Case Study: A 61-Year-Old Male with Hematuria and a Pancreatic Tail Mass

Servet Tatli, MD¹ ∙ Stanley W. Ashley, MD²
 

Citation: Tatli S, Ashley SW. Case Study: A 61-year-old male with hematuria and a pancreatic tail mass. J Surg Radiol. 2011 Jan 1;2(1). Download PDF J Surg Rad January 2011 S01.pdf 1151 Kb Received: October 1, 2010; Accepted: November 17, 2010; Published: November 23, 2010 Copyright: © 2010 Surgisphere Corporation. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Contents - Presentation - Findings - Diagnosis and Management - References

Presentation

A 61-year-old man presented with hematuria. An abdominal CT scan showed no reason for hematuria but demonstrated a 1.2 cm rounded, hypervascular mass (Figure 1) in the tail of the pancreas.

Figure 1. Axial enhanced CT scan image shows a 1.2 cm mass (arrow) in the tail of the pancreas. Note that the mass enhances uniformly and is isodense with the spleen.

Findings

The lesion was isodense with the spleen and raised the question of ectopic splenic tissue. MRI of the pancreas confirmed a 1.2 cm, well circumscribed, pancreatic tail mass, which was seen only on pre (Figure 2) and post -contrast (Figure 3), fat suppressed T1-weighted images as homogenously hypointense compared to the normal pancreatic parenchyma with ring-like enhancement. The rest of the pancreas looked normal and there was no lymphadenopathy. Because of its well-defined border, the mass was felt unlikely to be an adenocarcinoma. Although, the patient did not have any hormonal abnormality, it was felt to most likely represent a neuroendocrine tumor. Acinar cell carcinoma and solid pseudopapillary neoplasm can also be well-circumscribed but the later most frequently is seen in young women as an encapsulated mass with hemorrhagic, necrotic areas. To more completely exclude ectopic splenic tissue in the pancreatic tail, nuclear medicine splenic imaging with Tc-99m labeled, heat-denatured red blood cells (Figure 4) was performed and was negative. The patient underwent distal pancreatectomy and splenectomy, and pathology revealed a well-differentiated neuroendocrine tumor.

Figure 2. Axial fat suppressed, T1-weighted gradient-echo MR image shows that the mass (arrow) is hypointense compared to the rest of the pancreas.

Figure 3. Axial fat suppressed, contrast enhanced T1-weighted gradient-echo MR image shows the mass (arrow) enhances uniformly but less than the normal pancreatic parenchyma with thin ring-like peripheral enhancement.

Figure 4. Axial nuclear medicine splenic imaging with Tc-99m labeled, heat-denatured red blood cells shows that the mass does not accumulates the tracer; therefore, it is not splenic tissue.

Diagnosis & Management

Pancreatic neuroendocrine tumors arise from the endocrine pancreas (islet cells), and may present with endocrine abnormalities because of their hormone secretion. These hormonally active tumors are named after their dominant secreted hormone, for example insulinoma or gastrinoma. Some neuroendocrine tumors may not be hormonally active (nonfunctioning) but tend to be symptomatic due to their large size. Nonfunctioning tumors are believed to all have the potential for malignancy. Malignancy of neuroendocrine tumors of the pancreas is determined not by their hormonal status but by either local invasion into adjacent organs or distant metastases, most commonly to the liver.

On CT or MR imaging, neuroendocrine tumors are seen as small, well-circumscribed, hypervascular masses. They are typically hyperintense on T2-weighted images. Post-contrast images should be obtained in dynamic fashion since these tumors tend to enhance during arterial phase, which may be uniform or ring-like. Tumors can rarely be hypovascular. Unenhanced, T1-weighted, fat-suppressed MR images are also valuable to demonstrate these tumors as a hypointense mass on a background of hyperintense normal pancreatic parenchyma. Rarely, splenic tissue may be ectopically present in the pancreatic tail and may mimic a pancreatic neoplasm. Although this ectopic splenic tissue can be identified with MRI because of its signal intensity similar to the splenic parenchyma on all MRI sequences, a nuclear medicine study may sometimes be necessary for definite diagnosis.

References

1. 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. AJR 1995;165:1175-1179.
2. Mergo PJ, Helmberger TK, Buetow PC, Helmberger RC, Ros PR. Pancreatic neoplasms: MR imaging and pathologic correlation. RadioGraphics 1997; 17:281-301.
3. Cantisani V, Mortele KJ, Levy A, et al. MR imaging features of solid pseudopapillary tumor of the pancreas in adult and pediatric patients, AJR 2003;181:39-401.
4. Tatli S, Mortele KJ, Levy AD, Glickman JN, Ros PR, Banks PA, Silverman SG. CT and MRI features of pure acinar cell carcinoma of the pancreas in adults. AJR 2005;184(2):511-519.