Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

A Tale of the Pancreas Tail

Cullen Taniguchi, HMS III

Gillian Lieberman, M.D.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Patient G.B.• 60M with a hx of severe COPD and a

recently discovered 5x5cm right renal cell carcinoma

• An abdominal CT study was performed to plan for a nephrectomy, and a 2x2cm mass was discovered incidentally on the tail of the pancreas.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Patient G.B.

HH BBTT

SMV

Splenic vein

SpleenDuodenum

Image courtesy of Charles Vollmer, M.D., BIDMC

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Patient G.B.--Abdominal CT

2 cm pancreatic lesion

5 cm RCC

Transaxial abdominal C+

CT

Image courtesy of Charles Vollmer, M.D., BIDMC

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

ΔDx of a Solid Pancreatic LesionCommon• Adenocarcinoma• Focal PancreatitisUncommon• Spenule• Hemangioma• Islet Cell Tumor• Metastases (esp. from kidney, breast stomach,

lung, gallbladder, melanoma)• Lymphoma• Lipoma• Solid and papillary epithelial neoplasm• Many more…

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Pancreatic Adenocarcinoma

• The most common and concerning lesion on the differential is pancreatic adenocarcinoma

• In this instance, however, we can effectively rule out pancreatic adenocarcinoma since these lesions tend to be hypoenhancing on C+ abdominal CT

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Companion Patient: Pancreatic Adenocarcinomas

Image courtesy of Dr. Hines-Peralta, BIDMC

Transaxial abdominal C+

CT

Hypoenhancing mass in the head of the pancreas

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Our patient G.B.: Abdominal CT

Homogeneously hyperenhancingpancreatic lesion

Transaxial abdominal C+

CT

Image courtesy of Charles Vollmer, M.D., BIDMC

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

ΔDx of a Solid, Hyperenhancing Pancreatic Lesion on CT

• Metastases (esp. from kidney, breast stomach, lung, gallbladder, melanoma)

• Islet Cell Tumor• Hemangioma• Spenule

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

ΔDx of a Solid, Hyperenhancing Pancreatic Lesion on CT

• Metastases from RCC• Islet Cell Tumor• Hemangioma• Spenule

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

A RCC Met is less likely

• Pancreatic mets are rare, and usually come from cancers in adjacent organs (kidney, stomach, GB)

• Mets usually enhance in a pattern similar to the parent tumor, but you cannot make a diagnosis based on this trait alone

• Note that the renal lesion enhances very differently from the pancreatic lesion

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

The Pancreatic Lesion Enhances Differently than the Renal Mass

Image courtesy of Charles Vollmer, M.D., BIDMC

Homogeneously enhancingpancreatic lesion

Heterogeneously enhancing RCC

Transaxial abdominal C+

CT

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

ΔDx of a Solid, Hyperenhancing Pancreatic Lesion on CT

• Metastases from RCC• Islet Cell Tumor-the most likely culprit• Hemangioma• Spenule

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Islets of Langerhans Contain the Cells of the Endocrine Pancreas

Islet immunostained for insulinImage courtesy of Dr. Susan Bonner- Weir

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

β-cellα-cellδ-cellPP-cellε-cell

Islet Cell Tumors can Produce Clinical Syndromes Related to the Hormones they Secrete

GastrinomaGastrinomaGlucagonomaGlucagonomaVIPomaVIPoma

Islet

InsulinomaInsulinoma

SomatostatinomaSomatostatinomaPPomaPPoma

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Clinical Characteristics of Islet Cell Tumors

• Only 50% of islet cell tumors are produce symptoms related to hormone overproduction

• Non-hyperfunctional islet cell tumors (as with G.B.) tend to produce symptoms from mass effects and have the greatest potential for metastasizing.

• Islet cell tumors are difficult to manage once they metastasize.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Islets are Highly Vascularized Structures

Bonner-Weir and Orci, Diabetes 1982Corrosion cast of islet

microvasculature

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Radiologic Features of Islet Cell Tumors• Islet tumors are hyperenhancing on CT

(usually on both arterial and portal-venous phases) due to increased vascular supply related to their endocrine function

• Most sensitive radiologic modality for detecting islet cell tumors is abdominal CT +/- contrast, and is the gold standard.

• In patients that cannot tolerate contrast, MR has been shown to have similar sensitivity to contrast-enhanced CT.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

ΔDx of a Solid, Hyperenhancing Pancreatic Lesion on CT

• Metastases from RCC• Islet Cell Tumor• Hemangioma• Spenule

While an islet cell tumor is the most likely diagnosis in this instance, we need to rule out possible benign lesions, since this will drastically change the treatment plan.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

What about a hemangioma?

• Very rare, seen predominantly in kids, or in association with inherited disorders (von-Hippel-Lindau).

• Could be distinguished with endoscopic ultrasound (would be hyperechoic).

• Pt did not want a biopsy performed, especially if the procedure was going to be invasive and the diangosis rare.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

ΔDx of a Solid, Hyperenhancing Pancreatic Lesion on CT

• Renal Cell Metastases• Islet Cell Tumor• Hemangioma• Spenule

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Image courtesy of Karen Lee, M.D.

A Typical Accessory Spleen

LobulatedLobulated, surrounded by fat, surrounded by fatTransaxial

abdominal C+ CT

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Intrapancreatic Spenule• An intrapancreatic spenule is a rare, but

hypothetically possible “fake out.”

• Anatomically: A large post-mortem study found that the tail of the pancreas was the 2nd most common site of ectopic splenic tissue.

• Physiologically: Would mimic an islet tumor since splenic tissue is relatively vascular.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Image courtesy of Charles Vollmer, M.D., BIDMC

Transaxial abdominal C+

CT

Our patient G.B.: Abdominal CT

Hyperenhancing to the pancreas, isoenhancing

to the spleen

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

I know what some of you may be thinking…

From: http://alumnus.caltech.edu/~kantner/zebras/pictures.html

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Spleen Scintigraphy (99mTc-labeled Heat Damaged RBCs)

Pt’s RBCs

Tin

99mTc

T TTT

T 49°C

T TT

T

TT

Inject back into patient, and labeled RBCs selectively retained by reticuloendothelial

system of spleen.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Patient Course• The possibility of an intrapancreatic

spenule was explored because it is the most benign condition on the differential.

• The radiologic study to identify an intrapancreatic spenule is also the least invasive.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Image courtesy of Charles Vollmer, M.D.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

A Case Where Spleen Scintigraphy was Not Performed

Pancreas

Spleen

Gastroenterology 2006; 131 (2): 350

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Intrapancreatic Spenule• Only five case reports of an

intrapancreatic spleen mimicking a neuroendocrine tumor.

• It is rare for an intrapancreatic spenule to be large enough to mimic a non- functioning islet cell tumor.

• This rare, but interesting, “fake out” will probably rise in the future as the use of contrast-enhanced CT increases.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Patient Course• G.B. needed no further work-up for his

pancreatic lesion

• Pt decided to pursue RF ablation therapy for his RCC and is doing well.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Summary/Conclusions•Islet cell tumors can be differentiated from other solid pancreatic tumors by their tendency to be hyperenhancing on CT

•The differential diagnosis of hyperenhancing lesions must be tailored to each patient

•Understanding the radiologic features of pancreatic masses are essential for correctly diagnosing, localizing, and treating these lesions.

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

Acknowledgments• Charles Vollmer, M.D.• Andrew Hines-Peralta, M.D.• Kevin Donohoe, M.D.• Karen Lee, M.D.• Susan Bonner-Weir, M.D.• Vitaly Poylin, M.D.• Pamela Lepkowski• Gillian Lieberman, M.D.• Larry Barbaras, Webmaster

Cullen Taniguchi, HMSIIIGillian Lieberman, MD

November 2006

References• Buetow PC, Parrino TV, Buck JL, et al. “Islet Cell Tumors of the Pancreas: Pathologic-

Imaging Correlation Among Size, Necrosis and Cysts, Calcification, malignant behavior and Functional Status.” Am J Roentgenol 1995; 165:1175-1179.

• Buetow PC, Miller DL, Parrino TV, Buck JL. “ Islet Cell tumors of the Pancreas: Clinical, Radiologic, and Patholgic Correlation in Diagnosis and Localization.” Radiographics 1997; 17:453-472.

• Davidoff S, Fernandes A, Sideridis K, et al. “Clinical challenges and images in GI. Intrapancreatic accessory spleen mimicking nonfunctional neuroendocrine tumor.” Gastroenterology 2006; 131 (2): 350.

• England RJ, Woodley H, Cullinane C, et al. “Pediatric Pancreatic hemangioma: A Case report and literature review.” Journal of Pancreas 2006; 7(5):496-501.

• Fidler JL, Fletcher JG, Reading CC, et al. ‘Peroperative detection of pancreatic insulinomas on multiphasic helical CT” Am J Roentgenol 2003;181:775-780.

• Goldfinger, SE. “Localization of pancreatic endocrine tumors (islet cell tumors)” UpToDate Online 14.3

• Gouya H, Vignaux O, Augui J, et al. “CT, Endoscopic Sonography, and a combined protocol for Preoperative Evaluation of Pancreatic Insulinomas.” Am J Roentgenol 2003; 181:987-992.

• Horton KM, Hruban RH, Yeo C, Fishman EK. “Multi-detector Row CT of Pancreatic Islet Cell Tumors” Radiographics 2006; 26:453-464.