Imaging of cell trafficking and metastases of paediatric rhabdomyosarcoma.

OBJECTIVE: The aim of this study was to establish a preclinical mouse model to study metastases of paediatric rhabdomyosarcoma at the macroscopic and cellular levels, with different imaging methods. EXPERIMENTAL DESIGN: The alveolar rhabdomyosarcoma cell line Rh30 was stably transfected with the red fluorescent protein (DsRed2) then was xenotransplanted (intravenous injection [n = 8], and footpad injection [n = 8]) into nude mice (NMRI nu/nu). Macroscopic imaging of metastases was performed using DsRed2-fluorescence and flat-panel volumetric computed tomography scan. In a further series of animals (n = 8), in vivo cell trafficking of rhabdomyosarcoma cells using cellular imaging with an Olympus OV100 variable-magnification small-animal imaging system was used. RESULTS: Metastases in the pelvis, thoracic wall and skin were visualized by fluorescence imaging. Pelvic metastases were found after tail vein injection and at other metastatic sites after footpad injection. Flat-panel volumetric computed tomography scan data allowed highly specific analysis of contrast between tumour and surrounding tissue. Correlation between fluorescence and flat-panel volumetric computed tomography scan imaging data was observed. Single-cell imaging visualized tumour cells in the vessels and demonstrated the arrest of tumour cells at vessel junctions followed by extravasation of the tumour cells. CONCLUSION: We established a model for visualization of experimental metastatic invasion and describe relevant tools for imaging childhood rhabdomyosarcoma metastases at the macroscopic and cellular levels. Imaging of cell trafficking visualized the behaviour of tumour cells and development of metastases by accumulation and extravasation of rhabdomyosarcoma cells.

[Bronchioloalveolar carcinoma of the lung associated with a highly positive pANCA-titer and clinical signs of microscopic polyangiitis]. / Bronchioloalveoläres Karzinom der Lunge assoziiert mit einem hochpositiven pANCA-Titer und dem klinischen Bild einer mikroskopischen Polyangiitis.

Autoimmune paraneoplastic processes are investigated in detail concerning the Lambert-Eaton-Myasthenic-Syndrome for bronchial carcinomas. For the cutaneous leukocytoclastic vasculitis as a non-ANCA-associated vasculitis the paraneoplastic genesis is described. Litttle is known about ANCA-associated vasculitis as a paraneoplastic autoimmune phenomenon. We present the case of a 62 year old woman referred to our hospital presenting air-space shadows mainly in both upper lobes, skin rash with petechial bleeding and a highly positive pANCA-titer. A bronchioloalveolar carcinoma was diagnosed by surgical biopsy. The patient developed renal failure postsurgically and died a few weeks after the diagnosis was established. This is the 5 (th) case in literature of the temporal concurrence of a bronchial carcinoma and an ANCA-associated vasculitis. So far only 24 cases of a solid tumor occuring simultaneously with an ANCA-positive vasculitis are reported in literature.