PLAG1 activation in lipoblastoma coinciding with low-level amplification of a derivative chromosome 8 with a deletion del(8)(q13q21.2).

Lipoblastoma is a benign uncommon soft-tissue-tumor resembling fetal adipose tissue affecting mainly children under three years of age. In lipoblastoma, the typical cytogenetic changes are clonal rearrangements involving chromosomal region 8q11-->q13. The oncogene PLAG1 (pleomorphic adenoma gene 1) is located within this chromosomal region on band 8q12. Recent reports have demonstrated that in lipoblastoma, the PLAG1 gene is activated by 'promoter-swapping'. Herein, we demonstrate that in lipoblastoma, the PLAG1 gene may also be activated by low-level amplification. We report on a lipoblastoma with the karyotype 48 approximately 50,XX,del(8)(q13q21.2),+del(8)(q13q21.2)x4[cp12]. Subsequent FISH analysis on uncultured tumor cells confirmed this result and demonstrated a low-level amplification of the chromosomal region 8pter-->8q13 and 8q21.2-->8qter. A partial monosomy was seen for the chromosomal region 8q13-->8q21.2. No other gains or losses were observed by CGH analysis. RT-PCR analysis showed that the PLAG1 gene is activated in the tumor sample of the lipoblastoma analyzed, in contrast to normal fatty tissue without PLAG1 expression. In conclusion, our results demonstrate that low-level amplification is a further mechanism of PLAG1 activation in lipoblastomas.

Pineal epidermoid coinciding with pineocytoma.

Tumours of the pineal region are uncommon. We report on a 62-year-old male presenting with Parinaud's syndrome and aqueduct stenosis caused by a cystic tumour in the pineal region. During surgery, adjacent to the cystic tumour, a second smaller tumour was identified, which was clearly separate from the first tumour and from the pineal gland. Histological examination disclosed the cystic tumour as an epidermoid cyst, whereas the second tumour demonstrated histological and immunohistochemical features of a pineocytoma. The unique finding of two different types of tumours in the pineal region is evaluated with regard to the histogenesis of epidermoid cysts and pineocytomas.

[Unilateral pulmonary vein atresia in early adulthood]. / Unilaterale Pulmonalvenenatresie im frühen Erwachsenenalter.

Unilateral pulmonary vein atresia is a rare condition in adults that may cause serious diagnostic problems because of unspecific clinical findings. A 28-year old female patient is described who presented with signs of recurrent pulmonary embolism with shortness of breathing, unilateral thoracic pain and several episodes of haemoptysis. Ventilation and perfusion scans showed a total lack of perfusion in the right lung with only slight disturbance of ventilation. However, no marked increase of pulmonary artery pressure and no signs of a recent thrombosis of peripheral veins were found. Transoesophageal echocardiography and pulmonary angiography in combination with aortography revealed the diagnosis of unilateral pulmonary vein atresia with abnormal branches of bronchial arteries. There is a considerably left-to-right shunt with return of flow from the bronchial arteries to the right and afterwards to the left pulmonary artery. Clinical, radiological and nuclear medical findings as well as therapeutical options are described.

[Optimization of filtration and lighting parameters in pictures of the hand using digital luminescence radiography]. / Optimierung der Filterung und Belichtungsparameter von Aufnahmen der Hand mit der digitalen Lumineszenzradiographie.

The appearance of digital radiographs were markedly influenced by post-processing. To optimise images of the hand, radiographs of 7 patients with arthritis were modified by various filters. 6 observers evaluated the presence or absence of erosive changes during an ROC study and the advantages of low filtration were demonstrated. Further images were prepared of anatomical preparations in which para-articular defects had been made and of a hand phantom covered in perforated plexiglass. Limited filtration and low enhancement factors again provided the best results. Dose reduction of 50% resulted in a significant deterioration in the ability to recognise erosions and artificial lesions.

Storage phosphor versus screen-film radiography: effect of varying exposure parameters and unsharp mask filtering on the detectability of cortical bone defects.

Diagnostic performance with storage phosphor radiography is influenced by exposure parameters and digital filtering algorithms. The authors compared the detectability of cortical lesions in excised human femoral shafts on state-of-the-art screen-film radiographs and storage phosphor digital radiographs. For the digital system, the effect of varying exposure parameters (photon flux and tube voltage) and unsharp mask filtering (kernel size and enhancement factor) was tested. Analysis of receiver operating characteristics was performed for 10,560 observations made by eight radiologists. Under identical exposure conditions, storage phosphor imaging yielded no significant advantages over conventional screen-film radiography. Although large variations in exposure dose are possible with storage phosphors, the potential for dose reduction was limited even by means of an increase in tube voltage. The performance with unsharp masked images declined with decreasing kernel size and pronounced enhancement.