Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies of mesenchymal cells of the dermis using antibodies to factor XIIIa (FXIIIa) and CD34 have demonstrated immunophenotypic heterogeneity amongst the normal resident spindle/dendritic cells of the dermis. These immunohistochemical markers also have been reported to be useful in the distinction between two dermal mesenchymal tumors of uncertain histogenetic origin - the dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP). DFs are FXIIIa positive, CD34 negative while DFSPs are FXIIIa negative and CD34 positive. Expression of CD34 may also have histogenetic implications for these cutaneous neoplasms. In order to further study these tumors we studied 13 DFs and 12 DFSPs immunohistochemically using a microwave antigen retrieval technique in formalin fixed, paraffin embedded tissue with antibodies to FXIIIa, CD34, CD45, factor VIII related antigen (FVIII-RA), the Ki-67 antigen (MIB-1 antibody) and the lectin Ulex europaeus. Of the DFs, all 13 were FXIIIa positive; 12/13 were CD34 negative and 1 was strongly CD34 positive. All DFSPs were FXIIIa negative and CD34 positive. One DFSP also contained an area of fibrosarcoma which was negative for both markers. All tumors were negative with anti-FVIII-RA Ulex europaeus, and anti-CD45. MIB-1 staining demonstrated nuclear staining of the tumor cells in both DFs and DFSPs. Image analysis of MIB-1 stained sections revealed a significant difference in mean percent positive nuclear area between DFs (1.16% +/- 0.405) and DFSPs (2.265% +/- 0.963). In summary, FXIIIa reliably distinguished between DFs and DFSPs; however, CD34 immunoreactivity can be seen in DFs. No evidence for vascular or hematopoietic origin of these tumors was found using microwave antigen retrieval and anti-FVIII-RA, Ulex europaeus, or CD45 staining. With microwave enhancement trypsin was not necessary for FXIIIa staining; however, it did not significantly enhance detection of FVIII-RA, CD45, or Ulex antigens. DF and DFSP tumor cells are in the cell cycle as demonstrated by MIB-1 staining and there are significant differences in percent positive nuclear area between these neoplasms, being higher in DFSP compared to DF.
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PMID:Dermatofibroma and dermatofibrosarcoma protuberans: an immunohistochemical study reveals distinctive antigenic profiles. 886 61

We report an unusual case of hemangiopericytoma-like dermatofibroma in the right shoulder of an 82-year-old patient with a well-defined nodular growth located in the dermis. Microscopic study revealed a band of haphazardly arranged cells with a vascular component of gaping, simple, endothelial-lined vascular structures with intervening postcapillary venules and capillary-sized slit-like "staghorn" vascular channels filled with erythrocytes; abundant mast cells were also observed. The neoplasm cells were positive for CD68 and Factor XIIIA and negative for CD34. Few data have been published on the presence of abundant mast cells (tryptase and CD117 positive) in these neoplasm. The differential diagnosis of this entity should consider other spindle cell neoplasm, including hemangiopericytoma/solitary fibrous tumor, dermatofibrosarcoma protuberans, myopericytoma, angioleiomyoma, amelanotic melanoma, pecoma, and benign and malignant peripheral nerve tumors. We present an infrequent case of dermatofibroma with a vascular pattern resembling hemangiopericytoma and the presence of abundant mast cells, which may be responsible for this vascular component.
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PMID:Hemangiopericytoma-like dermatofibroma with mast cells. 2171 84