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Bettina G. Zelger - One of the best experts on this subject based on the ideXlab platform.

  • Dermatofibroma a critical evaluation
    International Journal of Surgical Pathology, 2004
    Co-Authors: B Zelger, Bettina G. Zelger, Walter H C Burgdorf
    Abstract:

    Dermatofibromas are common cutaneous lesions. In most cases, they can be readily identified clinically and show a typical histology. In a small percentage of cases they show unusual clinical and more often histologic features that may cause differential diagnostic problems. In addition there are reactive fibrous lesions with neural or smooth muscle features that we speculate may represent Dermatofibroma variants.

  • combined Dermatofibroma co existence of two or more variant patterns in a single lesion
    Histopathology, 2000
    Co-Authors: Bettina G. Zelger, Alexis Sidoroff, B Zelger
    Abstract:

    Aims: Based on a series of 25 cases, we define and characterize combined Dermatofibroma, a tumour comprising two or more variant patterns of Dermatofibroma in a single lesion. Method and results Dermatofibroma may present with a wide variety of architectural, cellular or stromal peculiarities. Architectural peculiarities include deep penetration, atrophy, collarette formation, fascicular to plexiform architecture, massive haemorrhage, prominent haemangiopericytoma-like vascularity and palisading; cellular peculiarities the presence of epithelioid cells, clear cells, granular cells, prominent myofibroblastic differentiation and atypical giant cells (‘monster cells’); or stromal peculiarities such as prominent sclerosis, mucin, haemosiderin and cholesterotic deposits. In combined Dermatofibromas two or more of these features are seen in complex or inhomogenous combination such as the silhouette of a deep penetrating Dermatofibroma with an ‘ordinary’ storiform pattern in the upper and granular cell differentiation in the lower part of the lesion; or a Dermatofibroma with ordinary features in the upper, prominent sclerosis in the middle and clear cells in the lower portion of the lesion; or the characteristic epidermal collarette and cells of epithelial cell histiocytoma with a plexiform (‘neurothekeoma-like’) architecture surrounded by a myxoid stroma with spindle-shaped to stellate cells. Clinically, these lesions preferentially occur on the lower extremities of young to middle-aged females, frequently with the diagnosis of a fibrohistiocytic lesion. Apart from one recurrence follow-up was uneventful in all other cases. Immunohistochemically, lesions are consistently positive with KiM1p, variably positive for factor XIIIa, smooth muscle specific actin and with KP1 (CD68), NK1C3 and E9. Conclusion Recognition of combined Dermatofibroma allows the histopathologist to apply a confident benign label to unusual lesions which might otherwise elude diagnosis, or tempt description of ‘new’ entities and to avoid a misdiagnosis of malignancy.

  • Cellular 'neurothekeoma' : an epithelioid variant of Dermatofibroma?
    Histopathology, 1998
    Co-Authors: Bettina G. Zelger, Hans-jörg Steiner, Heinz Kutzner, H. Maier, Bernhard Zelger
    Abstract:

    Aims Cellular neurothekeoma is a rare benign cutaneous neoplasm with conflicting opinions regarding its histogenetic origin (nerve sheath, smooth muscle, myofibroblasts) as well as its relation to myxoid neurothekeoma (nerve sheath myxoma). The present series describes 15 cases whose clinicopathological features indicate a relationship to Dermatofibroma. Methods and results In this retrospective clinicopathological study, the lesions preferentially occurred in adolescents to young adults on the upper half of the body, often clinically diagnosed as some kind of fibrohistiocytic tissue response. Besides characteristic whorled nests to fascicles of palely eosinophilic epithelioid cells, all lesions showed variable clues pointing to Dermatofibroma: acanthosis, ill-defined storiform periphery, peripherally accentuated prominent sclerosis and lymphocytic demarcation/infiltration. Immunohistochemically, all cases were positive with NK1C3 (CD57), KiM1p and proliferating cell nuclear antigen, seven were positive for neurone specific enolase, five for factor XIIIa, six for smooth muscle specific actin and three for E9, an antimetallothionein marker. These findings are similar to those of conventional Dermatofibromas, the variability of the profile being best explained by time cycle and function dependent changes. Ultrastructurally, two cases showed microfilaments, attachment plaques, prominent pinocytosis and focal remnants of basal lamina. A careful study of the data and photomicrographs from the literature reveals that in many cases similar conclusions could be reached. Obvious discrepancies are most likely due to the confusion with myxoid neurothekeoma, a well circumscribed, more spindly and myxoid, S100 positive lesion of Schwannian origin. Conclusion The appearance of Dermatofibromas is markedly influenced by architectural, e.g. in deep penetrating Dermatofibroma, and/or cellular/stromal criteria, e.g. in epithelioid cell histiocytoma or sclerosing Dermatofibroma. Cellular neurothekeoma seems to be a variant of Dermatofibromas with both architectural and cellular/stromal peculiarities, i.e. plexiform pattern, epithelioid cytology and stromal sclerosis.

  • clear cell Dermatofibroma
    Histopathology, 1997
    Co-Authors: B Wambachergasser, Bettina G. Zelger, Bernhard Zelger, Hans-jörg Steiner
    Abstract:

    This series presents six cases of a rare variant of Dermatofibroma, characterized by marked clear cell change. All lesions occurred on the lower extremities of middle-aged adults (four women, two men), mostly with the clinical diagnosis of fibrohistiocytic lesion. Histological examination revealed well circumscribed, faintly stained dermal to subcutaneous lesions which were due to the overwhelming presence of clear cells (> 90%), some with prominent PAS-positive cytoplasmic granulation. Overlying epidermal hyperplasia as well as storiform arrangement of spindle cells, sclerotic collagen and some interspersed lympho-histiocytic infiltrate at the periphery of the lesion indicated the fibrohistiocytic origin. Individual histopathological peculiarities included: bizarre giant cells in two cases, perifollicular arrangement and haemangiopericytoma-like features with iron deposition in one case each. Immunohistochemically three of four lesions showed moderate reactivity for factor XIIIa and two of four with an anti-metallothionen marker E9, but were otherwise negative with a broad panel of markers. Electronmicroscopy in two cases revealed large pools of glycogen beside focal, prominent endoplasmic reticulum and lysosomes in some granular cells, but only optically translucent cells in cases of clear cells. Recognition of clear cell Dermatofibroma is important as the differential diagnosis includes some entities with more serious outcome/considerations such as metastases of renal cell carcinoma, xanthogranulomatous reactions, balloon cell naevus/melanoma and clear cell sarcoma.

  • atrophic variants of Dermatofibroma and dermatofibrosarcoma protuberans
    Histopathology, 1995
    Co-Authors: B Zelger, Dietmar Ofner, Bettina G. Zelger
    Abstract:

    Dermal atrophy of more than 50% of the locoregional dermis may be the predominant histopathological feature in Dermatofibroma and dermatofibrosarcoma protuberans. This may cause diagnostic difficulties. In the present study 26 cases of atrophic Dermatofibroma were compared with three cases of atrophic dermatofibrosarcoma protuberans. Clinically, both conditions mostly occurred on the (upper) trunk of females. While atrophic Dermatofibroma usually presented as a reddish, umbilicated lesion (0.5-1cm), often suspected to be a basal cell carcinoma, atrophic dermatofibrosarcoma protuberans showed irregularly arranged tan-brown plaques (3-6 cm). Histologically, atrophic Dermatofibroma showed a regular silhouette with a smooth nodular (9/26) or scalloped lower margin with an intervening lace-like pattern of superficial fatty tissue infiltration (17/26) and variable sclerosis: atrophic dermatofibrosarcoma protuberans showed a deep, irregular infiltration of fatty tissue in a lacelike/honeycomb and/ or multilayered pattern, but no sclerosis. Immunohistochemically, atrophic Dermatofibroma was mostly negative with QBEnd 10 (CD34;24/26), variably positive for factor XIIIa (20/26) and metallothionein (11/26). Labelling for factor XIIIa and metallothionein was usually seen in 'early' (metabolically active) lesions, while 'late' sclerotic ones were negative. In contrast to atrophic Dermatofibroma all three atrophic dermatofibrosarcoma protuberans showed a consistently uniform profile: CD34 positive, factor XIIIa and metallothionein negative. Our study delineates atrophic Dermatofibroma and atrophic dermatofibrosarcoma protuberans as distinct entities clearly distinguishable from each other by clinicopathologic criteria.

B Zelger - One of the best experts on this subject based on the ideXlab platform.

  • Dermatofibroma a critical evaluation
    International Journal of Surgical Pathology, 2004
    Co-Authors: B Zelger, Bettina G. Zelger, Walter H C Burgdorf
    Abstract:

    Dermatofibromas are common cutaneous lesions. In most cases, they can be readily identified clinically and show a typical histology. In a small percentage of cases they show unusual clinical and more often histologic features that may cause differential diagnostic problems. In addition there are reactive fibrous lesions with neural or smooth muscle features that we speculate may represent Dermatofibroma variants.

  • combined Dermatofibroma co existence of two or more variant patterns in a single lesion
    Histopathology, 2000
    Co-Authors: Bettina G. Zelger, Alexis Sidoroff, B Zelger
    Abstract:

    Aims: Based on a series of 25 cases, we define and characterize combined Dermatofibroma, a tumour comprising two or more variant patterns of Dermatofibroma in a single lesion. Method and results Dermatofibroma may present with a wide variety of architectural, cellular or stromal peculiarities. Architectural peculiarities include deep penetration, atrophy, collarette formation, fascicular to plexiform architecture, massive haemorrhage, prominent haemangiopericytoma-like vascularity and palisading; cellular peculiarities the presence of epithelioid cells, clear cells, granular cells, prominent myofibroblastic differentiation and atypical giant cells (‘monster cells’); or stromal peculiarities such as prominent sclerosis, mucin, haemosiderin and cholesterotic deposits. In combined Dermatofibromas two or more of these features are seen in complex or inhomogenous combination such as the silhouette of a deep penetrating Dermatofibroma with an ‘ordinary’ storiform pattern in the upper and granular cell differentiation in the lower part of the lesion; or a Dermatofibroma with ordinary features in the upper, prominent sclerosis in the middle and clear cells in the lower portion of the lesion; or the characteristic epidermal collarette and cells of epithelial cell histiocytoma with a plexiform (‘neurothekeoma-like’) architecture surrounded by a myxoid stroma with spindle-shaped to stellate cells. Clinically, these lesions preferentially occur on the lower extremities of young to middle-aged females, frequently with the diagnosis of a fibrohistiocytic lesion. Apart from one recurrence follow-up was uneventful in all other cases. Immunohistochemically, lesions are consistently positive with KiM1p, variably positive for factor XIIIa, smooth muscle specific actin and with KP1 (CD68), NK1C3 and E9. Conclusion Recognition of combined Dermatofibroma allows the histopathologist to apply a confident benign label to unusual lesions which might otherwise elude diagnosis, or tempt description of ‘new’ entities and to avoid a misdiagnosis of malignancy.

  • clear cell Dermatofibroma case report of an unusual fibrohistiocytic lesion
    The American Journal of Surgical Pathology, 1996
    Co-Authors: B Zelger, Hans-jörg Steiner, Heinz Kutzner
    Abstract:

    A case of clear cell Dermatofibroma is presented. Clinically, a 41-year-old woman exhibited a hard brown nodule on her instep that was assumed to be a Dermatofibroma. Histologically, more than 90% of the lesion was composed of clear cells. Epidermal hyperplasia and a storiform arrangement of spindle cells and sclerotic collagen in some foci at the periphery of the lesion indicated the fibrohistiocytic origin. Moreover, prominent vascularity and some bizarre giant cells in the lower part of the lesion were reminiscent of multinucleate cell angiohistiocytoma. Of a broad panel of antibodies, the lesion was positive only for Factor XIIIa (and vimentin). Ultrastructurally, clear-cell changes corresponded to a mostly translucent cytoplasm, focally with some endoplasmic reticulum and prominent lysosomal structures. A review of 1,496 Dermatofibromas seen during the last 15 years at our institute revealed 12 cases (1%) with similar clear-cell changes in a minor part of the infiltrate (less than 10%). The differential diagnosis includes metastases of renal-cell carcinoma, which exhibit more atypia and mitoses and are positive for epithelial cell markers; clear-cell sarcoma, a lesion of tendons or aponeurosis with some moderate cytoplasmic melanin deposition and immunoreactivity with HMB-45; and various non-X histiocytic disorders, such as the predominantly vacuolated type of juvenile (or adult) xanthogranulomas or papular xanthoma, with a mixed infiltrate of various types of mononuclear and multinucleate histiocytes positive with a variety of macrophage markers.

  • atrophic variants of Dermatofibroma and dermatofibrosarcoma protuberans
    Histopathology, 1995
    Co-Authors: B Zelger, Dietmar Ofner, Bettina G. Zelger
    Abstract:

    Dermal atrophy of more than 50% of the locoregional dermis may be the predominant histopathological feature in Dermatofibroma and dermatofibrosarcoma protuberans. This may cause diagnostic difficulties. In the present study 26 cases of atrophic Dermatofibroma were compared with three cases of atrophic dermatofibrosarcoma protuberans. Clinically, both conditions mostly occurred on the (upper) trunk of females. While atrophic Dermatofibroma usually presented as a reddish, umbilicated lesion (0.5-1cm), often suspected to be a basal cell carcinoma, atrophic dermatofibrosarcoma protuberans showed irregularly arranged tan-brown plaques (3-6 cm). Histologically, atrophic Dermatofibroma showed a regular silhouette with a smooth nodular (9/26) or scalloped lower margin with an intervening lace-like pattern of superficial fatty tissue infiltration (17/26) and variable sclerosis: atrophic dermatofibrosarcoma protuberans showed a deep, irregular infiltration of fatty tissue in a lacelike/honeycomb and/ or multilayered pattern, but no sclerosis. Immunohistochemically, atrophic Dermatofibroma was mostly negative with QBEnd 10 (CD34;24/26), variably positive for factor XIIIa (20/26) and metallothionein (11/26). Labelling for factor XIIIa and metallothionein was usually seen in 'early' (metabolically active) lesions, while 'late' sclerotic ones were negative. In contrast to atrophic Dermatofibroma all three atrophic dermatofibrosarcoma protuberans showed a consistently uniform profile: CD34 positive, factor XIIIa and metallothionein negative. Our study delineates atrophic Dermatofibroma and atrophic dermatofibrosarcoma protuberans as distinct entities clearly distinguishable from each other by clinicopathologic criteria.

Oyvind Bakken Rognstad - One of the best experts on this subject based on the ideXlab platform.

Hans-jörg Steiner - One of the best experts on this subject based on the ideXlab platform.

  • Cellular 'neurothekeoma' : an epithelioid variant of Dermatofibroma?
    Histopathology, 1998
    Co-Authors: Bettina G. Zelger, Hans-jörg Steiner, Heinz Kutzner, H. Maier, Bernhard Zelger
    Abstract:

    Aims Cellular neurothekeoma is a rare benign cutaneous neoplasm with conflicting opinions regarding its histogenetic origin (nerve sheath, smooth muscle, myofibroblasts) as well as its relation to myxoid neurothekeoma (nerve sheath myxoma). The present series describes 15 cases whose clinicopathological features indicate a relationship to Dermatofibroma. Methods and results In this retrospective clinicopathological study, the lesions preferentially occurred in adolescents to young adults on the upper half of the body, often clinically diagnosed as some kind of fibrohistiocytic tissue response. Besides characteristic whorled nests to fascicles of palely eosinophilic epithelioid cells, all lesions showed variable clues pointing to Dermatofibroma: acanthosis, ill-defined storiform periphery, peripherally accentuated prominent sclerosis and lymphocytic demarcation/infiltration. Immunohistochemically, all cases were positive with NK1C3 (CD57), KiM1p and proliferating cell nuclear antigen, seven were positive for neurone specific enolase, five for factor XIIIa, six for smooth muscle specific actin and three for E9, an antimetallothionein marker. These findings are similar to those of conventional Dermatofibromas, the variability of the profile being best explained by time cycle and function dependent changes. Ultrastructurally, two cases showed microfilaments, attachment plaques, prominent pinocytosis and focal remnants of basal lamina. A careful study of the data and photomicrographs from the literature reveals that in many cases similar conclusions could be reached. Obvious discrepancies are most likely due to the confusion with myxoid neurothekeoma, a well circumscribed, more spindly and myxoid, S100 positive lesion of Schwannian origin. Conclusion The appearance of Dermatofibromas is markedly influenced by architectural, e.g. in deep penetrating Dermatofibroma, and/or cellular/stromal criteria, e.g. in epithelioid cell histiocytoma or sclerosing Dermatofibroma. Cellular neurothekeoma seems to be a variant of Dermatofibromas with both architectural and cellular/stromal peculiarities, i.e. plexiform pattern, epithelioid cytology and stromal sclerosis.

  • clear cell Dermatofibroma
    Histopathology, 1997
    Co-Authors: B Wambachergasser, Bettina G. Zelger, Bernhard Zelger, Hans-jörg Steiner
    Abstract:

    This series presents six cases of a rare variant of Dermatofibroma, characterized by marked clear cell change. All lesions occurred on the lower extremities of middle-aged adults (four women, two men), mostly with the clinical diagnosis of fibrohistiocytic lesion. Histological examination revealed well circumscribed, faintly stained dermal to subcutaneous lesions which were due to the overwhelming presence of clear cells (> 90%), some with prominent PAS-positive cytoplasmic granulation. Overlying epidermal hyperplasia as well as storiform arrangement of spindle cells, sclerotic collagen and some interspersed lympho-histiocytic infiltrate at the periphery of the lesion indicated the fibrohistiocytic origin. Individual histopathological peculiarities included: bizarre giant cells in two cases, perifollicular arrangement and haemangiopericytoma-like features with iron deposition in one case each. Immunohistochemically three of four lesions showed moderate reactivity for factor XIIIa and two of four with an anti-metallothionen marker E9, but were otherwise negative with a broad panel of markers. Electronmicroscopy in two cases revealed large pools of glycogen beside focal, prominent endoplasmic reticulum and lysosomes in some granular cells, but only optically translucent cells in cases of clear cells. Recognition of clear cell Dermatofibroma is important as the differential diagnosis includes some entities with more serious outcome/considerations such as metastases of renal cell carcinoma, xanthogranulomatous reactions, balloon cell naevus/melanoma and clear cell sarcoma.

  • clear cell Dermatofibroma case report of an unusual fibrohistiocytic lesion
    The American Journal of Surgical Pathology, 1996
    Co-Authors: B Zelger, Hans-jörg Steiner, Heinz Kutzner
    Abstract:

    A case of clear cell Dermatofibroma is presented. Clinically, a 41-year-old woman exhibited a hard brown nodule on her instep that was assumed to be a Dermatofibroma. Histologically, more than 90% of the lesion was composed of clear cells. Epidermal hyperplasia and a storiform arrangement of spindle cells and sclerotic collagen in some foci at the periphery of the lesion indicated the fibrohistiocytic origin. Moreover, prominent vascularity and some bizarre giant cells in the lower part of the lesion were reminiscent of multinucleate cell angiohistiocytoma. Of a broad panel of antibodies, the lesion was positive only for Factor XIIIa (and vimentin). Ultrastructurally, clear-cell changes corresponded to a mostly translucent cytoplasm, focally with some endoplasmic reticulum and prominent lysosomal structures. A review of 1,496 Dermatofibromas seen during the last 15 years at our institute revealed 12 cases (1%) with similar clear-cell changes in a minor part of the infiltrate (less than 10%). The differential diagnosis includes metastases of renal-cell carcinoma, which exhibit more atypia and mitoses and are positive for epithelial cell markers; clear-cell sarcoma, a lesion of tendons or aponeurosis with some moderate cytoplasmic melanin deposition and immunoreactivity with HMB-45; and various non-X histiocytic disorders, such as the predominantly vacuolated type of juvenile (or adult) xanthogranulomas or papular xanthoma, with a mixed infiltrate of various types of mononuclear and multinucleate histiocytes positive with a variety of macrophage markers.

S Astner - One of the best experts on this subject based on the ideXlab platform.