Audit of a series of 40 gastrointestinal stromal tumour cases.

AIMS: To analyze prognostic factors influencing survival and tumour recurrence after resection of gastrointestinal stromal tumours. METHODS: Forty patients who underwent surgery for a GIST at our institution were reviewed. Patients were classified on the basis of tumour size, mitotic rate and CD117 positivity. The overall survival and disease free survival were calculated using Kaplan-Meier method considering the extent of surgery comparing local tumour excisions with segmental organ resections. RESULTS: Tumours were localized in the oesophagus, stomach, duodenum, small bowel and large bowel and rectum. Sixty-five percent of the patients had an intermediate or high risk GIST according to tumour size and mitotic count. In 26/40 patients tumour resection was performed using segmental organ resection, in all other patients local tumour excision was carried out. The mean overall survival was 73 months. Disease free survival was significantly better after local tumour excision compared to segmental organ resection (73 months versus 53 months; p=0.05). Large tumour size (p=0.07) and high mitotic count (p=0.14) were negative prognostic factors for disease free survival, although statistical significance was not reached yet. CONCLUSION: Primary surgery remains the cornerstone in the treatment of primary and recurrent GIST. Risk adapted surgery is the most important factor to avoid early tumour recurrence. In case of small tumour size segmental organ resections can be avoided favouring local tumour excisions with a low risk of tumour recurrence.

[Cystic pancreas tumors and their classification: features old and new]. / Zystische Pankreastumoren und ihre Klassifikation. Alte und neue Gesichter.

Cystic tumors and tumor-like lesions of the pancreas are rare, but have attracted a great deal of attention because they are easily recognized with new imaging methods and, in contrast to ductal adenocarcinoma, they can usually be cured surgically. The increasing resection rate in recent years has also increased our knowledge of cystic pancreatic tumors by conspicuously enlarging their morphological spectrum. Known entities have been better characterized (i.e. solid pseudopapillary neoplasm, intraductal papillary mucinous neoplasm) and new ones described (serous oligocystic adenoma, mucinous non-neoplastic cyst, acinar cell cystadenoma and cystic hamartoma). This review discusses the most important cystic tumors and tumor-like lesions, presents a new classification, and summarizes the immunohistochemical differential diagnosis.

[Mesenchymal tumors of the pancreas. Surprising, but not uncommon]. / Mesenchymale Tumoren des Pankreas. Uberraschend, aber nicht ungewöhnlich.

Mesenchymal tumors of the pancreas are rare. They are resected because a solid or cystic pancreatic tumor is suspected. Benign mesenchymal tumors comprise lymphangiomas, hemangiomas, schwannomas, solitary fibrous tumors, adenomatoid tumors, clear cell tumors, and hamartomas. Inflammatory pseudotumors are a special case. Malignant mesenchymal tumors include leiomyosarcomas, malignant peripheral nerve sheath tumors (MPNST), liposarcomas, malignant fibrous histiocytomas, Ewing's sarcomas, and primitive neuroectodermal tumors (PNET). It is important to differentiate these tumors from anaplastic carcinomas and retroperitoneal tumors that infiltrate pancreatic tissue.

[Solid pseudopapillary neoplasms. Enigmatic entity with female preponderance]. / Solid-pseudopapilläre Neoplasien. Weiblich orientiert und rätselhaft.

Solid pseudopapillary neoplasms (SPN) of the pancreas represent a special tumor entity, both morphologically and biologically. They form large solitary tumors that occur predominantly in young women. Histologically, they show solid, pseudopapillary, and pseudocystic patterns. The tumor cells are monomorphous and typically express vimentin, neuron-specific enolase, nuclear beta-catenin, and the progesterone receptor. Complete resection cures the tumor in about 90% of the cases. However, because recurrences and even metastases may occur in a small number of cases, SPN are classified as low-grade malignant tumors. Predicting malignancy histologically is not yet possible. The most important differential diagnosis to consider is neuroendocrine tumor of the pancreas. The etiology and pathogenesis of SPN are obscure.

Cystic neoplasms of the pancreas and tumor-like lesions with cystic features: a review of 418 cases and a classification proposal.

Although cystic neoplasms and lesions of the pancreas are rare, they have attracted a great deal of attention because of their potential curability. Since, in recent years, several new entities have been identified, the relative frequency of the tumors and their classification need to be reevaluated. In a series of 1454 tumorous lesions of the pancreas collected between 1971 and 2003 in our surgical pathology files and consultation files, all cystic pancreatic neoplasms and tumor-like lesions were identified and typed both histologically and immunohistochemically. There were 418 cases (29%) showing cysts with a diameter ranging between 0.5 cm and 27 cm. Most common were solid pseudopapillary neoplasms (21%) and intraductal papillary-mucinous neoplasms (18%). When only the cystic neoplasms and lesions that had been resected in a single institution were considered, intraductal papillary mucinous neoplasms were the most frequent cystic neoplasms, while solid pseudopapillary neoplasms took fifth place behind ductal adenocarcinomas with cystic features, serous cystic neoplasms and mucinous cystic neoplasms. The most frequent cystic tumor-like lesions were pancreatitis-associated pseudocysts. New and rare entities that have recently been identified are mucinous nonneoplastic cysts, acinar cell cystadenomas and cystic hamartomas. Bearing in mind that figures from referral centers such as ours may be biased regarding the relative frequency of lesions, we concluded from our data that intraductal papillary-mucinous neoplasms are the most frequently occurring pancreatic cystic neoplasms, rather than solid pseudopapillary neoplasms. It was possible to classify all cystic lesions encountered in our files or described in the literature in a new system that distinguishes between neoplastic and nonneoplastic lesions, with further subdivisions into epithelial (adenomas, borderline neoplasms and carcinomas) and nonepithelial tumors. This classification is easy to handle and enables a distinction on the basis of clinical behavior and prognosis.