Endosonographische Morphologiekriterien nicht-funktioneller pankreatischer neuroendokriner Tumoren (pNET). Evaluation des endosonographischen Nachweises neuroendokriner Tumoren des Pankreas im Vergleich zu anderen bildgebenden Verfahren

Between September 2002 and August 2007 38 patients with MEN1-Syndrome as well as 13 Patients without MEN1-Syndrome but with neuroendocrine tumours of the pancreas where collected and recorded. The intention was to find endosonographic morphology-pattern to describe and later identify these tumours. Furthermore, the results of the endosonographic examinations were compared with corresponding diagnostic methods, such as computed tomography, magnetic resonance tomography and szintigraphy. The question behind was: Does endosonographic ultrasound detect small pancreatic tumours earlier than other diagnostic methods? And how big are these missed tumours? In this study, 415 tumours were detected endosonographically in association with MEN1. 339 were smaller than 1 cm (82 %). They had an average size of 7,2 mm. The pattern of morphology which occurred with the highest rate of 1/3 (33 %) was “sharp-margin, round and oval, low-echogenicity, homogenous and low-hyperperfusion”. The group of patients without MEN1-Syndrome showed a higher variation in tumour size than the MEN1 patients. The average size 17,7 mm, which was about double the size of the MEN1-tumours. 18 out of 39 lesions were smaller than 1 cm (46 %). In this group of patients, the most frequent patterns of morphology (22 % each) were “sharp-margin, round and oval, low-echogenicity, heterogenous and moderate-hyperperfusion” as well as “diffuse-margin, round and oval, low-echogenicity and high hyperperfusion”. It could be shown that in comparison, endosonographic ultrasound may detect lesions, which are not found by other diagnostic methods. In association with the group of MEN1-patients cross sectional imaging (CT, MRI) was not able to detect lesions in 74 % of examinations, whereas endosonographic ultrasound could describe a tumour. In 15 % of cases, lesions were described but their amount was not the same as described in endosonographic ultrasound. Only in 10 % the descriptions correlated. Only in one case cross sectional imaging described a lesion which was not found by endosonographic ultrasound. This was due to difficult circumstances and could be corrected in later examinations. Similarly was the comparison between endosonographic ultrasound and szintigraphy. In 21 % of recorded cases szintigraphy described a corresponding lesion in the pancreas. No specific accumulation was seen in 79 %. Within the group of patients without MEN1-Syndrome similar results appeared. CT and MRI could not detect lesions in 52 % of cases. In 3,7 % less lesions were described than by endosonographic ultrasound. In 44 % the number of described lesions matched. Cross sectional imaging missed 172 lesions during 60 examinations within the group of MEN1-patients. The average size of these lesions was 6,6 mm. 210 lesions were not described in 64 szintigraphy examinations, with an average size of 6,6 mm. 14 cross sectional imaging examinations of Non-MEN1 patients missed 20 out of 39 lesions with an average size of 10,2 mm. The 12 lesions, not detected by 9 szintigraphy examinations, measured 14,2 mm in average. Endosonography gives the possibility to demonstrate lesions of the pancreas, which are missed by other diagnostic methods. The results show, endosonographic ultrasound may detect non-functional neuroendocrine tumours of the pancreas in an early state of growth, which may allow an early intervention. Thus it is a helpful tool to diagnose these tumours and create a sufficient therapy plan.