cells. We studied the morphological and functional characteristics of interstitial dendritic cells (DC) located inside tumors obtained by injection of cancer cells into syngeneic rats. Single and double immunostaining of tumor sections revealed a dense network of cells which expressed class II major histocompatibility complex (MHC II) molecules. Cell morphology and surface markers were characteristic of DC populations in other tissues. These DC were in close contact with tumor cells and increased in number as the tumor grew larger. Unexpectedly, a subpopulation of morphologically characteristic TIDC expressed both CD8 and MHC II molecules. TIDC were purified from tumors by gradient centrifugation and immunobeads and characterized by morphology, ultrastructural study and surface markers studied by flow cytometry. TIDC were negative for the CD5 molecule (a pan T cell marker), and were not labeled with 3.2.3 monoclonal antibody (mAb) (an NK cell marker) or with Ki-M2R mAb (a macrophage marker). A subpopulation of TIDC expressed the CD8 molecule, confirming the in situ results. TIDC expressed high levels of class I and class II MHC molecules and the adhesion molecule ICAM-1. This expression is compatible with effective antigen presenting function. Purified TIDC triggered rapid and high levels of proliferation of tumor-immune T cells in vitro, demonstrating the potential of these cells to constitutively process and present tumor-associated antigens.

Distribution of S-100 protein-positive dendritic cells and expression of HLA-DR antigen in transitional cell carcinoma of the urinary bladder in relation to tumour progression and prognosis

The distribution of S-100 protein positive dendritic cells (S100-DCs) in cancer nests and the expression of HLA-DR antigen on cancer cells in 90 patients with transitional cell carcinoma of the urinary bladder were studied immunohistochemically. A dense infiltrate of S100-DCs (more than 10 S100-DCs/high power field) was detected in 47 out of 90 cases, while in the remaining tumours the infiltrate was sparse. HLA-DR positive cancer cells (DR-CCs) were detected in 24 cases, including 16 with dense DR-CCs (more than 100 DR-CCs/high power field); no expression was observed in the remaining tumours. In terms of the numbers of S100-DCs infiltrating the following statistically significant differences were observed: tumour grading G1 > G3, depth of penetration pT0 > pT3; (p < 0.05), G2 > G3, lymphatic invasion - > + and venous invasion - > +; (p < 0.01). A multivariate analysis demonstrated that the most important factor affecting prognosis was distant organ and/or lymph node metastasis (p < 0.01) the number of S100-DCs, with a hazard ratio (HR) of 0.26 (p < 0.01), and the number of DR-CCs with HR of 0.18 (p < 0.05); these were statistically significant. S100-DCs and DR-CCs may be regarded as independent prognostic factors of tumour growth and progression.

Langerhans cells in Langerhans cell histiocytosis and peripheral adenocarcinomas of the lung

The present paper deals with more precise characterization of Langerhans cells (LC) and accompanying lymphocytes in lung LC histiocytosis (LCH) and primary lung peripheral adenocarcinomas using immunohistochemical methods with various kinds of monoclonal antibodies against cell adhesion and activation markers and some cytokines. Tissue specimens were obtained from 4 patients with pulmonary LCH and from 29 patients with primary lung peripheral adenocarcinoma. In florid (exudative and granulomatous) nonfibrotic LCH lesions, LC, particularly those in contact with lymphocytes, were S100, CD1a, MHC Class II, CD11a and c, CD16, and CD54 positive. In this context, LC were CD4+ and CD25+. Lymphocytes around LC were CD3+ with a "memory" phenotype (CD45RO+) and, frequently, CD25+ and HLA-DR+. S100+ and CD1a+ LC were commonly observed in adenocarcinomas subclassified as papillary and as nonmucinous bronchioloalveolar, in both cases mainly where Clara cells and Type II pneumocytes were present. In carcinomas the vast majority of LC were HLA-DR+ and, rarely, weakly CD16+, CD25+, and CD54+. The infiltration of reactive cells in cancer tissue was mainly represented by T lymphocytes (CD3+CD45RO+). These T cells were HLA-DR- and CD25-. The presence of LC was associated with a strong reactivity of epithelial cells with antibodies PE-10 and 439-9B, both recognizing molecules mainly expressed by Type II alveolar cells. Several cells in LCH florid lesions showed immunoreactivity for both IL-1 alpha and beta. Immunostaining for IFN-gamma revealed the presence in the same areas of some positive cells showing lymphoid morphology. No IL-1 or IFN-gamma reactivity was found in adenocarcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of Langerhans cells and HLA class II molecules in prostatic carcinomas of different histopathological grade

We have investigated Langerhans cell (LC) distribution in 38 prostatic carcinomas, of various degrees of differentiation, by immunohistochemistry with a polyclonal anti-S-100 serum, furthermore evaluating the expression of HLA class II-DR by neoplastic cells using a monoclonal antibody (MoAb) that reacts with a monomorphic determinant in formalin-fixed paraffin-embedded tissue. Antiserum to S-100 protein identified LCs mostly in carcinomas ranging from grade 1 to grade 2, while LCs were inconspicuous in grade 4 and virtually absent in grade 5 cancers. Moreover, sections stained with the anti -HLA-DR MoAb displayed an immunoreactivity, both cytoplasmic and apical, especially confined to neoplastic glands of low grade (1-2) carcinomas. Although we did not find a direct correlation between the two parameters under investigation and lymphoid infiltrate, we were able to document an increased number of HLA class II-positive interstitial cells in low-grade carcinomas, corresponding mostly to macrophages. Our results indicate that LC number is inversely correlated to the histopathological grade and directly to the expression of HLA class II-DR molecules by tumor cells; we believe that this might be important in understanding the more favorable biological behavior of low-grade prostate carcinomas as opposed to the higher grades, since LCs and HLA class II molecules may provide a means of eliciting the immune response, both LCs and epithelial cells expressing HLA class II molecules being capable of direct antigen presentation to immune cells. In this context macrophages might play a primary role in controlling tumor progression. To the best of our knowledge this is the first time that an attempt is made to correlate LCs and HLA class II expression to histopathological grading of prostatic carcinomas. We would also suggest that the presence of LCs and HLA class II molecules, either singly or in combination, in carcinoma of the prostate represents a good prognostic indicator, being constantly associated with the clinically less aggressive low-grade tumors. The evaluation of these two parameters might prove useful in the assessment of intermediate grades where no valid histologic criteria have been found to predict the clinical course of the disease.

Immunohistochemical characterization of HLA-DR-antigen positive dendritic cells in phaeochromocytomas and paragangliomas as a prognostic marker

Twelve cases of phaeochromocytoma (PCC) and four cases of paraganglioma (PGG) were studied by immunohistochemistry and immunoelectron microscopy in order to demonstrate HLA-DR (Ia)-antigen-positive dendritic cells (IaDCs). Dense infiltration of IaDCs was detected in the majority of PCCs revealing high urinary or serum catecholamine levels, but in aggressively growing PCCs, a familial PCC and all PGGs, few IaDCs were demonstrated. Interestingly, these IaDCs were negative for S-100 protein. Although S-100-protein-positive sustentacular-like cells (SCs), morphologically similar to IaDCs, were also present, these were clearly distinguished from IaDCs by our double immunostaining method. Ultrastructurally, IaDCs had smooth or slightly indented nuclei and contained a moderate amount of endoplasmic reticulum, small mitochondria and vacuoles, extending elongated cytoplasmic processes. These results suggest that determination of the quantity of IaDCs is a highly effective method of assessing the character of PCCs, in particular, their prognosis.

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.

Langerhans cells in human lung tumours: an immunohistological study

In an immunocytochemical study of 41 human lung tumours we have shown that Langerhans cells can be reliably identified using the anti-CD1 monoclonal antibody NA1/34. Langerhans cells are present in all the main varieties of human lung tumour although they are infrequent in both small cell carcinoma and carcinoid tumour. There is considerable variation in numbers of Langerhans cells in both adenocarcinomas and squamous cell carcinomas. In this study tumours were divided into those with high numbers of Langerhans cells (greater than 2 per high power field) and those with low numbers (less than 2 per high power field). Analysing these results against patient survival showed a markedly worse survival in those tumours with a high number of Langerhans cells for all the tumours as a single group and for squamous cell carcinoma as a single entity.

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.