Echo-enhanced ultrasound with pulse inversion imaging: A new imaging modality for the differentiation of cystic pancreatic tumours

AIM： To describe and discuss echo-enhanced sonography in the differential diagnosis of cystic pancreatic lesions. METHODS： The pulse inversion technique （with intravenous injection of 2.4 mL SonoVue） or the power-Doppler mode under the conditions of the 2^nd harmonic imaging （with intravenous injection of 4 g Levovist） was used for echo-enhanced sonography. RESULTS： Cystadenomas frequently showed many vessels along fibrotic strands. On the other hand, cystadenocarcinomas were poorly and chaotically vascularized. ＂Young pseudocysts＂ were frequently found to have a highly vascularised wall. However, the wall of the ＂old pseudocysts＂ was poorly vascularized. Data from prospective studies demonstrated that based on these imaging criteria the sensitivities and specificities of echoenhanced sonography in the differentiation of cystic pancreatic masses were 〉 90%. CONCLUSION： Cystic pancreatic masses have a different vascularization pattern at echo-enhanced sonography. These characteristics are useful for their differential diagnosis, but histology is still the gold standard.

SOLID CYSTIC PAPILLARY TUMOR OF PANCREAS IN EIGHT CHILDREN

Objective To estimate the clinical and pathological features of pancreatic solid cystic papillary tumor (SCPT) in children. Methods From 2000 to 2005, 8 cases with SCPT of the pancreas were analyzed retrospectively. All cases but one were females. Average age was 12.8 years. By case review, we discussed the clinical and pathological features of SCPT in children. Results The chief complains were abdominal pain and palpable mass. There were 3 cases in the head, 1 case in the body, and 4 cases in the tail of pancreas. The procedures employed included local resection (1 case), distal pancreatectomy (5 cases), pancreaticoduodenectomy (1 case), and biopsy (1 case). Histological examination showed solid with cystic areas and papillary protrusions in the 8 cases; as for immunohistochemical examinations, the positive rate was 100% for α-antitrypsin (AACT), 87.5% for vinmentin, and 62.5% for neuron-specific enolase (NSE). The patients were followed up for 2 months to 4 years but one was lost by follow-up and all were alive postoperatively. SCPT in 2 cases relapsed. Conclusion Occurring predominantly in young females, SCPT is usually curable by surgical resection with a favorable prognosis.

Rupture of small cystic pancreatic neuroendocrine tumor with many microtumors

Pancreatic neuroendocrine tumors(p NETs) are particularly rare. The various forms of PNETs, such as cystic degeneration, make differentiation from other similar pancreatic lesions difficult. We can detect small lesions by endoscopic ultrasound(EUS) and obtain preoperative pathological diagnosis by EUS-guided fine needle aspiration(FNA). We describe, here, an interesting case of p NET in a 42-year-old woman with no family history. Computed tomography and magnetic resonance imaging revealed an 18 mm × 17 mm cystic lesion with a nodule in the pancreatic tail. Two microtumors about 7 mm in diameter in the pancreatic body detected only by EUS, cystic rim and nodules all showed similar enhancement on contrast-harmonic EUS. Preoperative EUS-FNA of the microtumor was performed, diagnosing multiple p NETs. Macroscopic examination of the resected pancreatic body and tail showed that the cystic lesion had morphologically changed to a 13-mm main nodule, and 11 new microtumors(diameter 1-3 mm). Microscopically, all microtumors represented p NETs. From the findings of a broken peripheral rim on the main lesion with fibrosis, rupture of the cystic p NET was suspected. Postoperatively, pituitary adenoma and parathyroid adenoma were detected. The final diagnosis was multiple grade 1 p NETs with multiple endocrine neoplasia type 1. To the best of our knowledge, no case of spontaneous rupture of a cystic p NET has previously been reported in the English literature. Therefore, this case of very rare p NET with various morphological changes is reported.