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)

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

Ten endometrial stromal tumors of the uterus with a prominent myxoid or fibrous appearance, or both, that led to problems in interpretation are reported. The patients were 32 to 52 (mean 39) years of age. Three presented with dysfunctional uterine bleeding and one with abdominal pain. An enlarged uterus or a pelvic mass was palpated in five patients; the tumor was an incidental postpartum finding in one patient. All patients underwent hysterectomy. The tumors ranged from 4 to 20 cm in greatest dimension. Six were soft, polypoid intracavitary masses and four were predominantly intramyometrial; two were gelatinous. On microscopic examination, nine tumors infiltrated the myometrium (stromal sarcomas) and one was well circumscribed (stromal nodule). Six tumors had a predominantly fibrous component with the neoplastic cells separated by variable amounts of collagen; extensive areas of hyalinization were present in three tumors. Two tumors were predominantly composed of hypocellular areas with an abundant myxoid matrix, and two had both components in roughly equal proportions. Alcian blue staining was positive, with the staining eliminated by hyaluronidase predigestion, in the myxoid areas. The typical morphologic features of endometrial stromal neoplasia were present focally in four tumors. All of them contained numerous small thin-walled vessels. Vimentin and smooth muscle actin were positive in nine of nine and seven of nine tumors, respectively, whereas desmin was negative in six of nine tumors and only focally positive in the other three. One patient had omental nodules at the time of the initial diagnosis and another had a pelvic recurrence 2 years after hysterectomy. Follow-up information is unavailable or short in the other cases. These tumors should be considered of endometrial stromal origin in view of the typical location of most of them, their growth pattern, content of characteristic arterioles, presence of typical endometrial stromal neoplasia in the primary or recurrent tumor in some cases, and absence of evidence of origin from a cell type other than endometrial stroma. These tumors may be identical, in some instances at least, to tumors referred to in the older literature as "myxofibrosarcomas."
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PMID:Myxoid and fibrous endometrial stromal tumors of the uterus: a report of 10 cases. 1054 38