Nucleolar organizer regions in soft tissue sarcomas.

Argyrophilic proteins of nucleolar organizer regions (AgNORs) were studied in a series of 65 sarcomas of the soft tissues and 2 cases of fibrohistiocytic tumors of intermediate malignancy. The numbers of AgNORs per nucleus and the size of AgNORs were determined and compared with pathomorphologic parameters such as grading of malignancy, cellularity and tumor diameter. The main finding of this study was that AgNOR counts showed significant differences between low-grade malignant (G 1) and high-grade malignant (G 3) tumors predominantly based on a correlation with the frequency of mitosis. All the other criteria of tumor grading (nuclear pleomorphism, differentiation, amount of necrosis), tumor diameter and cellularity showed no differences with regard to AgNOR counts. Though it was observed that tumor giant cells possessed predominantly coarse granular AgNORs, no correlation was found between AgNOR size and any of the parameters investigated. In spite of a clear statistically significant result gained by an evaluation of all cases, a heterogeneity of AgNORs in relation to mitotic activity within a few histological tumor types could be observed, making it difficult to suggest the determination of AgNORs as a parameter with general validity for all soft tissue sarcomas.

Immunohistochemical detection of the c-erbB-2 proto-oncogene product in normal, benign and malignant cartilage tissues.

Benign and malignant cartilage tumours as well as normal cartilage were stained immunohistochemically with antibodies raised to a synthetic peptide from the sequence of the c-erbB-2 protein. Positive staining was present in 18/23 of the chondrosarcomas and in one case of osteochondroma. Normal and benign neoplastic cartilage tissues revealed negative results. It is concluded that expression of the c-erbB-2 protein may contribute to cell transformation in chondrosarcomas; it is not apparent whether the expression of c-erbB-2 protein in chondrosarcomas characterizes a subpopulation of different prognostic significance.

Epithelial markers in synovial sarcoma. An immunohistochemical study on paraffin embedded tissues.

Immunohistochemical studies on synovial sarcomas have proved the potentiality of these neoplasm for epithelial and mesenchymal differentiation and antibodies detecting epithelial cells have been found to be helpful in determining the histological types. In this study different epithelial markers directed against various cytokeratins, HMFG-2 and EMA were investigated on paraffin embedded tissues of 13 cases of synovial sarcomas, with regard to their reliability in unmasking the epithelial components demonstrable in this type of neoplasm. The results lead to three conclusions: firstly, synovial sarcomas possess the capacity for generating different epithelial cell types with uncommon compositions of intermediate filaments as well as of membrane proteins, secondly, these features may be expressed in a heterogenous pattern even within the same tumour and finally, the use of wide range anti-cytokeratin antibodies covering the spectrum of basic as well as acidic type proteins seems to be necessary for the detection of all epithelial components demonstrable in synovial sarcomas.