Figure 4d. Mucinous cystadenocarcinoma of the entire pancreas in a 68-year-old man. (a) Transverse US image shows multiple small cysts in the pancreatic head and body (arrowhead). A 3-cm cyst is vaguely seen in the pancreatic tail (arrows). A = aorta, V = inferior vena cava. (b) Oblique sagittal US image obtained in the epigastric region and oriented toward the left side shows numerous small cysts in the tail of the pancreas (arrowhead). The 3-cm cyst is now more clearly seen at the distal end of the pancreatic tail (arrows). The walls of these cysts are not clearly delineated, making it more difficult to determine the cystic nature of the lesions at US than at CT. However, good through transmission is evident. Aspiration showed turbid dark brown fluid that revealed mucinous cystadenocarcinoma at cytologic examination. (c) CT scan corresponding to a shows numerous small cysts throughout the entire pancreas. The superior mesenteric artery (a) and superior mesenteric vein (V) are encased by the mass, indicating that the mass may be malignant. (d) CT scan obtained slightly inferior to c shows a 3-cm cyst in the distal tail of the pancreas (arrowhead). a = superior mesenteric artery, V = superior mesenteric vein.