Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of 46 malignant schwannomas occurring in soft parts of patients having von Recklinghausen's neurofibromatosis was analyzed. The diagnosis of malignant schwannoma was based upon the occurrence of malignant spindled cells closely resembling Schwann cells in the neoplasm and the close association or origin of the malignant schwannoma in a neurofibroma (27 tumors), or a large peripheral nerve (31 tumors). Additional histologic features useful in making the diagnosis of malignant schwannoma included the arrangement of the spindled tumor cells in a whorled pattern about thin-walled, gaping blood vessels, perivascular cellular proliferation and the presence of prominent myxoid stroma containing abundant hyaluronidase-sensitive acid mucopolysaccharides. Nuclear palisading was present in only one case. Eight tumors containing both neoplastic Schwann cells and rhabdomyoblasts and five containing both neoplastic Schwann cells and rhabdomyoblasts (malignant "Triton" tumors) and five containing foci of malignant cartilage cells were included in the series. The neoplasms occurred principally in adults (median age, 34 years) and were most common in the lower extremity (18 cases) and retroperitoneum (11 cases). A mass with or without pain was the most common presenting symptom (28 cases). The median size of excised tumors was 11 cm. The malignant schwannomas were highly malignant neoplasms, causing the death of 39 patients within five years and two patients within 6--10 years after diagnosis. Only four patients were alive and free of tumor 5--15 years after diagnosis.
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PMID:Malignant Schwannoma associated with von Recklinghausen's neurofibromatosis. 15 12

Nine cases are presented of a distinctive morphologic variant of myogenic gastrointestinal stromal tumor characterized by an unusually prominent myxoid stromal background reminiscent of a neural neoplasm but lacking the immunohistochemical or ultrastructural features of peripheral nerve sheath or ganglionic differentiation. The patients included six women and three men aged 42 to 86 years (mean, 70). The lesions occurred in the stomach (seven cases) and small intestine (two cases) and ranged in size from 2.5 to 9.5 cm. They were described grossly as well circumscribed, unencapsulated, with a prominently myxoid and often cystic cut surface. Histologically, the lesions were composed of a proliferation of round, spindle, or stellate cells embedded in an abundant myxoid stroma. Histochemical stains showed strong positive reaction of the myxoid stromal background with alcian blue at pH 2.5; this staining reaction was abolished by treatment with hyaluronidase, indicating an abundance of connective tissue mucosubstances rich in hyaluronic acid. Immunohistochemical stains showed strong positivity of the tumor cells with vimentin antibodies in all cases and focal weak to moderate positive staining with muscle actin (HHF35) in eight cases and with desmin in two. Stains for keratin, S-100; epithelial membrane antigen, and collagen type IV were uniformly negative. Ultrastructural examination carried out in all cases showed features consistent with those previously described for myogenic gastrointestinal stromal tumors, namely, scattered mitochondria and prominent Golgi apparati, strands of rough endoplasmic reticulum, focal accumulation of intracytoplasmic microfilaments with occasional focal condensations, subplasmalemmal attachment plaques and immature cell junctions, focal extracellular basal lamina material, and surface-oriented micropinocytotic activity. The myxoid changes observed in these tumors may represent a secondary, nonspecific reaction pattern of the tumor cells to some noxious stimulus, or they may be a form of degenerative phenomenon such as that commonly observed in smooth-muscle tumors of the uterus and other sites. Myogenic gastrointestinal stromal tumors with prominent myxoid stroma should be distinguished from benign schwannoma of the stomach and gastrointestinal autonomic nerve tumors. Because of the differences in prognosis for these entities, immunohistochemical and ultrastructural examinations are recommended for the evaluation of gastrointestinal stromal neoplasms with prominent myxoid features.
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PMID:Gastrointestinal stromal tumors with prominent myxoid matrix. Clinicopathologic, immunohistochemical, and ultrastructural study of nine cases of a distinctive morphologic variant of myogenic stromal tumor. 750 67