[Intravascular papillary endothelial hyperplasia (IPEH) : Masson's pseudoangiosarcoma on the forefoot]

Intravascular papillary endothelial hyperplasia (IPEH)/Masson's pseudoangiosarcoma is a rare (orphan) disease of the forefoot that has not yet been described in Europe. The pathoanatomic examination of a young patient with a vague interdigital space-consuming lesion revealed a intravascular papillary endothelial hyperplasia/Masson's pseudoangiosarcoma. The intravascular papillary endothelial hyperplasia can be mainly detected in the upper limbs as well as cervically. Heretofore, the intravascular papillary endothelial hyperplasia has only been described in Japan and the USA. For Europe, our case report is the first description of the clinical course of IPEH.

[Tumor of the peroneal compartment]

Degenerative nuclear atypia in mesenchymal neoplasia, especially in benign nerve sheath tumors, may become a pitfall leading to a wrong diagnosis of a sarcoma. Using a case of degenerative (ancient) schwannoma as an example, the characteristic findings of degenerative atypia are presented and discussed.

[Gastric ulcer suspected of being a carcinoma]

Following hepatic penetration by a gastric ulcer a pitfall diagnosis of gastric adenocarcinoma can result from a biopsy of the ulcer base. In cases of suspicious "hepatoid" epithelial cells in a gastric biopsy, the possibility of regular liver tissue from a gastric ulcer penetrating the liver should be kept in mind and verified, e.g. by immunohistochemistry.

[Myositis ossificans traumatica of the palm]

We present a 27-year-old female patient who developed a post-traumatic myositis ossificans with pain and restricted function after trigger finger release of the middle finger. After tumour resection an early recurrence made a re-resection necessary, followed by radiotherapy. Three years postoperatively the patient is free of complaints.

[Atypical lipomatous tumors of the stomach. Clinical, morphological and molecular findings]

Two cases of primary gastric atypical lipomatous tumors (ALT) are presented. In case No.1, a 7x4x3 cm submucosal ALT (lipoma-like subtype) of the antrum/pyloric region in a 60-year-old woman was completely resected. Using interphase dual-color-FISH, MDM2- and CDK4 amplifications could be detected in distinguished amplicons. The patient was continuously free of disease after 56 months. In case No. 2, a 3.5 cm (in diameter) submucosal ALT (lipoma-like subtype) of the gastric body in a 56-year-old woman was completely resected. FISH revealed MDM2 amplification while the CDK4 gene remained in diploid copies. This patient was continuously free of disease after 36 months. The morphologic and molecular biological findings of this rare primary gastric mesenchymal tumor are discussed in comparison with the corresponding soft tissue lesions.

[Cystic desmoplastic small round cell tumor: tumor development from cystic-"mesothelioblastic" areas?]

A 7-cm cystic lesion in the upper left abdomen and additional smaller solid tumor nodules were diagnosed incidentally in a 15-year-old boy without tumor symptoms. The main tumorous cystic lesion showed a flattened single-cell tumor cell component in gradual transition to stratified, papillary and truly "invasive" typical desmoplastic areas of a desmoplastic small round-cell tumor (DSRCT). The Ki-67-proliferation index gradually increased within three histologic tumor patterns up to about 70% in the typical desmoplastic (infiltrating) component. Using microdissection techniques, EWS-WT1-gene fusion transcripts were detected in the cystic (single-cell-layered), the papillary and the solid tumor proliferations (exon 7 of EWS on chromosome 22 with exon 8 of WT1 on chromosome 11). The presented case illustrates a predominant cystic growth pattern of DSRCT, in which a stepwise development in the pathogenesis of DSRCT from cystic (-"mesothelioblastic") towards a more papillary proliferation and finally typical "infiltrative" desmoplastic tumor pattern might be discussed. The cystic pattern could represent an initial stage in the development of the neoplasia. The presence of specific EWS-WT1-gene fusion transcripts in all tumor growth patterns in this respect would indicate an early event in t(11;22)(p13;q12) translocation in the pathogenesis of DSRCT.

Lymph node metastases in soft tissue sarcomas: a single center analysis of 1,597 patients

PURPOSE

The aim of this study was to examine the clinical course of patients with the rare finding of regional lymph node metastasis (RLNM) from soft tissue sarcoma.

MATERIALS AND METHODS

Data from 28 out of 1,597 consecutive soft tissue sarcoma patients with RLNM were from the patients' charts and interviewing patients and general practitioners. Survival, including possible influencing factors, was statistically calculated.

RESULTS

RLNM was seen in 21.4% for epithelioid sarcoma and 17.6% for clear cell sarcoma. All other entities presented RLNM rates below 10%. At follow-up after an average of 9.6 years, only three patients were alive with no evidence of disease. Survival was independent from surgical resection status of the primary tumor and the RLNM as well as from adjuvant radiation and chemotherapy. Tumor entity as well as the length of the time period from primary to RLNM affect survival.

CONCLUSIONS

Surgical treatment as well as radiation and chemotherapy may improve survival in selected cases but probably have their value much more in terms of local disease control and improvement life quality of patients who probably already suffer from an aggressive systemic disease at time of nodal involvement.

[Low-dose CT-guided transthoracic lung biopsy for evaluation of non-infectious chronic interstitial lung disease in children]

BACKGROUND

Children with interstitial pneumonitis (IP) of unknown origin often have to undergo open lung biopsy to establish a final diagnosis. Open lung biopsy is an invasive procedure with major potential complications. In the meantime, CT-guided transthoracic lung biopsy (TLB) has become a common diagnostic procedure in adults.

OBJECTIVE

The aim of this study was to retrospectively evaluate the efficacy and radiation exposure of low-dose CT-guided TLB in children with non-infectious IP of unknown origin.

METHODS

Twelve children (7-males, age range: 7 months-15 years) with non-infectious IP of unknown origin and inconclusive clinical tests underwent CT-guided TLB with a 20-gauge biopsy instrument. A low-dose protocol with acquisition of single slices was used on a 16-row CT scanner: 80 kVp, 20 mAs, slice thickness 10 mm. Biopsy specimens were processed by standard histopathological and immunohistochemical techniques and effective doses were individually calculated.

RESULTS

All biopsies were performed without major complications. Two children (17 %) developed a small pneumothorax/pulmonary haemorrhage that resolved spontaneously. A final diagnosis could be established in 9/12 patients (75 %) by CT-guided TLB. In 2 patients (17 %) the results of TLB were inconclusive; however, the clinical suspicion could be disproved. Open lung biopsy was performed in 1 patient (8 %), which demonstrated idiopathic pulmonary fibrosis. On average, the effective dose of CT-guided TLB was 0.78 mSv (0.4 - 1.1 mSv).

CONCLUSION

Low-dose CT-guided TLB can be a helpful method for investigating children with non-infectious IP of unknown origin thus making open lung biopsy unnecessary. Application of a low-dose protocol leads to a significant reduction of radiation exposure in CT-guided TLB.

[Aneurysmal bone cysts. First description of the extensive destruction of the upper cervical spine]

Aneurysmal bone cysts are not counted among the classic malignant tumors, although they are destructive locally as blood filled reactive bone lesions. Typically, they are found in the metaphysis of the long bones, while localizations on the spine are rare. A 16-year-old female patient presented with unspecific, progressive neck pain which had been present for half a year. The initial x-ray showed no noticeable pathology whatsoever. Subsequently, the complete destruction of the first cervical vertebrae was found. The tumor had completely infiltrated and completely surrounded the spinal chord. A combined approach was used as therapy: resection of the dorsal tumor portion with occipitocervical spondylodesis (C0-C4) and postoperative radiation of the remaining ventral portions. Currently, the patient is free of complaints and recurrence. The differential diagnosis of an aneurysmal bone cyst should also be considered in cases of unspecific cervical vertebral complaints in adolescents that are not otherwise explainable.

Metachronous bilateral soft tissue sarcoma of the extremities

BACKGROUND AND AIMS

Synchronous and heterochronous multiple soft tissue sarcoma of the extremities is very rare. Out of 1,201 of our patients, 4 patients presented with symmetrical bilateral soft tissue sarcoma of the extremities. The aim of this study was to identify possible reasons for this unusual manifestation of sarcomas.

MATERIALS AND METHODS

The patients' data was acquired by review of the patients' charts and follow-up information was gathered by phone calls to the patients or their relatives and their general practitioners.

RESULTS

All tumours were located at the extremities and were diagnosed as leiomyosarcoma in two patients, malignant fibrous histiocytoma and clear cell sarcoma in one patient each. No other individual or family history of cumulation of neoplasms was known in the patients. The median interval between the diagnoses was 3 1/2 years (range: 4 months to 9 1/2 years). In two patients a second primary sarcoma of the same entity was considered the most likely diagnosis, whereas in one patient a contralateral lymph node metastasis and in one other patient an atypical soft tissue metastasis had to be taken into account. A positive family history with a father with malignant fibrous histiocytoma may indicate a hereditary predisposition in one patient. Aside from irradiation effects, exposition to other carcinogenic agents or genetic predisposition, the reasons for the clustering of soft tissue sarcoma in one same patient remain still unclear. Only one patient, although suffering from disseminated metastatic disease was living at follow-up time, the other three patients had already died.

CONCLUSION

The interpretation of the bilateral manifestation of soft tissue sarcoma remains open, but predicts an unfavourable outcome.

[Epithelioid hemangioendothelioma of the lung (IVBAT)--clinicopathological and immunohistochemical analysis of 11 cases]

Epithelioid hemangioendothelioma (EHE) of the lungs (syn.: intravascular bronchioloalveolar tumor/IVBAT) is a neoplasm with a vascular line of differentiation. This study provides a clinicopathological analysis of 11 cases of this tumor. There were 7 female and 4 male patients. Patients' age ranged from 33 to 83 years (mean: 49.8, median: 48 years) showing 2 peaks (third/fourth and sixth/eighth decades). The typical radiological appearance revealed multiple bilateral lung nodules from 0.5 to 2 cm. In 2 cases, a striking perivascular and intravascular growth pattern associated to pulmonary veins was evident. All tumors were characterized by epithelioid tumor cells with nests, cords and strands embedded in a sclerosing, hyaline matrix with alveolar, bronchiolar and vascular extension. Necrosis was identified in 8 tumors and ossification in 2 tumors. The mitotic index was below one mitosis in 10 HPF. By immunohistochemistry, all tumors were positive for CD 31, CD 34, and vimentin, 60% positive for factor VIII, and negative for pancytokeratin and calretinin. Follow-up was available for 8 patients with a range of 6 to 105 months (mean: 51.5 months, median: 52 months): 3 patients died (2 certainly from their tumors), 4 are alive disease-free, and one is alive with metastases. EHE of the lungs (IVBAT) represents an intermediate-grade, malignant, mesenchymal neoplasm with a characteristic histological appearance and immunohistochemical profile.

Analysis of biodegradation of copolymer dermis substitutes in the dorsal skinfold chamber of balb/c mice

PEGT/PBT-block-copolymer dermis substitutes were inserted into dorsal skinfold chambers of balb/c mice (n=36). Scaffolding matrices with 3 different pore diameters (pore diameter: <75 micro m, 75-212 micro m and 250-300 micro m) were analyzed on days 7, 14, and 21 post implantation by scanning electron and light microscopy. The quantification of matrix fragmentation was performed using image-analytical software analySIS(R). The fragmentation rate in scaffolding matrices with a pore size of < 75 micro m was observed to be higher than in matrices of larger pore sizes. Image-analytical evaluation over 21 days revealed a reduction of the copolymer matrix by approximately 32% for the <75 micro m matrices, 23% for the 75-212 micro m matrices and 18% for the matrices, where pore size ranged between 250 micro m and 300 micro m. Twenty-one days after implantation, the matrix pores of 75-212 micro m and 250-300 micro m scaffolds were totally filled by vascularized fibrous tissue. Contrarily, an increased formation of foreign-body giant cells was observed in matrices with pore size <75 micro m. The pore size of the scaffolding PEGT/PBT dermis substitutes affects their degradative behaviour in vivo.

Spindelzelliges desmoplastisches Melanom

Desmoplastic neurotropic melanoma is an exceedingly rare variant of the malignant melanomas. Since the initial description, only about 500 cases have been reported in the literature. These melanomas mostly occur on the head, neck, and face, and a wide local excision of the tumor is probably the most important prognostic factor. Therefore, in most cases the tumor resections result in large tissue defects. To gain a good cosmetic result, tissue movement using flaps or grafts will most likely be required to cover the defect. In this paper, a 79-year-old patient with a basal cell carcinoma and desmoplastic melanoma on the scalp is described, and the therapeutic procedure is discussed.

Absolute beta-catenin concentrations in Wnt pathway-stimulated and non-stimulated cells

The intracellular level of the proto-oncoprotein beta-catenin is a parameter for the activity of the Wnt pathway, which has been linked to carcinogenesis. The paper introduces a novel sandwich-based ELISA for the determination of the beta-catenin concentration in lysates from cells or tissues. The advantages of the method were proven by determining beta-catenin levels in cell lines and in cells after activation of the Wnt pathway. Analysis revealed high beta-catenin concentrations in the cell lines HeLa, KB, HT1080, MCF-7, U-87 and U-373, which had not been described before. Beta-catenin concentrations were compared in HEK293 and C57MG cells after activation of the Wnt pathway. The beta-catenin concentrations increased by different factors depending on whether the Wnt pathway was activated by incubation with LiCl or with Wnt-3a-conditioned medium. This finding indicated that the beta-catenin level depends on the way and level of Wnt pathway activation. The quantitative analysis of beta-catenin in colorectal tumours revealed high beta-catenin levels in tumours with truncating mutations in the APC gene.

EGFR-Expression in pulmonalen neuroendokrinen Zellhyperplasien

15 cases of pulmonary neuroendocrine cell hyperplasia (carcinoid-tumorlets, diffuse idiopathic pulmonary neuroendocrine cell hyperplasia/DIPNECH) and 20 neuroendocrine pulmonary tumors (10 carcinoid tumors, 5 large cell neuroendocrine, and 5 small cell neuroendocrine lung carcinomas) were immunohistochemically analyzed for the expression of epidermal growth factor receptor (EGFR, = HER-1). All cases of neuroendocrine cell hyperplasia exhibited a maximum EGFR expression (score 3 in 100% of cells) showing predominantly membranous, partly cytoplasmic staining. 4 ot the 10 carcinoid tumors were strongly positive for EGFR, whereas the other 6 were EGFR-negative. A total of 90% of large cell neuroendocrine and small cell neuroendocrine carcinomas were negative for EGFR. Overexpression of EGFR in pulmonary neuroendocrine cell hyperplasia might be significant for the pathogenesis of these lesions. As DIPNECH is characterized by clinical signs and symptoms including mild cough and obstructive functional impairment, a specific antagonistic therapeutic trial could aim at blocking EGFR/HER-1 or its subsequent signal transduction pathway.

[Myoepithelioma of soft tissue -- case report with clinicopathologic, ultrastructural, and cytogenetic findings]

The case of a soft tissue myoepithelioma is presented including clinicopathologic, ultrastructural, and genetic findings. A 30-year-old male patient suffered from a soft tissue tumor within the deep soft tissues of the right lower leg measuring 13.2 x 8.2 x 9 cm. Histologically, the lesion was diagnosed as a myoepithelioma displaying a lobulated architecture with cords and nests of epithelioid and spindle cells without cytologic atypia lying within a fibromyxoid and partly chondroid matrix; immunohistochemistry was positive for pancytokeratin, S100-protein, calponin and partly for GFAP and EMA. Ultrastructural analysis revealed glycogen deposits and cell-membrane-associated plaque structures, whereas true myofilaments could not be identified (with immunohistochemistry being negative for actin). Using comparative genomic hybridization (CGH), a gain of chromosome Y was detected. A loss on 17p could not be detected unambiguously. However, based on the low resolution of CGH a small loss cannot be excluded. The patient was free of disease 25 months following complete tumor resection. Myoepitheliomas/mixed tumors of deep soft tissue represent rare soft tissue lesions that may reach a considerable size and may mimic other soft tissue tumors or sarcomas. Based on a local relapse rate of approximately 20% according to the literature, a complete resection with thorough follow-up should be recommended.

[Pigmented villonodular synovitis of the knee joint]

Pigmented villonodular synovitis is a rare proliferative disorder of the synovial membrane most frequently found in the knee. The etiopathology of the disease is still not understood. Present terminology differentiates between a localized (LPVNS) and a diffuse (DPVNS) form. Currently, MRI is the diagnostic imaging technique of choice. The localized form (LPVNS) can be cured definitely in almost all cases by partial arthroscopic synovectomy, whereas the treatment of the diffuse form (DPVNS) is discussed controversially concerning an arthroscopic or total synovectomy by open arthrotomy. We report a case rarely found in the literature of a patient suffering from a diffuse form of PVNS localized in the right knee joint. In this case PVNS acted as a locally aggressive and destructive lesion of immense extent invading femoral, tibial and fibular bone and the whole extending muscular system. We performed a radical synovectomy by open arthrotomy. By implanting a tumor prosthesis we prevented progression of the disease. Apart from adequate diagnosis, we recommend complete and aggressive resection of the affected tissue by performing an open arthrotomy.

[Serious complications of injections--retrospective analysis of incidences, complication-management, prophylaxis and economic aspects]

The parenteral drug application is a routinely used method in all medical disciplines. Intramuscular, intraarticular, intravenous injections and infusions can cause local complications such as abscesses, articular infections or paravasates. These local complications can lead to bacteraemia, sepsis and may lead to multiple organ failure associated with high morbidity and mortality. Although these complications are rare, they are sometimes disastrous and result in life threatening clinical conditions. During a retrospective analysis (review period 1998-2002) 24 patients were admitted and hospitalized in our department. Within this report we demonstrate 7 patients with fatal complications after injections. In the majority of cases minor patients' complaints were proceeding before major complications were present. A long and expensive treatment period with multiple surgical interventions ends up in functional disabilities and unsatisfactory aesthetic results. Instead of delayed surgical treatment immediate radical surgical care is crucial to prevent disastrous complications. In case of the inability of sufficient debridement, amputations are sometimes indicated in the sense of "life before limb". Besides the consequences for the patient these disastrous complications have a high socioeconomic impact and result in reduced reimbursement for the hospital stay.

[liposarcoma. Aspects of pathomorphology--an analysis of 209 tumos]

BACKGROUND

Among the heterogeneous group of adult soft tissue sarcomas, liposarcomas represent the largest entity along with malignant fibrous histiocytomas (MFH).

PATIENTS AND METHODS

This article summarizes the results of pathomorphological data on 209 liposarcomas resected over a 10-year period.

RESULTS

The most common tumor site was the thigh, and the peak age incidence was in the 5th and 6th decades. In general, three major subtypes of liposarcoma can be distinguished in terms of pathomorphology: well-differentiated/dedifferentiated liposarcoma, myxoid/round cell liposarcoma, and pleomorphic liposarcoma. Well-differentiated liposarcomas represent malignancy grade 1 tumors without biological potential to metastasize, but which are able to relapse locally in cases of incomplete resection. When a local relapse has occurred, the liposarcoma may show dedifferentiation and may metastasize.

CONCLUSIONS

In the pathologic-anatomical diagnosis of liposarcomas, conventional light-microscopic findings are decisive. Additional methods of molecular pathology may help in single cases to gain further insights.

[Liposarcoma of the extremities: recent developments in surgical therapy--analysis of 167 patients]

Liposarcoma is the second most common malignant soft-tissue tumor in adults. Between 1991 and 2002, 167 patients with extremity liposarcomas were treated in our center. Fifty tumors were classified as G1 liposarcomas (30%), 76 as G2 liposarcomas (45.5%), and 41 as G3 liposarcomas (24.5%). In 158 patients, (93.5%) wide tumor excision was performed. Major amputation was necessary in five patients. After a median follow-up of 36 months, 37 patients had developed local recurrence. The 5-year overall survival rate was 79%. The 5-year survival rate in primary tumors was 71/79 (90%, P<0.05) whereas 61/88 of recurrences relapsed locally (69%, P<0.05). Multidisciplinary cooperation in a tumor board is a precondition for adequate treatment.

[Therapy-induced tumor regression in adult soft tissue sarcomas-morphological findings]

Morphological findings of 21 soft tissue sarcomas of adulthood following preoperative chemo- and/or radiotherapy including perfusion therapy and resection are presented. The therapy-induced changes included a spectrum ranging from total tumor regression up to still completely vital tumor (median of all cases: 30% vital tumor tissue). 7 of 21 sarcomas (33%) were evaluated as responders (grade I-III). So-called malignant fibrous histiocytoma (MFH) revealed a good tumor response to preoperatively administered therapy (regression grades I and II). Myxoid/round-cell liposarcoma exhibited regression grades of IV-V (i.e. 30% up to 95% vital tumor tissue, non-responders). Synovial sarcoma was characterized by regression grades III up to VI (i.e. up to 100% vital tumor tissue without any signs of regression, 83% non-responders). Completely vital tumor was evident in 2 synovial sarcomas despite preoperative tumor therapy. These findings hint towards differences in response of distinct sarcoma entities to preoperative chemo-/radiotherapy. A grading of therapy-induced tumor regression in adult soft tissue sarcomas may best refer to already established grading schemes (e.g. according to the grading scheme for osteosarcomas following chemotherapy of Salzer-Kuntschik). A report of sarcoma resection specimens should include the percentage of vital tumor tissue.

Desmoidfibromatosen (aggressive Fibromatosen)

Desmoid-type fibromatoses (aggressive fibromatoses) represent infiltrative, locally destructively growing soft tissue tumors with a high potential for recurrence. Desmoid tumors of 33 adult patients were analysed regarding clinical and morphological aspects (sex, age distribution, site, size, mitotic rate, tumor microvessel density, surgical margins, additional radiotherapy). Possible statistical correlations were examined using log-rank-tests. No prognostic significance of tumor microvessel density was evident. A correlation between mitotic index (1 or more mitoses per 50 high power fields) and local relapse rate was notably striking, but not statistically significant (log-rank: 0.17). Additional postoperatively applied radiotherapy proved to be statistically significant to avoid local recurrences (log-rank: 0.01). The presented results may indicate an increased risk for local relapse in those desmoid-type fibromatoses which are mitotically active. Postoperative radiotherapy seems to be effective in the treatment of aggressive fibromatosis to avoid tumor recurrence. Differential diagnosis of desmoid-type fibromatosis/aggressive fibromatosis in adulthood include various fibroblastic/myofibroblastic soft tissue tumors such as nodular fasciitis, fibrosarcoma, low-grade fibromyxoid sarcoma, myofibroblastic sarcoma as well as leiomyosarcoma and soft tissue leiomyoma.

Tenosynovialer Riesenzelltumor

Morphological, ultrastructural, and immunohistochemical findings of 12 diffuse type-tenosynovial giant cell tumors/pigmented villonodular synovitis are presented compared to 30 localized tenosynovial giant cell tumors (giant cell tumor of tendon sheath). Diffuse-type-tenosynovial giant cell tumor is characterized by a striking vascularisation pattern composed of densely arranged thin-walled, partly slit-like and partly hyalinized small blood vessels within the papillary synovial fronds. These vessels may show abnormal structures with incompletely arranged endothelial cells/pericytes. The fibrohistiocytic tumor cells probably cause considerable compression/distortion or destruction of the small vessels which might be responsible for an increased blood deposition and massive hemosiderosis. Accompanying multinucleated osteoclast-like giant cells seemingly are recruited from circulating blood monocytes. Microhemorrhagic foci with multinucleated giant cells could be detected in 83% of diffuse-type and 67% of localized-type tumors. Apart from the described vessels, typical morphological findings in diffuse-type tenosynovial giant cell tumors included "giant" hemosiderotic granules, (at least 2-3 times the diameter of an erythrocyte) "giant" siderophages, pseudoalveolar clefts and irregularly anastomosing synovial fronds. Neither mitotic rate nor the amount of giant cells/amount of nuclei of giant cells revealed statistically significant differences between localized-type and diffuse-type of tenosynovial giant cell tumor. Immunohistochemically, the diffuse-type exhibited focal expression of CD31 (in 75% of tumors) and calretinin (in 63%) besides CD68-staining.

New model for in vivo investigation after microvascular breakdown in burns: use of intravital fluorescent microscopy

BACKGROUND

The breakdown of skin microcirculation is assumed to play a key role in the pathophysiology after burn injury. The aim of the present study was to develop a burn model, which allows repetitive quantitative in vivo analysis of the microcirculation after a burn injury, focusing on the interaction between leukocytes and the endothelium.

MATERIALS AND METHODS

Experiments were carried out on male hairless mice. Deep partial thickness burns were inflicted with a no-touch-technique to the ears. Intravital fluorescent microscopy in combination with FITC-dextran as a plasma marker was used to assess microcirculatory parameters. Leukocytes were stained with rhodamine 6G. Preburn baseline data was obtained before as well as 1, 3, 7 and 14 days subsequent to the burn injury.

RESULTS

The non-perfused area decreased significantly over the observed period and perfusion was almost completely restored at day 14. The functional vessel density was characterized by reduction of perfused vessels immediately after burn and an increase after 24h. Leukocyte endothelium interaction significantly increased immediately after injury; baseline values were reached 1 day later. The extravasation of the plasma marker into the surrounding tissue increased immediately after burn, decreased at day 1 and remained at this level during the following observation time. The venular as well as the arterial blood flow increased immediately subsequent to the burn injury, decreased after 1 day and reached baseline values at day 3.

CONCLUSION

The presented burn model allows quantitative assessment of the dynamics of microcirculatory disturbances after thermal trauma by high quality visualization of both plasma stained microvessels and leukocyte-endothelium interaction.

[Comparison of chromosomal defects in primary tumor and metastases by comparative genomic hybridization (CGH)]

Molecular methods can complement the classical methods in pathology like macroscopic, histological and immunohistochemical examinations.Comparative genomic hybridization is a cytogenetic method to screen for gains and losses of chromosomal material in tumor cells. This method allows defect studies of archival paraffin-embedded and formalin-fixed tumor material. CGH can detect gains and losses of chromosomal material that are at least 10 to 20 megabases in size. This genome-wide screening method allows to study the cytogenetic relationship between differently located tumors of a patient. To answer the question if these different tumors are metastases of the primary lung tumor or independent primary tumors CGH analysis is a supplementary method that introduces new prospectives.

[Misdiagnosis of a Leiomyosarcoma of the inferior vena cava as a renal cell carcinoma]

Leiomyosarcoma of the vena cava inferior (VCI) is a rare mesenchymal malignant tumor of the retroperitoneum. About 200 cases have been described in the literature so far. Leiomyosarcomas may resemble other tumors including renal cell carcinoma, adrenal carcinoma, and hepatic adenoma. Thus, misinterpretation of a leiomyosarcoma of the VCI is a common problem. We present a 71-year-old female with a large subhepatic, retroperitoneal tumorous mass which was diagnosed to be a renal cell carcinoma by sonography and computed tomography. After application of magnetic resonance imaging and retrospective analysis of the CT scan, diagnosis could be revised. Laparotomy and en bloc resection of the tumor was performed; histopathological examination confirmed a leiomyosarcoma of the VCI. The postoperative course was unremarkable. Leiomyosarcoma of the VCI may resemble advanced stages of renal cell carcinoma. High-resolution imaging modalities (computed tomography, magnetic resonance imaging) are able to precisely evaluate the typical imaging characteristics of leiomyosarcomas, thus determining correct diagnosis in affected patients. This is essential for successful operative therapy.

[Myofibroblastic sarcoma of the thoracic wall. Change in appearance in tumour recurrence]

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.

[Solitary plasmacytoma of the shoulder. Diagnosis and therapeutic methods]

5% of all multiple myelomas manifest as solitary plasmocytomas. The multiple myeloma is the most frequent malignant transformation of the haematopoetic system, with an incidence of 2:100,000 per year. 1% of all solitary plasmocytomas are found in the extremities, accounting for less than one case per year in Germany. In this article we present the case of a fifty year old patient with a solitary plasmocytoma of the shoulder region and discuss the diagnostic and therapeutic procedures involved.

[Retrogastral located gastrointestinal stromal tumor (GIST) as a sonographically detected rare incidental finding]

Gastrointestinal stromal tumors (GIST) represent compared to carcinomas a rare group of neoplasias of the gastro-intestinal tract of unclear dignity. We report the example of a patient suffering from a big retrogastral located gastrointestinal stromal tumor which had been detected as an incidental finding without previous complaints. Because origin and dignity of the process could not definitely be diagnosed, total resection (R0-resection) without systemic lymphadenectomy of the process measuring 11.5 cm x 11 cm x 7 cm was performed. Mitotic activity and tumor-size are regarded as predictive factors of potenzial malignancy of GISTs. In general tumors with low mitotic activity of up to 5 mitoses per 50 high power fields (HPFs) and a diameter smaller than 5 cm are regarded as benign. In the presented case, up to 4 mitoses per 50 HPFs could be detected and thus, in connection with tumor-size, an uncertain biological behaviour of the process has to be expected. Since no generally accepted consensus on the treatment of the GISTs exists, also patients originally suffering from tumors regarded as borderline-malignant should undergo a close-meshed follow-up in regular intervals.

Osteoid osteoma that occurred in a former fracture site

Diagnosis of osteoid osteoma often is delayed, despite its high incidence, because of similarities in presenting symptoms with other pathologic entities. The current case report describes a posttraumatic osteoid osteoma. Three years after osteosynthesis of a distal tibial fracture an osteoid osteoma was diagnosed at the former fracture site. After excluding osteomyelitis as a possible diagnosis, the tumor was excised successfully. Based on current knowledge of the pathogenesis of osteoid osteoma, it is unlikely that the lesion observed in the patient was attributable to the previous fracture.

[Etiology, clinical aspects and therapy of penoscrotal lymphedema]

Penoscrotal lymphedema has serious functional, cosmetic, psychological and potentially malignant consequences. In contrast to the relatively common occurrence of this disease in areas with endemic filariasis, the incidence in the rest of the world is almost exclusively due to therapeutic sequelae of other illnesses or as congenital entities. As conservative forms of treatment have proved to be inefficient, we discuss different surgical options based on the treatment of 12 patients seen in our clinic. Only the complete excision of the edematous and fibrotic tissues, together with reconstructive methods using local flaps and skin grafts, can guarantee a definitive solution, irrespective of the etiology. A detailed anatomical knowledge of the regional lymphatic drainage pathways allows safe operative treatment. Despite the rarity of this disease, a number of different surgical procedures have been reported in the literature that are compared with the findings in our patients.