Portal encasement: Significant CT findings to diagnose local recurrence after pancreaticoduodenectomy for pancreatic cancer.

BACKGROUND/OBJECTIVES: To demonstrate the utility of portal encasement as a criterion for early diagnosis of local recurrence (LR) after pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC). METHODS: A total of 61 patients who underwent PD for PDAC were included in this retrospective study. Portal stenosis was evaluated by sequential postoperative computed tomography (CT) scans and correlated with disease recurrence. In addition to the conventional LR diagnostic criterion of a growing soft tissue mass, LR was evaluated using portal encasement as an additional diagnostic criterion. Portal encasement was defined as progressive stenosis of the portal system accompanied by a soft tissue mass, notwithstanding the enlargement of the mass. RESULTS: Benign portal stenosis was found on the first postoperative CT imaging in 16 patients. However, stenosis resolved a median of 81 days later in all but one patient whose stenosis was due to portal reconstruction during PD. Portal encasement could be distinguished from benign portal stenosis based on the timing of emergence of the portal stenosis. Portal encasement developed in 13 of the 19 patients with LR, including 6 patients in whom the finding of portal encasement led to the diagnosis of LR a median of 147 days earlier with our diagnostic criterion compared with the conventional diagnostic criteria. CONCLUSIONS: Portal encasement should be considered as a promising diagnostic criterion for earlier diagnosis of LR after PD for PDAC.

A case of ß-catenin-positive hepatocellular adenoma with MR imaging sign of diffuse intratumoral fat deposition.

Hepatocellular adenoma (HCA) is a rare primary benign tumor of the liver, which occurs predominantly in young and middle-aged women. Recently, the subclassification of HCA was proposed by the Bordeaux group. Subsequently, characteristic radiological and clinical features have been revealed in each HCA subtype. According to the previous literature, diffuse intratumoral fat deposition is a very common finding in hepatocyte nuclear factor 1α-negative HCA, but this finding has been reported in ß-catenin-positive HCA in the literature for only one case. In this case report, we report the second case of ß-catenin-positive HCA with MR imaging sign of diffuse intratumoral fat deposition, confirmed immunohistologically on the basis of a surgical specimen. In addition, our case showed hypovascularity and isointensity on the hepatobiliary phase which have been reported as characteristic findings in ß-catenin-positive HCA. Diffuse intratumoral fat deposition can be observed in ß-catenin-positive HCA, which has a greater probability of malignant transformation than other types of HCA.

Pleural nodule with osteal protrusion anterior to the rib tubercle: a case report.

Pleural soft tissue density nodules with osteal protrusions are often detected at their characteristic site, the anterior portion of the rib tubercle. Herein, we report a pathologically proven case of this lesion. A 65-year-old man underwent surgery for primary lung cancer in the right middle lobe. Preoperative computed tomography showed a 10-mm pleural soft tissue density nodule with osteal protrusion anterior to the tubercle of the right sixth rib, and this lesion was concomitantly resected. Intraoperative findings showed that this pleural lesion originated from the parietal pleura and was pathologically diagnosed as a benign fibrous tissue. We can avoid unnecessary invasive examinations such as biopsies by recognizing these benign fibrous lesions.

Fishbone migration to bile ducts after pancreaticoduodenectomy: a case series.

We reviewed six cases suspected of having fish bones in the bile ducts on follow-up CT following pancreaticoduodenectomy. The period from surgery to CT examination in which fishbone migration was first suspected ranged from 282 to 1157 days with a median of 517 days. The fish bone in the bile duct disappeared in five out of six cases on subsequent CT. One case was complicated by hepatolithiasis, and the other five cases showed no biliary complications. In two cases, wandering of fish bones in the jejunal limb was observed on CT images before their migration into the bile ducts. Asymptomatic migration of fish bones to the bile ducts following pancreaticoduodenectomy is not rare, but serious complications can occasionally occur. Indications of intervention may be controversial in asymptomatic cases, but once fish bones are observed in the biliary tree or the jejunal limb, dietary instructions advising not to swallow fish bones may be a good option to prevent complications.

CT detection of fat retention in the bladder after partial nephrectomy.

PURPOSE: This study aimed to investigate the frequency of fat retention in the bladder using postoperative computed tomography (CT) and the associated imaging or clinical findings in patients who underwent renal tumor surgery. METHODS: We retrospectively reviewed postoperative CT images from 123 patients who underwent surgery for renal tumors (92 patients after partial nephrectomy and 31 after total nephrectomy). Furthermore, we evaluated preoperative tumor characteristics per an established standardized nephrometry scoring system (the R.E.N.A.L Nephrometry Score) for patients with partial nephrectomy. We also investigated whether collecting system repair occurred during surgery. RESULTS: Fat retention in the bladder was found in 5 patients (5.4%) after partial nephrectomy, but was not observed in any patients after total nephrectomy. No fat retention was seen immediately after partial nephrectomy (4-8 days), but occurred 2-15 months after the surgery. Subsequently, intravesical fat retention disappeared in 3 patients (8, 24, and 16 months later), and it persisted from 19-22 months after surgery in the remaining 2 patients. Collecting system repair occurred in 25 patients (27%) with partial nephrectomy. There was no statistically significant association between fat retention in the bladder and intraoperative collecting system repair (p = 0.12). The association with intravesical fat retention was not significant for either tumor size, distance to the collecting system, or the R.E.N.A.L. Nephrometry Score. CONCLUSION: Fat retention in the bladder after partial nephrectomy can be observed using CT, although it is relatively rare. It is clinically asymptomatic and disappears spontaneously in most cases.