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The case of a lipomatous tumor with a predominant lipoma component and transition to an atypical lipomatous tumor is presented. A deep-seated soft tissue tumor of the right thigh with a maximum size of 14 cm was resected in a 70-year-old female patient. Corresponding to a comparable macroscopic aspect, the lesion revealed the histological features of an ordinary lipoma without atypia in about 80% of the specimen. In the remaining portion (approximately 20%) histopathology showed an atypical lipomatous tumor (ALT, lipoma-like subtype). Immunohistochemistry for MDM 2 and CDK4 revealed no immunoreactivity in the lipoma component, but within the ALT component. Interphase dual-color fluorescence in situ hybridization showed no amplification of the MDM 2 gene and rarely CDK4 gene amplification within the lipoma component, but high level amplification of MDM 2/CDK4 gene in the ALT area, further supporting the morphologically based diagnosis of a lipomatous tumor including areas of a true lipoma and ALT. This case underlines the concept of a continuous stepwise development of lipomatous soft tissue tumors from benign to malignant counterparts as a biological continuum.

The existence of malignant mesenchymal tumours with myofibroblastic differentiation (myofibroblastic sarcoma, myofibrosarcoma) is controversially discussed. In the present case report a low-grade myofibroblastic sarcoma of the thoracic wall with varying morphological appearance in numerous recurrences over a number of years is described. The varying immunophenotypes of tumour cells with myofibroblastic differentiation suggests that changing of morphological and immunohistochemical phenotypes may occur in tumour cells with myofibroblastic characteristics corresponding to the "plasticity" of the myofibroblast. The classification of soft tissue tumours is based on a discernible line of differentiation. If cells of a malignant mesenchymal tumour show characteristic features of myofibroblasts by light microscopy and immunohistochemistry, this neoplasm should be classified as a myofibroblastic sarcoma, even if the ultrastructural detection of "fibronexus" is not possible.

Breakdown of skin microcirculation is supposed to play a key role in pathophysiology of burn injury. The aim of the study was to develop a burn model, which allows repetitive quantitative in vivo analysis of microcirculation after burn injury with special focus on leukocyte endothelium interaction over a longer period of time. Male hairless mice (SKH-1/hr) were used. Deep partial thickness burns were inflicted in no-touch-technique to the ears. Intravital fluorescent microscopy in combination with FITC-dextran as a plasma-marker was used to assess standard microcirculatory parameters. Leukocytes were stained with rhodamine-6-G to study their interaction with the endothelium.

Adjunct diagnostic techniques might help surgeons to accurately analyse the depth of a burn. However, despite all technical innovations an ideal device for such an application has not been established for routine use as yet. OPS imaging implemented into the CYTOSCAN A/R is a new, recently introduced technique which allows to obtain high contrast images of the microcirculation without the necessity for fluorescent dyes. The aim of the study was to validate OPS imaging as a tool to study microcirculation in skin after burn injury. OPS imaging was applied by no-touch technique and capillary blood flow was videotaped. Subsequent measurements of the microcirculation were performed at the identical site of the burn. Quantitative analysis of the microcirculation was performed off-line using CapImage. OPS imaging produces high quality images of the microcirculation in a burn wound. Data is given as the number of perfused capillaries per observation area (functional capillary density; FCD) [n/cm2]. OPS imaging allows for direct in vivo visualization and quantification of the microcirculation in burned skin. Our preliminary results of the use of OPS imaging in assessing the microcirculation in burns appear promising, and we hope that this novel technique will allow to improve the knowledge of the dynamics of the microcirculation in the pathophysiology of thermal injury.

Exposed irradiated joints are characterized by bone and cartilage necrosis with a chronically infected joint space. The indication for treatment results from possible infection spreading and more often because of severe pain. The usual concept of sequential debridement, joint replacement and regional flap coverage, is often impossible due to the radiodermitis and bone necrosis in the neighbourhood of the joint. Even free flaps are associated with a higher failure rate, because of the irradiation of the recipient vessels long vein grafts are often needed. If regional flap coverage is desired, distant flaps with long, not irradiated pedicles must be chosen. Prevention due to special considerations during the first surgery is essential.

The incidence of burns of the genitalia and peri-anal region which may cause a reconstructive intervention is very low. In the most cases the use of split thickness skin grafts yields a sufficient permanent wound closure. Upcoming problems such as painful scare formation require a reconstructive intervention (Z-plasty, full thickness skin grafting, pedicled flaps etc.). In case that the anal sphincter is involved with the consequence of incontinence or major damage of the genitalia occurred, sophisticated operative solutions are necessary.

The intratesticular tissue oxygen tension (= IT-pO2) depends on the testicular perfusion. Polarographic microcatheter probes have recently become available and are suitable for continuous measurements of the tissue oxygen tension. In 20 adult albino rats flexible Clark-type oxygen electrodes (1.5 F) were used for simultaneous monitoring of IT-pO2 of the ipsi- and contralateral testicle during unilateral torsion. A counterclockwise 720 degrees torsion caused a decrease of IT-pO2 from 21 mm Hg (+/- 5 mm Hg) to 5 mm Hg (+/- 1.5 mm Hg) in the twisted testicle within 5-7 min. After detorsion the IT-pO2 returned to normal level in the following 25 min. The IT-pO2 of the contralateral testicle showed no significant changes during torsion for 1 h or after detorsion. Thus, if the oxygen utilization is unchanged a unilateral acute torsion for 1 h does not cause a decrease in perfusion in the contralateral testicle. It will probably also prove possible to use oxygen tissue tension measurements to improve our understanding of testicular perfusion in humans.