D. Katenkamp

Epithelioid hemangioendothelioma of skin and soft tissues: clinicopathologic and immunohistochemical study of 30 cases.

Epithelioid hemangioendothelioma of soft tissues (EHE) represents a distinct entity with an unpredictable clinical course. We analyzed the clinicopathologic and immunohistochemical features in a series of 30 patients. Patient age range was 16-74 years (median 50); 18 of 30 patients were female. Eight tumors arose in the lower and two in the upper extremities, seven on the trunk, five each in the head/ neck and anogenital regions, two in the mediastinum, and one in the abdomen. Seventeen neoplasms were located in deep soft tissues, nine were subcutaneous or perifascial, and four were dermal; size ranged from 0.4 to 10 cm; in 11 cases the tumor was > 5 cm. Tumors with an infiltrative growth pattern were more common than entirely circumscribed lesions. The tumors were composed histologically of short strands, cords, or small clusters of epithelioid, round, to slightly spindled endothelial cells that formed at least focally, intracellular lumina and were set in a frequently myxohyaline stroma. Thirteen of 30 lesions showed angiocentric growth, which was occlusive in many cases. Immunohistochemically, all cases tested were positive for at least one endothelial marker (CD31, CD34, factor VIII, Ulex europaeus), six of 23 (26%) were positive for cytokeratin, and five of 11 (45%) were positive for alpha-smooth muscle actin. Median follow-up of 36 months (range 2-96) in 24 cases showed local recurrence in three cases and systemic metastases in five cases (21%); four patients (17%) died of tumor. Although more aggressive histologic features (striking nuclear atypia in eight cases, numerous spindled cells in 10, more than two mitoses per 10 high-power fields in nine, and small, more solid angiosarcomalike foci in four cases) tended to be related to poor clinical outcome, there was no clear correlation. Two metastasizing cases showed no histologically atypical features whatever. We suggest that EHE of soft tissue is better regarded as a fully malignant, rather than borderline, vascular neoplasm, albeit the prognosis is better than in conventional angiosarcoma.

Fibrosarcomatous (high-grade) dermatofibrosarcoma protuberans: Clinicopathologic and immunohistochemical study of a series of 41 cases with emphasis on prognostic significance

The fibrosarcomatous variant of dermatofibrosarcoma protuberans (FS-DFSP) represents an uncommon form of DFSP, in which the prognostic influence of the fibrosarcomatous component is still debated. We analyzed the clinicopathologic and immunohistochemical features in a series of 41 patients. Patient age ranged from 8 to 87 years (median, 48 years), and 19 patients were female. Twenty five lesions were seen on the trunk, 6 on the upper limbs, and 4 on the lower limbs, and five neoplasms were located in the head/neck region; in one case, exact anatomic site was unknown. Twenty seven tumors involved purely dermal and subcutaneous tissues, in 10 cases, deeper structures were also involved, 1 case arose in the breast, and, in 3 cases, it was impossible to define exact depth of the lesion. Preoperative duration ranged from 1 month to 60 years (median, 3 years). Twenty six tumors were excised locally with clear margins, 7 were treated by wide excision, 3 by incomplete excision, and, in 4 patients, the lesion was shelled out. In one case, exact treatment was unknown. In addition, radiotherapy was administered in three cases and chemotherapy in one case. Histologically, the lesions showed areas of typical, low-grade DFSP adjacent to fibrosarcomatous areas. In four cases, a previously ordinary DFSP recurred as pure fibrosarcoma, in two cases, local recurrence of FS-DFSP showed features of ordinary DFSP. Fibrosarcomatous change was more common in the primary (de novo) lesions than in recurrent lesions (3.6:1). Proportion of fibrosarcoma varied between < 30% in 6 cases to > 70% of tumor tissue in 21 cases. An abrupt transition between both components was seen in 19 cases. The fibrosarcomatous component showed focal necrosis in seven cases and showed a higher mitotic rate in comparison with ordinary DFSP areas (mean, 13.4 versus 2.3 mitoses in 10 high-power fields). Additional histologic features included progression to pleomorphic sarcoma in 2 recurrent cases, melanin-pigmented cells (Bednar FS-DFSP) in 1 case, focal myxoid change in 13 cases, plaque or keloidlike hyalinization in 3 cases, and myoid bundles and nodules in 9 cases. Immunohistochemically, tumor cells in DFSP areas stained positively for CD34, whereas, in FS-DFSP areas, only 15 out 33 cases were positive for CD34. Follow-up in 34 of 41 patients (mean, 90 months; median, 36 months) revealed local recurrence in 20 patients (58%) (recurrence occurred in 5 patients on two or more occasions). Metastases (5 lung, 1 bone, and 1 soft tissue) were seen in 5 patients (14.7%), and 2 patients have died of tumor to date (5.8%). Necrosis, high mitotic rate (> 10 mitoses per 10 high-power fields), and presence of pleomorphic areas in FS-DFSP tended to be related with poor clinical outcome, but no statistically significant association was detected. Fibrosarcomatous change in DFSP represents a form of tumor progression in DFSP and is associated with a significantly more aggressive clinical course than in ordinary DFSP, indicating a possible need for treatment intensification in such cases.

Solitary fibrous tumour : clinicopathological, immunohistochemical, and ultrastructural analysis of 12 cases arising in soft tissues, nasal cavity and nasopharynx, urinary bladder and prostate

Abstract The clinicopathological features of 12 extraserosal solitary fibrous tumours (SFT) are described. The age of the patients ranged from 18 to 72 years (mean: 48.2 years; median: 54 years); 5 were female patients. Seven lesions arose in soft tissue (5 in perifascial, and 1 each in subcutaneous and intramuscular tissues). They were situated in the groin (2 cases) and the neck, right buttock, left scapula, upper arm, and anterior abdominal wall (1 case each). One polypoid lesion was seen in in the nasal cavity and 1 in the nasopharynx; 2 neoplasms arose in the urinary bladder and 1 was located in the prostate and periprostatic tissue. Nine lesions were excised; in 1 patient wide excision was performed and in 2 patients, transurethral resection. Limited follow-up of 3 cases revealed a benign clinical course. The size of the neoplasms ranged from 1.7 cm to 20.0 cm (mean: 5.4 cm; median: 3.5 cm). Histologically, the neoplasms were well circumscribed and composed of cytologically bland spindle cells arranged without an obvious pattern; focally storiform or fascicular growth patterns were seen. Tumour cells were separated by thick bands of collagen demonstrating foci of keloid-like hyalinization. Prominent vascularity showing a haemangiopericytoma-like vascular pattern and vessels with thick, hyalinized vessel walls were seen in all cases. Increased mitotic activity was noted in 2 soft tissue cases (4–6 mitoses in 10 high-power fields); the other cases showed fewer than 2 mitotic figures in 10 high-power fields. Immunohistochemically, all cases tested stained positively for vimentin, CD34 and CD99, and 2 cases showed focal myofibroblastic differentiation. Two cases examined ultrastructurally showed a fibroblastic phenotype; focally pinocytic vesicles and microfilaments were identified. SFT represents a distinct neoplasm that should be included in the differential diagnosis of spindle-cell neoplasms in soft tissue, nasal cavity and nasopharynx, urinary bladder, and prostate. Strict diagnostic criteria are necessary to avoid overdiagnosis or confusion with more aggressive neoplasms in these locations.

Low-grade myofibroblastic sarcoma: analysis of 18 cases in the spectrum of myofibroblastic tumors.

The clinicopathologic, immunohistochemical, and ultrastructural features of a seemingly distinctive low-grade spindle cell sarcoma showing myofibroblastic differentiation have been analyzed in a series of 18 patients. The age range of the patients (7 women and 11 men) was 19-72 years (median: 42 years). A painless, enlarging mass was the most common clinical presentation. Five tumors arose in the oral cavity (including four lesions in the tongue), four in the lower extremities and three in the upper extremities, four cases in the abdominal/pelvic cavity, and two on the trunk. Eight soft-tissue cases involved skeletal muscle, three cases were located in perifascial tissues, and two arose in subcutaneous tissue. Tumor size ranged from 1.4 to 17 cm (median: 4 cm); in six cases (of which four were abdominal/pelvic) the lesion was larger than 5 cm. All patients were treated surgically, and four received additional adjunctive therapy. Histologically, most cases were cellular lesions showing a diffusely infiltrative pattern, and were composed of spindle-shaped tumor cells arranged mainly in fascicles. Tumor cells had poorly defined, palely eosinophilic cytoplasm and fusiform nuclei, which were either tapering and wavy or plumper and vesicular with indentations and small inconspicuous nucleoli. Tumor cells were set in a collagenous matrix often with prominent hyalinization. Mild nuclear atypia was noted in 16 cases; in the other 2 cases, and in the metastases of one other lesion, a greater degree of nuclear atypia was seen. In all but one case, the mitotic rate ranged from 1 to 6 mitoses in 10 HPFs (mean: 2/10 HPFs); in a single case, there were more than 20 mitoses in 10 HPFs. Immunohistochemically, all cases stained positively for at least one myogenic marker; 12 cases were positive for desmin, 11 for alpha-smooth muscle actin, and 6 for muscle actin (HHF35). Seven neoplasms were desmin positive/ alpha-smooth-muscle actin negative, and five cases were desmin negative/alpha-smooth-muscle actin positive emphasizing the variable immunophenotype of myofibroblastic lesions. In addition, 7 of 10 tumors stained at least focally positive for fibronectin. Ultrastructural examination in five cases showed characteristic features of myofibroblasts. Follow-up in 11 patients (median: 29 months) revealed local recurrence in 2 cases, and multiple distant soft-tissue, intraosseous, and pulmonary metastases in one other patient. Low-grade myofibroblastic sarcoma seems to represent a distinct entity in the spectrum of low-grade myofibroblastic neoplasms and is distinguishable from fibromatosis, myofibromatosis, solitary fibrous tumor, fibrosarcoma, and leiomyosarcoma.

MYC High Level Gene Amplification Is a Distinctive Feature of Angiosarcomas after Irradiation or Chronic Lymphedema

Angiosarcomas (AS) are rare vascular malignancies that arise either de novo as primary tumors or secondary to irradiation or chronic lymphedema. The cytogenetics of angiosarcomas are poorly characterized. We applied array-comparative genomic hybridization as a screening method to identify recurrent alterations in 22 cases. Recurrent genetic alterations were identified only in secondary but not in primary AS. The most frequent recurrent alterations were high level amplifications on chromosome 8q24.21 (50%), followed by 10p12.33 (33%) and 5q35.3 (11%). Fluorescence in situ hybridization analysis in 28 primary and 33 secondary angiosarcomas (31 tumors secondary to irradiation, 2 tumors secondary to chronic lymphedema) confirmed high level amplification of MYC on chromosome 8q24.21 as a recurrent genetic alteration found exclusively in 55% of AS secondary to irradiation or chronic lymphedema, but not in primary AS. Amplification of MYC did not predispose to high grade morphology or increased cell turnover. In conclusion, despite their identical morphology, secondary AS are genetically different from primary AS and are characterized by a high frequency of high level amplifications of MYC. This finding may have implications both for the diagnosis and treatment of these tumors.

Molecular variants of fibronectin and laminin: structure, physiological occurrence and histopathological aspects

This review deals with biological and pathological aspects of various isoforms of the matrix molecules fibronectin and laminin. They are generated by different molecular mechanisms: ED-A+ and ED-B+ fibronectin by alternative splicing of pre mRNA, de novo-glycosylated fibronectin by alternative post-translational O-linked glycosylation of the IIICS region, and the laminin isoforms by exchange of single chains of the heterotrimeric molecule. In contrast to the “common” fibronectin, the distribution of ED-B+ and de novo-glycosylated fibronectin is restricted to embryonic tissues; they subsequently reappear in granulation tissue, in fibrosing processes and in tumour stroma. The expression of these so-called oncofetal fibronectins is stimulated by growth factors (TGFβ). The association of the ED-B+ fibronectin with proliferative activity and newly formed vessels identifies this fibronectin variant as a marker of cellular activity in the process of fibrosis and as a suitable agent for the evaluation of tumour angioneogenesis. Initial results suggest a correlation between the amount of ED-B+ and de novo-glycosylated fibronectin in tumour stroma and the behaviour of carcinomas with regard to their invasiveness and propensity for metastatic dissemination. The current nomenclature of the laminin molecule family is presented. The laminin chain constitution of basement membranes switches from embryonic or proliferatively active to adult terminally differentiated tissues [disappearance of the laminin β2 (s) chain] and depends on the tissue type. The discrepancy between the loss of basement membranes (multiple basement membrane defects) in carcinomas and the recently reported increased laminin chain synthesis in these tumours may be explained by abundant laminin chain deposition outside the basement membrane in the carcinoma invasion front, possibly associated with enhanced adhesion of budding tumour cells.

Sclerosing, pseudovascular rhabdomyosarcoma in adults

Abstract Rhabdomyosarcoma in adults represents a rare soft tissue neoplasm which is seen most frequently in its pleomorphic subtype in this age group. Very rarely, clear cell and spindle-cell variants have been reported. In this study we describe three cases of rhabdomyosarcoma in adult patients, characterised by prominent hyaline sclerosis and a pseudovascular growth pattern. All cases were identified in the consultation files of one of the authors and routinely processed. Immunohistochemical studies were performed on paraffin sections with the alkaline phosphatase–antialkaline phophatase method. The patients, two women and one man, were 40, 41, and 56 years old. One developed a deep-seated soft tissue mass in the left lower leg, and one, a tumour of the left upper jaw. In one patient a bone tumour in the proximal body of the sacrum without extension into soft tissues was seen. The patients were treated by wide excision, piecemeal excision and incomplete excision in one case each; additional radiotherapy was performed in all three cases, and chemotherapy in two patients. In one patient multiple pulmonary metastases were noted, which showed progression despite systemic chemotherapy. Histologically, the neoplasms were composed of round/polygonal and spindle-shaped tumour cells including typical rhabdomyoblasts. In all cases a pseudovascular pattern and prominent hyaline sclerosis of the intercellular matrix was seen. Immunohistochemically, tumour cells stained positively for desmin and muscle actin (HHF35) and also for markers of striated muscle differentiation (myogenin, MyoD1, fast myosin). In this paper an unusual morphological variant of rhabdomyosarcoma arising in adult patients is described, which should be added to the morphological spectrum of these neoplasms.

Appearance of the Myofibroblastic Phenotype in Dupuytren’s Disease Is Associated with a Fibronectin, Laminin, Collagen Type IV and Tenascin Extracellular Matrix

The proliferative nodules of Dupuytrens disease are electron microscopically characterized by the occurrence of myofibroblasts with a basal lamina-like material. As reported in the literature, immunohistochemical investigations showed a fibronectin matrix but failed to demonstrate laminin. This discrepancy between electron microscopic features and immunohistochemical findings prompted us to examine the composition of extracellular matrix (fibronectin, laminin, collagen type IV and tenascin) in relation to the myofibroblast phenotype in proliferative nodules from 13 native surgical specimens of nodular palmar fibromatosis (Dupuytrens disease). The immunohistochemical staining for fibronectin was positive within the whole palmar aponeurosis and was particularly intense in the proliferative areas, whereas laminin, collagen type IV and tenascin labelling was restricted to the alpha-smooth muscle actin-positive proliferative nodules. To exclude definitively an unspecific laminin labelling, SDS-PAGE and immunoblot were performed. The electrophoretic pattern of Dupuytrens disease tissue revealed laminin and was in congruence with human placental tissue used as positive control. The results substantiate an extracellular matrix formation by myofibroblasts with fibronectin, laminin, collagen type IV and tenascin as constituents. Therefore, laminin expression can no longer be considered to be a distinguishing feature between myofibroblasts and smooth muscle cells.

TGFβ and bFGF synthesis and localization in Dupuytren's disease (nodular palmar fibromatosis) relative to cellular activity, myofibroblast phenotype and oncofetal variants of fibronectin

SummaryNodular palmar fibromatosis is a self-limited proliferation of fibro-/myofibroblasts associated with growth factor synthesis and abundant fibronectin extracellular matrix deposition. bFGF and TGFβ are potent modulators of fibro-/myofibroblast proliferation and differentiation. Moreover, in vitro investigations evidenced a TGFβ1-dependent regulation of alternative splicing of fibronectin mRNA. To investigate a possible implication of these growth factors in the tissue formation process of palmar fibromatosis, TGFβ1/2 and bFGF synthesis, as well as TGFβ1/3 and bFGF tissue distribution, is demonstrated by RNA in situ hybridization and/or immunohistochemistry in relation to myofibroblast phenotype development (α-smooth muscle actin, desmin immunohistochemistry), expression of different fibronectin isoforms (ED-A+, ED-B+ and oncofetal glycosylated fibronectin immunohistochemistry, fibronectin RNA in situ hybridization) and cellular activity (cyclin RNA in situ hybridization, Ki-67 immunolabelling). The myofibroblast phenotype (α-smooth muscle actin, desmin), the growth factor synthesis (TGFβ1 and 2, bFGF), fibronectin matrix synthesis (RNA in situ hybridization with cDNA) and ED-A+, ED-B+ and oncofetal glycosylated fibronectin immunostaining are exclusively localized in the active proliferative nodules (Ki-67 immunolabelling and cyclin mRNA demonstration). Whereas the growth factor synthesis is restricted to the proliferative areas of the fibromatosis only, TGFβ1, TGFβ3 and bFGF proteins can also be detected immunohistochemically with a lower intensity in the surrounding aponeurotic tissue. The spatial correlation of myofibroblast phenotype, TGFβ and bFGF synthesis and the occurrence of the oncofetal molecular fibronectin variants (ED-B+ and oncofetal glycosylated fibronectin) in the active proliferative fibromatosis nodules suggests a pathogentic role of these growth factors and matrix components in the tumorous tissue formation process. The presence of the bFGF and TGFβ1/3 proteins in fibroblasts neighbouring the proliferative nodules may point to a recruitment of quiescent aponeurotic fibroblasts in the fibromatous tissue formation process.

Cellular composition of the so-called dermatofibroma (Histiocytoma cutis)

9 typical cases of dermatofibroma or histiocytoma cutis resp. were studied by the aid of histochemical, enzyme histochemical and electron microscopical methods to examine the cellular composition of these lesions. The results suggest an anabolic and katabolic function of cells. Electron microscopically a broad spectrum of patterns of mesenchymal cells was found. Besides defined fibroblast-like and histiocyte-like elements a cell type was detected which was characterized by particular traits, as irregularnuclear outline, abundant rough endoplasmic reticulum, free ribosomes, bundles of filaments with single dense zones, micropinocytotic vesicles and a basement membrane-like material on the outer cell surface. This cell type constitutes the majority of cells in dermatofibroma or histiocytoma cutis resp. In some cells an arrangement of filament bundles resembling that in smooth muscle could be seen. By reason of these findings a certain resemblance to the so-called myofibroblasts can be stated. The variegation of the morphological picture suggests a multipotent precursor cell; the possibility of an origin from pericytes is discussed. An Hand 9 typischer Fälle von Dermatofibrom bzw. Histiocytoma cutis wurde mittels histochemischer, enzymhistochemischer und elektronenmikroskopischer Methoden die celluläre Zusammensetzung untersucht. Dabei waren Hinweise auf anabolische und katabolische Eigenschaften der Zellen zu erheben. Elektronenmikroskopisch ergab sich ein breites Spektrum mesenchymaler Zellformen. Neben definierten fibroblasten- und histiocytenähnlichen Zellelementen fand sich eine Zellart, die das morphologische Bild zahlenmäßig beherrschte und die durch besondere Merkmale, wie unregelmäßige Kernformen, reichlich rauhes endoplasmatisches Reticulum, freie Ribosomen, Filamentbündel mit einzelnen Verdichtungsbezirken, Mikropinocytosevesikel und ein basalmembranähnliches Material an der ZellaußenScite charakterisiert war. Gelegentlich konnte eine Anordnung der Faserbündel wie in der glatten Muskulatur nachgewiesen werden. Auf Grund dieser Befunde ist eine gewisse Ähnlichkeit zu sogenannten Myofibroblasten festzustellen. Die Vielgestaltigkeit des morphologischen Bildes weist auf eine multipotente Vorläuferzelle hin; die Möglichkeit, daß es sich dabei um Pericyten handelt, wird diskutiert.