Ji Soo Song

Multicystic biliary hamartoma of the liver.

Multicystic biliary hamartoma (MCBH) is a very rare hamartomatous cystic nodule of the liver, which has recently been described as a new entity of a hepatic nodular lesion. We report a unique case of MCBH with a review of the literatures. A hepatic multicystic mass of segment 3 was detected in a 52-year-old male by abdominal computed tomography, and resection of this lesion was performed. Macroscopic examination revealed a 2.7×2.0 cm nodular mass with a multicystic honeycomb cut surface. Histologically, this lesion consisted of multiple dilated cystic ducts lined by biliary type epithelial cells, periductal glands and connective tissue, which included small amounts of hepatic parenchyma and blood vessels. Recognition of this unusual lesion is essential to avoid confusion with other cystic tumors of the liver, and to learn more about its natural history and response to treatment.

An unusual presentation of an inflammatory fibroid polyp of the ileum: A case report

Inflammatory fibroid polyps (IFP) are rare, benign lesions of the gastrointestinal tract. Recent molecular studies of IFPs identified platelet-derived growth factor receptor α (PDGFRA)-activating mutations, suggesting possible neoplastic qualities to IFPs. IFPs originate from the submucosa and often extend into the overlying mucosa. Although certain IFPs infiltrate the muscularis propria focally, disruption of the muscularis propria and penetration into the subserosa is extremely rare. The current study presents an unusual case of an ileal IFP. A 48-year-old female visited the Department of Surgery, Chonbuk National University Hospital (Jeonju, Republic of Korea) due to abdominal pain. Radiological study demonstrated an ileocecal-type intussusception due to a luminal polypoid mass of the ileum. The excised tumor consisted of haphazardly arranged epithelioid and spindled cells in a fibromyxoid stroma, with an abundant vascular network, accompanied by an inflammatory reaction predominantly composed of eosinophilic infiltrates. The infiltrating tumor cells disrupted the muscularis mucosa above the tumor cells and the muscularis propria below the tumor cells, and extended into the subserosa. Immunohistochemically, the tumor cells were positive for vimentin and cluster of differentiation 34, while they were negative for keratin, PDGFRA, smooth muscle actin, desmin, S-100 protein, DOG-1 and c-kit. Sequencing analysis of c-kit exons 9, 11, 13 and 17, and PDGFRA exons 12 and 18 indicated a wild-type status. The patient has remained well for 12 months after surgery without further treatment, with no recurrence of the tumor. Although spread of IFP under the muscularis propria is rare, identification of similar cases and further study will enhance our understanding of the nature of this tumor.

Mucinous Non-neoplastic Cyst of the Pancreas

Cystic pancreatic lesions consist of a diverse range of pathological entities and can be classified into neoplastic and non-neoplastic cysts. Diagnosis of cystic pancreatic lesions has increased during the past two decades due to technological progress and increased use of various imaging modalities. Recently, a novel and distinct cystic pancreatic lesion was reported with the name of mucinous non-neoplastic cyst of the pancreas (MNCP).1 We present the first reported case of MNCP in Korea.

Intra-individual comparison of hepatocellular carcinoma imaging features on contrast-enhanced computed tomography, gadopentetate dimeglumine-enhanced MRI, and gadoxetic acid-enhanced MRI

Background Gadoxetic acid is being widely used for detection and characterization of hepatic nodules. However, there are no data regarding intra-individual comparison of imaging features of hepatocellular carcinoma (HCC) on dynamic computed tomography (CT), gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-DTPA-MRI), and gadoxetic acid-enhanced MRI (Gd-EOB-MRI). Purpose To evaluate typical imaging features of HCC and capsule appearance with dynamic CT, Gd-DTPA-MRI, and Gd-EOB-MRI. Material and Methods We retrospectively reviewed 56 HCCs in 49 patients. Lesion attenuation/signal intensity was graded using a five-point scale based on dynamic phase and hepatobiliary phase (HBP) imaging. Subjective washout and capsule appearance were evaluated on portal venous phase (PVP) or delayed/transitional phase (DP/TP) imaging. The tumor-to-liver contrast ratio (TLCR) was calculated. Results Gd-DTPA-MRI and Gd-EOB-MRI was graded higher than CT on arterial phase (P < 0.001). Gd-EOB-MRI was graded lower than Gd-DTPA-MRI on PVP and DP/TP (P < 0.05). The detection rate of subjective washout and capsule appearance did not differ among the three imaging studies on either PVP or DP/TP. TLCR of Gd-EOB-MRI was lower than CT on PVP (P = 0.004) and was lower than Gd-DTPA-MRI on DP/TP (P = 0.001). Conclusion Arterial phase hyperenhancement and washout appearance of HCC were well demonstrated in Gd-EOB-MRI. The detection of capsule appearance using Gd-EOB-MRI was not inferior to Gd-DTPA-MRI or CT.

C-KIT-positive undifferentiated tumor of the liver: A case report.

With recent advances in cancer stem cell analysis, it has been postulated that the transformation of hepatic stem and progenitor cells underlies the development of certain liver cancers. Human C-KIT is a transmembrane type III receptor protein with intrinsic tyrosine kinase activity that has been proposed as a marker for human embryonic stem cells. In addition, human C-KIT functions in maintaining the undifferentiated state of stem cells, and has been identified as a marker for human hematopoietic and hepatic stem/progenitor cells. The present study identified an unusual case of a C-KIT-positive hepatic tumor with an undifferentiated stem cell phenotype distinct from existing descriptions of liver tumors. A 69-year-old male with Ampulla of Vater (AoV) cancer was admitted to the hospital for the treatment of a hepatic mass that was incidentally detected during evaluation of AoV cancer. Microscopically, the hepatic tumor was composed of solidly packed small, round and uniform undifferentiated cells, which resembled that of a small-blue-round-cell tumor. The immunophenotype of neoplastic cells (C-KIT+/EpCAM+/E-cadherin+/keratin 7−/keratin 19−/α-fetoprotein−/albumin−) supported primitive stem cell features with no hepatic or biliary phenotypes. Polymerase chain reaction and direct DNA sequencing revealed no C-KIT mutations. It is suggested that this tumor may have originated from transformed C-KIT+/EpCAM+/E-cadherin+ cells, which are more primitive and undifferentiated than bipotential hepatic progenitor cells.

Hypovascular hypointense nodules in hepatobiliary phase without T2 hyperintensity: long-term outcomes and added value of DWI in predicting hypervascular transformation

PURPOSE To evaluate outcomes and risk factors associated with hypervascularization in hypovascular, hepatobiliary phase (HBP) hypointense nodules (HHNs) without T2 hyperintensity on gadoxetic acid-enhanced magnetic resonance (MR) images in chronic liver disease patients. MATERIALS AND METHODS 222 HHNs were analyzed. Multivariate analysis with a Cox proportional hazard regression model was used. RESULTS 41 nodules became hypervascular hepatocellular carcinoma (HCC). History of HCC, hyperintensity on T1WI or DWI, and higher growth rate were risk factors for hypervascularization (P < .05). CONCLUSION History of HCC, hyperintensity on T1WI or DWI, and higher growth rate were associated with nodular progression to hypervascular HCC.

Cystic metastasis from a mucinous adenocarcinoma of duodenum mimicking type II choledochal cyst: A case report

A 51-year-old male patient was referred to our hospital because of an incidentally detected cystic mass near the common bile duct (CBD). Imaging studies demonstrated a cystic mass that was suspected to communicate with the CBD. Gastroscopy showed irregular mucosal thickening with hyperemic change in the second portion of the duodenum. A type II choledochal cyst combined with duodenal malignancy was suspected. The patient underwent surgical resection and the histological diagnosis was mucinous adenocarcinoma of the duodenum with cystic metastasis. Although its incidence is extremely rare, care should be taken to check for other sites of malignancy when a pericholedochal cystic mass is detected.

Giant inflammatory polyposis with Crohn disease-like colitis

Sir, Giant inflammatory polyposis (GIP), defined as a mass-like conglomeration of inflammatory polyps >15 mm in diameter or length, is quite rare. The majority of reported cases are associated with pre-existing inflammatory bowel disease (IBD). However, GIP may also be encountered in patients without a history of IBD. In this report, we present an unusual case with two separate lesions of GIP associated with a localised Crohn disease (CD)-like lesion in the descending colon. A 61-year-old man presented with a 1 month history of abdominal pain and haematochezia. He had no previous history of IBD or lower gastrointestinal symptoms. Laboratory findings revealed a haemoglobin level of 8.1 g/dL. Other laboratory tests, including tumour markers, were within normal limits. Contrastenhanced abdominal computed tomography (CT) demonstrated two large polypoid masses in the proximal and distal descending colon measuring approximately 12.0 cm in longitudinal diameter (Fig. 1A). The lesions showed relatively well-defined margins with homogeneous enhancement. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (F-18 FDG PET/CT) was performed and revealed diffuse FDG uptake in the descending colon. There was no evidence of lymph node metastasis or distant metastasis. Colonoscopy demonstrated a large fungating mass in the descending colon that caused near complete obstruction of the bowel, such that the scope was not able to pass