[Signet ring cell carcinoma of the bile duct: a case report]

A 72-year-old man was admitted with obstructive jaundice. Computed tomography revealed a 4cm tumor with multiple cystic components obstructing the common bile duct. Endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography and intraductal ultrasonography demonstrated the tumor, which derived from the lower bile duct, grew into the bile duct lumen. Peroral cholangioscopy revealed distended tumor vessels on the surface of the tumor. Signet ring cell carcinoma of the bile duct was diagnosed by biopsy. The patient died 3 months after the first hospital admission despite chemotherapy.

Genetic heterogeneity of hepatitis C virus in association with antiviral therapy determined by ultra-deep sequencing

Background and Aims

The hepatitis C virus (HCV) invariably shows wide heterogeneity in infected patients, referred to as a quasispecies population. Massive amounts of genetic information due to the abundance of HCV variants could be an obstacle to evaluate the viral genetic heterogeneity in detail.

Methods

Using a newly developed massive-parallel ultra-deep sequencing technique, we investigated the viral genetic heterogeneity in 27 chronic hepatitis C patients receiving peg-interferon (IFN) α2b plus ribavirin therapy.

Results

Ultra-deep sequencing determined a total of more than 10 million nucleotides of the HCV genome, corresponding to a mean of more than 1000 clones in each specimen, and unveiled extremely high genetic heterogeneity in the genotype 1b HCV population. There was no significant difference in the level of viral complexity between immediate virologic responders and non-responders at baseline (p = 0.39). Immediate virologic responders (n = 8) showed a significant reduction in the genetic complexity spanning all the viral genetic regions at the early phase of IFN administration (p = 0.037). In contrast, non-virologic responders (n = 8) showed no significant changes in the level of viral quasispecies (p = 0.12), indicating that very few viral clones are sensitive to IFN treatment. We also demonstrated that clones resistant to direct-acting antivirals for HCV, such as viral protease and polymerase inhibitors, preexist with various abundances in all 27 treatment-naïve patients, suggesting the risk of the development of drug resistance against these agents.

Conclusion

Use of the ultra-deep sequencing technology revealed massive genetic heterogeneity of HCV, which has important implications regarding the treatment response and outcome of antiviral therapy.

FDG uptake, GLUT-1 glucose transporter and cellularity in human pancreatic tumors

We previously reported that grading of GLUT-1 glucose transporter expression was related closely to FDG accumulation in FDG PET in human cancers. But in this strong GLUT-1 expression group, there was an enormous range of standardized uptake values (SUVs) within them.

METHODS

To evaluate other factors determining the FDG PET uptake, FDG PET was performed in 36 preoperative patients (mean age 62.0 yr) suspected of having pancreatic tumors, including 33 malignant and 3 benign neoplastic tumors. FDG uptake at 50 min after injection of 185 MBq 18F-FDG with > 5 hr fasting condition was semiquantitatively analyzed as SUVs. The GLUT-1 expression was studied by immunohistochemistry of paraffin sections from these tumors after the operation using the antiGLUT-1 antibody. The number of tumor cells within a 5- x 5-mm square was counted manually using x200 magnification photographs and was graded immunohistochemically as strong, weak or negative.

RESULTS

In all 36 cases there were 3 cases of GLUT-1 negative, 8 of GLUT-1 weak positive and 25 of GLUT-1 strong positive. In all cases, the total number of tumor cells had no significant value for SUVs. Among 33 GLUT-1 positive cases, the number of GLUT-1 positive tumor cells correlated significantly with SUVs (p < 0.01). Only in 25 strong grade cases, the number of GLUT-1 strong positive tumor cells had a more significant value for SUVs (p < 0.005). Computational multivariate analysis using multiple regression for SUVs was performed evaluating the five variables as follows: tumor size, GLUT-1 immunohistochemical grading, number of total tumor cells, number of total GLUT-1 positive tumor cells and number of GLUT-1 strong positive cells. This analysis revealed that only the variable, the number of GLUT-1 strong positive cells, had a significant regression coefficient for SUVs (standard regression coefficient = 0.855, p < 0.0001).

CONCLUSION

These data indicate that GLUT-1 expression plays an essential role in higher FDG accumulation in pancreatic tumor FDG PET, and the cellularity has a significant influence on SUVs only in the condition of GLUT-1 strong positive expression.

Expression of glucose transporters in human pancreatic tumors compared with increased FDG accumulation in PET study

Although overexpression of GLUT-1 glucose transporter has already been reported in human cancers, the mechanism of glucose entry into pancreatic cancers remains unknown. To evaluate the relationship between GLUT glucose transporters and FDG uptake, FDG-PET was performed in 34 preoperative patients (mean age, 60.9 yr) with suspected pancreatic tumors, including 28 malignant and 6 benign tumors.

METHODS

FDG uptake at 50 min after injection of 185 MBq of [18F]FDG with >5 hr of fasting was semiquantitatively analyzed as standardized uptake values (SUVs). The GLUT expression was studied by immunohistochemistry of paraffin sections from these tumors after operation using anti-GLUT-1, -2, -3, -4 and -5 antibodies to obtain immunohistochemical grading ("strong," "weak" and "negative") by three experienced physicians.

RESULTS

Of 26 malignant tumors proved by histological examination, 23 (88%) tumors were positive for the expression of GLUT-1 glucose transporter, and 17 (61%) showed strong expression. On the other hand, 13 (46%), 0 (0%), 9 (36%) and 13 (46%) malignant tumors were positive for the expression of GLUT-2, -3, -4 and -5 glucose transporters, respectively. Three of six benign tumors showed strong GLUT-1 expression. Concerning GLUT-2, -3, -4 and -5, only one benign tumor showed positive GLUT-5 expression. Thus, GLUT-1 showed relatively high sensitivity but low specificity (50%) for detecting malignant tumors, whereas GLUT-2, -3, -4 and -5 had lower sensitivities but higher specificities. Correlations between SUVs and grading of GLUT immunoreactivity were significant in GLUT-1 (strong, 4.49 +/- 2.95; weak, 3.42 +/- 1.21; negative, 2.52 +/- 0.84) (p < 0.05) but not in the remaining four GLUT transporters.

CONCLUSION

These data indicate that GLUT-1 has a significant role in the malignant glucose metabolism and may contribute to the increased uptake of FDG in PET imaging in patients with pancreatic tumor.

Acute hepatic failure following transcatheter arterial embolization for the treatment of hepatocellular carcinoma

We conducted a retrospective analysis to evaluate the risk factors associated with the occurrence of acute hepatic failure following transcatheter arterial embolization (TAE) for hepatocellular carcinoma. From 1984 to 1993 we performed a total of 623 embolization procedures in 369 patients with both hepatocellular carcinoma and chronic liver disease. Within 2 weeks after TAE, 13 patients (2.1%) experienced hepatic failure as characterized by a rapid increase in serum bilirubin levels and the development of hepatic encephalopathy of grade 2 or higher. These results indicated that the following are risk factors for acute hepatic failure after TAE: poor hepatic functional reserve; high-dose infusion of chemotherapeutic agents, and a history of multiple embolization procedures.

[Imaging of somatostatin receptor using 111In-pentetreotide]

Recently radiolabeled somatostatin analog, [111In]pentetreotide, was developed and its usefulness for the diagnosis and localization of neuroendocrine tumors has been described. In this paper, we reported the results of [111In]pentetreotide scintigraphy in four patients with gastroenteropancreatic endocrine tumors. Two patients with metastatic gastrinoma, one patient with gastric carcinoid, and one patient suspected with gastrinoma, were injected with 119-156 MBq of [111In]pentetreotide. Planar and SPECT images were obtained 4, 24, and 48 hours postinjection. Both primary and metastatic tumors were well visualized in patients with metastatic gastrinoma. Especially in one patient small liver metastases which were not detected by CT or MRI were imaged. We could not obtain positive images in the other two patients. Four-hour or 24-hr images were better than 48-hr images because of higher count density and lower gut activity. No significant adverse effect were seen in any patient. [111In]pentetreotide scintigraphy is a useful procedure for the localization of gastroenteropancreatic endocrine tumors.

In vivo assessment of glucose metabolism in hepatocellular carcinoma with FDG-PET

The present study was designed to assess glucose metabolism in hepatocellular carcinoma (HCC) with PET and [18F]fluorodeoxyglucose (FDG) and to compare the results with the measured in vitro enzymatic activity of glucose metabolism and the histologic grading of HCC.

METHODS

Dynamic FDG-PET scans were obtained in 17 preoperative patients with HCC. From the serial tissue and arterial radioactivities obtained by dynamic PET, FDG kinetic rate constants (K1 to k4) were obtained. The standardized uptake value (SUV) was also determined from the images acquired 48 to 60 min after FDG administration. These PET results were compared with hexokinase and glucose-6-phosphatase (G6Pase) activities and histologic grading of HCC in surgically resected tumor materials. According to histologic grading, the tumors were divided into low-grade and high-grade HCCs.

RESULTS

The k3 and SUV of high-grade HCCs were significantly higher than those of low-grade HCCs (p < 0.005, each). In addition, high correlations were observed between the hexokinase activities and these two parameters (r = 0.715 0.768, respectively). In some HCCs, relatively high G6Pase activities and k4 values modified tumor FDG uptake.

CONCLUSION

FDG PET is a valuable method for assessing glucose metabolism and histologic grading of HCC.

[MR angiography in the evaluation of endoscopic injection sclerotherapy for esophago-gastric varices]

We evaluated the utility of magnetic resonance angiography (MRA) for the detection of esophago-gastric varices and assessment of their therapeutic response to endoscopic injection sclerotherapy (EIS). MRA was performed in a total of 12 patients with esophago (E)-gastric (G) varices (V) (9 EV and 3 GV patients) both before and two-weeks after EIS. 25-35 horizontal images were obtained during single breath holding and data were reconstructed by using the two dimension time of flight method. MRA detected varicose lesions in all GV patients and in 7 of 8 EV patients of the grades F2 or higher. Varicose lesion in grade F1 EV patients were initially undetectable before EIS but became evident on MRA after EIS. The portal collaterals were equally well displayed by MRA and the superior mesenteric arteriography at its portogram phase. MRA and endoscopy were concordant for the disappearance or persistence of varicose lesions after EIS. We conclude that MRA is useful for the detection of esophago-gastric varices and other portal collaterals. MRA provides a non-invasive and workable technique in evaluation of patients with esophago-gastric varices undergoing EIS.

Evaluation of pancreatic tumors with positron emission tomography and F-18 fluorodeoxyglucose: comparison with CT and US

PURPOSE

To assess the clinical value of positron emission tomography (PET) with fluorine-18-labeled fluorodeoxyglucose (FDG) for identification of pancreatic carcinoma.

MATERIALS AND METHODS

Forty-six patients suspected of having a pancreatic neoplasm and who were to undergo surgery prospectively underwent FDG PET, computed tomography (CT), and transabdominal ultrasound (US). Endoscopic US was performed in 40 patients. Images were independently interpreted and compared with the histopathologic findings at surgery (41 patients) or with clinical follow-up findings (five patients).

RESULTS

In 33 of 35 patients, foci of pancreatic carcinomas (10-100 mm in diameter) were identified as an increase in FDG uptake, whereas CT, transabdominal US, and endoscopic US depicted the foci in 31, 31, and 28, cases, respectively. Among 11 benign lesions, nine showed no increased FDG uptake (specificity = 82%). Specificities of the other modalities were lower. False-positive findings were obtained in a case of chronic active pancreatitis and in a serous cystadenoma.

CONCLUSION

FDG PET, which provides "biochemical" information, is accurate in identifying pancreatic carcinoma and may be a method of choice when imaging equivocal masses detected with other "anatomic" imaging studies.

Value of fluorine-18-fluorodeoxyglucose and thallium-201 in the detection of pancreatic cancer

This study compares the diagnostic value of 18F-FDG PET imaging and 201TI-SPECT imaging in patients with pancreatic cancer.

METHODS

Twenty-five patients with histologically-proven pancreatic cancer were studied. Following PET transmission scanning, 3 mCi of 201TI were administered after patients had fasted overnight. Thallium-201-SPECT images were obtained 15 min later. Immediately after 201TI-SPECT imaging, 4 mCi of FDG were administered and PET images were obtained 60 min later. The PET and SPECT images were compared qualitatively and quantitatively. For quantitative analysis, 10 x 10 mm2 regions of interest (ROIs) were selected in areas of the tumor showing the highest tracer accumulation and in the normal pancreas. The tumor to nontumor activity ratio (T/N ratio) was calculated.

RESULTS

Although both techniques delineated focal lesions with an increase in tracer accumulation in 16 patients, PET identified eight additional patients in whom 201TI-SPECT images did not visualize any lesion. Thus, FDG-PET provided significantly higher sensitivity (96%) than 201TI-SPECT (64%). Among the patients showing increased tracer accumulation, the T/N ratio was significantly higher with FDG-PET (3.24 +/- 1.27) than with 201TI-SPECT (1.77 +/- 0.37) (p < 0.0001).

CONCLUSION

We conclude that FDG-PET has a larger clinical value for noninvasive detection of pancreatic cancer than 201TI-SPECT. If a PET camera is available, FDG-PET is considered to be the method of choice for the evaluation of patients with suspected pancreatic cancer.

Value of fluorine-18-FDG-PET to monitor hepatocellular carcinoma after interventional therapy

METHODS

Thirty-two tumors in 30 patients with hepatocellular carcinoma (HCC) were studied preoperatively using PET with 18F-labeled 2-fluoro-2-deoxy-D-glucose (FDG) to evaluate the metabolic activity of the lesions after interventional therapy. All patients had received transcatheter arterial chemoembolization therapy using iodized oil (Lipiodol, Laboratoire Guerbet, Alnaysous-Bois, France) before the PET study. The tumors were 2 to 18 cm in diameter. FDG uptake at 48 to 60 min after tracer injection was used to determine the standardized uptake value (SUV). The SUVs of the tumor and nontumor regions of the liver were calculated to obtain the tumor-to-nontumor ratio (SUV ratio). The PET results were compared with the findings of CT and histologic examination.

RESULTS

The tumors were divided into three types, consisting of those with increased FDG uptake (SUV ratio of 1.07-2.66, Type A, n = 19), similar FDG uptake to the surrounding nontumor region (SUV ratio of 0.77-1.04, Type B, n = 7) and decreased or absent FDG uptake (SUV ratio of 0.13-0.58, Type C, n = 6). In histologic examination, viable HCC tissue remained in all Type A and B tumors, whereas more than 90% necrosis was found in the Type C tumors, indicating that interventional therapy had been effective. These PET findings reflected tumor viability more accurately than the extent of intratumor Lipiodol retention on CT images.

CONCLUSION

FDG-PET appears to be a valuable method for the assessment of tumor viability after interventional therapy for HCC.

Vestibular neuronitis: epidemiological survey by questionnaire in Japan

An epidemiological survey on vestibular neuronitis in Japan was conducted by means of a questionnaire filled in by major neuro-otology clinics (otolaryngologists) during 1988-1990 (3 years). The diagnostic criteria of vestibular neuronitis settled on in 1986 by the Standardization Committee of the Japan Society of Equilibrium Research were applied. Gross analysis of questionnaire answers showed that i) there was no sexual difference, ii) the peak of age distribution was between 40-50 years, iii) about 30% of all cases had had common colds prior to the disease, the rate being highest among children below 10 years, iv) disappearance of positional and positioning nystagmus appeared in about 60% of all cases within 3 months, and that v) caloric CP was observed in about half of the cases at the follow-up test. Progress was not as favorable when compared to previous studies.

Vestibular neuronitis in aged patients: results from an epidemiological survey by questionnaire in Japan

An epidemiological survey of vestibular neuronitis in Japan was done using a questionnaire. Answer sheets were obtained from 619 patients with vestibular neuronitis. In order to evaluate data from aged patients, 74 cases were singled out. The following results were obtained: i) There was no sexual difference and no laterality of affected side; ii) There was no case of bilateral vestibular neuronitis; iii) Ten cases were reported as recurrent. Aged patients had a relatively high rate of recurrence; iv) About 10% of 74 cases had had an upper respiratory tract infection, and this rate was lower than that for patients under 65 years of age; v) Thirty-five cases had complications. Hypertension was the most common complication; vi) The caloric test was re-used in 28 cases. The continued existence of caloric CP was observed in 23 cases upon re-examination.

Giant cell tumor-like cholangiocarcinoma associated with systemic cholelithiasis

A cholangiocarcinoma of the hepatic hilus with an element of giant cell tumor that occurred in a 59-year-old man is reported. His medical history included systemic cholelithiasis and repeated operations on the biliary passages. Four years after the last operation, which was a hepatic segmentectomy, he was readmitted because of persistent fever. A computed tomography scan showed a low-density area and stones in the hepatic hilus. He died of hepatic failure approximately 1 month later. At autopsy, a fist-sized tumor and gallstones were found at the hepatic hilus. Histologically, the tumor mainly showed sarcomatoid features and some tubular adenocarcinoma. An element of giant cell tumor consisting of many osteoclast-type giant cells also was noted. The results of immunohistochemical studies showed a positive reaction to cytokeratin and vimentin in some of the spindle-shaped sarcomatoid cells. Sarcomatoid bile duct carcinomas are rare, as are those with osteoclast-type giant cells. The authors also discuss the histogenesis of these giant cells.

Giant cell tumor-like cholangiocarcinoma associated with systemic cholelithiasis

A cholangiocarcinoma of the hepatic hilus with an element of giant cell tumor that occurred in a 59-year-old man is reported. His medical history included systemic cholelithiasis and repeated operations on the biliary passages. Four years after the last operation, which was a hepatic segmentectomy, he was readmitted because of persistent fever. A computed tomography scan showed a low-density area and stones in the hepatic hilus. He died of hepatic failure approximately 1 month later. At autopsy, a fist-sized tumor and gallstones were found at the hepatic hilus. Histologically, the tumor mainly showed sarcomatoid features and some tubular adenocarcinoma. An element of giant cell tumor consisting of many osteoclast-type giant cells also was noted. The results of immunohistochemical studies showed a positive reaction to cytokeratin and vimentin in some of the spindle-shaped sarcomatoid cells. Sarcomatoid bile duct carcinomas are rare, as are those with osteoclast-type giant cells. The authors also discuss the histogenesis of these giant cells.

Giant cell tumor-like cholangiocarcinoma associated with systemic cholelithiasis

A cholangiocarcinoma of the hepatic hilus with an element of giant cell tumor that occurred in a 59-year-old man is reported. His medical history included systemic cholelithiasis and repeated operations on the biliary passages. Four years after the last operation, which was a hepatic segmentectomy, he was readmitted because of persistent fever. A computed tomography scan showed a low-density area and stones in the hepatic hilus. He died of hepatic failure approximately 1 month later. At autopsy, a fist-sized tumor and gallstones were found at the hepatic hilus. Histologically, the tumor mainly showed sarcomatoid features and some tubular adenocarcinoma. An element of giant cell tumor consisting of many osteoclast-type giant cells also was noted. The results of immunohistochemical studies showed a positive reaction to cytokeratin and vimentin in some of the spindle-shaped sarcomatoid cells. Sarcomatoid bile duct carcinomas are rare, as are those with osteoclast-type giant cells. The authors also discuss the histogenesis of these giant cells.