Acute abdomen during adjuvant chemotherapy: superior mesenteric artery thrombosis associated with CMF chemotherapy.

We report a case of superior mesenteric artery thrombosis in a 57-year-old woman undergoing chemotherapy for T1N1M0, breast cancer. Although cancer itself is associated with an increased risk of thrombotic events, treatment with chemotherapy and/or tamoxifen in breast cancer patients increases this risk. Most cases reported are of venous thromboembolism; arterial events are rare.

Intranodal myofibroblastoma: report of a case.

Palisaded myofibroblastoma (hemorrhagic spindle cell tumor) is a recent addition to the group of benign primary spindle cell lesions of lymph nodes. These tumors are characterized histologically by hemorrhage, palisading, and foci of collagen called amianthoid fibers. We report a further typical example with the aim of discussing its differentiation. Tumor cells were positive for smooth-muscle actin and vimentin. The cytoplasm contained moderate numbers of rough endoplasmic reticulum cisternae and some smooth-muscle type myofilaments. Subplasmalemmal densities and plasmalemmal caveolae, as well as material interpreted as external lamina, were identified at the cell surface, whereas the fibronexus junctions typical of myofibroblasts were not seen. Immunostaining for type IV collagen was positive. Intranodal myofibroblastomas have largely been considered as myofibroblastic, but the observations presented here raise the alternative possibility of simple smooth-muscle differentiation. The foci of collagen widely referred to as amianthoid fibers contained fibrils mostly of conventional diameter, 50-83 nm. The giant collagen fibrils typical of true amianthoid change were absent. It is suggested that the term amianthoid be used only after ultrastructural confirmation of the presence of giant collagen fibrils.

Labelling of cells of the mononuclear phagocyte system in routinely processed archival biopsy specimens with monoclonal antibody EBM/11.

When first reported, EBM/11 reacted with mononuclear phagocyte system cells only in fresh frozen sections, but it has been shown to have similar cellular specificity in routine formalin fixed, paraffin wax embedded tissue. This was achieved by limited proteolysis with protease XIV before immunocytochemical staining. In archival biopsy specimens EBM/11 produced granular cytoplasmic staining of alveolar macrophages, Kupffer cells, tingible body macrophages and sinus histiocytes, cells of splenic cords, cortical and medullary macrophages of thymus; blood monocytes, peritoneal and mesothelial macrophages; bone marrow mononuclear cells, megakaryocytes and osteoclasts; lamina propria macrophages in the gastrointestinal tract, and connective tissue cells (presumptive macrophages) of thyroid, gall bladder, skin, pancreas, ovary, myometrium, endometrium, cervix, kidney, prostate, placenta, myocardium and breast. Unlike other anti-macrophage antibodies, EBM/11 did not react with granulocytes, lymphocytes, plasma cells, platelets, endothelial and epithelial cells in paraffin wax sections. It did not label skin Langerhans' cells, microglial cells, and interdigitating reticulum cells (as in frozen sections). This study opens a new area for the specific identification by EBM/11 of mononuclear phagocyte system cells in archival biopsy specimens. It also raises the possibility that some monoclonal antibodies, believed to be reactive only in frozen sections, may react in archival tissue after limited proteolysis with an appropriate enzyme.