a 3-year - old girl was admitted to our hospital with unexplained fever and paroxysmal abdominal pain that had persisted for three days .
her body temperature at the time of admission was 39.5. physical examination showed abdominal tension , though there was no obvious tenderness and rebound tenderness .
the blood platelets count ( 24010/l ) was normal , and the c - reactive protein ( > 1.6 mg / dl ) , the white blood cell count ( 13.910/l ) and eosinophil count ( 4% , 0.5810/l ) were elevated , while hepatic glutamic oxalacetic transaminase ( 24 u / l ) and glutamate pyruvate transaminase ( 21 u / l ) were normal . however , the level of cholinesterase ( 2,395
the abdominal non - contrast ct obtained on the fifth hospital day revealed diffusely hypodense nodular lesions in the hepatic parenchyma with marked hepatomegaly , retroperitoneal lymphadenopathy and ascites in the pelvic cavity .
eight days after admission , an abdominal mri revealed marked hepatomegaly with diffuse high intensity of the homogeneous nodular lesions ( 2 - 4 mm diameter ) throughout the hepatic parenchyma and retroperitoneal lymphadenopathy .
in addition , disseminated miliary nodules of high signal intensity were located on the peritoneum on the t2-weighted images , as well as a group of diffuse , low intensity nodular lesions were seen throughout the hepatic parenchyma on the axial t1-weighted images ( fig .
, a chest ct showed multiple small hyperdense nodules ( 2 - 4 mm in diameter ) in both lungs ( fig .
after the small intestinal wall and peritoneal biopsy , histological examination revealed parenchymal tubercles containing several larvae of pentastomids and a large amount of inflammatory cell infiltration surrounding them ( fig .
at this point , it was revealed by the patient 's parents that the patient had consumed snake meat several months prior to her admission . following the diagnosis ,
she was administered praziquantel ( 0.5 g , tid , per day ) and albendazole ( 0.75 g , bid , per day ) in order to expel the intestinal worms .
the patient 's temperature began to slowly decrease two days after the start of the therapy , and after 10 days of the therapy the fever had disappeared and the abdominal pain was diminished . on examination , pentastomid worms were observed in a stool ( fig .
the patient made an uneventful recovery after a half a month of therapy and she was discharged from our hospital .
human pentastomiasis is divided into two types : the more common visceral pentastomiasis ( which is the main portion of the cases of pentastomiasis ) and nasopharyngeal pentastomiasis ( 1 ) .
visceral pentastomiasis is an unusual parasitic zoonosis that is caused by the larval stages ( nymphs ) of several species of pentastomes ( ' tongue worms ' ) , and these are parasites that form a unique phylum with characteristics of both arthropods and annelids ( 2 ) . at present , there are ten known pathogenic species of pentastomid parasites and six known kinds of human pentastomiasis .
the latter include armilliferosis , linguatulosis , porocephalosis , raillietiellosis , leiperiosis and sebekiosis ( 3 ) .
the species that affect humans belong to the families linguatulidae , armilliferidae and porocephalidae , and all of which have different geographic distributions .
more than 90% of the human cases are caused by the nymphs of only two species , l. serrata and a. armillatus ( 4 ) .
the infection develops in humans when parasite ova are ingested from the respiratory secretions or feces from the final hosts ( dogs and other carnivores for linguatula , several species of large snakes for armillifer and porocephalus ) . in the digestive tract of the human host , the minute four - legged primary larvae hatch and
invade the viscera of the digestive tract in the human host ( 5 , 6 ) .
the nymphs involve many organs , including the liver , esophagus , stomach , duodenum , jejunum , ileum , colon , appendix , rectum , mesentery , gallbladder , lung , pleura , broad ligament , pancreas , omentum , bladder , adrenal gland , heart ( pericardium ) , lymph nodes , skin , epididymis , eye , brain , inguinal hernia sac , etc ; however , the liver is the most common site ( 7 ) .
visceral pentastomiasis causes the majority of asymptomatic infections in humans , but a small number of cases are fatal , and the severity of symptoms is related to the organs that are infected and the degree of infection by the nymph ( 8) . the patients with a heavy infestation showed chronic fever , ascites , abdominal pain , diarrhea , mild anemia , hepatosplenomegaly , eosinophilia in the bone marrow and blood , and multiple polyps in the whole colon .
the pathologic features of the liver biopsy are degeneration and necrosis of hepatocytes , along with obvious infiltration of eosinophils .
as was demonstrated in this study , praziquantel or mebendazole is a medical treatment for this disease ( 9 ) .
only a few cases of pentastomiasis infections have been reported in humans around the world , and there is limited literature about the imaging features of pentastomiasis infection .
we report here a case where the patient had a history of eating snake meat several months prior to her hospital admission , and her main symptoms were a high fever and abdominal pain .
an abdominal mri demonstrated diffuse nodules throughout the liver , an enlarged liver , a little ascites , diffuse retroperitoneal lymphadenopathy and disseminated miliary nodules of high signal intensity on the peritoneum .
the laparoscopy revealed that the liver was diffusely enlarged , as well as there were diffusely scattered micro - cyst nodules of varying sizes on the surface of the liver and the peritoneum .
microscopically , the small intestinal wall and peritoneal biopsy showed several larvae of pentastomids in the cyst nodules .
the parasite worms were surrounded by a group of macrophages , inflammatory cells and fibrosis .
when liver enlargement and diffuse hepatic hypodense nodular lesion is seen on a t1-weighted image , it is necessary to differentiate pentastomiasis hepatic involvement from other diseases that present with diffuse liver enlargement , high fever and abdominal pain ( 10 , 11 ) such as diffuse liver metastasis , diffuse hepatocellular carcinoma , lymphoma and diffuse granulomatosis ( 12 ) .
biopsy or autopsy is necessary to determine the cause of the symptoms . in this report
we studied the patient with magnetic resonance imaging . due to the spatial resolution of the current t2-weighted mr imagers ,
the detection of these microcysts and larvae within the microcysts was well accomplished in tandem with the clinical features and epidemiology , which aided in making the differential diagnosis ( 13 ) . in summary
, we have presented a rare case of pentastomiasis infection that involved many organs , including the liver , small intestine , peritoneum , lung and retroperitoneal lymph nodes .
the patient 's symptoms consisted of high fever , abdominal pain , abdominal tension and anemia .
the imaging features of the abdominal mri revealed marked hepatomegaly with diffuse homogeneous nodular lesions throughout the hepatic parenchyma , diffuse retroperitoneal lymphadenopathy and disseminated miliary nodules on the peritoneum .
the chest ct showed scattered small nodules in both lungs . when liver enlargement and hepatic disseminated miliary nodules are identified , it is necessary to differentiate pentastomiasis hepatic involvement from other diseases .
pentastomiasis infections should be considered in the diagnoses of patients with a history of such abdominal symptoms and who have consumed snake meat , though the definite diagnosis depends on the pathology report .
 we report here a case of pentastomiasis infection in a 3-year - old girl who had high fever , abdominal pain , abdominal tension and anemia . 
 ultrasound scanning of the abdomen revealed disseminated hyperechoic nodules in the liver and a small amount of ascites . 
 abdominal mri showed marked hepatomegaly with disseminated miliary nodules of high signal intensity throughout the hepatic parenchyma on t2-weighted images ; retroperitoneal lymphadenopathy and disseminated miliary nodules on the peritoneum were also noted . 
 chest ct showed scattered small hyperdense nodules on both sides of the lungs . 
 the laparoscopy demonstrated diffuse white nodules on the liver surface and the peritoneum . 
 after the small intestinal wall and peritoneal biopsy , histological examination revealed parenchymal tubercles containing several larvae of pentastomids and a large amount of inflammatory cell infiltration around them . 
 the pathological diagnosis was parasitic granuloma from pentastomiasis infection . 