The light microscopic, immunohistological and ultrastructural findings in two cases of malignant fibrous histiocytoma arising in salivary glands are presented and the features of seven previously reported cases are reviewed. This neoplasm is extremely rare in this site and may pose problems in diagnosis. It has to be distinguished from other spindled cell tumours, in particular from epithelial ...

A patient with metastatic lymphocyte predominant thymoma was studied and an immunohistological analysis of frozen and paraffin sections was performed. The immunophenotype of the lymphoid cells was similar to that of primary thymomas and T cell lymphoblastic lymphomas. The epithelial cells reacted with an anticytokeratin monoclonal antibody. The results have diagnostic implications for the histo...

Gastrointestinal stromal tumors (GISTs) represent the majority of primary non-epithelial neoplasms of the digestive tract, most frequently expressing the KIT protein detected by immunohistochemical staining for the CD117 antigen. Extragastrointestinal stromal tumors (EGISTs), neoplasms with immunohistological features overlapping those of GISTs, are found in the abdomen outside of the gastroint...

Immunohistological staining procedures with enzymes as markers make use of enzyme substrate reactions which convert colorless chromogens into colored and insoluble end products. Enzyme labels offer the advantage of instant visualization and great sensitivity. Furthermore, enzyme markers may be utilized for both light and electron microscopic studies. Generally, either direct or indirect labelin...