Brian Eyden

..Immunohistochemistry and electron microscopy, used together, are emphasised as being important for maximum diagnostic confidence in some myofibroblastic lesions...

..Its function remains uncertain, although it may implement adhesion to other cells, as part of the immune functions that plasma cells and other hemolymphoid cells perform in the gut, for example, and elsewhere...

..They might also function as mechanotransducers of extracellular stress in the extracellular milieu. The present observations constitute a further, rare example of endothelium-associated fibronexuses in reactive human vessels...

..Given the four lines of differentiation--striated muscle, smooth muscle, fibroblastic, and histiocytic--a name reflecting its phenotype would be pleomorphic rhabdomyosarcoma showing smooth-muscle and fibrohistiocytic differentiation...

..This is one of the occasions where dewaxing (of an immunohistochemically defined wax block) offers positive advantages, despite compromised structural preservation, in the search for diagnostically important organelles...

..The findings are discussed in relation to the unusually varied differentiation reported for this tumor...

..In a subset of cells myofilaments were absent, but structures resembling solitary focal densities were identified. These are discussed as possible indicators of a primitive level of smooth-muscle differentiation...

..However, given the right histological appearance, use of a panel of antibodies that includes α-smooth muscle actin, desmin, and h-caldesmon, serves as an acceptable practical way of diagnosing myofibrosarcoma...

..PAX:FKHR fusion transcript was identified in case 2, case 3 had a variant PAX3 transcript, and case 1 was negative. The data presented expands the known differentiation of alveolar rhabdomyosarcoma...

..This is also the first case of small cell melanoma to be studied by electron microscopy...

..Results indicated overlap between poorly differentiated leiomyosarcoma and GIST, and between GIST and GANT. GANT is emphasized as a neuronal tumor identifiable by electron microscopy, and thereby distinguishable from GIST...

..The recognition that these cells are showing smooth-muscle or fibroblastic but not true myofibroblastic differentiation should inform our understanding of the function of these cells...

..The patient had no clinical evidence of inherited Gaucher's disease. These pseudo-Gaucher cells obscured neoplastic plasma cells causing diagnostic difficulty...

..The present case represents an unambiguous demonstration of the co-expression within individual tumor cells of Schwannian and fibroblastic differentiation in a low-grade MPNST. The literature on this subject is reviewed...

..Both cases reported here were confirmed by immunohistochemistry. Both cases were also studied by electron microscopy, and one showed distinctive ultrastructural features of striated muscle...

..Myofibroblastoma is among many lesions described as myofibroblastic which, however, appear to show a kind of smooth-muscle differentiation. Some spindle-cell malignancies express myofibroblastic features...

..Ultimately, our understanding of the molecular events controlling differentiation in cancer will lead to control, cure and prevention...

..It extends the known distribution of the fibronexus and expands the ultrastructural spectrum of squamous carcinoma...