The presence of cytokines in Langerhans' cell histiocytosis.

Langerhans' cell histiocytosis (LCH) is characterized by an accumulation and/or proliferation of cells with a Langerhans' cell (LC) phenotype. The aetiology and pathogenesis of LCH are unknown; it is suggested that LCH is caused by an immunological dysregulation. Production of cytokines is a central feature of immunological regulation. LCH lesions and normal LCs were studied for the presence of cytokines known to influence the functioning of LCs: IL-1 alpha, IL-1 beta, IL-4, GM-CSF, IFN-gamma, TGF-alpha, TGF-beta, bFGF, and TNF-alpha. Cytokines were abundantly present within LCH lesions; LCH cells stained for IL-1 alpha, IL-1 beta, IL-4, GM-CSF, TGF-alpha, TGF-beta, TNF-alpha, and IFN-gamma. Macrophages, lymphocytes, eosinophil granulocytes, and, surprisingly, multinucleated giant cells were also sources of cytokines. These results suggest that cytokines play a prominent role in the pathogenesis of LCH and may explain phenomena that often occur in LCH, such as osteolysis and fibrosis and the recruitment of typical inflammatory infiltrates. The results also suggest that a 'down-regulatory' signal is lacking in LCH, resulting in an accumulation and/or proliferation of abnormal LCs.

Enhancement of cisplatin and etoposide cytotoxicity after all-trans retinoic-acid-induced cellular differentiation of a murine embryonal carcinoma cell line.

The potential of a combination of differentiation induction and chemotherapy was analyzed. Treatment of the murine embryonal carcinoma (EC) cell line PCC4 in vitro with all-transretinoic acid (RA) was followed by exposure to cisplatin (CDDP) or etoposide (VP-16). The expression of EC-cell-specific markers decreased upon 96 hr exposure to 10(-9), 10(-8), 10(-7) and 10(-6) M RA, indicating a loss of embryonal phenotype of the cells, whereas expression of markers specific for cytokeratins and neurofilaments was increased after this treatment. These data suggest early somatic differentiation of PCC4 cells upon treatment with RA. Cellular growth rate of PCC4 cells was not affected by preincubation with RA at 10(-9) M for 96 hr, but was reduced at 10(-8) and 10(-7) M RA and inhibited at 10(-6) M RA. Culture of PCC4 cells in the presence of 10(-7) M RA for 96 hr led to accumulation in G1 of the cell cycle, whereas at 10(-8) M RA cell-cycle distribution was not affected. RA-treated and -untreated PCC4 cells were compared for CDDP and VP-16 sensitivity. Pre-treatment with 10(-9), 10(-8) and 10(-7) M RA increased CDDP sensitivity, resulting in a 1.9-, 2.7- and 2.6-fold decrease in the concentrations inhibiting survival by 50% (IC50s) respectively. Pre-treatment with 10(-8) and 10(-7) M RA increased VP-16 sensitivity 2.5- and 3.0-fold, respectively. Enhanced CDDP sensitivity at RA concentrations not affecting cell-cycle distribution was not attributable to changes in cellular platinum (Pt) accumulation, or to changes of Pt-DNA binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of aneuploidy in melanoma of the extremity.

Tumor nuclear DNA content was determined by flow cytometry in routinely prepared paraffin blocks from 25 primary malignant melanomas of the extremities. Twelve of the tumors were aneuploid, and 13 were euploid. In this series the presence of aneuploidy appeared to have no prognostic value.

Two epithelioid malignant schwannomas in a patient with neurofibromatosis. Cytology, histology and DNA-flow-cytometry.

Cytological, histological and DNA-ploidy findings of 2 epithelioid malignant schwannomas arising in a patient with von Recklinghausen's neurofibromatosis are described. In both primary tumors, i.e. in the thigh and in the thoracic wall, origin from a neurofibromatous nerve could be established. Within 2 years after the manifestation of the first malignant tumor the patient died of widely metastasized disease. DNA-flow cytometry of several neurofibromas revealed diploid stemlines, but both malignant primary tumors and a lung metastasis appeared to be aneuploid. Presumably, the primary tumors also contained cell populations with a diploid stem line.

Epithelioid sarcoma or malignant rhabdoid tumor of soft tissue? Epithelioid immunophenotype and rhabdoid karyotype.

Two children and one young adult with extremity sarcomas demonstrating an aggressive clinical behavior are described. Histologically, all three tumors displayed features compatible with a deep-seated epithelioid sarcoma or with a malignant rhabdoid tumor of soft tissue. Immunohistologically, both vimentin and epithelial antigens were demonstrated; however, no desmin was detectable. In all three cases, the DNA profile was diploid. In one case, a trisomy of chromosome 2 was found in the tumor cells, a phenomenon also observed in embryonal rhabdomyosarcomas. It is concluded that, although the immunohistologic findings support the epithelioid character of the tumors, this chromosomal finding suggests a relationship with rhabdomyosarcomas and justifies the designation of rhabdoid.

The use of DNA flow cytometry in the diagnosis of triploidy in human abortions.

The ploidy of placental tissue from 59 abortions was determined using DNA flow cytometry. The specimens were also screened histologically for features considered to be characteristic of a partial mole. Triploidy was found in six cases; three of these cases presented histologically as partial moles. From the four specimens histologically classified as partial moles, three appeared to be triploid. The most specific histologic features of triploidy were cystic change of the placental villi and trophoblastic hyperplasia with vacuolation of the syncytiotrophoblast; however, these changes were also found in some of the nontriploid abortions. Irregularity of villous contours was less specific.

Dedifferentiated parosteal osteosarcoma of the femur with aneuploidy and lung metastases.

In this report, the pathologic findings and the results of cellular DNA measurements of a tumor that on first presentation seemed to be a classical parosteal osteosarcoma are described. After resection 8 months later, part of the tumor appeared to display highly malignant features. DNA flow cytometry of this part of the tumor showed an aneuploid cell population. The aggressive nature of the tumor was confirmed by the development of lung metastases approximately 1 year after resection of the primary tumor.

DNA-aneuploidy in rhabdomyosarcomas as compared with other sarcomas of childhood and adolescence.

In the current study DNA-ploidy was determined in a group of 11 desmin-positive rhabdomyosarcomas and found to be aneuploid in all of them. In three cases, synchronous metastases could be studied as well. In two of them a hypotetraploid peak was observed not present in the primary tumor. In two other cases residual tumors obtained after chemotherapy appeared to have DNA-profiles similar to those observed in their primary tumors. These findings suggest either a selection of metastasizing clones or tumor progression. No apparent selection of clones responding to therapy could be established. For comparison, a group of other childhood sarcomas (four Ewing's sarcomas, two primitive neuroectodermal tumors, and two epithelioid sarcomas) was also studied. All except one of these cases appeared to have diploid or near-diploid stemlines. These results suggest that DNA-ploidy may be used as an additional criterion in the differential diagnosis of childhood sarcomas.