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.

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.

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.

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.