Differentiation of neuroendocrine tumors from other pancreatic lesions by echo-enhanced power Doppler sonography and somatostatin receptor scintigraphy

BACKGROUND AND AIMS

Echo-enhanced power Doppler sonography is a noninvasive procedure that has been increasingly used for the differential diagnosis of pancreatic tumors. However, to our knowledge, the diagnostic accuracy of this procedure in comparison with somatostatin receptor scintigraphy for the differentiation of neuroendocrine lesions from other pancreatic tumors has never been investigated in a prospective, controlled study.

SUBJECTS AND METHODS

One hundred thirty-seven patients were included in the study; the patients were selected from 190 consecutive patients (mean age, 59.8 years; range, 16-85 years) who presented to our department from January 1998 through June 2001 with suspicion of a pancreatic tumor. An experienced examiner who was unaware of the patients' clinical diagnoses performed sonography. Twenty-nine patients with sonographically and/or clinically suspected neuroendocrine tumors were investigated additionally by somatostatin receptor scintigraphy. The exact diagnosis was based upon histologic evidence from biopsy examination (surgical and transabdominal fine-needle biopsy) or a follow-up of at least 18 months.

RESULTS

The sensitivity of echo-enhanced power Doppler sonography for diagnosing a neuroendocrine pancreatic tumor was 94%, and its specificity was 96%. The corresponding values for somatostatin receptor scintigraphy were 54% and 81%, respectively.

CONCLUSIONS

Echo-enhanced power Doppler sonography has high sensitivity and high specificity for the differentiation of neuroendocrine lesions from other pancreatic tumors. However, histologic evidence is the standard of reference for the differential diagnosis of pancreatic tumors.

Differentiation of pancreatic tumours by conventional ultrasound, unenhanced and echo-enhanced power Doppler sonography

BACKGROUND

Echo-enhanced power Doppler sonography (power Doppler sonography after injection of a contrast agent) is a non-invasive and increasingly used procedure for differentiating between pancreatic tumours. However, the diagnostic accuracy of this method compared to conventional ultrasound or unenhanced power Doppler sonography has never been investigated in a large prospective controlled study.

METHODS

137 patients were included in the study, selected from 190 consecutive patients with a mean age of 60 years (range 16-85) who presented at our department in the period January 1998 through June 2001 with clinical suspicion of a pancreatic tumour. Sonography was performed by an experienced examiner blind to the patients' clinical diagnoses. The exact diagnosis was based on histological evidence from biopsy examination (surgical and fine needle biopsy) or on a follow-up of at least 18 months.

RESULTS

Of the 137 patients, 47 had pancreatic cancer; 41 had masses associated with pancreatitis; 17 had neuroendocrine tumours; 12 had cystic lesions of the pancreas; and 10 had other pancreatic diseases. A normal pancreas was found in 10 patients. The sensitivity of echo-enhanced power Doppler sonography with respect to diagnosing pancreatic carcinoma was 87% and its specificity 94%. The corresponding values for chronic pancreatitis were 85% and 99%, respectively.

CONCLUSIONS

Echo-enhanced power Doppler sonography has a high sensitivity and specificity in the differential diagnosis of pancreatic tumours. However, histology is the standard of reference.

[Differential diagnosis of frequent pancreatic tumours with echo-enhanced power-Doppler sonography - presentation of case reports]

The echo-enhanced Power-Doppler sonography is useful for the differential diagnosis of pancreatic tumours. Tumour criteria for the differentiation of pancreatic tumours with this procedure are explained using selected cases in the present publication. Ductal carcinomas are often hypovascularised compared with the surrounding tissue. On the other hand, neuroendocrine tumours are hypervascularised lesions. Tumours associated with pancreatitis have a different vascularisation pattern depending on inflammation and necrosis. Cystadenomas frequently show many vessels along the fibrotic strands.

CONCLUSIONS

Pancreatic tumours have different vascularisation patterns in the echo-enhanced Power-Doppler sonography. These characteristics can be used for the differential diagnosis.

[Pancreatic metastases of renal cell carcinomas - evaluation of the contrast behavior at echo-enhanced power-Doppler sonography in comparison to primary pancreatic tumors]

BACKGROUND

Renal cell carcinomas are the most common primary tumors leading to pancreatic metastases. The differentiation of metastases from primary pancreatic tumors is important for the prognosis. Echo-enhanced power-Doppler sonography may be used for the differential diagnosis of tumors. In this study, the contrast behavior of metastases of renal cell carcinomas was evaluated in comparison to primary pancreatic tumors.

PATIENTS AND METHODS

Each 5 patients with pancreatic metastases of a renal cell carcinoma, a ductal carcinoma, a neuroendocrine tumor and a pancreatitis-associated mass were investigated by B-mode sonography, fundamental and echo-enhanced power-Doppler sonography.

RESULTS

Similar to neuroendocrine tumors, metastases of renal cell carcinomas were found to be hypervascularized. In contrast, ductal carcinomas are hypovascularized compared to the surrounding tissue. Tumors associated with pancreatitis show different vascularization pattern depending on inflammation and necrosis.

CONCLUSIONS

Metastases of renal cell carcinomas and ductal carcinomas show different vascularization pattern at echo-enhanced power-Doppler sonography. Renal cell metastases and neuroendocrine tumors have similar contrast behaviors, therefore, clinical symptoms should be referred for their differentiation. However, histology is the standard of reference for the differential diagnosis of pancreatic tumors.

[Evaluation of doppler ultrasonography criteria for the differential diagnosis of pancreatic tumors]

AIM

In order to improve the differential diagnosis of pancreatic lesions, dopplersonographic criteria for the tumours were evaluated.

METHODS

35 patients diagnosed by conventional ultrasound as having a tumour of pancreas were further investigated by B-mode sonography, fundamental and echo-enhanced power-Doppler sonography focusing on specific properties of the tumours. The results were correlated to the histological findings.

RESULTS

Ductal carcinomas and cystadenocarcinomas are often hypovascularized in comparison to the surrounding tissue. In contrast to this, neuroendocrine tumours and cystadenomas are mostly hypervascularized. Tumours associated with pancreatitis show different vascularization patterns depending on inflammation and the extent of necrosis.

CONCLUSIONS

Pancreatic tumours display different vascularization patterns in the echo-enhanced power-Doppler sonography. These characteristics can be useful for the differential diagnosis of pancreatic tumours.