Differentiation between pancreatic metastases from renal cell carcinoma and hypervascular neuroendocrine tumour: Use of relative percentage washout value and its clinical implication

Refinement of nBCA embolization technique in treatment of metastatic spinal tumors: Case series and technical report

BACKGROUND AND OBJECTIVES

Preoperative embolization of metastatic spinal tumors (MSTs) has proven advantageous in limiting intraoperative blood loss (IBL) during resection. N-butyl cyanoacrylate (nBCA) is a liquid embolic agent known for its rapid hemostatic effects. However, nBCA is associated with a higher risk of distal nontarget embolization. This study highlights the refinement of the embolization technique and assesses its efficacy in performing an initial distal segmental artery plug with concentrated nBCA followed by proximal diluted nBCA for MSTs.

METHODS

A retrospective review of patients with MST (2018-2023) was performed. Patients who underwent preoperative nBCA endovascular embolization prior to tumor resection and spinal instrumentation were included. Baseline standard spinal angiography was performed.

RESULTS

Sixteen patients (13 men, 3 women; 56.0 ± 12.4 years) met inclusion criteria. And 43.75% (7 of 16) had thoracic levels, 37.5% (6 of 16) lumbar, and 18.75% (3 of 16) sacral. The most common primary tumor was renal cell carcinoma (43.75%, 7 of 16). A total of 43 pedicles were embolized (median 3), resulting in complete/near complete obliteration of the tumor blush. Most pedicles (83.7%, 36 of 43) received a single dilute concentration of nBCA; however, 16.3% (7 of 43) received two separate concentrations of nBCA, a denser concentration distally into the segmental artery and a diluted concentration proximally into the tumor bed. Mean IBL was 1150 ± 1201 mL in 3 distal plug patients distal plug patients versus 1625 ± 681 mL in 12 other patients. There were no complications related to embolization.

CONCLUSION

Performing a distal, concentrated nBCA plug during preoperative nBCA embolization of MSTs may increase tumor penetration and reduce IBL.

Metastatic Renal Cell Carcinoma to Pancreas: Case Series and Review of the Literature

Metastasis to the pancreas represents a small proportion of all pancreatic malignancies. Among primary tumors that metastasize to the pancreas, renal cell carcinoma (RCC) is one of the most common causes of metastatic pancreatic lesions. We herein report a case series of three patients with pancreatic metastasis from RCC. The first is a 54-year-old male with a history of left nephrectomy for RCC, in whom an isthmic pancreatic mass suggestive of a neuroendocrine lesion was found during oncological follow-up. Endoscopic ultrasound (EUS)-guided fine needle biopsy (FNB) identified pancreatic metastasis of RCC and the patient was referred for surgery. The second case is a 61-year-old male, hypertensive, diabetic, with left nephrectomy for RCC six years previously, who complained of weight loss and was found with a hyperenhancing mass in the head of the pancreas and a lesion with a similar pattern in the gallbladder. EUS-FNB from the pancreas proved to be a metastatic pancreatic lesion. Cholecystectomy and treatment with tyrosine kinase inhibitors were recommended. The third case is a 68-year-old dialysis patient referred for evaluation of a pancreatic mass, also confirmed by EUS-FNB, who was started on sunitinib treatment. We report a literature summary on epidemiology and clinical features, diagnosis and differential diagnosis and treatment and outcomes in pancreatic metastasis of RCC.

Metastatic Renal Cell Carcinoma to Pancreas: Case Series and Review of the Literature

Metastasis to the pancreas represents a small proportion of all pancreatic malignancies. Among primary tumors that metastasize to the pancreas, renal cell carcinoma (RCC) is one of the most common causes of metastatic pancreatic lesions. We herein report a case series of three patients with pancreatic metastasis from RCC. The first is a 54-year-old male with a history of left nephrectomy for RCC, in whom an isthmic pancreatic mass suggestive of a neuroendocrine lesion was found during oncological follow-up. Endoscopic ultrasound (EUS)-guided fine needle biopsy (FNB) identified pancreatic metastasis of RCC and the patient was referred for surgery. The second case is a 61-year-old male, hypertensive, diabetic, with left nephrectomy for RCC six years previously, who complained of weight loss and was found with a hyperenhancing mass in the head of the pancreas and a lesion with a similar pattern in the gallbladder. EUS-FNB from the pancreas proved to be a metastatic pancreatic lesion. Cholecystectomy and treatment with tyrosine kinase inhibitors were recommended. The third case is a 68-year-old dialysis patient referred for evaluation of a pancreatic mass, also confirmed by EUS-FNB, who was started on sunitinib treatment. We report a literature summary on epidemiology and clinical features, diagnosis and differential diagnosis and treatment and outcomes in pancreatic metastasis of RCC.

Misdiagnosis of pancreatic metastasis from renal cell carcinoma: A case report

BACKGROUND

Pancreatic metastases account for only a small proportion of all pancreatic malignancies. Isolated pancreatic metastasis from renal cell cancer (isPM-RCC) is extremely rare and may be difficult to differentiate from more common primary neoplasms. A history of nephrectomy is crucial for the diagnosis.

CASE SUMMARY

We report the case of a 64-year-old Asian man who was diagnosed with a mass in the pancreatic head using computed tomography. He had no related symptoms, and his medical history was unremarkable, except for unilateral nephrectomy performed to remove a “benign” tumor 19 years ago. All preoperative imaging findings suggested a diagnosis of pancreatic neuroendocrine tumor. However, ultrasound-guided biopsy revealed features of clear cell renal cell carcinoma (ccRCC). Re-examination of the specimen resected 19 years ago confirmed that he had a ccRCC. The pancreatic mass was resected and pathological examination confirmed isPM-RCC.

CONCLUSION

Misdiagnosis of isPM-RCC is common because of its rarity and the long interval from resection of the primary tumor and manifestation of the metastasis. The history of the previous surgery may be the only clue.

Differentiation between pancreatic metastases from renal cell carcinoma and pancreatic neuroendocrine neoplasm using endoscopic ultrasound

OBJECTIVES

Pancreatic metastases from renal cell carcinoma (PRCC) often appear many years after treatment of the primary tumor, and differentiation from pancreatic neuroendocrine neoplasm (PanNEN) can be challenging due to their hypervascularity. Here, we investigated the utility of endoscopic ultrasound (EUS) for differentiation of these conditions.

METHODS

A retrospective analysis was performed in 17 and 79 consecutive patients with pathologically proven PRCC and non-functional PanNEN who were examined by EUS. In cases examined by EUS elastography or contrast-enhanced harmonic EUS (CH-EUS), the lesions were classified as stiff or soft, or into three vascular patterns as hypoechoic, isoechoic, and hyperechoic. CH-EUS images at 20 s, 40 s, 60 s, 3 min and 5 min were used for evaluation. EUS images were independently reviewed by two readers who were blinded to all clinical information.

RESULTS

The patients with PRCC were significantly older than those with PanNEN (median, 71 (range, 45-81) vs. 58 (22-76), P = 0.001) and more often had multiple tumors (6/17 (35%) vs. 7/79 (9%), P = 0.010). In EUS findings, PRCC lesions significantly more frequently had a marginal hypoechoic zone (MHZ) (11/17 (65%) vs. 27/79 (34%), P = 0.028), being classified as soft (12/13 (92%) vs. 26/58 (45%), P = 0.002), and showed sustained hyperechoic vascular patterns at 5 min (7/8 (88%) vs. 4/59 (7%), P < 0.001) compared to PanNEN lesions.

CONCLUSIONS

The presence of a MHZ, a soft lesion, and a sustained hyperechoic vascular pattern in EUS may be useful for differentiating PRCC from PanNEN.

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.

A case of hypervascular tumors in the liver and pancreas: synchronous hepatocellular carcinoma and pancreatic metastasis from renal cell carcinoma 36 years after nephrectomy

It is sometimes difficult to distinguish between multiple cancers and metastases using only diagnostic imaging, particularly when multiple hypervascular tumors are found in multiple organs. We present a case in which the preoperative histological evaluation was essential to determine the management of a hypervascular pancreatic tumor and liver tumor.

CT and MRI of pancreatic tumors: an update in the era of radiomics

Radiomics is a relatively new approach for image analysis. As a part of radiomics, texture analysis, which consists in extracting a great amount of quantitative data from original images, can be used to identify specific features that can help determining the actual nature of a pancreatic lesion and providing other information such as resectability, tumor grade, tumor response to neoadjuvant therapy or survival after surgery. In this review, the basic of radiomics, recent developments and the results of texture analysis using computed tomography and magnetic resonance imaging in the field of pancreatic tumors are presented. Future applications of radiomics, such as artificial intelligence, are discussed.

Current Challenges in Diagnosis and Assessment of the Response of Locally Advanced and Metastatic Renal Cell Carcinoma

Locally advanced and metastatic renal cell carcinoma (RCC) present a specific set of challenges to the radiologist. The detection of metastatic disease is confounded by the ability of RCC to metastasize to virtually any part of the human body long after surgical resection of the primary tumor. This includes sites not commonly included in routine surveillance, which come to light after the patient becomes symptomatic. In the assessment of treatment response, the phenomenon of tumor heterogeneity, where clone selection through systemic therapy drives the growth of potentially more aggressive phenotypes, can result in oligoprogression despite overall disease control. Finally, advances in therapy have resulted in the development of immuno-oncologic agents that may result in changes that are not adequately evaluated with conventional size-based response criteria and may even be misinterpreted as progression. This article reviews the common challenges a radiologist may encounter in the evaluation of patients with locally advanced and metastatic RCC. ^©RSNA, 2019.

Rare Solid Tumor of the Exocrine Pancreas: A Pictorial Review

Numerous other solid primary neoplasms may arise from the pancreas besides primary ductal adenocarcinomas and neuroendocrine tumors. Although diagnosis can be difficult because of the very low incidence of these tumors, knowledge of several, typical, epidemiologic, biological, and imaging features can help obtain a correct diagnosis. This pictorial review describes the features of solid rare primary pancreatic neoplasms on computed tomography and magnetic resonance imaging focusing on characteristics that can help radiologists differentiate them from classical forms of ductal pancreatic adenocarcinoma and neuroendocrine tumors. Cystic pancreatic neoplasms are beyond the scope of the current review.

Resection of pancreatic metastatic renal cell carcinoma: experience and long-term survival outcome from a large center in China

Purpose

This study aimed to determine the outcome of pancreatic metastatic renal cell carcinoma (PmRCC) after treatment and share the relevent results.

Methods

In total, 13 patients with PmRCC were diagnosed and treated in our institution from December 2013 to October 2017. We retrospectively reviewed the records and analyzed the patient demographics, perioperative outcomes, and overall survival. Simultaneously, our experience including treatment and misdiagnosis was shared.

Results

The median time between nephrectomy and reoperation for pancreatic recurrence was 11 years (range 1–20 years). Four patients had multiple tumors and nine patients had solitary tumor. Five patients accepted distal pancreatectomy, and five patients underwent pancreaticoduodenectomy. One patient underwent total pancreatectomy, one patient underwent duodenum-preserving pancreatic head resection plus distal pancreatectomy, and one patient underwent exploratory laparotomy and gastrointestinal bypass due to widespread metastasis with clear obstructive symptoms. The misdiagnosis rate of preoperative diagnosis at our center was 69.2% (9/13). The median follow-up duration was 26 months (range 7–53 months, until June 2018). By the end of follow-up, 12 patients were alive and one patient died of gastrointestinal bleeding within 1 month after surgery.

Conclusions

PmRCCs are uncommon, but pancreatic metastasectomy has a relatively good prognosis and may, therefore, be a good therapeutic choice for patients with PmRCCs. Because PmRCC occurs long after the primary tumor resection, long-term follow-up is necessary. Besides, detailed medical history and specific manifestation in imaging features could contribute to avoiding misdiagnosis.

Differentiation of pancreatic neuroendocrine tumors from pancreas renal cell carcinoma metastases on CT using qualitative and quantitative features

PURPOSE

To assess qualitative and quantitative imaging features on enhanced CT that may differentiate pancreatic neuroendocrine tumors (PNETs) from pancreatic renal cell carcinoma (RCC) metastases.

METHODS

This IRB-approved multi-center retrospective case-control study compared 43 resected PNETs and 28 resected RCC metastases with pre-operative enhanced CT identified consecutively between 2003 and 2017. Two blinded radiologists (R1/R2) independently assessed tumor location, attenuation (relative to pancreas), composition (solid/cystic/mixed), homogeneity (homogeneous/heterogeneous), calcification, multiplicity, and for main pancreatic duct (MPD) dilation. Tumors were segmented for quantitative texture analysis. Data were analyzed with Chi square, logistic regression, and receiver operating characteristic (ROC). Inter-observer agreement was assessed (Cohen's kappa).

RESULTS

There was no difference in age, gender, location, attenuation, or composition (P > 0.05) between groups. PNETs were larger than RCC metastases (37 ± 23 mm vs. 26 ± 21 mm, P = 0.038), more frequently solitary (P < 0.001), subjectively more heterogeneous (P = 0.033/0.144, R1/R2), and associated with calcification (P = 0.002/0.004) and MPD dilation (P = 0.025/0.006). Agreement for subjective features was moderate-to-almost perfect (K = 0.4879-0.9481). Quantitative texture analysis showed higher entropy in PNETs (6.32 ± 0.49 versus 5.96 ± 0.53; P = 0.004) with no difference in other features studied (P > 0.05). Entropy had ROC area under the curve for diagnosis of PNET of 0.77 ± 0.06, with optimal sensitivity/specificity of 71.4/79.1%.

CONCLUSIONS

Compared to pancreatic RCC metastases, PNETs are larger, more frequently solitary, contain calcification, show MPD dilation, and are subjectively and quantitatively more heterogeneous tumors.

Laparoscopic pancreaticoduodenectomy for metastatic pancreatic melanoma: A case report

RATIONALE

Pancreatic metastases from other malignant tumors are an uncommon clinical condition and account for approximately 2% of all pancreatic malignancies. The most common primary malignancy that metastasizes to pancreas is renal cell cancer. We reported a rare clinical case of metastatic melanoma to pancreas who underwent a successful laparoscopic pancreaticoduodenectomy (LPD) at our department.

PATIENT CONCERNS

A 54-year-old Chinese man complaining an unexplained jaundice was found to have a pancreatic mass and he was diagnosed with cutaneous melanoma (CM) 6 years ago.

DIAGNOSES

Contrast-enhanced computed tomography (CECT) revealed a solid hypovascular mass measuring about 3.1 × 2.4 cm localized at the junction of pancreatic head and uncinate process, which compressed the lower common bile duct resulting in expansion of the upstream bile ducts.

INTERVENTIONS

We performed an LPD and regional lymphadenectomy on this patient.

OUTCOMES

This patient was discharged home on postoperative day 19. Postoperative pathological results revealed a malignant melanoma with negative margins. Immunohistochemical (IHC) findings also suggested a malignant pancreatic tumor accompanied by necrosis and pigmentation, which confirmed the pathological diagnosis. Immunoreactivity was strongly positive for anti-S-100 protein (+++) and positive for anti-Vimentin (+). The cancer cells were negative for CEA, CK8/18, P53, Violin, CK19, SMA with Ki-67 over 40%. So this pancreatic mass was proved to be a metastatic pancreatic melanoma from the primary cutaneous lesion. After LPD, this patient was followed up by readmission to hospital every 2 month in the first half year. The serum bilirubin and tumor markers such as CA199 were normal. CECT and did not find any newly developed neoplasm at the pancreas or metastasis at other organs. At the last follow-up at 6 months after LPD, the patient's general condition was acceptable and the physical examination and imaging studies revealed no significant findings of melanoma.

LESSONS

Metastatic pancreatic tumors are often associated with well-defined margins, tumor necrosis, enhancement, and distant metastases without pancreatic duct dilatation and parenchymal atrophy. As the most common type of metastatic pancreatic tumor, renal cell cancers tend to have higher attenuation values than that of primary pancreatic cancer, while they had similar attenuation values on the portal phase. Primary pancreatic cancer was always associated with an elevated CA199, total bilirubin, and fasting plasma glucose levels. Surgical resection for metastases to pancreas should be aggressively considered in selected patients due to its unique value of providing palliation and a chance to cure. For patients with unresectable lesions, new therapeutic protocols should be recommended such as the combination of BRAF with MEK inhibitor and PD-1 blocker with or without ipilimumab.

Differentiation between pancreatic metastases from clear cell renal cell carcinoma and pancreatic neuroendocrine tumor using double-echo chemical shift imaging

PURPOSE

The purpose of the study was to retrospectively analyze whether double-echo gradient-echo (GRE) chemical shift imaging (CSI) can differentiate between pancreatic metastases from clear cell renal cell carcinoma (PM-ccRCC) and pancreatic neuroendocrine tumor (pNET).

METHODS

Institutional review board approval and informed consent were waived. CSI, T2WI, DWI, and DCE magnetic resonance imaging (MRI) were performed in patients with PM-ccRCC and pNET. Eleven patients with PM-ccRCC and 24 patients with pNET were enrolled into this retrospective study. The signal intensity was measured in the pancreatic tumor and spleen on in-phase and opposed-phase images. The signal intensity index (SII) and tumor-to-spleen ratio (TSR) in PM-ccRCC and pNET were calculated and compared. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic accuracy of SII and TSR in the differentiation between PM-ccRCC and pNET.

RESULTS

The SII between PM-ccRCC and pNET (20.3% ± 16.8% vs. - 3.2% ± 11.4%) was significantly different (P < 0.001), as was the TSR (- 19.2% ± 16.6% vs. 6.0% ± 13.8%) (P < 0.001). The area under the ROC curve was 0.917 for the SII and 0.902 for the TSR. Additionally, an SII threshold value of 8.1% permitted the differentiation of PM-ccRCC from pNET with a sensitivity of 90.9%, a specificity of 91.7%, a positive predictive value of 90.1%, a negative predictive value of 91.7%, and an accuracy of 91.4%. A TSR cut-off value of - 4.7% enabled the differentiation of the two groups with a sensitivity of 79.2%, a specificity of 90.9%, a positive predictive value of 90.9%, a negative predictive value of 79.2% and an accuracy of 82.9%.

CONCLUSION

Double-echo GRE chemical shift MR imaging can accurately differentiate between PM-ccRCC and pNET.

Prediction and clinical implications of portal vein/superior mesenteric vein invasion in patients with resected pancreatic head cancer: the significance of preoperative CT parameters

AIM

To determine the preoperative computed tomography (CT) parameters that predict portal vein/superior mesenteric vein (PV-SMV) invasion in patients with pancreatic head cancer, and to assess whether PV-SMV invasion affects patient survival.

MATERIALS AND METHODS

Sixty patients with PV-SMV invasion, and 60 randomly selected patients without it, who had undergone preoperative CT and subsequent surgery for pancreatic head cancer were enrolled. The following CT parameters were evaluated using multivariate logistic regression and receiver operating characteristic analyses to predict vessel invasion (tumour size and margin, length of involved vessel, distance from the tumour to the vessel, vessel irregularity, the teardrop sign, and tumour-vein interface [TVI]). The Cox proportional hazard model was used to evaluate the effects of PV-SMV invasion on survival.

RESULTS

In multivariate analysis, tumour size (odds ratio [OR]=1.99) and TVI (OR=3.79 [≤90°], 20.66 [>90°, ≤180°], and 47.24 [>180°]) were independent CT predictors of PV-SMV invasion (p<0.05); they achieved a sensitivity of 87%, a specificity of 75%, and an accuracy of 81%; however, PV-SMV invasion did not affect patient survival after surgery (p=0.374).

CONCLUSION

In patients with pancreatic head cancer, preoperative CT parameters can predict PV-SMV invasion with high accuracy. PV-SMV invasion did not affect treatment outcome after surgery.

Recurrent renal cell carcinoma following nephrectomy and ablation therapy: Radiology perspective

Renal cell carcinoma (RCC) is the most common renal malignancy, accounting for approximately 2% of adult malignancies and 4% of new cancer cases in the United States every year. Imaging guided ablative therapy, including radiofrequency (RF) ablation, cryotherapy and microwave has gained popularity over the last decade in treatment of small tumors. Antiangiogenic therapy has set itself to be the standard of care for many patients with metastasis these days. With hope for more research, survival rates of metastatic RCC may increase from a current 2-year survival rate of approximately 20%. Variation in imaging surveillance protocol in terms of frequency, modality, and duration is noted among guidelines developed by several organizations. In this review article, we will discuss follow-up imaging protocols, patterns of RCC recurrence following different modalities of treatment, imaging appearance, as well as usual and unusual sites of metastatic disease.

Imaging of neuroendocrine tumors of the pancreas

Pancreatic neuroendocrine tumors (PNETs) are rare and represent a heterogeneous disease. PNET can be functioning or non-functioning with different clinical presentations and different prognosis based on WHO and pTNM classifications. The role of imaging includes the localization of small functioning tumor, differentiation of these tumors from adenocarcinoma, identification of signs of malignancy and evaluation of extent. PNETs have a broad spectrum of appearance. On CT and MRI, most of functioning PNETs are well defined small tumors with intense and homogeneous enhancement on arterial and portal phases. However, some PNETs with a more fibrous content may have a more delayed enhancement that is best depicted on the delayed phase. Other PNETs can present as purely cystic, complex cystic and solid tumors and calcified tumors. Non-functioning PNETs are larger with less intense and more heterogeneous enhancement. Functional imaging is useful for disease staging, to detect disease recurrence or the primary but also to select patient candidate for peptide receptor radiometabolic treatment. Somatostatin receptor scintigraphy (SRS) (Octreoscan^®) is still the most available technique. Gallium 68-SST analogue PET have been demonstrated to be more sensitive than SRS-SPEC and it will be the future of functional imaging for NET. Finally, ¹⁸FDG PET/CT is indicated for more aggressive PNET as defined either by negative SRS and huge tumor burden or ki67 above 10% or poorly differentiated PNEC tumors.