Cancer of the exocrine pancreas: the pathologic aspects

Case report: First case of early adenoid cystic carcinoma and squamous cell carcinoma collision cancer treated by endoscopic submucosal dissection

Background

Collision cancer, a rare tumor, rarely occurs in the esophagus. Most reported cases of esophageal collision cancers are advanced cancers that can only be treated with surgery or palliative chemoradiotherapy. Here, we report a rare case of collisional squamous cell carcinoma (SqCC) and adenoid cystic carcinoma (AdCC) that was detected in the early stages by endoscopy.

Case summary

A 66-year-old man presented with retrosternal pain after swallowing and underwent endoscopy. Pathological biopsy showed high-grade squamous intraepithelial neoplasia. The lesion was removed by endoscopic submucosal dissection (ESD) after magnification and endoscopic ultrasonography. Postoperative pathology proved that the lesion was collision cancer comprising SqCC and AdCC. After six months of postoperative follow-up, there was no recurrence of esophageal cancer.

Conclusions

We provided a case report related to the diagnosis and treatment of esophageal collision cancer, especially early collision cancer. More research is needed to provide insights into the management of collision cancers.

CT and MR imaging features of mixed neuroendocrine-non-neuroendocrine neoplasm of the pancreas compared with pancreatic ductal adenocarcinoma and neuroendocrine tumor

OBJECTIVE

This study aimed to assess the computed tomography (CT) and magnetic resonance imaging (MRI) features of pancreatic mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) and compare them with those of pancreatic ductal adenocarcinoma (PDAC) and neuroendocrine tumor (NET).

METHODS

Twelve patients with pancreatic MiNEN, 24 patients with PDAC, and 24 patients with NET, who underwent both contrast-enhanced CT and MRI, were included. Clinical data and the key imaging features were retrospectively evaluated by two independent readers and compared between MiNEN and PDAC or NET. Univariate and multivariable logistic regression analyses were performed to obtain predictors for pancreatic MiNEN.

RESULTS

Patients with pancreatic MiNEN more frequently presented with large size and heterogeneous and cystic components compared with PDAC (p < 0.031) and ill-defined irregular margins, progressive enhancement, and adjacent organ involvement compared with NET (p < 0.036). However, vascular invasion was less commonly seen in MiNEN than PDAC (p = 0.010). Moderate enhancement was observed more frequently in MiNEN than in PDAC or NET (p < 0.001). Multivariate logistic analyses demonstrated that moderate enhancement and ill-defined irregular margin were the most valuable features for the prediction of pancreatic MiNEN (p ≤ 0.044). The combination of the two features resulted in a specificity of 93.8%, sensitivity of 83.3%, and accuracy of 91.7%.

CONCLUSIONS

We have mainly described the radiological findings of pancreatic MiNEN with ill-defined irregular margin and moderate enhancement compared with PDAC and NET. The combination of imaging features could improve diagnostic efficiency and help in the selection of the correct treatment method.

Concurrent ductal adenocarcinoma, pseudocyst, and neuroendocrine tumor of the pancreas: A case report

INTRODUCTION

Pancreatic pseudocyst is one of the most common cystic lesions. It always occurs following pancreatitis and is rarely found in combination with pancreatic adenocarcinoma. The coexistence of exocrine and neuroendocrine tumors of the pancreas is also infrequent. We herein report a case of simultaneous occurrence of a pancreatic ductal adenocarcinoma (PDAC), pseudocyst, and neuroendocrine tumor (NET), showing a "side-by-side pattern."

PATIENT CONCERN

A 74-year-old man was hospitalized for epigastric pain and poor appetite. He had no history of pancreatitis, alcohol consumption, or smoking.

DIAGNOSIS AND INTERVENTION

Abdominal enhanced computed tomography and magnetic resonance imaging revealed a 15 × 8 cm cystic lesion with poor enhancement located in the tail of the pancreas. The distal aspect of the main pancreatic duct was dilated. The pancreatic parenchyma adjacent to the cystic lesion showed slightly heterogeneous enhancement on computed tomography and magnetic resonance imaging. Laboratory examination showed an elevated carbohydrate antigen 19-9 serum level. The patient was preoperatively diagnosed with intraductal papillary mucinous neoplasm and subsequently underwent laparotomy. During the operation, a hard white tumor measuring about 4 × 3 cm was palpated adjacent to the cystic lesion on the duodenal side, and a 0.6-cm nodule was simultaneously found in the pancreatic tail. Therefore, total pancreatectomy and splenectomy were performed. Histopathological examination showed that the tumor was PDAC with an adjacent pseudocyst, and the small nodule was suggestive of a NET.

OUTCOMES

The patient survived without recurrence or metastasis in the follow-up visit 10 months after the operation and adjuvant chemotherapy.

CONCLUSIONS

The concomitant occurrence of a PDAC, pseudocyst, and NET has not been previously reported. We suggest that if a pancreatic cyst is found, the coincidental occurrence of a malignant tumor should be considered, especially if the carbohydrate antigen 19-9 level is increased. Additionally, dilation of the pancreatic duct may be a diagnostic clue. Furthermore, the simultaneous occurrence of pancreatic endocrine and exocrine tumors is very uncommon. Preoperative diagnosis becomes difficult because of the lack of specific symptoms and radiological features.

Incidence of Venous Thromboembolism in Patients With Newly Diagnosed Pancreatic Cancer and Factors Associated With Outcomes

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDAC) is associated with the highest incidence of venous thromboembolism (VTE) of any cancer type. However, little is known about risk factors for VTE or its outcomes in patients with PDAC.

METHODS

We collected data from a prospective, observational study performed at multiple centers in France from May 2014 through November 2018 (the Base Clinico-Biologique de l'Adénocarcinome Pancréatique [BACAP] study) linked to a database of patients with a new diagnosis of PDAC of any stage. Data were collected from 731 patients at baseline and during clinical follow-up or in the event of symptoms. The primary endpoint was the onset of VTE during follow-up. The secondary endpoints were progression-free survival (PFS) and overall survival (OS) times.

RESULTS

During a median follow-up of 19.3 months, 152 patients (20.79%) developed a VTE. The median time from PDAC diagnosis to the onset of VTE was 4.49 months. Cumulative incidence values of VTE were 8.07% (95% confidence interval [CI], 6.31-10.29) at 3 months and 19.21% (95% CI, 16.27-22.62) at 12 months. In multivariate analysis, PDAC primary tumor location (isthmus vs head: hazard ratio [HR], 2.06; 95% CI, 1.09-3.91; P = .027) and stage (locally advanced vs resectable or borderline: HR, 1.66; 95% CI, 1.10-2.51, P = .016; metastatic vs resectable or borderline: HR, 2.50; 95% CI, 1.64-3.79; P < .001) were independent risk factors for the onset of VTE. Patients who developed VTE during follow-up had shorter times of PFS (HR, 1.74; 95% CI, 1.19-2.54; P = .004) and OS (HR, 2.02; 95% CI, 1.57-2.60; P < .001).

CONCLUSION

In an analysis of data from the BACAP study, we found that frequent and early onsets of VTE after diagnoses of PDAC are associated with significant decreases in times of PFS and OS. Studies are needed to determine whether primary prophylaxis of VTE in patients with PDAC will improve morbidity and mortality related to VTE. (ClinicalTrials.gov, Number: clinicaltrials.gov as number NCT02818829).

Retrospective analysis of seven cases of pancreatic mixed adenoneuroendocrine carcinoma from a high-volume center and review of the literature

Backgrounds

The clinicopathologic features and biological behaviors of pancreatic mixed adenoneuroendocrine carcinoma (pMANEC) and its impacts on survival are poorly known.

Methods

We retrospectively reviewed seven pMANEC cases from a single institution from September 2010 to January 2017 along with twenty-one previously reported cases from the literature. Survival and prognostic analyses were conducted using Kaplan-Meier estimates and Cox regression, respectively.

Results

Seven pMANEC cases were identified during the study interval. Among the six patients who underwent operations, five reached R0 resections, one experienced postoperative pancreatic fistula, and two suffered other complications. The median progression-free survival (PFS) and disease-specific survival (DSS) were 7.5 months (2 to 36 months) and 15 months (6 to 36 months), respectively. A total analysis of twenty-eight pMANEC cases showed that patients were mostly older (median age, 59.5 years) and male (64.3%). The two most common symptoms were abdominal pain (53.6%) and obstructive jaundice (35.7%). The majority of pMANECs were non-functional (89.3%) and located in the pancreatic head (64.3%). The median diameter of pMANEC was 3.0 cm, with a wide range (0.5 to 19.0 cm). Lymph node metastasis (P = 0.015) was associated with decreased DSS, while age (P = 0.414), sex (P = 0.125), tumor size (P = 0.392), location (P = 0.913), functional status (P = 0.313), CA19–9 level (P = 0.608), and liver metastasis (P = 0.935) did not show significant prognoses on DSS.

Conclusions

We reported seven pMANEC cases and outlined their clinical behaviors and prognoses with a review of twenty-one cases from the literature. Lymph node metastasis was found to be a negative prognostic factor of DSS based on the present study.

Neoplasms of the Neuroendocrine Pancreas: An Update in the Classification, Definition, and Molecular Genetic Advances

This review focuses on discussing the main modifications of the recently published 2017 WHO Classification of Neoplasms of the Neuroendocrine Pancreas (panNEN). Recent updates separate pancreatic neuroendocrine tumors into 2 broad categories: well-differentiated pancreatic neuroendocrine tumors (panNET) and poorly differentiated pancreatic neuroendocrine carcinoma (panNEC), and incorporates a new subcategory of "well-differentiated high-grade NET (G3)" to the well-differentiated NET category. This new classification algorithm aims to improve the prediction of clinical outcomes and survival and help clinicians select better therapeutic strategies for patient care and management. In addition, these neuroendocrine neoplasms are capable of producing large quantity of hormones leading to clinical hormone hypersecretion syndromes. These functioning tumors include, insulinomas, glucagonomas, somatostatinomas, gastrinomas, VIPomas, serotonin-producing tumors, and ACTH-producing tumors. Although most panNENs arise as sporadic diseases, a subset of these heterogeneous tumors present as parts on inherited genetic syndromes, such as multiple endocrine neoplasia type 1, von Hippel-Lindau, neurofibromatosis type 1, tuberous sclerosis, and glucagon cell hyperplasia and neoplasia syndromes. Characteristic clinical and morphologic findings for certain functioning and syndromic panNENs should alert both pathologists and clinicians as appropriate patient management and possible genetic counseling may be necessary.

Synchronous pancreatic tumors in a patient with history of Wilms tumor: A case of pancreatic adenocarcinoma and lipid-rich neuroendocrine tumor diagnosed by cytopathology

Synchronous tumors represent a very small portion of pancreatic tumors. Although there is a higher incidence of secondary malignant neoplasms (SMN) in patients with history of Wilms tumor (WT), pancreatic tumors are very infrequent SMNs in this population. We report the first case of synchronous pancreatic tumors in a patient with history of WT. Two separated pancreatic lesions were identified by abdominal computerized tomography (CT) scan. Fine-needle aspiration of both lesions was performed for cytopathology examination. A pancreatic adenocarcinoma was diagnosed in the head of pancreas, and the pancreatic body lesion was found to be a neuroendocrine tumor (NET). The NET had characteristic vacuolated lipid-rich cytoplasm. Further molecular testing was done on both tumors, but no common cancer-associated mutation was found.

Collision of ductal adenocarcinoma and neuroendocrine tumor of the pancreas: a case report and review of the literature

BACKGROUND

Simultaneous occurrence of exocrine and neuroendocrine tumors of the pancreas is very infrequent. We report a patient with an endocrine tumor in the pancreatic-duodenal area and extensive exocrine carcinoma involving the whole pancreas.

CASE PRESENTATION

A 69-year-old woman was hospitalized in May 2016 for epigastric pain and weight loss. Her past medical history revealed an undefined main pancreatic duct dilation that was subsequently confirmed at CT scan (23 mm) and endoscopic ultrasound. There was no evidence of pancreatic masses, but the cephalic portion of the main pancreatic duct presented hypoechoic nodules. A diagnosis of the main-duct intraductal papillary mucinous neoplasm was made, and the patient underwent total pancreatectomy. Pathological examination showed a collision tumor constituted by a ductal adenocarcinoma involving the whole pancreas and a neuroendocrine tumor located in the duodenal peripancreatic wall and the head of the pancreas. There was one peripancreatic lymph node metastasis from the ductal adenocarcinoma and eight node metastases from the neuroendocrine tumor. These findings suggested a diagnosis of collision of neuroendocrine and ductal adenocarcinomas of the pancreas. The postoperative course was uneventful.

CONCLUSIONS

The coexistence of pancreatic endocrine and exocrine tumors is very uncommon. When present, problems in differential diagnosis may arise between mixed exocrine-endocrine carcinoma or the collision of separate tumors.

Significant Radiologic Response of Pancreatic Metastasis After Targeted Therapy of Ceritinib (LDK378) for ALK-Rearranged Lung Adenocarcinoma Presenting With Hyperglycemia

Pancreatic metastasis from non-small cell lung cancer (NSCLC) is usually asymptomatic or presents with abdominal pain, acute pancreatitis, or jaundice. A lung primary is associated with worse survival compared to pancreatic metastases from other organs. Surgical treatment of solitary metastasis to the pancreas from NSCLC has been reviewed in several studies, one of which had a notable disease-free interval. To our knowledge, there are no prior reports of targeted therapy of pancreatic metastasis of NSCLC followed by a significant response. Herein we report the case of a 31-year-old female with a solitary pancreatic metastasis from ALK-rearranged lung adenocarcinoma despite treatment with chemotherapy and crizotinib; she presented with symptoms of hyperglycemia. Targeted therapy with ceritinib (LDK378) led to symptomatic improvement and a significant radiologic response in the lung and pancreas, but not in the brain.

A mixed adenoneuroendocrine carcinoma of the pancreas: a case report

A tumor consisting of an adenocarcinoma component and a neuroendocrine carcinoma component, with each component accounting for at least 30% of the tumor, is defined as a mixed adenoneuroendocrine carcinoma (MANEC). We report a case of MANEC of the pancreas. A 63-year-old man presented with hyperglycemia and was referred to our hospital for further examination. Abdominal contrast-enhanced computed tomography (CT) revealed a mass of 2 cm in size in the pancreas head with portal vein narrowing. Fluorin-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) CT revealed increased accumulation in the mass of the pancreas head. Endoscopic retrograde cholangiopancreatography (ERCP) showed severe narrowing of the main pancreatic duct. Cytological analysis by endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) suggested a neuroendocrine tumor. Under the diagnosis of neuroendocrine tumor, pancreaticoduodenectomy with portal vein resection and regional lymph node dissection was performed with curative intent. Histological examination revealed that the tumor consisted of two cell populations. One was well- to moderately differentiated tubular adenocarcinoma. This cell component accounted for 45% of the whole tumor. The second component was non-adenocarcinoma cells arranged in a nest, and the cells had round nuclei, abundant cytoplasm, and coarse chromatin. The Ki67 labeling index was 40%. Immunohistochemically, the adenocarcinoma cells were positive for CEA but negative for chromogranin A (CgA) and synaptophysin (Syn), while the non-adenocarcinoma cells were positive for the expression of CgA and Syn but negative for CEA. Based on the findings, a diagnosis of MANEC of the pancreas was made. Postoperatively, lymph node metastasis and peritoneal dissemination developed rapidly and he died the 6 months after the operation. Due to the small number of reported cases of MANEC of the pancreas, its clinical behavior remains unclear and a standardized management protocol has not been established. Further investigation of more cases of this rare entity is necessary.

In vivo18F-fluorodeoxyglucose-positron emission tomography/computed tomography imaging of pancreatic tumors in a transgenic rat model carrying the human KRASG12V oncogene

A novel KRAS-mediated transgenic rat model has previously been demonstrated, in which animals develop multiple pancreatic ductal adenocarcinoma (PDAC) that is histologically similar to human PDAC within two weeks. Positron emission tomography (PET)/computed tomography (CT) is commonly used for the diagnosis and staging of PDAC in humans, and can be adopted for optimal use in animal experiments. The aim of the present study was to evaluate the carcinogenic process in a rat pancreatic carcinoma model using small-animal multimodality imaging systems. The utility of fluorodeoxyglucose (FDG)-PET/CT in detecting the location and size of PDAC during tumor development in the present transgenic rat model was assessed. A small animal multimodality PET/CT system and contrast-enhanced CT (CECT) system were used for the imaging analysis of KRAS^G12V male transgenic rats (n=6), which developed pancreatic tumors following the administration of an injection of Cre recombinase (Cre)-carrying adenovirus. Laparotomies performed at six weeks post-treatment revealed that all three (100%) Cre-expressing rats developed pancreatic tumors that were <2 mm in diameter, none of which were detected by ¹⁸F-FDG PET/CT or CECT. At eight weeks post-treatment, the pancreatic tumors were heterogeneously visualized by ¹⁸F-FDG-PET/CT and CECT in two of the three rats. Furthermore, the autopsies confirmed that all three rats had developed pancreatic tumors. These novel findings provide evidence that the FDG-PET/CT imaging system is a valuable tool for the evaluation of the carcinogenic process, and one which may aid in treatment and preventive methods for pancreatic tumors in mammalian models. A limitation associated with the early detection of PDACs warrants further investigation.

Collision of extensive exocrine and neuroendocrine neoplasms in multiple endocrine neoplasia type 1 revealed by cytogenetic analysis of loss of heterozygosity: a case report

The combination of exocrine and neuroendocrine neoplasms is rarely found in the pancreas. These combined lesions vary from a clonal tumor with mixed differentiation to the incidental co-existence of two or more independent tumors, but the differential diagnosis is sometimes difficult. Here we report a case of multiple endocrine neoplasia type 1 (MEN1) with extensive ductal and neuroendocrine neoplastic changes. These two types of tumors admixed markedly in some parts, which made it difficult to determine the pathological diagnosis based on histological findings. Cytogenetic analysis showed that loss of heterozygosity (LOH) of the MEN1 locus exists in neuroendocrine but not in exocrine neoplasms, indicating that independent mechanisms of tumorigenesis may occur in these two types of tumors. This case shows the usefulness of cytogenetic analysis for the diagnosis of combined tumors of the pancreas. Extensive exocrine neoplastic change, including pancreatic intraepithelial neoplasia (PanIN) in virtually all pancreatic ducts and a focus of intraductal papillary mucinous neoplasm (IPMN) with focal invasion, was a distinguishing feature of the present case. The possible association of ductal tumorigenesis and a MEN1 background is discussed.

False-negative rate of endoscopic ultrasound-guided fine-needle aspiration for pancreatic solid and cystic lesions with matched surgical resections as the gold standard: one institution's experience

BACKGROUND

The diagnosis of pancreatic tumors is often complicated because of sampling and interpretive challenges. The current study was performed to determine the rates, types, and causes of diagnostic discrepancies.

METHODS

The authors retrospectively reviewed cytology cases from 2004 to 2010 using matched surgical resection cases as the gold standard.

RESULTS

A total of 733 cases were divided into 3 categories: 1) positive or suspicious (290 cases); 2) negative or atypical (403 cases); and 3) unsatisfactory (40 cases). Of these cases, 101 fine-needle aspiration (FNA) cases had matched surgical resections including 58 positive diagnoses, 39 negative diagnoses, and 4 unsatisfactory diagnoses. All 19 discrepant cases represented false-negative diagnoses without any false-positive cases noted, which included 2 cases with interpretive errors (10%) and 17 cases with sampling errors (90%). All matched cytology cases were divided into 5 subgroups based on the type of lesion or type of error and were analyzed for sensitivity and specificity. The sampling error rate in cystic lesions (8 of 24; 33%) was significantly higher than that in solid lesions (9 of 73; 12%). The false-negative rate in the interpretive error group (3%) was significantly lower than that in the sampling error group (23%).

CONCLUSIONS

The results of the current study confirm that pancreatic endoscopic ultrasound-guided FNA diagnosis has a very low false-positive rate but a relatively high false-negative rate using matched surgical resections as the gold standard. The major cause of a false-negative cytology diagnosis is sampling error and the rate of sampling error in cystic lesions is significantly higher than that in solid lesions.

Primary pancreatic cystic neoplasms of the pancreas revisited. Part IV: rare cystic neoplasms

Primary pancreatic cystic neoplasms are being recognized with increasing frequency due to modern imaging techniques. In addition to the more common cystic neoplasms-serous cystadenoma, primary mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm-there are many other less common neoplasms that appear as cystic lesions. These cystic neoplasms include solid pseudopapillary neoplasm of the pancreas (the most common rare cystic neoplasm), cystic neuroendocrine neoplasm, cystic degeneration of otherwise solid neoplasms, and then the exceedingly rare cystic acinar cell neoplasm, intraductal tubular neoplasm, angiomatous neoplasm, lymphoepithelial cysts (not true neoplasms), and few others of mesenchymal origin. While quite rare, the pancreatic surgeon should at the least consider these unusual neoplasms in the differential diagnosis of potentially benign or malignant cystic lesions of the pancreas. Moreover, each of these unusual neoplasms has their own natural history/tumor biology and may require a different level of operative aggressiveness to obtain the optimal outcome.

Mixed ductal-endocrine carcinoma of the pancreas occurring as a double cancer: report of a case

We present a successfully treated case of mixed ductal-endocrine carcinoma of the pancreas complicated by right renal cell carcinoma. The patient had no symptoms, and laboratory data were close to the normal range. Enhanced computed tomography demonstrated a marked enhanced tumor, which appeared to be an endocrine tumor, at the pancreas uncus. We performed pyrolus-preserving pancreaticoduodenectomy, regional lymph node resection, and right nephrectomy. Histologically and immunohistochemically, the pancreas tumor had both a ductal (exocrine) and an endocrine component. The renal tumor was a typical clear cell carcinoma. A diagnosis of synchronous double cancer was made. As demonstrated in previously published reports, this type of mixed tumor has malignant potential for invasive ductal carcinoma. We propose that mixed ductal-endocrine carcinoma of the pancreas should be treated by surgical resection with a sufficient surgical margin and regional lymph node resection to improve the patient's prognosis.

[Clinical characteristics of pancreatic metastases]

BACKGROUND/AIMS

Histologically confirmed metastatic pancreatic cancers are infrequent. The aim of this study was to analyze clinical, therapeutic and prognostic features of pancreatic metastases.

METHODS

We retrospectively evaluated stage of primary malignancies, interval between diagnosis of primary tumors and detection of pancreatic metastases, treatment for metastases to the pancreas, survival rate, and prognostic factors in 31 patients with pancreatic metastases.

RESULTS

The mean age at the time of primary cancer diagnosis was 52.4 ± 13.2 years. Primary cancers were renal cell carcinoma (n=16), non-small cell lung cancer (n=6), small cell lung cancer (n=3), colorectal carcinoma (n=2), osteosarcoma (n=1), gastric carcinoma (n=1), malignant melanoma (n=1), and thymic carcinoma (n=1). Pancreatic metastases were synchronous in six cases and metachronous in twenty five cases, with median interval time of 40.8 months (range 3-186) between the diagnosis of primary tumor and detection of pancreatic metastases. The median survival after the detection of the metastases was 16 months. In multivariate analysis, non-renal cell carcinoma as primary malignancy and positive symptom related to pancreatic metastases were associated with poor prognosis (hazard ratio [HR], 8.33; 95% CI, 2.1-33; p=0.003, and HR, 4.02; 95% CI, 1.27-12.7; p=0.018).

CONCLUSIONS

Metastatic tumors to the pancreas have to be kept in mind when a patient with pancreatic mass has a history of other malignancy, even if treated several years before. In the absence of widely metastatic disease, aggressive diagnostic and therapeutic approach may offer the chance of long-term survival in selected patients.

Imaging findings in a case of mixed acinar-endocrine carcinoma of the pancreas

Mixed acinar-endocrine carcinoma (MAEC) of the pancreas is extremely uncommon. We report here a rare case of MAEC of the pancreas presenting as watery diarrhea. This is the first report in the English-language literature that describes the imaging findings of MAEC of the pancreas, including computed tomography (CT), magnetic resonance (MR) imaging, and MR cholangiopancreatography features.

Cystic pancreatic neoplasms evaluation by CT and magnetic resonance cholangiopancreatography

CT provides limited assistance in the differentiation between serous and mucinous neoplasms. Because of the variability in the radiographic appearance of serous cystadenomas and overlap in CT characteristics with mucinous neoplasms, most serous neoplasms still require ancillary testing such as biopsy to reach a definitive diagnosis. MRCP is useful in differentiating benign and malignant mucinous tumors including IPMT of the pancreas. The presence of mural nodules is suggestive of malignancy; however, the absence of mural nodules does not indicate that the tumor is benign. A maximum main pancreatic duct diameter of greater than 15 mm and diffuse dilatation of the main pancreatic duct are suggestive of malignancy in main duct-type tumors. Among branch duct-type tumors, malignant tumors tend to be larger than benign tumors; however, this finding is variable. The presence of main pancreatic duct dilatation may be helpful in determining malignancy of branch duct-type tumors.

Long-term effect of tumor necrosis factor and gamma interferon in human pancreatic carcinoma cells

The long-term cytotoxic/cytostatic effects of recombinant human tumor necrosis factor alpha (rhTNF) and gamma interferon (rhIFN-gamma) were studied in five human pancreatic carcinoma cell lines. The pancreatic tumor cell lines were heterogenous in their response to individual cytokines. During a 7-d incubation, MIA PaCa-2 cells were more sensitive to rhTNF than rhIFN-gamma, whereas ASPC-1, T3M4, and COLO 357 cells were more sensitive to rhIFN-gamma than rhTNF. PANC-1 cells were relatively insensitive to both cytokines. In a previous report, we demonstrated synergistic cytotoxic effects of rhTNF and rhIFN-gamma during 48-h incubations in ASPC-1 and COLO 357 cells (Raitano et al, Pancreas, April, 1990). In this study, a 7-d treatment with both rhTNF and rhIFN-gamma did not produce synergistic effects in any of the cell lines. However, a 24-h treatment with rhIFN-gamma, followed by removal of the cytokine, markedly increased the long-term cytotoxic/cytostatic effects of rhTNF in ASPC-1, COLO 357, and T3M4 cells. In contrast, a similar pretreatment with rhTNF did not increase the long-term cytotoxic/cytostatic effects of rhIFN-gamma in any of the cell lines. These data suggest that, in some human pancreatic carcinoma cell lines, rhIFN-gamma may be especially useful in the long-term suppression of growth. Furthermore, brief pulses of rhIFN-gamma may also be especially efficacious when followed by a subsequent prolonged exposure of cells to rhTNF.