Metastases to the pancreas

The Role of MRI in the Diagnosis of Solid Pseudopapillary Neoplasm of the Pancreas and Its Mimickers: A Case-Based Review with Emphasis on Differential Diagnosis

Solid pseudopapillary neoplasm (SPN) is rare pancreatic tumor occurring most commonly in young females. The typical imaging appearance of SPN is of well-defined, encapsulated, and large heterogeneous tumors, consisting of solid and cystic components due to various degrees of intralesional hemorrhage and necrosis. However, atypical imaging presentation in the form of small solid tumors or uniformly cystic lesions might also be seen, which can be explained by specific pathological characteristics. Other imaging features such as a round shape, the absence of main pancreatic duct dilatation, and slow growth, in combination with vague symptoms, favor the diagnosis of SPNs. Nevertheless, the radiological findings of SPN might overlap with other solid and cystic pancreatic neoplasms, such as neuroendocrine tumors, serous and mucinous neoplasms, and even small pancreatic adenocarcinomas. In addition, a few benign non-tumorous conditions including walled-of-necrosis, and intrapancreatic accessory spleen may also pose diagnostic dilemmas simulating SPNs on imaging studies. The aim of this manuscript is to provide a comprehensive overview of the typical and atypical imaging features of SPNs and to describe useful tips for differential diagnosis with its potential mimickers.

Isolated Pancreatic Metastases of Renal Cell Carcinoma-Clinical Particularities and Seed and Soil Hypothesis

A meta-analysis of 1470 isolated pancreatic metastases of renal cell carcinoma revealed, that, in addition to the unusual exclusive occurrence of pancreatic metastases and the favourable treatment results, the isPMRCC is characterised by further peculiarities of the clinical course: The lack of prognostic significance of volume and growth rate dependent risk factors and the independence of treatment results from standard or local resections. As an explanation for all these peculiarities, according to today's knowledge, a strong acting seed and soil mechanism can serve, which allows embolized tumour cells to grow to metastases only in the pancreas, and prevents them definitively or for years in all other organs. The good prognosis affects not only isolated PM, but also multi-organ metastases of the RCC, in which the additional occurrence of PM is also associated with a better prognosis. Genetic studies revealed specific changes in cases of PM of RCC: Lack of loss of 9p21.3 and 14q31.2, which are otherwise specific gene mutations at the onset of generalization, a low weight genome instability index, i.e., high genetic stability, and a low rate of PAB1 and a high rate of BPRM1 alterations, which signal a more favourable course. The cause of pancreatic organotropism in isPMRCC is still unclear, so only those factors that have been identified as promoting organotropism in other, more frequent tumour entities can be presented: Formation of the pre-metastatic niche, chemokine receptor-ligand mechanism, ability to metabolic adaptation, and immune surveillance.

Isolated Pancreatic Metastases of Renal Cell Cancer: Genetics and Epigenetics of an Unusual Tumour Entity

Isolated pancreatic metastases of renal cell carcinoma (isPMRCC) are a rare manifestation of metastatic renal cell carcinoma (mRCC) characterized by two peculiarities: (1). The definite or at least long-term exclusive occurrence of metastases in the pancreas and (2). an unusual low tumour aggressiveness with slow tumour progression and consecutive, good treatment results. According to current knowledge, the exclusive occurrence of pancreatic metastases is due to a highly specific and highly selective seed and soil mechanism, which does not allow metastases settlement outside the pancreas, and whose detailed genetic/epigenetic causes are not yet elucidated. Recent studies have shed light on some of the pathways involved for the protracted course of the disease and highlighted a special genetic profile (lack of loss of 9p, lower weight genome instability index, low frequency of BAP1 alterations, and a high frequency of PBRM1 loss), which deviates from the conventional mRCC profile. Finally, the question of the reasons for the long-term relative genetic stability of the involved cell clones, which is an essential prerequisite for a favourable prognosis, remains unanswered.

Utility of CT to Differentiate Pancreatic Parenchymal Metastasis from Pancreatic Ductal Adenocarcinoma

Simple Summary

The purpose of this retrospective study was to report the computed tomography (CT) features of pancreatic parenchymal metastasis (PPM) and identify CT features that may help discriminate between PPM and PDAC. At multivariable analysis, well-defined margins (OR, 6.64; 95% CI: 1.47–29.93; p = 0.014), maximal enhancement during arterial phase (OR, 6.15; 95% CI: 1.13–33.51; p = 0.036), no vessel involvement (OR, 7.19; 95% CI: 1.51–34.14) and no Wirsung duct dilatation (OR, 10.63; 95% CI: 2.27–49.91) were independently associated with PPM. A nomogram based on CT features identified at multivariable analysis yielded an AUC of 0.92 (95% CI: 0.85–0.98) for the diagnosis of PPM vs. PDAC.

Abstract

Purpose: To report the computed tomography (CT) features of pancreatic parenchymal metastasis (PPM) and identify CT features that may help discriminate between PPM and pancreatic ductal adenocarcinoma (PDAC). Materials and methods: Thirty-four patients (24 men, 12 women; mean age, 63.3 ± 10.2 [SD] years) with CT and histopathologically proven PPM were analyzed by two independent readers and compared to 34 patients with PDAC. Diagnosis performances of each variable for the diagnosis of PPM against PDAC were calculated. Univariable and multivariable analyses were performed. A nomogram was developed to diagnose PPM against PDAC. Results: PPM mostly presented as single (34/34; 100%), enhancing (34/34; 100%), solid (27/34; 79%) pancreatic lesion without visible associated lymph nodes (24/34; 71%) and no Wirsung duct enlargement (29/34; 85%). At multivariable analysis, well-defined margins (OR, 6.64; 95% CI: 1.47–29.93; p = 0.014), maximal enhancement during arterial phase (OR, 6.15; 95% CI: 1.13–33.51; p = 0.036), no vessel involvement (OR, 7.19; 95% CI: 1.512–34.14) and no Wirsung duct dilatation (OR, 10.63; 95% CI: 2.27–49.91) were independently associated with PPM. The nomogram yielded an AUC of 0.92 (95% CI: 0.85–0.98) for the diagnosis of PPM vs. PDAC. Conclusion: CT findings may help discriminate between PPM and PDAC.

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Tumour Evolution and Seed and Soil Mechanism in Pancreatic Metastases of Renal Cell Carcinoma

In metastatic renal cell carcinoma, pancreatic metastases can appear in two clinical manifestations: (a) very rarely as isolated pancreatic metastases and (b) in the context with multi-organ metastatic disease. Both courses are characterised by rare, unusual clinical features. For isolated pancreatic metastases, the literature shows no effect on survival in all 11 publications that examined the effect of singular versus multiple pancreatic metastases; a lack of effect on survival time was also present in all 8 studies on pancreatic metastases size, in 7 of 8 studies on the influence of disease-free interval (DFI), and in 6 of 7 studies on the influence of synchronous versus metachronous metastases. In multi-organ site metastases observations, on the other hand, all five available references showed significantly better results in patients with concurrent pancreatic metastases compared to those without pancreatic metastases, although the total number of affected organs in the pancreatic metastases cohort was larger. Tumour volume-dependent risk factors thus remain surprisingly ineffective in both groups, which contradicts the usual behaviour of solid tumours. The reasons for this unusual behaviour and possible relations to tumour evolution and the hypothesis of an influence of a seed and soil mechanism in the occurrence of pancreatic metastases in metastatic renal cell carcinoma are discussed.

Metastatic small cell lung cancer presenting as acute pancreatitis: Diagnosis with magnetic resonance cholangiopancreatography

We detail a case of a right hilar small cell lung cancer with pancreatic metastases presenting as acute pancreatitis and being diagnosed on Magnetic Resonance Cholangiopancreatography (MRCP). A 59-year-old male patient had an MRCP performed following an initial computed tomography scan of the abdomen as part of the investigations following admission with acute pancreatitis. The diagnosis was not clear on CT but MRCP was able to confirm the likely diagnosis of pancreatic metastases with primary lung cancer as the underlying cause. The case illustrates the clinical radiological conundrum concurrent acute pancreatitis can produce to the diagnosis of pancreatic metastases along with how the superior tissue characterization of MRI despite the absence of intravenous contrast can be utilized to better identify solid pancreatic lesions and contribute towards the diagnosis. The superior field of view T2 coronal and localizer images on MRCP, compared to other standard abdominal imaging modalities, in this scenario enabled the right hilar lung primary to be diagnosed.

Isolated Pancreatic Metastases of Renal Cell Carcinoma-A Paradigm of a Seed and Soil Mechanism: A Literature Analysis of 1,034 Observations

Previously documented arguments, in favor of the suspected impact of a seed and soil mechanism, in the development and progression of isolated pancreatic metastasis of renal cell carcinomas (isPM) are: (1) uniform and independent from the side of the primary tumor distribution of isPM within the pancreas and, (2) the similar survival rates for singular and multiple isPM. In addition, the present study adds new arguments that further confirm the importance of an seed and soil mechanism in isPM: (1) Within the singular isPM, the size of the metastasis does not affect the overall survival; (2) Within the group of multiple isPMs, the overall survival does not depend on the number of metastases; (3) For synchronous and metachronous isPM, survival rates are also not different, and (4) Within the group of metachronous isPM there is also no correlation between the overall survival and interval until metastases occurs. This unusual ineffectiveness of otherwise known risk factors of solid cancers can be explained plausibly by the hypothesis of a very selective seed and soil mechanism in isPM. It only allows embolized renal carcinoma cells in the pancreas to complete all steps required to grow into clinically manifest metastases. In all other organs, on the other hand, the body is able to eliminate the embolized tumor cells or at least put them into a dormant state for many years. This minimizes the risk of occult micrometastases in distant organs, which could later—after isPM treatment—grow into clinically manifest metastases, so that the prognosis of the isPM is only determined by an adequate therapy of the pancreatic foci, and prognostic factors, such as total tumor burden or interval until the occurrence of the isPM remain ineffective.

68Ga-Prostate-Specific Membrane Antigen Uptake in a Pancreatic Neuroendocrine Tumor

We present a 60-year-old man with known prostate cancer treated with robot-assisted radical prostatectomy. Prostate-specific antigen levels did not decline accordingly, and a second Ga-PSMA PET/CT demonstrated a new focus with high Ga-PSMA uptake in the pancreatic tail. A subsequent CT scan did not display the lesion as a typical pancreatic tumor, and a spleen scintigraphy was also negative excluding an ectopic intrapancreatic accessory spleen. Ga-DOTATOC PET/CT showed uptake in the same area of the pancreatic tail consistent with a neuroendocrine tumor. This case illustrates that neuroendocrine tumors can be important pitfalls in Ga-PSMA PET/CT performed in prostate cancer patients.

Observations on Solitary Versus Multiple Isolated Pancreatic Metastases of Renal Cell Carcinoma: Another Indication of a Seed and Soil Mechanism?

Isolated pancreas metastases are a rare type of metastasis of renal cell carcinoma, characterized by the presence of pancreatic metastases, while all other organs remain unaffected. In a previous study, we determined arguments from the literature which (a) indicate a systemic-haematogenic metastasis route (uniform distribution of the metastases across the pancreas and independence of the metastatic localization in the pancreas of the side of the renal carcinoma); and (b) postulate a high impact of a seed and soil mechanism (SSM) on isolated pancreatic metastasis of renal cell carcinoma (isPM) as an explanation for exclusive pancreatic metastases, despite a systemic haematogenous tumor cell embolization. The objective of the study presented was to search for further arguments in favor of an SSM with isPM. For that purpose, the factor's histology, grading, and singular/multiple pancreas metastases were analyzed on the basis of 814 observations published up to 2018. While histology and grading allowed for no conclusions regarding the importance of an SSM, the comparison of singular/multiple pancreas metastases produced arguments in favor of an SSM: 1. The multiple pancreas metastases observed in 38.1% prove that multiple tumor cell embolisms occur with isPM, the exclusive "maturation" of which in the pancreas requires an SSM; 2. The survival rates (SVR), which are consistent with singular and multiple pancreas metastases (despite the higher total tumor load with the latter), prove that the metastasized tumor cells are not able to survive in all other organs because of an SSM, which results in identical SVR when the pancreatic foci are treated adequately.

FDG-PET CT in the evaluation of primary and secondary pancreatic malignancies

PURPOSE

Primary pancreatic carcinoma and pancreatic metastases are rare in the pediatric population. Pancreatoblastoma is the most common pancreatic malignant tumor in young children and solid-pseudopapillary tumor in teenagers. Pancreatic adenocarcinoma is extremely rare under the age of 40 and is usually associated with underlying genetic abnormalities. Secondary malignancies of the pancreas occur more frequently than primary pancreatic malignancies in children and are most commonly seen with non-Hodgkin lymphomas (NHL) and mesenchymal sarcomas. The purpose of this study was to characterize the metabolism of primary and secondary tumors of the pancreas in pediatric patients.

MATERIALS AND METHODS

A retrospective analysis of all primary and secondary pancreatic malignancies imaged with 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) computed tomography (CT) was conducted.

RESULTS

Three patients with primary pancreatic cancers were identified, one each with pancreatoblastoma, solid-pseudopapillary tumor, and adenocarcinoma. Each tumor showed elevated uptake of FDG. Metastatic disease in the pancreas was identified in 12 patients-five NHL (including three Burkitt lymphomas), six sarcomas (three osteosarcomas, two rhabdomyosarcomas, and one Ewing sarcoma family tumor), and one malignant rhabdoid tumor. Elevated but variable uptake of FDG was found in each of the tumors of patients with metastatic disease within the pancreas.

CONCLUSION

Both primary malignancies and metastatic disease within the pancreas, though very rare in children, adolescents, and young adults, are metabolically active and can be functionally characterized using FDG-PET CT.

Isolated pancreatic metastases from renal cell carcinoma: an outcome of a special metastatic pathway or of specific tumor cell selection?

Isolated pancreatic metastases (isPM) are a rare metastasizing pattern in the natural history of renal cell cancer. Their clinical hallmark is that they are confined to a single organ, the pancreas, while all other organs are unaffected for a long time. Almost all workers in the field suggested that mechanical tumor cell propagation to the pancreas may be the mechanism underlying this metastasizing pattern. In 2006 our group, by contrast, proposed an alternative mechanism, i.e. a special affinity of the tumor cells for the pancreas. In the present study an attempt was made to shed more light on the settlement of isPM by reviewing recent literature data. 666 observations of isPM reported in the literature were reviewed. The analyses showed that local lymphatic spread does not play a major role because the lymphatic system is, in general, rarely involved in isPM. This also applies to a local venous spread, because the site of pancreatic metastases is independent of the side affected by the primary renal cancer. But the results are compatible with a systemic metastatic pathway. That metastases in other organs, which would be expected given a systemic spread, are absent can plausibly be explained by a seed and soil mechanism: only the pancreas offers the tumor cell emboli an environment which is conducive to the growth of clinically manifest metastases, while settlement of metastatic tumor cells is prevented in all other organs.

Rare pancreatic tumors

In this review, we will focus on rare pancreatic tumors. Most of these tumors do not have distinct characteristic appearances so the key to diagnosis requires a combination of imaging appearance, laboratory data, patient demographics, and associated medical syndromes in order to narrow the differential diagnosis. Nonetheless, imaging plays a vital role in narrowing the differential and guiding management. While there are many variant pathologic entities that cannot be encompassed by a single review, we aim to illustrate the imaging appearance of less common pancreatic tumors highlighting key distinctive diagnostic characteristics and discuss the implications for management. While there is overlap in the imaging appearances of many of these entities, for educational purposes, lesions will be categorized into solid (hypoenhancing and hyperenhancing), cystic lesions, mesenchymal neoplasms, and neoplasms seen in younger patients (< 40 years).

Gastrointestinal bleeding due to pancreatic metastasis of non-small cell lung cancer: A report of two cases and a literature review

The current study presents two cases of gastrointestinal (GI) bleeding due to pancreatic metastasis of non-small cell lung cancer (NSCLC). The two patients had a history of lung adenocarcinoma prior to pancreatic metastasis. The first patient presented with melena, epigastric pain and weight loss, and the second patient presented with melena and weight loss. The diagnoses were confirmed by biopsy of the metastatic lesions. Immunohistochemistry is useful for managing the differential diagnosis between lung cancer and pancreatic carcinoma in patients with a history of lung cancer. Chemotherapy prolonged the survival of the second patient. However, the first patient received no chemotherapy and succumbed to NSCLC six weeks after the diagnosis of metastatic pancreatic cancer. GI bleeding as a result of pancreatic metastasis of NSCLC is extremely rare; including the present two cases, only three cases have been reported in the English literature. The current study is presented in order to increase the awareness of GI hemorrhage as a manifestation of this relatively rare condition.

Metastasis-Induced Acute Pancreatitis Successfully Treated with Chemotherapy and Radiotherapy in a Patient with Small Cell Lung Cancer

Although involvement of pancreas is a common finding in small cell lung cancer (SCLC), metastasis-induced acute pancreatitis (MIAP) is very rare. A 50-year-old female with SCLC who had limited disease and achieved full response after treatment presented with acute pancreatitis during her follow-up. The radiologic studies revealed a small area causing obliteration of the pancreatic duct without mass in the pancreatic neck, and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) confirmed the metastasis of SCLC. The patient was treated successfully with systemic chemotherapy and radiotherapy delivered to pancreatic field. In SCLC, cases of MIAP can be encountered with conventional computed tomography with no mass image, and positron emission tomography and EUS-FNA can be useful for diagnosis of such cases. Aggressive systemic and local treatment can prolong survival, especially in patients with good performance status.

MR imaging of the pancreas

Magnetic resonance (MR) imaging of the pancreas is useful as both a problem-solving tool and an initial imaging examination of choice. With newer imaging sequences such as diffusion-weighted imaging, MR offers improved ability to detect and characterize lesions and identify and stage tumors and inflammation. MR cholangiopancreatography can be used to visualize the pancreatic and biliary ductal system. In this article, the use of MR to evaluate the pancreas, including recent advances, is reviewed and the normal appearance of the pancreas on different imaging sequences, as well as inflammatory diseases, congenital abnormalities, and neoplasms of the pancreas, are discussed.

Pancreatic involvement in small cell lung cancer

Background

Few data are available concerning incidence, clinical picture, and prognosis for pancreatic metastases of small cell lung carcinoma. In this paper we review the related literature available in English language.

Conclusions

Although pancreatic metastases are generally asymptomatic, they can rarely produce clinical symptoms or functional abnormalities. The widespread use of multi-detector computerised tomography (CT) in contemporary medical practice has led to an increased detection of pancreatic metastases in oncology patients. Tissue diagnosis is imperative because radiological techniques alone are incapable of differentiating them from primary pancreatic tumours. Pancreatic metastases occur in the relative end stage of small cell lung cancer. The main complications of these lesions, although rare, are acute pancreatitis and obstructive jaundice. Early chemotherapy can provide a survival benefit even in patients with mild acute pancreatitis or extrahepatic biliary obstruction.

Nestin delineates pancreatic cancer stem cells in metastatic foci of NOD/Shi-scid IL2Rγ(null) (NOG) mice

Pancreatic ductal adenocarcinoma (PDAC) is associated with a high incidence of hepatic metastases, as well as occasional pulmonary metastases. To delineate the potential role of cancer stem cells (CSCs) in PDAC metastasis, human PDAC cells were injected into the spleen of mice. The characteristics and expression of markers associated with CSC and epithelial-mesenchymal transition (EMT) of metastatic cells that developed in the liver and lung were then compared with parental cells. The metastatic cells were polygonal, and larger than parental cells. Metastatic cells also exhibited decreased proliferation and increased adhesion to extracellular matrices, as well as enhanced migration and invasion in vitro and increased metastatic capacity in vivo. The CSC markers ALDH1A1, ABCG2, and nestin were expressed at high levels in metastatic cells and exhibited changes consistent with EMT (eg, decreased E-cadherin expression). Moreover, metastatic cells readily formed spheres in culture and exhibited an increased side population by flow analysis. Nestin and ABCG2 were also expressed at high levels in metastatic lesions from PDAC patients, and silencing nestin with shRNA in PDAC cells derived from lung metastases resulted in a marked decrease in the capacity of the cells to form spheres and to yield pulmonary or hepatic metastases. Thus, the metastatic potential of human PDAC cells correlates with CSCs and with EMT characteristics and is dependent on nestin expression.

Pancreatic solitary and synchronous metastasis from breast cancer: a case report and systematic review of controversies in diagnosis and treatment

Background

Metastases from breast cancer cause the frequent involvement of lung, bone, liver, and brain, while the occurrence of metastases to the gastrointestinal tract is rare, and more frequently discovered after a primary diagnosis of breast cancer. Solitary pancreatic metastases from breast cancer, without widespread disease, are actually unusual, and only 19 cases have been previously described; truly exceptional is a solitary pancreatic metastasis becoming evident together with the primary breast cancer.

Case presentation

A 68-year-old woman reported general fatigue, lethargy, and jaundice. Abdominal ultrasound (US) and magnetic resonance imaging (MRI) showed an ampulloma of Vater’s papilla; moreover, a neoplastic nodule in the left breast was diagnosed. She underwent surgery for both breast cancer and ampulloma of Vater’s papilla. Pathological examination of pancreatic specimen, however, did not confirm primary carcinoma of the duodenal papilla, but showed a metastatic involvement of pancreas from lobular breast cancer. Immunohistochemistry has been essential to confirm the origin of the malignancy: hormone receptors and mammaglobin were expressed in both the primary breast tumor and the pancreatic metastasis.

Conclusions

This is one of the few reported cases in literature of an isolated and synchronous pancreatic metastasis from breast cancer, where the definitive diagnosis was obtained only after surgery. We discuss the controversies in this diagnosis and the choice of correct treatment. The surgical resection of solitary metastases can be performed in the absence of disseminated disease.

Solid-pseudopapillary neoplasm of the pancreas: cytomorphologic findings and literature review

BACKGROUND

Solid-pseudopapillary neoplasm (SPN) is a rare pancreatic malignancy with an excellent prognosis. It is most commonly diagnosed in young women. This article comprehensively reviews the clinical, pathological and radiological features of this neoplasm, as well as its clinical management.

METHODS

A literature review of SPN was performed of all articles published in the English language in PubMed prior to November 1, 2013. Cytomorphological features, histopathology, immunohistochemistry, patient general demographics, molecular studies, radiologic imaging and clinical management were reviewed.

RESULTS

SPN displays distinct cytomorphological features on fine-needle aspiration - thin, delicate, branching vessels in a 'Chinese character' pattern lined by one to several layers of loosely cohesive neoplastic cells. Nuclear features include indented or grooved nuclei with an evenly distributed chromatin pattern and small inconspicuous nucleoli. SPN is characteristically immunoreactive for CD10, β-catenin (in an abnormal nuclear pattern), CD99 in a perinuclear dot-like pattern, α1-antitrypsin, and progesterone receptor. Almost all SPNs harbor an activating point mutation in exon 3 of the β-catenin gene (CTNNB1). Clinicopathological features generally do not correlate with prognosis, and most patients experience excellent long-term survival.

CONCLUSIONS

SPN can mimic other neoplasms of the pancreas, which can lead to diagnostic challenges in a limited cytologic specimen. Distinct cytomorphological features can help distinguish SPNs from other pancreatic neoplasms. Complete surgical resection as well as resection of metastatic disease is preferred given a low rate of tumor recurrence and long periods of disease-free intervals.

Interest of intraoperative ultrasonography during pancreatectomy for metastatic renal cell carcinoma

BACKGROUND

Isolated pancreatic metastases from renal cell carcinoma may be treated by surgical resection in a curative intent. As they are frequently multiple, a good imaging workup is mandatory to plan the appropriate resection. The aim of this study was to define the imaging workup that should be performed in this setting.

METHODS

We reviewed all patients who underwent pancreatic resection for metastasis of renal cell carcinoma in a single centre during a 20-year period. The results of the intraoperative ultrasonography were compared to those of the preoperative imaging and the final pathology results.

RESULTS

Thirteen patients were studied. A CT scan was always performed whereas only three patients had a MRI (only one revealed another tumor). Intraoperative ultrasonography found new tumors in 50% of patients when it was performed (4/8) and modified the management in 40% of them, while preoperative PET scan was useless.

CONCLUSIONS

Intraoperative ultrasonography is a low-cost and non-invasive technique that should be routinely included in the surgical exploration of pancreatic metastases from renal carcinoma.

Accuracy of endoscopic ultrasound-guided fine-needle aspiration in the suspicion of pancreatic metastases

Background

Metastases to the pancreas are rare, and usually mistaken for primary pancreatic cancers. This study aimed to describe the histology results of solid pancreatic tumours obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for diagnosis of metastases to the pancreas.

Methods

In a retrospective review, patients with pancreatic solid tumours and history of previous extrapancreatic cancer underwent EUS-FNA from January/1997 to December/2010. Most patients were followed-up until death and some of them were still alive at the end of the study. The performance of EUS-FNA for diagnosis of pancreatic metastases was analyzed. Symptoms, time frame between primary tumour diagnosis and the finding of metastases, and survival after diagnosis were also analyzed.

Results

37 patients underwent EUS-FNA for probable pancreas metastases. Most cases (65%) presented with symptoms, especially upper abdominal pain (46%). Median time between detection of the first tumour and the finding of pancreatic metastases was 36 months. Metastases were confirmed in 32 (1.6%) cases, 30 of them by EUS-FNA, and 2 by surgery. Other 5 cases were non-metastatic. Most metastases were from lymphoma, colon, lung, and kidney. Twelve (32%) patients were submitted to surgery. Median survival after diagnosis of pancreatic metastases was 9 months, with no difference of survival between surgical and non-surgical cases. Sensitivity, specificity, positive and negative predictive values, and accuracy of EUS-FNA with histology analysis of the specimens for diagnosis of pancreatic metastases were, respectively, 93.8%, 60%, 93.8%, 60% and 89%.

Conclusion

EUS-FNA with histology of the specimens is a sensitive and accurate method for definitive diagnosis of metastatic disease in patients with a previous history of extrapancreatic malignancies.

Role of endoscopic ultrasonography in evaluation of metastatic lesions to the pancreas: a tertiary cancer center experience

OBJECTIVES

Metastatic lesions to the pancreas pose diagnostic challenges with regards to their differentiation from primary pancreatic cancer. Data on the yield of endoscopic ultrasonography (EUS)-guided fine-needle aspiration in detection of these lesions are limited.

METHODS

This is a retrospective review of 23 patients referred to a tertiary referral center for further evaluation of suspected pancreatic metastases. Main outcome measures were diagnostic yield of endoscopic ultrasonography-guided fine-needle aspiration in evaluation of metastatic lesions to the pancreas.

RESULTS

Of 644 patients, 23 (3.6%) undergoing EUS of the pancreas were diagnosed to have metastatic disease to the pancreas based on clinical, radiological, and cytological results. Mean (SD) age was 64.3 (11.7) years. Of the 23 patients, 18 (78.3%) were asymptomatic. Mean (SD) size of lesion on EUS was 39.1 (19.9) mm. A diagnosis of malignant lesion was made in 21 of 23 cases, with a diagnostic accuracy of 91.3%.

CONCLUSIONS

Metastatic lesions to the pancreas present as incidental, solitary mass lesions on staging or surveillance imaging. Endoscopic ultrasonography-guided fine-needle aspiration is an important tool in the characterization and further differentiation of metastatic lesions to the pancreas from primary pancreatic cancer.

State-of-the-art PET/CT of the pancreas: current role and emerging indications

Fused positron emission tomography (PET)/computed tomography (CT) is a recently developed technology that couples the functional information of PET with the anatomic details of CT. Integrated PET/CT scanners produce both PET and contrast material-enhanced CT images of the entire body in one setting. Typically, the amount of fluorine 18 (18F) fluorodeoxyglucose (FDG) uptake in normal pancreatic parenchyma is insignificant compared with that of the liver. However, both malignant (eg, adenocarcinoma) and benign (eg, acute pancreatitis) pancreatic conditions may demonstrate intense FDG uptake. PET/CT provides an opportunity to depict pancreatic tumors and distant metastases, perform preoperative staging, and monitor response to treatment, and it has proved useful in distinguishing postoperative fibrosis from recurrence. In selected cases, PET/CT findings may be used to help diagnose autoimmune pancreatitis mimicking a mass by depicting systemic involvement. PET/CT may also be used to direct biopsy to sites more likely to yield representative tumor tissue. Novel radiolabeled molecules, such as sigma-receptor ligands and 18F-3'-fluoro-3'-deoxy-l-thymidine (FLT), may play an even greater role in distinguishing tumor recurrence from postoperative fibrosis or inflammation.

Metastatic disease to the pancreas: an imaging challenge

Metastatic lesions of the pancreas are uncommon, accounting for approximately 2% of pancreatic malignancies. Many tumours involve the pancreas secondarily and may manifest with different clinical and imaging characteristics. Although many patients have widespread disease, isolated metastases can be found. Surgical management is associated with improved survival in these cases. The experience of the pancreatic surgery unit and imaging department of our hospital in many patients presenting with pancreatic metastases is presented, and a review of the recent literature is undertaken. Main Messages • The early recognition of secondary pancreatic tumours on US, CT and MRI is extremely important. • Pancreatic metastases may mimic primary pancreatic adenocarcinoma or induce acute pancreatitis. • Most pancreatic metastases are discovered on a CT examination performed for follow-up.

Unusual solid pancreatic tumors

The vast array of possible histologies for a given pancreatic mass makes the specific diagnosis of a solid pancreatic mass in an individual patient challenging. This article discusses and reviews the imaging findings of those entities that are likely to be encountered in clinical practice, specifically pancreatic endocrine tumors, solid pseudopapillary tumor, secondary pancreatic masses, and heterotopic spleen.

Multimodality imaging of neoplastic and nonneoplastic solid lesions of the pancreas

Solid lesions of the pancreas represent a heterogeneous group of entities that can be broadly classified as either neoplastic or nonneoplastic. Neoplastic lesions include pancreatic adenocarcinoma, pancreatic neuroendocrine tumor, solid pseudopapillary tumor, pancreatoblastoma, pancreatic lymphoma, metastases to the pancreas, and rare miscellaneous neoplasms. Nonneoplastic lesions include focal pancreatitis, fatty infiltration-replacement, intrapancreatic accessory spleen, congenital anomalies such as prominent pancreatic lobulation and bifid pancreatic tail (pancreatic bifidum), and rare miscellaneous lesions (eg, pancreatic sarcoidosis, Castleman disease of the pancreas). A variety of imaging modalities are available for assessing these solid lesions, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging, endoscopic US, and hybrid nuclear imaging techniques such as single photon emission computed tomography-CT and positron emission tomography-CT, each of which has its own strengths and limitations. Accurate diagnosis can be challenging, and use of a multimodality imaging approach is often helpful in equivocal or complex cases. Knowledge of relevant clinical information and key radiologic features is essential for confident lesion characterization and differentiation.

Resection for secondary malignancy of the pancreas

OBJECTIVES

This study tried to clarify the role of pancreatic resection in the treatment of secondary malignancy with metastasis or local invasion to the pancreas in terms of surgical risk and survival benefit.

METHODS

Data of secondary malignancy of the pancreas from our 19 patients and cases reported in the English literature were pooled together for analysis.

RESULTS

There were 329 cases of resected secondary malignancy of the pancreas, including 241 cases of metastasis and 88 cases of local invasion. The most common primary tumor metastatic to the pancreas and amenable to resection was renal cell carcinoma (RCC) (73.9%). More than half (52.3%) of the primary cancers with local invasion to the pancreas were colon cancer, and nearly half (40.9%) were stomach cancer. The median metastatic interval was 84 months (7 years) for overall primary tumors and 108 months (9 years) for RCC. The 5-year survival for secondary malignancy of the pancreas after resection was 61.1% for metastasis and 58.9% for local invasion, with 72.8% for RCC metastasis, 69.0% for colon cancer, and 43.8% for stomach cancer with local invasion to the pancreas.

CONCLUSIONS

Pancreatic resection should not be precluded for secondary malignancy of the pancreas because long-term survival could be achieved with acceptable surgical risk in selected patients.

Multidetector computed tomography in the study of pancreatic metastases

PURPOSE

The aim of this study was to explore the diagnostic performance of multidetector computed tomography (MDCT) in characterising pancreatic metastases.

MATERIALS AND METHODS

CT examinations of 17 patients affected by pancreatic metastases were retrospectively reviewed. The primary malignancy was renal cell carcinoma (RCC) in eight cases, uterine leiomyosarcoma in two, lung carcinoma in four and breast carcinoma in three. CT images were assessed for lesion number, size and morphology.

RESULTS

Pancreatic lesions were solitary in seven cases and multiple in ten. Lesion size ranged between 8 and 40 mm. Metastases from RCC were hyperattenuating in the arterial phase, metastases from breast cancer and lung cancer were hypoattenuating and metastases from uterine leiomyosarcoma were inhomogeneous. Precise lesion characterisation was obtained by using CT examination in 12 cases. In the remaining five patients, all with solitary metastases from RCC, a precise diagnosis was not possible because the lesions could not be differentiated from a neuroendocrine tumour.

CONCLUSIONS

MDCT allowed pancreatic metastases characterisation in 70.5% of cases. The lesions were the manifestation of widely disseminated neoplastic disease, with the exception of metastases from RCC, which were exclusively located in the pancreas.

FDG PET/CT demonstration of pancreatic metastasis from prostate cancer

We report the hybrid FDG PET/CT appearance of a biopsy-proven pancreatic metastasis from prostate cancer in a man with castrate-resistant metastatic disease. The common sites of metastases from prostate cancer are bone and locoregional lymph nodes. Pancreas is an atypical location of metastasis from prostate cancer. PET/CT in this case helped with the targeted pathologic confirmation to differentiate primary pancreatic tumor from an unusual metastasis from prostate cancer which in turn impacted the clinical management.

Part 1: CT characterisation of pancreatic neoplasms: a pictorial essay

The pancreas is a site of origin of a diverse range of benign and malignant tumours, and these are frequently detected, diagnosed and staged with computed tomography (CT). Knowledge of the typical appearance of these neoplasms as well as the features of locoregional invasion is fundamental for all general and abdominal radiologists. This pictorial essay aims to outline the characteristic CT appearances of the spectrum of pancreatic neoplasms, as well as important demographic and clinical information that aids diagnosis. The second article in this series addresses common mimics of pancreatic neoplasia.

Pancreatic metastasis from prostate cancer

The pancreas is an unusual location for metastases from other primary cancers. Rarely, pancreatic metastases from kidney or colorectal cancers have been reported. However, a variety of other cancers may also spread to the pancreas. We report an exceptional case of pancreatic metastasis from prostate cancer. Differences in management between primary and secondary pancreatic tumors make recognition of metastases to the pancreas an objective of first importance. Knowledge of unusual locations for metastatic spread will reduce diagnostic delay and lead to a timely delivery of an appropriate treatment.

Isolated pancreatic metastasis of hepatocellular carcinoma after curative resection

Hepatocellular carcinoma (HCC) is a highly malignant tumor and extrahepatic metastasis is not rare. The most common organ of HCC metastasis is lung, followed by bone and adrenal gland. To the best of our knowledge, isolated pancreatic metastasis of HCC that developed after curative resection has not been described previously. We report a case of solitary pancreatic metastasis of HCC, which was found 28 mo after left hemihepatectomy for HCC. The lesion was successfully resected with the pancreas, and no other metastatic lesions have been found in follow-up.

Localized intrapancreatic malignant mesothelioma: a rare entity that may be confused with other pancreatic neoplasms

Malignant mesothelioma usually presents with diffuse involvement of the pleura or peritoneum. Circumscribed or localized malignant mesothelioma has been described in these locations, as well as the viscera, in which case it may cause diagnostic confusion with other, more common entities. Herein, we describe the first well-documented case of primary intrapancreatic malignant mesothelioma in the English literature. The patient was an otherwise healthy 39-year-old woman who presented with a symptomatic mass in the head of the pancreas that was completely resected via pancreaticoduodenectomy. The tumor was composed of cysts, papillae, and tubules lined by cells with abundant eosinophilic cytoplasm and immunohistochemically expressed CA-125, calretinin, and D2-40. Follow-up revealed no evidence of residual or recurrent disease 32 months after surgery. This report also describes the clinical and pathologic characteristics of an intrapancreatic mesothelioma and provides a review of the literature regarding entities that may be considered in the differential diagnosis of this tumor.

Acute cholangitis due to pancreatic metastasis from squamous cell lung carcinoma: a case report and review of literature

Introduction

The pancreas is a well-documented but relatively uncommon site of non-small-cell cancer metastases. However, at the time of diagnosis the disease is usually locoregionally advanced, therefore therapeutic management is mostly palliative and symptomatic.

Case Presentation

We report the case of a 77-year-old Caucasian male patient who presented initially with a clinical picture of acute cholangitis approximately 2 years after a left lower lobectomy for a low-grade squamous lung carcinoma. CT scan imaging of the abdomen and chest revealed an abnormal growth of the pancreatic head and distention of both the intra- and extra-hepatic billiary tree, whereas osteolytic abnormalities were observed of the 5th left rib, consistent with secondary deposits. Initially an endoscopic retrograde cholangio-pancreatography (ERCP) and sphincterectomy was performed and a plastic stent was placed in the common bile duct to decompress the biliary tree. Cytological examination of the aspirate collected by FNA of the pancreatic lession under EUS guidance revealed cells consistent with a low grade squamous lung carcinoma. Two months later an open cholecystectomy along with a gastrojejunostomy was performed to relieve the patient's gastric outlet obstruction symptoms. Following remission of the patient's attack of acute cholangitis and excessive vomiting he was released from the hospital and instructed to initiate chemotherapy with vinorelbine. The patient succumbed to disseminated disease almost 5 months later.

Conclusion

Symptomatic metastatic lesions of the pancreas from squamous cell carcinoma of the lung are infrequent. Typically, the patients remain asymptomatic until their disease reaches a fairly advanced stage and therapeutic options are limited to palliative measures. A high index of suspicion is the only way of early detection and potentially effective treatment for this rare localization of metastatic squamous lung carcinoma.

Systematic review of pancreatic surgery for metastatic renal cell carcinoma

BACKGROUND

This study examined the clinical outcome of patients with pancreatic metastases from renal cell carcinoma (RCC).

METHODS

A systematic literature search produced individual data for 311 surgically and 73 non-surgically treated patients with pancreatic RCC metastases. A further ten patients underwent resection at the authors' institution.

RESULTS

In the resected group, pancreatic metastases were solitary in 65.3 per cent, symptomatic in 57.4 per cent, and were preceded and/or accompanied by extrapancreatic disease in 22.3 per cent. Respective values in the unresected group were 59, 60 and 58 per cent. Disease-free survival rates were 76.0 and 57.0 per cent respectively at 2 and 5 years after resection, and overall survival rates were 80.6 and 72.6 per cent. The only significant risk factor for disease-free survival after pancreatic resection was extrapancreatic disease (P = 0.001), and that for overall survival was symptomatic RCC metastasis (P = 0.031). Two- and 5-year overall survival rates were 41 and 14 per cent respectively in unresected patients.

CONCLUSION

The actuarial 5-year overall survival rate following pancreatic surgery for RCC metastases was 72.6 per cent, as determined by pooled analysis from published series. Extrapancreatic disease was an independent risk factor for recurrence, but had no significant impact on overall survival.

Metastasis to the pancreas from colorectal cancer: is there a place for pancreatic resection?

PURPOSE

Pancreatic metastases from colorectal cancer are very rare, and the possible benefit of surgical treatment is not clearly defined. This study was designed to evaluate the outcome of patients undergoing pancreatic resection for metastatic colorectal cancer to the pancreas.

METHODS

Nine patients underwent pancreatic resection for metastatic colorectal cancer between January 1980 and December 2006. The primary cancers were colon (n = 7) and rectal carcinoma (n = 2). The median interval between primary treatment and detection of pancreatic metastases was 32.5 months. In three cases pancreatic metastases were synchronous with the primary tumor.

RESULTS

Five patients underwent pancreaticoduodenectomy, and four underwent distal pancreatectomy. A left lateral liver section and three colon resections were simultaneously performed in four patients. There was no postoperative mortality, and only two patients experienced complications. Survival averaged 19.8 (median, 17.0; range, 5-30) months: seven patients died of metastatic disease, one for unrelated disease after five months, and one is alive with liver metastases 30 months after surgery.

CONCLUSION

Surgical resection can be performed safely in patients with isolated pancreatic metastases from colorectal cancer and in selected patients with associated extrapancreatic disease. Although long-term survival is rare, surgery should be included, whenever possible, in the multimodality approach to this disease.

Usefulness of FDG-PET/CT in the detection of pancreatic metastases from lung cancer

OBJECTIVE

The objective of this study was to assess the ability to detect pancreatic metastasis of lung cancer and to clarify the degree of fluorodeoxyglucose (FDG) accumulation and computed tomography (CT) characteristics of pancreatic metastasis from lung cancer.

METHODS

A total of 573 patients (415 men and 158 women) with lung cancer were retrospectively evaluated. All patients underwent FDG-positron emission tomography (PET)/CT with contrast-enhanced CT for first=stage (313 patients; initial study group) or follow-up study (260 patients; follow-up study group). A lesion was regarded as positive for metastasis on the basis of visual judgment of the degree of increased metabolism by two experienced and independent interpreters, supported by semiquantitative evaluation on the basis of calculation of the maximum standardized uptake value (SUV(max)).

RESULTS

Abnormal accumulations in the pancreas were detected in 5 of 313 patients (1.60%) in the initial study group, and 6 of 260 patients (2.31%) in the follow-up study group. Seven of these patients had adenocarcinoma, three had small cell carcinoma, and the rest had large cell endocrine carcinoma. Tumor sizes (longitudinal diameter), measured by CT, of these 11 patients ranged from 6 mm to 52 mm (mean +/- SD 8.3 mm +/- 11.9 mm), and SUV(max) for 1 h ranged from 3.37 to 11.1 (mean +/- SD 6.12 +/- 2.43). Three of these pancreatic lesions were difficult to determine by routine transaxial images, and detection was obvious only by thin-slice images or multiplanar reconstruction images. Contrast-enhanced CT showed gradual fill-in from the peripheral portion to the center. In addition, 10 of 11 cases did not show main pancreatic duct dilatation even if the tumor size was large.

CONCLUSIONS

Metastases to the pancreas in lung cancer patients are not so rare and radiologists first have an important role to detect the pancreatic mass and then suggest to metastasis as the likely diagnosis. For this purpose, FDG-PET/CT has an advantage in depicting unsuspected pancreatic metastasis from lung cancer, particularly that which is not detected by CT alone.

Diffuse pancreatic ductal adenocarcinoma: Characteristic imaging features

PURPOSE

To evaluate imaging findings of diffuse pancreatic ductal adenocarcinoma.

MATERIALS AND METHODS

We included 14 patients (4 men and 10 women; mean age, 64.5 years) with diffuse pancreatic ductal adenocarcinoma on the basis of retrospective radiological review. Two radiologists retrospectively reviewed 14 CT scans in consensus with respect to the following: tumor site, peripheral capsule-like structure, dilatation of intratumoral pancreatic duct, parenchymal atrophy, and ancillary findings. Eight magnetic resonance (MR) examinations with MR cholangiopancreatography (MRCP) and seven endoscopic retrograde cholangiopancreatography (ERCP) were also reviewed, focusing on peripheral capsule-like structure and dilatation of intratumoral pancreatic duct.

RESULTS

CT revealed tumor localization to the body and tail in 11 (79%) patients and peripheral capsule-like structure in 13 (93%). The intratumoral pancreatic duct was not visible in 13 (93%). Pancreatic parenchymal atrophy was not present in all 14 patients. Tumor invasion of vessels was observed in all 14 patients and of neighbor organs in 8 (57%). On contrast-enhanced T1-weighted MR images, peripheral capsule-like structure showed higher signal intensity in five patients (71%). In all 11 patients with MRCP and/or ERCP, the intratumoral pancreatic duct was not dilated.

CONCLUSION

Diffuse pancreatic ductal adenocarcinoma has characteristic imaging findings, including peripheral capsule-like structure, local invasiveness, and absence of both dilatation of intratumoral pancreatic duct and parenchymal atrophy.

Ultrasonography of the pancreas. 1. Conventional imaging

Ultrasound imaging has made significant advances in recent years and plays an important role in the detection, characterization and staging of pancreatic diseases. Conventional ultrasonography (US) is a noninvasive imaging modality, which continues to be the first diagnostic step in the evaluation of the pancreas. Over its various decades of application, US have detected pancreatic pathology of great diversity. This article reviews the wide utility of US and the many examinations techniques, such as filling the stomach with water, changing the patient's position or suspending inspiration or expiration, allowing us to visualize all portions of the pancreas in a high percentage of patients.

[Pancreas. Part II: Tumors]

Adenocarcinoma is the most common malignant pancreatic tumor, affecting the head in 60-70% of cases. By the time of diagnosis, approximately 80% of tumors are unresectable. Helical CT is very effective in detection and staging of adenocarcinoma, with a sensitivity of 76-92% for detection and an accuracy of 80-90% for staging, but it has limitations in the detection of small cancers (< or =2 cm). Multidetector CT (MDCT) has brought substantial improvements with its inherent 3D imaging capability. Mangafodipir-enhanced MRI is a problem-solving tool in the depiction of small cancers following an equivocal CT imaging result. Gadolinium-enhanced 3D gradient-echo MRI is helpful in the assessment of vascular invasion of cancer and in determining the etiology of cystic lesions. Serous cystadenoma is benign, has a lobulated contour and contains innumerable small cysts of 0.1-2 cm in diameter. Mucinous cystic neoplasms are unilocular or multilocular (fewer than six cysts), and the cyst diameter exceeds 2 cm. The presence of solid nodular components should alert the radiologist to suspect cystadenocarcinoma. Neuroendocrine tumors are mostly hypervascular. Diagnosis of insulinoma is a challenge: they are <2 cm in 90% of cases and mostly hypervascular at CT or MRI. A combination of contrast-enhanced MDCT, MRI, endosonography, and/or somatostatin receptor scintigraphy is used to detect these small tumors. This review summarizes the imaging features of the most common pancreatic tumors and discusses the limitations of CT, MRI and endosonography.

Surgical treatment of metastatic tumors to the pancreas: a single center experience and review of the literature

BACKGROUND

Unlike primary pancreatic carcinoma, metastases to the pancreas are rare, and their resection may be performed as palliative treatment. The aim of this study was to review our experience with the operative management of pancreatic metastases.

MATERIALS AND METHODS

Between January 1994 and December 2004 13 patients (nine women and four men; median age: 59 years; range: 36-79 years) were admitted to our institution with metastatic lesion to the pancreas. The clinical features of the treatment and results were examined.

RESULTS

Primary tumors were renal cell carcinoma (n=5), lobular carcinoma of the breast (n=3), endometrioid carcinoma of the ovary (n=1), colonic adenocarcinoma (n=1), jejunal leiomyosarcoma (n=1), melanoma (n=1), and non-small-cell lung cancer (n=1). The median interval between primary tumor and pancreatic metastases was 36 months (range: 5-192 months). Six patients (46%) were asymptomatic, while the other seven patients presented with jaundice, pain, and duodenal obstruction. Two patients with extrapancreatic disease underwent palliative surgery, and the remaining 11 patients underwent operative procedures that included seven pancreaticoduodenectomy and four distal pancreatectomies with splenectomy. Postoperative mortality was nil, and the morbidity rate was 30%. The two patients who underwent palliative surgery died after 7 and 9 months, respectively. The median survival of the resected patients was 26 months (range: 13-95 months). Five patients died of disease, eight are alive at the time of this report.

CONCLUSION

A trend towards improved survival, even if not statistically significant, was observed in the renal carcinoma patients reported here. Surgical resection can be performed safely in selected patients with isolated metastases to the pancreas, achieving long-term survival as well as good palliation.