Pancreatic serous cystic neoplasm mimicking intraductal papillary mucinous neoplasm: Two case reports and literature review.

RATIONALE: Serous cystic neoplasms (SCNs) are treated as benign lesions. It is widely known that SCN rarely have a connection with the main pancreatic duct (MPD), which helps differentiate them from other cystic lesions, such as intraductal papillary mucinous neoplasm (IPMN). However, very rare cases where the SCN appears connected to the MPD cause diagnostic confusion. PATIENT CONCERNS: We present 2 patients with SCN (1 male, 54, and 1 female, 42). Both patients were asymptomatic, without abnormal laboratory results. DIAGNOSIS: In both cases, abdominopelvic computed tomography and pancreatic magnetic resonance imaging scans revealed a multilobulated cystic lesion in communication with the MPD. Since the size of each patient's lesion was >3 cm and there was connectivity with the MPD, it was strongly suspected to be a branch duct-type IPMN with worrisome features rather than SCN and surgical intervention was considered. INTERVENTIONS: Both neoplasms were misdiagnosed as IPMN due to appearing connected with the MPD on radiologic imaging. Surgery was performed. OUTCOMES: A final diagnosis of microcystic serous cystadenoma of the pancreas without connectivity of MPD was confirmed in both patients. LESSONS: An unnecessary surgery was performed due to atypical radiologic features in which the pancreatic duct seems to be connected to the pancreatic cystic lesion on magnetic resonance imaging, leading to misdiagnosis of SCN as IPMN. Particular attention should be paid to interpretation of clinicoradiologic findings of pancreatic cystic lesions, especially to the decision of surgical intervention. Also, awareness of presence of the atypical radiologic features of SCN may broaden the knowledge base of radiologists. LESSONS: An unnecessary surgery was performed due to atypical radiologic features in which the pancreatic duct seems to be connected to the pancreatic cystic lesion on magnetic resonance imaging, leading to misdiagnosis of SCN as IPMN. Particular attention should be paid to interpretation of clinicoradiologic findings of pancreatic cystic lesions, especially to the decision of surgical intervention. Also, awareness of presence of the atypical radiologic features of SCN may broaden the knowledge base of radiologists.

Mesothelial cyst of the spleen mimicking a metastasis: a case report.

Mesothelial cyst of the spleen is a developmental disorder. Previous reports have elaborated on the radiological features of splenic mesothelial cysts as being unilocular with a smooth and well-defined margin. However, due to its rarity, it is unclear whether these characteristics are representative and specific for the diagnosis of mesothelial cysts. Herein, this case report presents an atypical case of splenic mesothelial cyst mimicking a malignant tumour, especially splenic metastasis in a 66-year-old woman with ascending colon cancer. Due to an overlapping imaging finding of hypodense splenic lesions, and considering the clinical history, a mesothelial cyst that developed as a multilocular hypodense mass from an ill-defined small nodule was inevitably misdiagnosed as metastasis. Although rare, it is important to consider the possibility of mesothelial cyst in a patient with multilocular hypodense lesions of the spleen.

Differentiation of Adenomyoma from Localized Adenocarcinoma of the Ampulla of Vater Using Multidetector CT.

Purpose: To determine the multidetector CT (MDCT) findings that differentiate adenomyoma of the ampulla of Vater (AOV) from localized adenocarcinoma of the AOV. Materials and Methods: Sixteen and 30 patients with adenomyoma and localized adenocarcinoma of the AOV, respectively, were evaluated using MDCT. We analyzed the size and attenuation value and presence of uniform enhancement of the lesions, diameters of the extrahepatic bile duct (EHD) and main pancreatic duct, presence of regional lymph node enlargement, and laboratory findings. We determined the independent findings for differentiating adenomyoma from localized adenocarcinoma of the AOV using multivariate analysis. Results: The size of the lesion and diameter of the EHD were significantly smaller for adenomyoma than those for localized adenocarcinoma of the AOV (all p < 0.001). In multivariate analyses, a lesion size of ≤ 1.3 cm, an EHD diameter of ≤ 1.3 cm, and an alanine transaminase level of ≤ 31 IU/L significantly differentiated adenomyoma from localized adenocarcinoma of the AOV. When all of these three findings were met, the specificity for adenomyoma of the AOV was 93.3%. Conclusion: MDCT imaging may facilitate the differential diagnosis of adenomyoma and localized adenocarcinoma of the AOV based on the size of the lesion and diameter of the EHD.

Successful Endovascular Treatment of an Infected Aortic Aneurysm Induced by Klebsiella pneumoniae.

Aortic aneurysms infected by Klebsiella pneumoniae are rarely seen. We describe a 50-year-old man with infected aortic aneurysm that was successfully treated with endovascular aneurysm repair (EVAR). Diagnosis was confirmed using blood culture and computed tomography (CT). Intravenous antibiotics were immediately administered, with improvements in clinical findings and negative blood cultures before the procedure. Twenty-four months after the procedure, the patient was stable and serial CT revealed regression of the infected aortic aneurysm. Therefore, after controlling bacteremia and fever with targeted antibiotic therapy, EVAR can be considered as an alternative for patients who have serious comorbidities and are ineligible for conventional surgery.

Primary hepatic peripheral T-cell lymphoma mimicking hepatocellular carcinoma: a case report.

Peripheral T-cell lymphomas (PTCLs) are aggressive neoplasms which may involve the liver. The imaging manifestations of hepatic lymphoma are highly variable and show overlapping appearances of numerous other hepatic diseases. As the management and prognosis of lymphoma differ markedly from those of other malignant diseases, prompt diagnosis and early effective treatment are very important. Here, we report an atypical case of primary PTCL not otherwise specified involving the liver that exhibited a solitary hepatic mass mimicking hepatocellular carcinoma (HCC) on CT. Liver biopsy is not commonly recommended in highly suspicious cases of HCC. However, in a patient without risk factors for HCC, consideration of other diagnostic possibilities is required and needle biopsy may be a more rational choice. An imaging approach, based on a careful review of clinical and laboratory findings is essential to prevent false-positive diagnosis of HCC and subsequent invasive treatment.

Relationship between divided-shaped kidney and collecting system duplication.

PURPOSE: We aimed to assess the incidence of divided-shaped kidney and the relationship between divided-shaped kidney and collecting system duplication. SUBJECTS AND METHODS: Between May 1 and June 30, 2012, 857 patients (men:women, 493:364; mean age 39.6 years; age range 2-98 years) with 1699 kidneys underwent enhanced computed tomography of the abdomen and pelvis at our institution. Sixty kidneys were excluded (tumor, 3; percutaneous nephrostomy, 9; polycystic kidney disease, 4; renal injury, 1; infarct, 1; hydronephrosis, 18; parapelvic cyst, 17; artifact, 5; horseshoe kidney, 2). Finally, 845 patients and 1639 kidneys were included. The number of cases of prominent column of Bertin (divided by grade of prominence as either divided-shaped kidney or hypertrophy) and collecting system duplication (bifid, partial, and complete) were evaluated. Fisher exact test was used to determine the relationship between divided-shaped kidney and collecting system duplication, and between hypertrophy and collecting system duplication. RESULTS: Of 1639 kidneys, 66 (4%) were divided-shaped kidneys, and 88 (5%) had collecting system duplication (bifid, 69; partial, 19; complete, 0); among the 66 divided-shaped kidneys, 28 (42%) had collecting system duplication. Among the 429 cases of hypertrophy and 1144 normal kidneys, 51 (11.9%) and 9 (0.8%) had collecting system duplication, respectively. CONCLUSIONS: The incidence of divided-shaped kidney was 4%, and there was a significant association between divided-shaped kidney and collecting system duplication.

Unilateral hydronephrosis and hydroureter by foreign body in urinary bladder: a case report.

Foreign bodies inserted through the urethra are often found in the urinary bladder. We presently report the first case of hydronephrosis and hydroureter due to direct compression in the urinary bladder by silicon, which had been introduced by the patient himself 2 yr prior to presentation with severe right flank pain. Computed tomography indicated a convoluted, high-attenuation mass in the urinary bladder; unilateral hydronephrosis and hydroureter were also present due to direct compression by the mass. The foreign body was removed using a cystoscope. This foreign body was proven to be silicon.

Narrow duplicated or triplicated internal auditory canal (3 cases and review of literature): can we regard the separated narrow internal auditory canal as the presence of vestibulocochlear nerve fibers?

The narrow duplicated internal auditory canal (IAC) is a very rare malformation, and there is no report about the narrow triplicated IAC in the literature. It has been believed to be associated with congenital sensorineural hearing loss and to be a result of aplasia or hypoplasia of the vestibulocochlear nerve or the cochlear branch. We present 2 cases of unilateral narrow duplicated IAC and 1 case of unilateral narrow triplicated IAC with ipsilateral sensorineural hearing loss. The separated, accessory bony canals delineated on high-resolution computed tomography do not mean the presence of nerve fibers. In previously presented cases and in our case, the separated small canals were vacant and without a cochlear nerve fiber. We present new common radiological findings as follows: the bony canal to the cochlea is very thin and the connection with the modiolus of the cochlea is interrupted in narrow separated IAC.

[A case of simple type Caroli's disease confined to right lobe of the liver].

Caroli's disease is a rare congenital hepatobiliary disease characterized by multifocal segmental dilatation of intrahepatic bile ducts affecting all or parts of the liver. Two forms of Caroli's disease are described, the pure form and that associated with periportal fibrosis. The disease may diffusely affect the liver or be localized to one lobe or segment. Less than 20% of all reported cases of Caroli's disease are monolobar type. We report a case of simple type Caroli's disease confined to right lobe of the liver in a 22 year old man. He was admitted due to right upper abdominal pain and diagnosed by magnetic resonance cholangiopancreatography. He was treated with right hepatic lobectomy and recovered completely.