Prominent pancreatic duct on ultrasound
CT Abdomen and pelvis
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There is a hypodense mass identified on the arterial phase, located in the inferior aspect of the pancreatic head, measuring approximately 2.0 cm, with an associated mildly ectatic main pancreatic duct (3.0 mm). No other lesions identified. A few regional lymph nodes are non-specific and uncertain if involved. Previous cholecystectomy. Sigmoid diverticulosis without diverticulitis. The remainder of the imaged viscera are unremarkable.
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As part of staging, the patient had a CT chest, which demonstrates diffuse bilateral lymphadenopathy. There are a few peripheral pulmonary nodules, which are non-specific. No interstitial lung disease.
Macroscopy: A. Labelled "Lymph node from porta hepatis. For frozen section". A piece of tan soft tissue. Half on for frozen section. Frozen Section Diagnosis: Granulomatous, consistent with sarcoid. No malignancy. B. Labelled "Pancreatic margin". An irregular fragment of tan congested tissue. All on for frozen section. Frozen Section Diagnosis: No evidence of malignancy. C. Labelled "Whipple's procedure". The specimen consists of duodenum and head of the pancreas. There is a small amount of fibroadipose tissue at the anterior and posterior adventitial margin. There is an ill-defined, firm, infiltrative lesion within the head of the pancreas. The lesion is located medial to the common bile duct but does not appear to have invaded into the common bile duct. The entire length of the common bile duct is patent, with a circumference of up to 10 mm. The lesion adheres to the serosal surface of the duodenum but does not appear to have infiltrated the duodenum. The proximal 22 mm of the pancreatic duct is patent. The distal 20 mm of the pancreatic duct appears to be obstructed by the lesion, however, the ampulla of Vater is patent. The lesion abuts the anterior adventitial resection margin. The lesion is 6 mm from the closest posterior adventitial resection margin. Three posterior pancreaticoduodenal lymph nodes are identified, 2-18 mm in greatest dimension. Representative sections. D. Labelled "Hepatic artery node". A piece of fibrofatty tissue within which there is a lymph node. The specimen is bisected longitudinally.
Microscopy: A. The sections show lymph node within which there are numerous non-necrotic bare histiocytic granulomas. There is no evidence of metastatic malignancy. Some of the granulomas show multinucleated giant cells. B. Sections show unremarkable pancreas. C. Sections through the pancreas show a florid granulomatous inflammatory reaction with loss of pancreatic acinar tissue. The granulomata are composed of histiocytic cells, with scattered multinucleated giant cells and clusters of giant cells are seen within the pancreatic interstitium. There is no evidence of any malignant infiltrate. The bile duct and pancreatic duct epithelium are unremarkable. The small bowel epithelium is unremarkable. There is no necrosis within the granulomata. Further lymph nodes from the Whipple's resection show extensive replacement by epithelioid granulomata with no evidence of necrosis and multinucleated giant cells. Resection margins are unremarkable. D. Lymph node, showing sarcoidal granulomata.
Conclusion: A. Lymph node porta hepatis - granulomatous inflammation, consistent with sarcoid. B. Pancreatic margin - unremarkable pancreatic tissue. C. Whipple's resection - extensive non-necrotising granulomatous inflammation of head of the pancreas with granulomatous inflammation of lymph nodes. No evidence of malignancy. D. Lymph node, showing sarcoidal granulomata. Comment - the findings raise the possibility of pancreatic sarcoidosis. There are rare documented findings of this. I can see no evidence of a malignancy.
Sarcoid involvement of the pancreas is uncommon and, when it happens, it may pose a challenge for radiologists and surgeons because, as in this case, it can be completely indistinguishable from pancreatic cancer. In the literature, pancreatic sarcoidosis has been described in two forms: diffusely nodular and a focal pancreatic mass, usually in the head of the pancreas 1.
The features found on the CT chest are not concerning for metastatic disease and would favor a granulomatous process, particularly the symmetrical hilar lymphadenopathy.
With thanks to Dr Wa Cheung, Alfred Hospital, Melbourne, Australia.