1/9. Bednar tumor (pigmented dermatofibrosarcoma protuberans) occurring in a site of prior immunization: immunochemical findings and therapy.Bednar tumor is a rare pigmented variant of dermatofibrosarcoma protuberans (DFSP). Because of its rarity, information is lacking regarding the optimal therapy and potential utility of immunohistochemistry in diagnosis. We report a case of Bednar tumor in which the diagnosis was aided by immunohistochemistry for CD34, an antigen known to be expressed in DFSP but not previously reported in Bednar tumor. Our case was also striking because it represents the first reported appearance of a Bednar tumor at a site of prior immunization, a phenomenon previously noted in some cases of DFSP. The patient was treated effectively with mohs surgery and is without recurrence at 9 months.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/9. dermatofibrosarcoma protuberans with EMa cells. Report of a case suggesting perineurial cell differentiation.A case of dermatofibrosarcoma protuberans (DFSP) with epithelial membrane antigen (EMA)-positive cells is described. The tumor was excised from the left groin of a 28-year-old woman. It showed characteristic histologic features of DFSP with typical diffuse immunohistochemical positivity for CD34. Moreover, scattered neoplastic cells expressed EMA, suggesting perineural cell differentiation. Ultrastructural study found perineurial cell features, such as thin long bipolar cytoplasmic processes, pinocytotic vesicles, fragments of external lamina and/or external lamina-like material, attachment plaques, and desmosome-like junctions. This observation, together with previous immunohistochemical findings of EMA-positive cells in a subset of DFSPs, strongly suggests perineurial cell differentiation in these tumors. DFSP should be included in the differential diagnosis of EMA-positive spindle cell lesions of superficial soft tissue and skin.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/9. Congenital dermatofibrosarcoma protuberans with fibrosarcomatous and myxoid change.This report describes a case of congenital dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous (FS) and myxoid areas. Immunohistochemical results showed that tumour cells in ordinary DFSP areas were diffusely positive for CD34, whereas in the FS and myxoid areas, few tumour cells were positive for this antigen. Ki-67 positive tumour cell numbers were greater in the FS (11.8%) and myxoid areas (19.8%) relative to ordinary DFSP areas (2.2%). reverse transcription polymerase chain reaction and sequence analysis showed the presence of an identical COL1A1-PDGFB fusion transcript in ordinary DFSP (plaque-like area), FS, and myxoid areas of DFSP. These results indicate that the three components of DFSP have a common histogenesis. This study documents the first application of gene analysis involving the myxoid area of DFSP.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/9. Myoid differentiation and EMA expression in fibrosarcomatous dermatofibrosarcoma protuberans.dermatofibrosarcoma protuberans (DFSP) is a relatively unusual, locally aggressive cutaneous tumor of intermediate malignancy. Fibrosarcomatous DFSP (FS-DFSP), a rare variant of DFSP, has a higher tendency for recurrence and metastasis. Recently, a small number of cases of another variant of FSDFSB characterized by areas of myoid differentiation have been reported. We present here a 35 yearold female patient with myoid differentiation in FS-DFSP. The tumor on the left scapular region had slowly grown over six years. Examination revealed a domeshaped, firm, nontender, violaceous dermal nodule. Histologically, it was composed of a monotonous spindle cell population arranged predominantly in a storiform pattern and to a lesser extent in a fascicular fibrosarcomatous pattern with a parallel arrangement of the cells. Immunohistochemically, the tumor cells showed diffuse expression for vimentin and CD34. In the center of the tumor areas with frequent mitosis, hypercellular and negative reactive for CD34 were seen. In addition, approximately 10% of the cells were positive for epithelial membrane antigen. Myoid differentiation was found around the blood vessels. The myoid areas were positive for smooth muscle actin and negative for desmin. It is possible that the presence of hyperplastic myofibroblasts is a reactive phenomenon to the proliferation of tumor cells. We believe that this finding around blood vessels may be present in DFSP or FS-DFSP. However, when myoid areas, myoid fascicles and myoid nodules are seen in the stroma, it may be a new morphological variant of DFSP and/or FS-DFSP.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/9. Immunohistochemical margin control applied to Mohs micrographic surgical excision of dermatofibrosarcoma protuberans.BACKGROUND. Surgical treatment of dermatofibrosarcoma protuberans has a high rate of recurrence presumably secondary to persistent residual tumor. Recently an antigenic marker, CD34, has demonstrated specificity for this tumor. OBJECTIVE. To improve the microscopic detection of dermatofibrosarcoma protuberans tumor elements in Mohs micrographic surgical sections by incorporating immunohistologic staining. methods. Standard Mohs micrographic surgical technique was used, coupled with standard immunohistochemical procedures using an antibody to the CD34 antigen. RESULTS. Immunohistochemical staining with anti-CD34 of Mohs micrographic sections clearly delineated the extent of the tumor elements. CONCLUSIONS. We anticipate that the application of this immunohistochemical-modified Mohs surgical technique will further enhance the detection of insidious portions of tumor thereby enhancing removal and reducing recurrence.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/9. dermatofibrosarcoma protuberans treated with mohs surgery. A case with CD34 immunostaining variability.BACKGROUND. Immunohistochemical stains for CD34 antigen can help in differentiating dermatofibrosarcoma protuberans (DFSP) from other fibrohistiocytic tumors and in demarcating its surgical margins during mohs surgery. However, variable expression of CD34 antigen in nodular areas can sometimes result in negative staining of tissue sections creating diagnostic and therapeutic dilemmas. OBJECTIVE. To show the variable expression of CD34 antigen in a DFSP tumor. methods. Case presentation of DFSP with immunohistochemical staining using the ABC peroxidase macromolecular complex. RESULTS. Microscopic examination of paraffin-embedded sections showed CD34-negative DFSP tumor cells with positive staining of endothelial cells. On frozen sections at the time of surgery the tumor cells stained strongly positive for CD34. CONCLUSION. This case demonstrates the variable expression of CD34 antigen by DFSP tumors and emphasizes the need to interpret with caution the results of these immunostains during mohs surgery.- - - - - - - - - - ranking = 4keywords = antigen (Clic here for more details about this article) |
7/9. CD34-reactive fibrous papule of the nose.In human skin, the CD34 antigen is expressed on endothelium, periadnexal cells, and a population of reticular dermal interstitial cells. CD34 expression is characteristic of dermatofibrosarcoma protuberans and several other neoplasms, but not of typical fibrous papules of the nose. We describe a 16-year-old white girl with a slowly growing papule on the nose. Histopathology showed a dermal tumor with a superficial component of branched, thin-walled blood vessels and a deeper component of benign-appearing, spindle-shaped cells. These cells uniformly and strongly expressed CD34, but not factor xiiia or markers of melanocytic, neural, muscular, vascular, or histiocytic differentiation. We consider this lesion a CD34-reactive fibrous papule. This benign tumor must be clearly distinguished from dermatofibrosarcoma protuberans, which also is composed of bundles of CD34-reactive spindle-shaped cells in most cases but has locally aggressive behavior.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/9. A cutaneous case of giant cell angiofibroma occurring with dermatofibrosarcoma protuberans and showing bimodal CD34 fibroblastic and FXIIIa histiocytic immunophenotype.Dei Tos and colleagues in 1995 reported a series of seven distinctive orbital tumors in adults which they named giant cell angiofibroma (GCA). The morphologic features are intermediate between giant cell fibroblastoma and solitary fibrous tumor with a richly vascularized, patternless spindle cell proliferation forming a collagenous or myxoid stroma with pseudovascular angiectoid spaces. The spindled tumor cells have large, rounded nuclei, sometimes with complex folded shape and pseudoinclusions. There also are multi- or mononuclear giant cells, and these tumor cells partly line so-called angiectoid spaces. Cells express human progenitor cell antigen CD34 and vimentin. One case in the buccinator fascia was also noted by the authors, but similar cutaneous lesions are thus far unknown. We report our experience with a polypoid tumor that ocurred on the thigh of a 49-year-old woman that conforms to the description of GCA. The tumor has variegated vessels admixed with patternless spindle and giant cell stroma with angiectoid spaces as well as areas of dermatofibrosarcoma protuberans (DFSP). Most tumor cells express vimentin and CD34, including giant and spindle cells lining angiectoid spaces. Focally up to 40% of the lesional cells express coagulation factor xiiia with histiocytoid to highly dendritic cytosomes. The DFSP component is composed of admixed CD34 and FXIIIa dendritic cells arranged in a storiform pattern. Tumor cells are negative for actin, desmin, S-100, and cytokeratin. The Ki67 proliferation index is 1% in GCA areas and 3% in DFSP areas; Ki 67 stains mainly fibroblasts. We conclude that this cutaneous GCA is a fibrohistiocytic tumor closely related to and representing a more organoid angioformative analog of GCF, with both being related histogenetically also to DFSP. These lesions represent part of a greater spectrum of fibrovascular tissue patterns, all probably derived from proliferations of interactive microvascular CD34 fibroblasts and FXIIIa histiocytes.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/9. Myxoid dermatofibrosarcoma protuberans: morphological, ultrastructural and immunohistochemical features.Two uncommon cases of dermatofibrosarcoma protuberans with prominent myxoid changes are presented. The tumors appeared as large multinodular cutaneous plaques that arose at the sites of excision of previous tumors some years earlier. In addition to limited fibrous storiform features, focally observed in deep and peripheral portions of the tumors, a diffuse myxoid pattern could be observed. The latter consisted of homogeneous areas of rare, stellate or spindle-shaped cells, haphazardly scattered in abundant myxoid matrix. Cells of myxoid neoplastic tissue showed mainly a positive immunoreaction for fibrohistocytic markers and the absence either of muscular, neural or human progenitor cell antigens. Mitotic figures were fewer and cell proliferation rates were lower in myxoid as compared to those of typical dermatofibrosarcoma protuberans used as a control. The ultrastructural examination of myxoid areas revealed a prevalent fibroblast-like cell population showing dilated cytoplasmic vesicles, sometimes containing glycosaminoglycans-like substances. The extent of myxoid changes together with the characteristic morphological, ultrastructural and immunohistochemical features confirm that myxoid dermatofibrosarcoma protuberans is a distinct variant of this fibrohistiocytic tumor to be considered in the differential diagnosis among myxoid tumors of the skin.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |