Solitary necrotic nodule of the liver

Solitary necrotic nodule of the liver is a rare benign lesion; only 22 cases have been reported to date. An unsolved problem in treating these lesions involves the difficulties in differential diagnosis; specific features of necrotic nodule of the liver in preoperative examinations have not been identified. Here, we report a patient with resected solitary necrotic nodule of the liver with preoperative features shown on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) examinations. A 48‐year‐old woman was referred to our hospital on December 13, 1999 because a hypoechoic lesion in Couinaud's segment VIII of the liver had been incidentally detected on US. A CT scan confirmed the presence of a round hypodense lesion, measuring 2 cm in diameter. No significant enhancement was recognized on dynamic MRI study. T1‐Weighted MRI examinations demonstrated a low intensity showing a triple‐layered pattern with low‐iso‐low intensity in the lesion, while T2‐weighted images demonstrated a slightly high intensity in the lesion. These features suggested fibrous tissue. Histological examinations following partial resection of the liver revealed a solitary necrotic nodule of the liver. Combination studies, including MRI examinations, would be useful for the preoperative diagnosis of a solitary necrotic nodule of the liver.     

Spontaneous regression of a solitary necrotic nodule of the liver

Solitary necrotic nodules of the liver occur rarely. Although these nodules are usually benign, they are surgically removed in most cases because they cannot be differentiated from malignant lesions. To date, the natural history of solitary fibrous nodules remains unclear. We present the case of an incidentally detected hepatic mass (diameter 2 cm) in a 35-year-old man. The hepatic mass was diagnosed as a solitary necrotic nodule by liver biopsy. Follow-up radiologic examination revealed that the solitary necrotic nodule had spontaneously regressed. This is the first report on the natural course history of a solitary necrotic nodule.     

"Solitary" necrotic nodule of the liver: an enigmatic entity mimicking malignancy

Aim The aim of the study is to further investigate the clinicopathological features of solitary necrotic nodules. Material and methods Twenty-three archived cases of solitary necrotic nodule of the liver, which were preoperatively misdiagnosed as liver metastases were studied. The pathological findings were correlated with the clinical data of the patients. Results The nodules were solitary in 20 cases and multiple (2) in three cases, and measured from 0.5–1.5 cm in diameter. Twenty-one cases were located in the right lobe of the liver (91.6%) and two in the left lobe (8.69%). Twenty nodules were found in the subcapsular region (86.95%), while three nodules were located within the hepatic parenchyma (13.04%). More then half of our cases (12) were accompanied by extended calcification. Granulomatous tissue resembling “burnt-out” parasitic granulomas was found in three cases. Conclusions Solitary necrotic nodules of the liver often mimic malignancy in abdominal imaging. Thus, permanent histopathology of the operative specimen remains the only accurate method of diagnosis. Their pathogenesis is most likely variable, and most reported cases are linked either to a parasitic or a vascular origin. Despite the designation of these lesions as “solitary” they may occasionally be multiple. In addition to the standard histological criteria of solitary necrotic nodules, the relatively small size (15 mm or less) and the frequent presence of calcifications seem to further characterize this enigmatic entity. Solitary necrotic nodule should be included in the differential diagnosis of small liver lesions with extensive necrosis.     

Case of solitary necrotic nodule of the liver difficult to distinguish from malignant hepatoma]

In a 72 years old woman, abdominal computed tomography (CT) disclosed multicentric hypervascular tumor in S4 of the liver, and it was T1.T2 by the MRI, and a high signal was presented together. Stenosis was shown by ERCP at the same site. Cholangiocellular carcinoma was suspected before operation, but malignant change was not recognized by frozen section, so the operation was finished. Later, a diagnosis of solitary necrotic nodule of the liver was established by pathological diagnosis. Solitary necrotic nodule of the liver is a benign tumor.     

Case report of a focal nodular hyperplasia-like nodule present in cirrhotic liver

An 81-year-old female was referred to Sapporo Medical University Hospital because of a nodular lesion 20 mm in diameter found in the liver S8 during follow-up for type C liver cirrhosis. Abdominal ultrasonography showed a capsule-like structure, and contrast computed tomography revealed hypervascularity at the early phase and inner pooling of the contrast medium with ring enhancement at the late phase. Magnetic resonance T2-weighted imaging (T2WI) demonstrated a hyperintensity nodule with further hyperintensity signals in some parts of the nodule, and the signal pattern differed from that of typical fibrosis. SPIO-magnetic resonance imaging showed partial hypointensity signals by T2WI, which indicated the presence of Kupffer cells. Angiography did not show a spoke-wheel pattern. The results by imaging modalities indicated that the nodule was atypical for hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH), and liver nodule biopsy was performed for histological diagnosis. Compared with the background liver, the nodule revealed high cellular density, cellular dysplasia at the periphery, a pseudo-crypt structure and irregular hepatic cord arrangement in some parts of the nodule. Among them, there was immature fibrous tissue containing arterioles with muscular hypertrophy. There has been no report of well-differentiated HCC with a central scar, and this case was presumed to be an FNH-like nodule with dysplasia physically associated with cirrhotic tissue.     

Solitary fibrous tumors in abdomen and pelvis:Imaging characteristics and radiologic-pathologic correlation

AIM:To describe the imaging features of solitary fibrous tumors(SFTs)in the abdomen and pelvis,and the clinical and pathologic correlations.METHODS:Fifteen patients with pathologically confirmed SFTs in the abdomen and pelvis were retrospectively studied with imaging techniques by two radiologists in consensus.Patients underwent unenhanced and contrast-enhanced imaging,as follows:3 with computed tomography(CT)and magnetic resonance imaging(MRI)examination,8 with CT examination only,and 4 with MRI examination only.Image characteristics such as size,shape,margin,attenuation or intensity,and pattern of enhancement were analyzed and correlated with the microscopic findings identified from surgical specimens.In addition,patient demographics,presentation,and outcomes were recorded.RESULTS:Of the 15 patients evaluated,local symptoms related to the mass were found in 11 cases at admission.The size of the mass ranged from 3.4 to 25.1cm(mean,11.5 cm).Nine cases were round or oval,6were lobulated,and 10 displaced adjacent organs.Unenhanced CT revealed a heterogeneous isodense mass in 7 cases,homogeneous isodense mass in 3 cases,and punctuated calcification in one case.On MRI,most of the lesions(6/7)were heterogeneous isointense and heterogeneous hyperintense on T1-weighted images and T2-weighted images,respectively.All tumors showed moderate to marked enhancement.Heterogeneous enhancement was revealed in 11 lesions,and 7of these had cysts,necrosis,or hemorrhage.Early nonuniform enhancement with a radial area that proved to be a fibrous component was observed in 4 lesions,which showed progressive enhancement in the venous and delayed phase.No statistical difference in the imaging findings was observed between the histologically benign and malignant lesions.Three patients had local recurrence or metastasis at follow-up.CONCLUSION:Abdominal and pelvic SFTs commonly appeared as large,solid,well-defined,hypervascular masses with variable degrees of necrosis or cystic change that often displaced adjacent structures.     

Dermatofibrosarcoma Protuberans: Computed Tomography and Magnetic Resonance Imaging Findings

The aim of this study was to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of dermatofibrosarcoma protuberans (DFSP), with a view to improving the diagnosis of this kind of tumor.A total of 27 cases of histopathologically confirmed DFSP were analyzed retrospectively. Of these, 18 patients underwent a CT scan and 9 patients underwent an MRI. All patients underwent unenhanced and contrast-enhanced examinations; 1 patient underwent multiphrase CT enhancement examination. Imaging characteristics, including location, shape, size, number, edge, and attenuation or intensity of each lesion, both unenhanced and contrast enhanced, were analyzed.Of the 27 cases, 24 were solitary, 2 had 2 nodules, and 1 had multiple confluent tumors. The lesion with multiple confluent tumors was ill defined and irregular; the other lesions were oval or round, well-defined nodules or masses. The unenhanced CT images showed 19 homogenous isodense lesions. There was no calcification in any of the patients. The contrast-enhanced CT images showed intermediate and marked nonhomogeneous enhancement in 13 lesions, intermediate homogeneous enhancement in 4 lesions, and a mild heterogeneous enhancement in 2 lesions. MR T1-weighted images revealed 1 ill-defined and 9 well-defined homogeneous isointense lesions. T2-weighted images showed homogeneous hyperintensity to the muscles in 6 lesions, 3 mild hyperintense lesions with hypointense lesions, and 1 mixed, mild hyperintense and isointense lesion. Contrast-enhanced T1-weighted images demonstrated intermediate and marked nonhomogeneous enhancement in 9 lesions and intermediate homogeneous enhancement in 1 lesion.DFSP is characterized by a subcutaneous well-defined soft tissue nodule or mass on plain CT/MR scans, and shows intermediate-to-marked enhancement on contrast-enhanced CT/MR scans. The imaging findings for DFSP are nonspecific, but may help to define the diagnosis in an appropriate clinical setting.Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade malignant cutaneous tumor. It was first reported by Darier and Ferrand and called “progressive and recurrent skin fibroma” in 1924.¹ In 1925, Hoffman named it as DFSP.² DFSP often occurs in the dermis and subcutaneous layers. Typical DFSP shows superficial skin nodules or masses, and often protrudes from the skin surface. DFSP is often misdiagnosed, especially for larger tumors with deep tissue invasion and atypical manifestations, which often results in improper treatment leading to vulnerability to relapse. DFSP is often superficial; therefore, there are few reports focusing on imaging findings of DFSP.^3–12 Herein, we provide a retrospective review of the imaging findings of 27 cases of DFSP with the aim to improve our knowledge of DFSP.     

Intracystic hemorrhage of a simple liver cyst mimicking a biliary cystadenocarcinoma

Simple liver cysts are rarely complicated by intracystic hemorrhage. We encountered a case of simple liver cyst that was morphologically similar to biliary cystadenocarcinoma, which was complicated by asymptomatic intracystic hemorrhage and successfully treated by right lobectomy. A large cystic lesion of the liver was detected in a 57-year-old woman during a mass screening health check. Abdominal ultrasonography (US) revealed that the cystic lesion, containing many hyperechoic papillary structures, occupied almost the entire region of the right hepatic lobe. In addition, a round mural nodule, measuring approximately 5 cm in diameter, was detected in the cystic wall. Abdominal computed tomography (CT) revealed that the inner part of the cystic lesion showed homogeneous low density, but CT did not show the round nodule detected by US. On T1-weighted sequence of magnetic resonance imaging (MRI), the lesion showed homogeneous high signals, together with a low-signal tumorous lesion in the cystic wall. T2-weighted sequence of MRI showed unhomogeneous high signals, together with high signals in the tumorous part. These findings did not exclude the possibility of a malignant cystic tumor, such as biliary cystadenocarcinoma. Therefore, right lobectomy was performed. Histological examinations of resected tissue specimens revealed that the lesion was a liver cyst containing a large amount of blood clot, and that the tumorous lesion detected by US and MRI was a large mass of blood clot which was partly liquefied. This case indicates the diagnostic importance of the morphological discordance between CT and US or MRI findings for liver cyst containing a large amount of blood clot. Received: May 7, 2001 / Accepted: December 27, 2001 Reprint requests to: Y. Kitajima     

Solitary true cyst of the pancreas in an adult: report of a case

Background: Solitary true cyst of the pancreas is rare in adults, and the differential diagnosis of cystic lesions of the pancreas is challenging. Aim of the Study: To describe a solitary true cyst of the pancreas in an adult and discuss the differential diagnosis. Methods: A 50 yr old woman presented with a mass lesion in the right upper quadrant of the abdomen. Abdominal computed tomography showed a cystic lesion, with a maximum diameter of 12 cm, between the inferior surface of the liver and the ascending colon. The cyst was homogenous and had smooth edges. On magnetic resonance imaging, a unilocular cyst was seen that was low intensity on T1-weighted images and very high intensity on T2-weighted images. No connection between the cyst and the pancreatic ductal system was demonstrated on endoscopic retrograde cholangiopancreatography. Laparotmy was performed with a presumptive diagnosis of cystic tumor of the pancreas. Results: On pathologic examination, the cyst was serous and was lined with a single layer of normal cuboidal epithelium that was periodic acid Schiff stain negative. Meticulous examination failed to identify honeycomb-like microcysts characteristic of serous cystadenoma. The final diagnosis was a solitary true cyst of the pancreas. Conclusion: The differential diagnosis of solitary true cyst from other cystic lesion of the pancreas usually is based on histology. Particular care must be taken to distinguish this lesion from macrocystic serous cystadenoma.     

A solitary fibrous tumor originating from the liver surface

The case was a 30-year-old woman found to have a 7-cm mass around the pancreatic head during a company health examination. No abnormal values other than anemia were observed in the physical findings, blood exam, and various tumor markers at the initial visit. An abdominal computed tomography (CT) revealed a tumor, 6.5 cm in diameter, accompanying a hypervascular cystic lesion in contact with the dorsolateral side of the descending portion of the duodenum and showed a dense stain in the early phase. Abdominal magnetic resonance imaging (MRI) demonstrated a lesion of isosignal intensity in a T1-weighted image and of slightly high signal intensity in a T2-weighted image. Endoscopy identified no mucosal lesion and endoscopic ultrasonography (EUS) showed an unclear border with the liver. The laparoscopic findings revealed a multilocular, elastic tumor that was prone to bleeding within the abdominal cavity. The tumor was resected immediately, as it was in contact with multiple organs but continuous with the Glisson’s capsule in the posterior portion of the liver. The tumor was positive for CD34/Bcl-2 and negative for S100 protein/c-kit/EMA, therefore a diagnosis of solitary fibrous tumor (SFT) was made. The postoperative course has been favorable. The patient was discharged on day 10 and her course is currently being monitored on an outpatient basis. SFTs are relatively uncommon as extrathoracic lesions, and those originating from the liver surface are extremely rare.     

Primary squamous cell carcinoma of the liver concomitant with primary colon cancer: report of a case

A 55-year-old Japanese female was admitted to our hospital to treat colon cancer. Computed tomography revealed a 2.6 × 2.0 cm liver mass considered to be liver metastasis. She synchronously underwent right colectomy with D3 lymph node dissection and subsegmentectomy 8 under the diagnosis of advanced colon cancer with liver metastasis. The pathology examination revealed the liver nodule was pure squamous cell carcinoma (SCC), whereas histology of colon cancer was a well differentiated tubular adenocarcinoma containing no squamous component. The patient underwent intensive checkup by imaging for a primary site of SCC. However, no lesion considered as possible primary site of SCC was found. Therefore, the liver nodule was finally diagnosed as a primary hepatic SCC. Primary SCC of the liver is a rare and high-grade malignant tumor. Recurrent multiple liver nodule was found at 13 months after surgery and the patient died of cancer 17 months after surgery.     

Collagenous nodule mixed simple cyst and hemangioma coexistence in the liver

A 20-year-old female patient presented with two masses located in the left liver.In this patient, a computed tomography(CT) scan revealed a hypodense mass and a second well-defined mass with a calcified nodule in the left hepatic lobe.No enhancements were apparent in or around the masses.A laparotomy was performed due to the patient's symptoms, namely, the atypical CT findings and a risk of rupture of the subcapsular lesion.The operation revealed two masses in the left hepatic lobe and a left liver resection was subsequently performed.One of the masses involved segment Ⅲ and the other mass was located in segment Ⅳ.The histopathologic findings supported a diagnosis of collagenous nodule mixed simple cyst and hemangioma.A diagnosis of collagenous nodule mixed simple hepatic cyst is extremely rare and radiologically mimics a teratoma, hepatolithiasis, parasitic cyst, or hemangioma.Although hepatic hemangiomas are the most common benign tumors found in the liver, the present case showed atypical radiographic features.     

MRI长时间延迟增强扫描诊断肝脏孤立性坏死性结节价值研究*

目的 探讨磁共振成像（MRI）长时间延迟增强扫描诊断肝脏孤立性坏死性结节（SNNL）的价值。方法 2013年5月~2018年5月我院就诊的17例SNNL患者和15例肝脏恶性肿瘤患者（其中10例为肝细胞癌和5例为肝转移癌）,所有患者均行常规CT/MRI增强扫描及MRI多期长时间延迟至120 min扫描,分别比较两组病灶影像学特征,如病灶密度、强化类型,探讨长时间延迟扫描在鉴别SNNL与肝脏恶性肿瘤中的作用。结果 在SNNL患者,CT和MRI共检出17个病灶,均位于肝右叶,且均为单发病灶,直径为（2.1±0.4） cm;在10例HCC患者,MRI检查发现11个病灶,位于肝右叶者8个,位于肝左叶者3个。单发病灶9例,多发病灶1例,直径为 （5.4±1.6） cm;在5例肝脏转移癌患者中,共检出12个病灶,位于肝右叶者9个,位于肝左叶者3个,直径为 （3.1±0.9）cm;在SNNL病灶中有4个病灶在T2WI上表现为“靶征”,与肝转移癌病灶的影像学表现类似;在延迟期（DP）3/5 min扫描,HCC和肝转移癌病灶边缘多呈中度-重度环形强化,SNNL病灶边缘强化水平随着延迟时间延长而逐渐增强。在DP 1 h时,17个病灶均表现为中度-重度环形强化,病灶中心无强化,而肝脏恶性肿瘤病变边缘强化均已消失。结论 MRI 长时间延迟增强扫描能有效区分SNNL与肝脏恶性肿瘤,主要表现为在延迟扫描时呈病灶边缘和间隔环形强化,且病变中心无强化。     

Spontaneous necrosis of solid gallbladder adenocarcinoma accompanied with pancreaticobiliary maljunction

A 71-year-old Japanese man with acute cholecystitis and an incarcerated gallbladder （GB） stone was admitted. Plain ultrasonography （US） incidentally detected a mass-like lesion in the fundus. Doppler US revealed that this elevated lesion had no blood flow. Computed tomography showed a relatively low-density mass, measuring 5 cm x 4 cm in diameter, with no positive enhancement. Magnetic resonance imaging showed a mass in the fundus with a slightly low intensity on Tl-weighted images and a slightly high intensity on T2-weighted images. We were agonized in making the qualitative diagnosis of mass-like lesions of the fundus, such as a benign tumor, cancer, or debris. We performed laparoscopic cholecystectomy, because the incarcerated GB stone clearly caused acute cholecystitis. Intra-operative cholangiography clearly revealed pancreaticobiliary maljunction. Amylase levels in the common bile duct and gallbladder were quite high. The elevated lesion in the fundus dearly showed severe necrosis. Although this necrotic nodule included non-viable adenocarcinoma cells, viable cancer cell nests were located in the muscularis propria and subcutaneous layer. Histopathological examination confirmed a solid adenocarcinoma. Thus, we diagnosed it as a gallbladder cancer, based on histopathological analysis of the resected specimen. We therefore undertook radical surgery, including wedge resection of the liver, radical dissection of regional lymph nodes, and resection of the extrahepatic bile duct. Histopathological findings revealed no cancer, hyperplasia or dysplasia in the additionally resected specimens. The patient was finally staged as T2, N0, H0, P0, M（-）, stage Ⅱ. We present the first case of spontaneous necrosis of solid gallbladder adenocarcinoma, with a review of previous studies.     

Solitary Necrotic Nodules of the Liver: Histology and Diagnosis With CT and MRI

Background

A solitary necrotic nodule (SNN) of the liver is an uncommon lesion, which is different from primary and metastatic liver cancers.

Objectives

To analyze the classification, CT and MR manifestation, and the pathological basis of solitary necrotic nodule of the liver (SNN) in order to evaluate CT and MRI as a diagnosing tool.

Patients and Methods

This study included 29 patients with liver SNNs, out of which 14 had no clinical symptoms and were discovered by routine ultrasound examinations, six were found by computed tomography (CT) due to abdominal illness, four had ovarian tumors, and five had gastrointestinal cancer surgeries, previously. Histologically, these SNNs can be divided into three subtypes, i.e., type I, pure coagulation necrosis (14 cases); type II, coagulation necrosis mixed with liquefaction necrosis (five cases); and type III, multi-nodular fusion (10 cases). CT and magnetic resonance imaging (MRI) patterns were shown to be associated with SNN histology. All patients were treated surgically with good prognosis.

Results

CT and MRI appearance and correlation with pathology types: three subtypes of lesions were hypo-density on both pre contrast and post contrast CT, 12 lesions were found the enhanced capsule and 1 lesion of multi- nodular fusion type showed septa enhancement. The lesions were hypo-intensity on T2WI and the lesions of type II showed as mixed hyperintensity on T2WI. The capsule showed delayed enhancement in all cases, and all lesions of multi- nodular fusion type showed delayed septa enhancement on MR images. 15 cases on CT were misdiagnosed and Four cases on MRI were misdiagnosed and the accuracy of CT and MRI were 48.3% and 86.2% respectively.

Conclusions

In conclusion, CT and MRI are useful tools for SNN diagnosis.     

Spontaneous regression of colorectal liver metastasis

A 72-year-old woman with advanced ascending colon cancer and an intraductal papillary mucinous neoplasm (IPMN) of the pancreatic head was treated by right hemicolectomy (RHC) and pylorus-preserving pancreaticoduodenectomy (PpPD). Adjuvant chemotherapy was not administered. Multimodal examinations at 5 months after surgery detected a solitary metastatic liver tumor derived from cancer of the ascending colon. Liver resection proceeded at 7 months after the first surgery. A pathological study of a surgical specimen of the liver identified a necrotic nodule that did not contain viable tumor cells. However, an immunohistological study of the hepatic mass indicated metastasis derived from cancer of the ascending colon. These findings were consistent with total necrosis of a liver metastasis of colorectal cancer. The mechanism of spontaneous regression of tumors remains unexplained. In our case, pancreaticoduodenectomy was performed at the same time as right hemicolectomy, which involved a risk of continuous biliary infection after biliary tract reconstruction. A host immune response to chronic biliary tract infection might have been involved in the spontaneous regression of liver metastasis. Spontaneous regression of colorectal liver metastasis is rare, and the mechanism remains unknown. This needs to be investigated in more tissues from patients who have experienced this phenomenon.     

Sclerosed hemangioma of the liver: Report of a case and review of the literature.

A sclerosed hemangioma of the liver is an extremely rare type of benign hepatic tumor. A 77-year-old female was referred to Tokushima University Hospital with fever, abnormal liver function tests and a large liver mass. The tumor, 10 x 5 cm in size and located in segment 5-6 of the liver, was depicted as a low density tumor with enhancement by computed tomography (CT). Magnetic resonance imaging (MRI) showed it to be a tumor with a low signal on T1-weighted and a high signal on T2-weighted images. The patient was negative for hepatitis B surface antigen and hepatitis C antibody. She underwent a right hepatectomy for possible malignant liver tumors, including intrahepatic cholangiocarcinoma or fibrolamellar hepatocellular carcinoma. The following histological examination of the surgical specimen revealed the tumor to be a hepatic sclerosed hemangioma with characteristic dense collagenous tissues. We report here on the case of this unusual tumor and review the relevant literature.     

CT and MR Imaging Findings of Pancreatic Paragangliomas: A Case Report

Previous studies on pancreatic paraganglioma, a rare neoplasm, have primarily reported its ultrasound and routine and contrast-enhanced computed tomography (CT) findings. To our knowledge, we are the first to report the contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) sequence findings of pancreatic paraganglioma.A male patient, ages 41 years, was admitted to our hospital due to a pancreatic space-occupying lesion that had been present for more than 10 days. The patient had no obvious discomfort. He had a history of hypertension and hyperthyroidism. Physical examination revealed upper abdominal tenderness without a palpable mass. Routine and contrast-enhanced abdominal CT showed a soft tissue mass at the pancreatic head/uncinate process, with patchy calcification within the lesion. On a contrast-enhanced CT scan, severe enhancement of the mass in the arterial phase was noted, as was slightly reduced but still marked enhancement in the venous phase. The celiac trunk and superior mesenteric artery segment were wrapped by the tumor. Thickened, tortuous vessels were observed at the lesion edges, around which there were multiple enlarged lymph nodes. The main pancreatic duct was markedly dilated. Routine and contrast-enhanced pancreatic MRI demonstrated an abnormal nodular signal in the pancreatic head/uncinate process that was approximately 4.3 × 6.4 cm² in size. T1-weighted imaging (T1WI) revealed hypointensity, whereas T2-weighted imaging (T2WI) revealed nonhomogeneous, slight hyperintensity. Patchy hypointensity on both T1WI and T2WI was observed within the lesion. DWI showed slight hyperintensity. Grossly heterogeneous enhancement of the mass was observed on a contrast-enhanced MRI scan, with the tumor wrapped around the adjacent vasculature, and multiple enlarged lymph nodes were observed peripherally. After preoperative preparation, the patient underwent pancreatoduodenectomy. Histopathology and immunohistochemistry of the resected tumor indicated pancreatic paraganglioma. After surgery, the patient recovered well, without presenting any recurrence or metastasis during short-term follow-up.For hypervascular pancreatic tumors on contrast-enhanced CT or MRI, and particularly those occurring in the pancreatic head, with a clear display of draining veins, the possibility of pancreatic paraganglioma should be considered. These tumors usually exhibit necrosis or cystic changes and are occasionally accompanied by calcification.     

Hepatocellular carcinoma with extensive peliotic change

Peliosis hepatis is a rare lesion histologically characterized by multiple cavities representing dilated sinusoids filled with blood in the liver. Although it has been observed in the liver parenchyma in association with several diseases and medications, there are few reports of nodules of hepatocellular carcinoma (HCC) showing extensive peliotic change. We describe a case of HCC showing extensive peliotic change in the cancer nodule. A 73-year-old man with a liver tumor was referred to our hospital for further investigation. Abdominal ultrasonography revealed an 8-cm hyperechoic lesion with a halo and mosaic pattern in segment 8 (S8) of the liver. Dynamic magnetic resonance imaging of the liver showed early irregular enhancement of the peripheral part of the lesion, and the effect persisted into the late phase, spreading into the central part of the nodule. Hepatic arteriography showed the “cotton–wool” sign, usually observed in cavernous hemangiomas. Fine-needle aspiration biopsy revealed the diagnosis of HCC. Anterior sectionectomy of the liver was conducted. Histological examination of the resected specimen showed that the tumor was a well-differentiated HCC with extensive dilated sinusoid-like structures in the main portion of the nodule, suggestive of peliotic change.