CT features of intraperitoneal manifestations of parasitic infestation

Distinct MDCT imaging features to differential diagnosis of hepatic paragonimiasis and small hepatocellular carcinoma

We used multi-row detector computed tomography (MDCT) to identify the distinguishing characteristics of hepatic paragonimiasis and small hepatocellular carcinoma lesions. We analyzed a cohort of 60 patients, of which 26 had hepatic paragonimiasis and 34 with a small (≤ 3cm) hepatocellular carcinoma. MDCT detected 65 lesions that were retrospectively reviewed and analyzed based on their imaging features. Both groups showed distinct MDCT imaging features that could contribute to an accurate diagnosis. In the paragonimiasis group, 75% (21/28) lesions were located in the hepatic subcapsular region, whereas only 10.8% (4/37) of lesions in the hepatocellular carcinoma group were subcapsular. Most hepatic paragonimiasis lesions (57.1%; 16/28) also showed characteristic tubular or tunnel features that were not present in hepatocellular carcinomas. Further, 71.4% (20/28) paragonimiasis lesions were rim enhanced with irregular tract-like non-enhanced internal areas with a characteristic target loop, while 94.6% (35/37) of small hepatocellular carcinoma lesions showed homogenous enhancement in the arterial and venous phase. In addition, the period CT values for hepatic paragonimiasis were less than those of hepatic carcinomas (P<0.001). These clinically significant findings illustrate the diagnostic features that enable one to distinguish hepatic paragonimiasis from small hepatocellular carcinomas.

Pleuropulmonary and abdominal paragonimiasis: CT and ultrasound findings

OBJECTIVES

The purpose of this study was to review radiological images of patients with Paragonimus westermani (PW) that simultaneously involved the chest and abdomen.

METHODS

Our study included four patients with serologically and histopathologically confirmed paragonimiasis. Abdomen CT (n=3) and chest CT (n=3) scans were available, and abdominal wall ultrasonography was performed in all patients. We retrospectively reviewed the clinical, radiological and histopathological findings of these patients.

RESULTS

The most common abdominal CT findings were ascites and intraperitoneal or abdominal wall nodules. Low-attenuated serpentine lesions of the liver were another common and relatively specific feature.

CONCLUSION

Radiologists should consider the possibility of PW when these abdominal CT findings are noted, especially with pleural effusion or subpleural nodules in patients with initial abdominal symptoms.

Correlations between MDCT features and clinicopathological findings of hepatic paragonimiasis

AIM

To illustrate the MDCT features of hepatic paragonimiasis and correlate the results with clinicopathological findings.

MATERIALS AND METHODS

Eighteen patients (8 male, 10 female; mean age 37years) with hepatic paragonimiasis were included in this study. MDCT features of their hepatic lesions were retrospectively reviewed and correlated with clinicopathological findings.

RESULTS

All patients were lifelong residents in endemic areas of paragonimiasis, especially Paragonimiasis skrjabini variety. Abdominal pain or discomfort, fever and high eosinophil percentage were the predominant clinical features. In total, 21 lesions were detected on MDCT images, 18 (85.7%) directly contacted the hepatic capsule and 3 (14.3%) were adjacent to the capsule. Segment V (26%), VIII (26%) and VI (18.5%) were the most commonly involved sites. Sixteen lesions (76%) were conglomerated cystic or multilocular and 5 (24%) were solid. On plain MDCT scan, the margin and internal detail of the lesions were not clear except for one cystic variety, while they were clearly demonstrated on enhanced images. Single or multiple cysts with different diameters were commonly detected in the non-solid lesions, and some of them were mutually connected with tortuous tract formation. Among the solid lesions, 2 and 3 showed tubular and homogeneous enhancement, respectively.

CONCLUSION

Peripherally distributed lesions, mutually connected cysts with tortuous tract formation, and tubular enhancement, which may be closely associated with the infection route and migration of the worm, could be seen as the main MDCT features of hepatic paragonimiasis.

Excretory-secretory products from Paragonimus westermani increase nitric oxide production in microglia in PKC-dependent and -independent manners

Excretory-secretory products (ESP) from helminthic parasites may play pivotal roles in the immune regulation in hosts. Previously, we reported that ESP produced from Paragonimus westermani induced morphological activation of microglial cells and markedly stimulated nitric oxide (NO) production via activation of mitogen-activated protein kinases (MAPKs). In the present study, we investigated the role of protein kinase C and protein kinase A in MAPKs-dependent NO production by ESP. We found that treatment with protein kinase C inhibitor Go6976 strongly inhibited the phosphorylation of p38 and JNK, but not ERK, of MAPKs and decreased the production of NO in ESP-stimulated microglial cells. Inhibition of ERK, p38 or PKC decreased the ESP-induced activation of NF-kappaB, an important transcription factor for iNOS expression. Furthermore, ESP increased the level of p-CREB in microglial cells. However, adenylyl cyclase activator (forskolin), adenylyl cyclase inhibitor (SQ22536), cAMP analogue (db-cAMP) or protein kinase A inhibitor (H89) was not able to change iNOS expression and NO production in ESP-treated microglial cells. It implies that the cAMP-PKA-CREB pathway is not implicated in the ESP-evoked NO production in microglial cells. Thus, our results indicate that ESP stimulates microglial expression of iNOS via both PKC-dependent and -independent MAPKs phosphorylation and NF-kappaB activation.

Peritoneal manifestations of parasitic infection

The purpose of this study was to describe of peritoneal manifestations of parasitic infection at CT. A broad spectrum of CT findings can be seen in the peritoneal cavity, including a varying degree of omental or mesenteric infiltration, single or multiple peritoneal mass or nodule, and peritoneal thickening or stranding. Recognition of these findings are crucial for establish an early diagnosis and helps avoid unnecessary surgery.

Imaging findings of hepatic paragonimiasis : a case report

Hepatic paragonimiasis is a rare form of ectopic infestation caused by Paragonimus. We experienced a case of hepatic paragonimiasis that showed characteristic imaging findings. CT and MR images showed a cluster of small cysts with rim enhancement in the subcapsular area of the liver. This finding seems to be characteristic for hepatic paragonimiasis, considering imaging findings in paragonimiasis involving other organs.

Heterotopic paragonimiasis in the omentum

Paragonimus westermani is a lung fluke but may be found in organs other than the lungs. A case of omental paragonimiasis was found incidentally by plain radiography and computed tomography and showed multiple, irregularly shaped, conglomerated calcifications in the intraperitoneum. Many P. westermani ova were detected in the resected omentum. This uncommon calcification on the plain abdominal radiography and computed tomography scan was considered to represent radiologic findings of ectopic paragonimiasis.