Imaging of the Pancreas

Secondary Tumors of the Pancreas: A Multicenter Analysis of Clinicopathological and Endosonographic Features

Many tumors may secondarily involve the pancreas; however, only retrospective autopic and surgical series are available. We retrospectively collected data from all consecutive patients with histologically confirmed secondary tumors of the pancreas referred to five Italian centers between 2010 and 2021. We described clinical and pathological features, therapeutic approach and treatment outcomes. EUS characteristics of the lesions and the tissue acquisition procedures (needle, passages, histology) were recorded. A total of 116 patients (males/females 69/47; mean age 66.7) with 236 histologically confirmed pancreatic metastases were included; kidney was the most common primary site. EUS was performed to confirm the diagnosis in 205 lesions which presented as predominantly solitary (59), hypoechoic (95) and hypervascular (60), with a heterogeneous (n = 54) pattern and well-defined borders (n = 52). EUS-guided tissue acquisition was performed in 94 patients with an overall accuracy of 97.9%. Histological evaluation was possible in 88.3% of patients, obtaining final diagnosis in all cases. When cytology alone was performed, the final diagnosis was obtained in 83.3% of cases. A total of 67 patients underwent chemo/radiation therapy, and surgery was attempted in 45 (38.8%) patients. Pancreatic metastases are a possible event in the natural history of solid tumors, even long after the diagnosis of the primary site. EUS-guided fine needle biopsy may be suggested to implement the differential diagnosis.

The Role of Endoscopic Ultrasonography in the Diagnosis and Staging of Pancreatic Cancer

Pancreatic cancer is the fourth leading cause of cancer-related death and the second gastrointestinal cancer-related death in the United States. Early detection and accurate diagnosis and staging of pancreatic cancer are paramount in guiding treatment plans, as surgical resection can provide the only potential cure for this disease. The overall prognosis of pancreatic cancer is poor even in patients with resectable disease. The 5-year survival after surgical resection is ~10% in node-positive disease compared to ~30% in node-negative disease. The advancement of imaging studies and the multidisciplinary approach involving radiologists, gastroenterologists, advanced endoscopists, medical, radiation, and surgical oncologists have a major impact on the management of pancreatic cancer. Endoscopic ultrasonography is essential in the diagnosis by obtaining tissue (FNA or FNB) and in the loco-regional staging of the disease. The advancement in EUS techniques has made this modality a critical adjunct in the management process of pancreatic cancer. In this review article, we provide an overall description of the role of endoscopic ultrasonography in the diagnosis and staging of pancreatic cancer.

Gastrointestinal Intramural Pancreatic Pseudocysts in a Dog: A Case Report and Human Literature Review

A 9.5 yr old Yorkshire terrier presented with chronic intermittent vomiting and lethargy of 1.5 yr duration that progressed to generalized weakness. Insulin:glucose ratio was consistent with an insulinoma. Triple-phase computed tomography revealed a mid-body pancreatic nodule. The mid-body pancreatic nodule was enucleated; histopathology was consistent with an insulinoma. Two weeks after the operation, the dog presented for anorexia and diarrhea. Abdominal ultrasound revealed a thick-walled cystic lesion along the dorsal stomach wall. An intramural gastric pseudocyst was diagnosed via exploratory laparotomy and intraoperative gastroscopy. Comparison of amylase and lipase levels of the cystic fluid with that of concurrent blood serum samples confirmed the lesion was of pancreatic pseudocyst origin. The gastric pseudocyst was omentalized. Two weeks after the operation, the dog re-presented for anorexia, regurgitation, and diarrhea. An intramural duodenal pseudocyst was identified and treated with a duodenal resection and anastomosis. The dog has remained asymptomatic and recurrence free based on serial abdominal ultrasounds 22 mo following insulinoma removal. To our knowledge, this phenomenon of pancreatic pseudocysts forming in organs other than the pancreas has not been reported in dogs. This case report and comprehensive human literature review purpose is to raise awareness of this disease process in dogs.

The Role of Imaging in Current Treatment Strategies for Pancreatic Adenocarcinoma

In pancreatic cancer, imaging plays an essential role in surveillance, diagnosis, resectability evaluation, and treatment response evaluation. Pancreatic cancer surveillance in high-risk individuals has been attempted using endoscopic ultrasound (EUS) or magnetic resonance imaging (MRI). Imaging diagnosis and resectability evaluation are the most important factors influencing treatment decisions, where computed tomography (CT) is the preferred modality. EUS, MRI, and positron emission tomography play a complementary role to CT. Treatment response evaluation is of increasing clinical importance, especially in patients undergoing neoadjuvant therapy. This review aimed to comprehensively review the role of imaging in relation to the current treatment strategy for pancreatic cancer, including surveillance, diagnosis, evaluation of resectability and treatment response, and prediction of prognosis.

New era for pancreatic endoscopic ultrasound: From imaging to molecular pathology of pancreatic cancer

With recent advances in molecular pathology and the development of new chemotherapy regimens, the knowledge of the molecular alterations of pancreatic ductal adenocarcinoma (PDAC) is becoming appealing for stratifying patients for prognosis and response to a defined treatment. Archival formalin-fixed, paraffin-embedded samples are a useful source of genomic deoxyribonucleic acid; nevertheless, most studies employed formalin-fixed, paraffin-embedded samples deriving from surgical specimens, which are therefore representative of <20% of PDAC patients. Indeed, the development of a reliable methodology for endoscopic ultrasound-guided tissue acquisition, stabilization, and analysis is crucial for the development of molecular markers for clinical use in order to achieve “personalized medicine”. With the development of new needles, this technique is able to retrieve a high quantity and quality of PDAC tissue that can be used not only for diagnosis but also for mutational and transcriptome evaluations and for the development of primary cell or tissue cultures. In the present editorial, we discuss the current knowledge regarding the use of endoscopic ultrasound as a tool to obtain samples for molecular analyses, its possible pitfalls, and its use for the development of disease models such as xenografts or organoids.

Piezoelectric needle sensor reveals mechanical heterogeneity in human thyroid tissue lesions

Palpable thyroid lesions are common, and although mostly benign, lethal malignant nodules do occur and may be difficult to differentiate. Here, we introduce the use of a piezoelectric system called Smart-touch fine needle (or STFN) mounted directly onto conventional biopsy needles, to evaluate abnormal tissues, through quantitative real-time measurements of variations in tissue stiffness as the needle penetrates tissue. Using well-characterized biomaterials of known stiffness and explanted animal tissue models, we first established experimental protocols for STFN measures on biological tissues, as well as optimized device design for high signal-to-noise ratio. Freshly excised patient thyroids with varying fibrotic and malignant potential revealed discrete variations in STFN based tissue stiffness/stiffness heterogeneity and correlated well with final histopathology. Our piezoelectric needle sensor reveals mechanical heterogeneity in thyroid tissue lesions and provides a foundation for the design of hand-held tools for the rapid, mechano-profiling of malignant lesions in vivo while performing fine needle aspiration (FNA).

Reduced Contrast Volume and Radiation Dose During Computed Tomography of the Pancreas: Timing-Specific Contrast Media Protocol

RATIONALE AND OBJECTIVE

To investigate the opacification of the pancreatic vasculature and parenchyma during computed tomography utilizing a patient-specific contrast formula.

MATERIALS AND METHODS

This hybrid prospective and retrospective study was approved by the institution review board. In 220 consecutive patients, pancreatic CT was performed with one of two protocols: protocol A, 100mL of contrast material injected via timed bolus triggering technique; or protocol B, employing a patient-specific contrast media protocol specifically timed at the gastroduodenal artery; both protocols employed 4.5 mL/s contrast media and 100mL saline chaser. Attenuation of pancreatic parenchymal, arterial, and venous vasculature supplying the pancreas was measured. Effective dose was calculated. Data were compared to the independent two-sample t test. Receiver operating characteristic, visual grading characteristic, and Cohens' kappa analyses were performed.

RESULTS

Mean pancreatic density measurements in each of the pancreatic segments during the arterial and venous phase were significantly higher in Protocol B (mean ± standard deviation, art: 96.59 HU ± 27.37; venous: 91.28 HU ± 20.88) compared to A (art: 77.86 HU ± 21.14; venous: 73.99 HU ± 14.75) (p < 0.0001). Mean arterial opacification was significantly higher in protocol B compared to A with the abdominal aorta (p < 0.007), superior mesenteric (p < 0.0002), gastroduodenal (proximal segment only p < 0.014), and splenic arteries (p < 0.036). In the venous circulation, the inferior vena cava, superior mesenteric, portal and splenic veins (all segments) demonstrated significant reduction in vascular opacification protocol B compared to A (p < 0.001). The contrast media volume in protocol B (57.60 ± 12.25 mL) was significantly lower than in protocol A (100 ± 1 mL) (p < 0.001). Effective dose was significantly reduced in protocol B (2.75 ± 0.63 mSv) compared to A (4.015 ± 0.89 mSv) (p < 0.001). Receiver operating characteristic and visual grading characteristic analysis demonstrated significantly higher area under the curve for protocol B (p < 0.0001) (p < 0.034) respectively, with inter-reader agreement increasing from good to excellent in pancreatic lesion detection.

CONCLUSION

Timing-specific contrast media protocol enhances image quality at reduced contrast volume and radiation dose during computed tomography of the pancreas.

Irreversible electroporation in a case of pancreatic leiomyosarcoma: a novel weapon versus a rare malignancy?

Background

Primary pancreatic leiomyosarcoma is an extremely rare entity that needs high clinical suspicion in order to diagnose it at an early stage. Clinical characteristics, diagnosis, and management still remain challenging and controversial, especially in advanced stages, when tumor invades adjacent vessels and organs or gives distant metastases.

Case presentation

Herein, we describe a case of a 57-year-old woman suffering from advanced pancreatic leiomyosarcoma with thrombosis of the superior mesenteric vein, as well as liver lesions which were suspicious for metastasis. Multidisciplinary team decided for upfront chemotherapy to assess tumor response. Follow-up imaging after the completion of chemotherapy led tumor board to decide for subsequent surgical exploration. The patient underwent exploratory laparotomy and irreversible electroporation ablation of the pancreatic tumor. Postoperative course was uneventful, and she was discharged 10 days later with a plan to receive adjuvant therapy. To the best of our knowledge, this is the first case of pancreatic leiomyosarcoma ever reported, treated with this novel technique of irreversible electroporation that could be an alternative and feasible way for the management of these rare malignancies.

Conclusions

In conclusion, primary pancreatic leiomyosarcoma is a rare and highly malignant tumor associated with poor prognosis. Nowadays, R0 surgical resection remains the cornerstone treatment, combined with adjuvant and/or neoadjuvant chemotherapy prior to resection. In the advanced setting, when major vessel invasion and distant metastases occur, chemotherapy along with irreversible electroporation ablation could be a helpful and possibly effective modality for the management of this highly aggressive tumor.

Subharmonic and Endoscopic Contrast Imaging of Pancreatic Masses: A Pilot Study

OBJECTIVES

To use subharmonic imaging (SHI) to depict the vascularity of pancreatic masses compared to contrast-enhanced endoscopic ultrasound (EUS) and pathologic results.

METHODS

Sixteen patients scheduled for biopsy of a pancreatic mass were enrolled in an Institutional Review Board-approved study. Pulse-inversion SHI (transmitting/receiving at 2.5/1.25 MHz) was performed on a LOGIQ 9 system (GE Healthcare, Milwaukee, WI) with a 4C transducer, whereas contrast harmonic EUS (transmitting/receiving at 4.7/9.4 MHz) was performed with a radial endoscope (GF-UTC180; Olympus Corporation, Tokyo, Japan) connected to a ProSound SSD α-10 scanner (Hitachi Aloka, Tokyo, Japan). Two injections of the contrast agent Definity (Lantheus Medical Imaging, North Billerica, MA) were administrated (0.3-0.4 and 0.6-0.8 mL for EUS and SHI, respectively). Contrast-to-tissue ratios (CTRs) in the mass and an adjacent vessel were calculated. Four physicians independently scored the images (benign to malignant) for diagnostic accuracy and inter-reader agreement.

RESULTS

One patient dropped out before imaging, leaving 11 adenocarcinomas, 1 gastrointestinal stromal tumor with pancreatic infiltration, and 3 benign masses. Marked subharmonic signals were obtained in all patients, with intratumoral blood flow clearly visualized with SHI. Significantly greater CTRs were obtained in the masses with SHI than with EUS (mean ± SD, 1.71 ± 1.63 versus 0.63 ± 0.89; P = .016). There were no differences in the CTR in the surrounding vessels or when grouped by pathologic results (P > .60). The accuracies for contrast EUS and SHI were low (<53%), albeit with a greater κ value for SHI (0.34) than for EUS (0.13).

CONCLUSIONS

Diagnostic accuracy of contrast EUS and transabdominal SHI for assessment of pancreatic masses was quite low in this pilot study. However, SHI had improved tumoral CTRs relative to contrast EUS.

Intramural gastric pseudocyst: A case report and a comprehensive literature review

RATIONALE

Intramural pseudocyst, although first reported several decades ago, is a rare entity. Scientific knowledge regarding its clinical management is sparse.

PATIENT CONCERNS

We present three cases to show the diverse clinical patterns of patients diagnosed with an intramural gastric pseudocyst.

DIAGNOSIS

A final diagnosis should rest on proper evaluation by cross sectional imaging, including computer tomography and magnetic resonance imaging. Endoscopic ultrasound adds to the work-up.

INTERVENTIONS

Previously, identified "lesions of the gastric wall" were not well recognized as an intramural pseudocyst, and treatments including resectional surgery were employed. Contemporary proper diagnostics should provide support to a less aggressive treatment approach.

OUTCOMES

While an indolent natural history without any clinical symptoms or discomfort could be expected in most cases, individual clinical evaluation should be applied.

LESSONS

A heterogeneous information pattern from the limited number of cases in the literature makes it difficult to draw any firm conclusions. Attention to this rare condition should be increased to help clinicians arrive at a correct diagnosis and possibly prevent some patients from being over treated or from the use of unnecessary surgery.

Primary Leiomyosarcoma of the Pancreas-a Case Report and a Comprehensive Review

Purpose

Primary mesenchymal tumors of the pancreas are rare, with leiomyosarcomas the most encountered entities among the pancreatic sarcomas. With few exceptions, single case reports published over the last six decades constitute the entire scientific literature on this topic. Thus, evidence regarding clinical decision-making is scant.

Methods

Based on a case report and an extensive literature search in PubMed, we discuss the clinical aspects and current management of this rare malignancy.

Results

We identified only two papers with more than a single case presentation; these institutional patient series were limited to five and nine patients. Additionally, a few papers sought to summarize the individual case reports published in the English and/or Chinese language. The clinical presentation is rather non-specific. Moreover, modern imaging modalities are insufficiently accurate to diagnose leiomyosarcoma of the pancreas. Treatment goals include a complete resection with free margins. Proper morphologic examination using immunohistochemistry and the application of a grading system are clinically important for prognostication. The efficacy of adjuvant treatments has not been established.

Conclusion

Primary pancreatic leiomyosarcoma is extremely rare, and the scientific literature is primarily based on single case reports. Conclusions on management and prognosis should be drawn with caution. A multidisciplinary team consultation is warranted to discuss a thorough individual treatment plan based on the available scientific literature, despite its low evidence level.