Pyogenic Pancreatic Abscess Mimicking Pancreatic Neoplasm: A Four-Case Series

Abstract

A pyogenic pancreatic abscess mimicking pancreatic neoplasm in the absence of acute pancreatitis is rare. We report four patients who each presented with a pancreatic mass at the pancreas head or body without acute pancreatitis. The presenting symptoms were abdominal pain, fever, or weight loss. Abdominal CT scans showed low-density round masses at the pancreas head or body with/without lymphadenopathy. In each case, a PET-CT scan showed a mass with a high SUV, indicating possible malignancy. Comorbid diseases were identified in all patients: chronic pancreatitis and thrombus at the portal vein, penetrating duodenal ulcer, distal common bile duct stenosis, and diabetes mellitus. Diagnoses were performed by laparoscopic biopsy in two patients and via EUS fine needle aspiration in one patient. One patient revealed a multifocal microabscess at the pancreatic head caused by a deep-penetrating duodenal ulcer. He was treated with antibiotics and a proton-pump inhibitor. The clinical symptoms and pancreatic images of all the patients were improved using conservative management. Infective causes should be considered for a pancreatic mass mimicking malignancy. ( However, some cases manifest with abdominal pain or weight loss. A pyogenic pancreatic abscess mimicking pancreatic neoplasm in the absence of acute pancreatitis is rare and difficult to diagnose. 4 We report on four patients who each presented with a pancreatic mass at the pancreas head or body that mimicked malignancy but was diagnosed as a pancreatic abscess (Table 1). CASE REPORT Case 1A 51-year-old woman was admitted following two days of abdominal pain. There was no history of fever or weight loss. CA 19-9 was normal. An abdominal CT scan showed a 2.7-cm ill-defined low-density mass with peripancreatic fat infiltration located at the pancreatic body (Fig. 1A). An ill-defined soft tissue density lesion around the celiac axis, common hepatic artery, splenic artery, and portal vein was noted (Fig. 1B), which was suggestive of lymphadenopathy with vascular invasion. A PET-CT scan showed hot uptake (SUV 3.8) at the pancreatic body and peripancreatic lymph nodes, which indicated possible malignancy (Fig. 1C). Based on the image findings, borderline respectable pancreatic cancer was U/L, and CRP 24.44 mg/dL. CA 19-9 was normal. An abdominal CT scan showed a 5.0-cm well-defined low-density mass with heterogenous enhancement at the pancreas head and mild pancreatic duct dilatation with a calcifying stone ( Fig. 2A). The portal vein and common hepatic artery were encased by the mass (Fig. 2B). Based on the CT findings, the diagnosis was suspected pancreatic neoplasm against the background of chronic pancreatitis. A laparoscopy was per-

Pancreatic Abscess Misdiagnosed and Treated as Pancreatic Cancer

“…Kim et al reported four cases of pancreatic abscess; three patients had diabetes, and three had a normal blood CA 19-9 level. 7 A pancreatic abscess without fever and an elevated leukocyte count but with diabetes has been rarely reported. Our case was rare in that the patient just had an elevated CA 19-9 level.…”

Infected Pancreatic Necrosis Mimicking Pancreatic Cancer

“…Several case reports on pancreatic abscesses (infected pancreatic necrosis) have been published that would come close to misdiagnosis as malignancy. These lesions were finally diagnosed based on diagnostic laparoscopy, CT-guided percutaneous aspiration, and EUS-FNA (Table 1) [5][6][7][8]. Among these modalities, EUS with FNA has an advantage because it is less invasive in diagnosing pancreatic disease.…”

Unusual presentation of peripancreatic abscess associated with streptococcus anginosus and colonic diverticulosis

“…However, preoperative contrastenhanced endoscopic ultrasonography (EUS) has been reported to be very useful for the diagnosis of pancreatic disorders. 14 In addition, EUS-guided fine needle aspiration cytology has proved to be very sensitive and specific for a cystic pancreatic lesion. 15 In our centre, the EUS is not available.…”

“…[15][16][17][18][19][20] Extension of the abscess from nearby anatomic structures, hematogenous spread from a distant focus of infection, or lymphatic spread from the intestinal tract, are other possible causes for pancreatic abscesses having no history of acute pancreatitis. 14,21 Streptococcus anginosus group, as part of the normal gastrointestinal flora, it is rarely implicated in disseminated infections originating from colon diseases. 12,22 Nevertheless, there are reports that describe an association between Streptococcus anginosus infection and colorectal, oesophageal, gastric cancers and endocarditis.…”