Alveolar hydatid cyst mimicking cerebellar metastatic tumor

Diagnosis and Management Approaches for Cerebellar Hydatid Cysts: A Systematic Review of Cases

Cerebellar hydatid cysts are uncommon lesions, with limited cases reported in the literature. This systematic review aimed to summarize current diagnostic and management approaches, given the low suspicion index of hydatid cysts in the cerebellum. The review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD42023437853. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-P) reporting guidelines. Two independent researchers searched PubMed, Scopus, and Google Scholar databases on June 27, 2023. We included 15 studies published between 1965 and 2022, comprising 12 case reports and three case series. A pooled analysis of reported cases (nine females and seven males) with cerebellar hydatid cysts revealed a mean age of 24 ± 20 years. Most of the cases were reported in Turkish hospitals (n = 8). The prominent signs and symptoms observed were headaches (10, 62.5%), ataxic gait (9, 56.25%), and visual disturbances (9, 56.25%). The time from symptom onset to hospital visit varied, with most patients seeking medical attention within the first three months. The left cerebellar hemisphere was the most common location of the cysts (6, 37.5%), and compression of the fourth ventricle was frequently observed. Computed tomography (CT) and magnetic resonance imaging (MRI) were the primary diagnostic tools used in three-fourths of cases, and surgical intervention was the primary treatment approach. Albendazole and praziquantel were commonly prescribed postoperatively, and two patients underwent preoperative needle decompression. This systematic review contributes to a better understanding of cerebellar hydatid cysts and guides future research and clinical management of this entity.

Safety of Three-Dimensional Conformal Radiotherapy on the Sheep with Pulmonary Cystic Echinococcosis: A Preliminary Study

PURPOSE

Radiotherapy showed the potential to effectively kill the cysts of pulmonary cystic echinococcosis (CE). However, little is known about its safety. This study was designed to investigate the safety of three-dimensional conformal radiotherapy (3D-CRT) on the normal lung tissue adjacent to the cyst and blood of sheep naturally infected with pulmonary CE.

METHODS

Twenty pulmonary CE sheep were randomly divided into control group (n = 5) and radiation groups with a dose of 30 Gray (Gy) (n = 5), 45 Gy (n = 5), and 60 Gy (n = 5), respectively. Animals in control group received no radiation. Heat shock protein 70 (Hsp70), tumor growth factor-β (TGF-β), matrix metalloproteinase-2 (MMP-2) and MMP-9 in the lung tissues adjacent to the cysts, which were considered to be closely related to the pathogenesis of CE, were evaluated after 3D-CRT. A routine blood test was conducted.

RESULTS

The results showed that there were multiple cysts of various sizes with protoscoleces in the lung tissues of sheep, and necrotic cysts were found after 3D-CRT. 3D-CRT significantly increased the mRNA level of Hsp70, enhanced the protein level of TGF-β and slightly increased the expression of MMP-2 and MMP-9 in lung tissues adjacent to the cysts. 3D-CRT did not significantly alter the amount of WBC, HB and PLT in sheep blood.

CONCLUSIONS

The results suggested that 3D-CRT may suppress the inflammation and induce less damage of the normal lung tissues and blood. We preliminarily showed that 3D-CRT under a safe dose may be used to treat pulmonary CE.

Intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis: a multicenter cohort study

BACKGROUND

The main endemic areas of alveolar echinococcosis (AE) are in central Europe and western China. The infiltration of intrahepatic vascular and bile ducts as well as extrahepatic disease can lead to complications and may increase morbidity in AE.

PURPOSE

To evaluate the vascular/biliary involvement of hepatic alveolar echinococcosis (HAE) and distant extrahepatic disease at each of four locations in Germany, France, and China.

MATERIAL AND METHODS

Contrast-enhanced abdominal magnetic resonance imaging (MRI) scans of patients with HAE, 200 in total, were evaluated by five examiners. AE liver lesions were classified according to Kodama's classification. Furthermore, distant extrahepatic manifestations were documented with additionally performed imaging modalities. Vascular/biliary involvement of hepatic manifestations as well as the presence of extrahepatic manifestations were correlated with the respective Kodama type of the liver lesion.

RESULTS

Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (12/100 vs. 3/100; Fisher's exact test: P=0.0286). A significant relationship exists between presence of distant extrahepatic disease manifestation and size of the AE liver lesion (132.53 ± 48.65 vs. 92.49 ± 50.06; P = 0.0030). Vascular/biliary involvement is significantly more frequent in China than in Europe (86/100 vs. 65/100; χ² = 11.92; P = 0.0006). Vascular/biliary involvement depends on lesion size (111.10 ± 47.44 vs. 47.36 ± 24.36; P<0.0001). Different types of AE liver lesions are associated with differences in vascular/biliary involvement and extrahepatic manifestations.

CONCLUSION

Vascular/biliary involvement and presence of distant extrahepatic manifestations depend on size of the HAE lesions and are more frequently detected in China. Different MRI morphological patterns influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations.

Primary Posterior Fossa Hydatid Cyst in a Child

ABSTRACT

A 7-year-old boy referred to our emergency department complaining of headache, nausea, vomiting, dizziness, generalized fatigue, ataxia and diplopia. Neurological exam showed bilateral papilledema and ataxic gait. Routine blood test, plain chest x-ray and abdominal ultrasonography were normal. Brain computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed well-defined intra-axial unilocular cystic lesion in the left cerebellar hemisphere, causing mass effect on brain stem and fourth ventricle with associated tonsillar herniation and mild obstructive hydrocephalus. The authors started the treatment with Albendazole and the patient was operated with left sub-occipital craniotomy. Cyst was delivered with intact capsule. Postoperative period was uneventful and patient's symptoms improved totally after 1 week. Histopathologic examination confirmed the diagnosis of hydatid cyst.

Evaluation of intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis

BACKGROUND

The main endemic areas of alveolar echinococcosis (AE) are in Central Europe and Western China. Both the infiltration of intrahepatic vascular and bile duct structures as well as extrahepatic disease can lead to further complications and may increase morbidity in patients with AE.

AIM

To evaluate vascular/biliary involvement in hepatic AE and its distant extrahepatic disease manifestations in an international collective was the aim.

METHODS

Consecutively, five experienced examiners evaluated contrast-enhanced abdominal computed tomography (CT) scans for 200 patients with hepatic AE of each of four locations (n = 50) in Germany, France and China. Therefore, we retrospectively included the 50 most recent abdominal contrast-enhanced CT examinations at each center, performed because of hepatic AE from September 21, 2007 to March 21, 2018. AE liver lesions were classified according to the echinococcosis multilocularis Ulm classification for CT (EMUC-CT). Distant extrahepatic manifestations were documented either by whole body positron emission tomography–CT or with the addition of thoracic CT and cranial magnetic resonance imaging. Vascular/biliary involvement of the hepatic disease as well as the presence of distant extrahepatic manifestations were correlated with the EMUC-CT types of liver lesion. Statistical analysis was performed using SAS Version 9.4 (SAS Institute Inc., Cary, NC, United States).

RESULTS

Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (P = 0.0091). A significant relationship was found between the presence of distant extrahepatic disease and AE liver lesion size (P = 0.0075). Vascular/biliary structures were involved by the liver lesions significantly more frequently in China than in Europe (P < 0.0001), and vascular/biliary involvement depended on lesion size. Different morphological types of AE liver lesions led to varying frequencies of vascular/biliary involvement and were associated with different frequencies of distant extrahepatic manifestations: Vascular/biliary involvement as a function of lesions primary morphology ranged from 5.88% of type IV liver lesions to 100% among type III lesions. Type IV differed significantly in these associations from types I, II, and III (P < 0.0001). With respect to extrahepatic disease, the primary morphology types IV and V of liver lesions were not associated with any case of distant extrahepatic disease. In contrast, distant extrahepatic manifestations in types I–III were found to varying degrees, with a maximum of 22% for type III.

CONCLUSION

Different CT morphological patterns of hepatic AE lesions influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations. There are intercontinental differences regarding the characteristics of AE manifestation.

Serological validation of an alveolar echinococcosis rat model with a single hepatic lesion

Serology is important for the diagnosis and follow-up of human alveolar echinococcosis (AE). However, patient conditions are highly variable among those with AE, and antibody responses in serological follow-up have not been well-defined. We recently described a new AE rat model established by implantation of small AE tissue into a single arbitrary location in the liver; no metastasis and dissemination were observed. In the present study, we examined the serological characteristics in our rat model before and after surgical treatment. The results showed that antibody responses against crude antigens were increased at one month after transplantation and similar to those of other model animals. For the antigen Em18, antibody responses were slower in our rat model than in other animal models. After surgical resection, changes in antibody responses against Em18 were similar to those observed in human patients with AE. Because of the slow growth of lesions, establishment of a single hepatic lesion and patterns of antibody responses, our rat model may be useful for clarifying follow-up serodiagnoses in human AE and determining the mechanisms of multi-organ involvement by primary infection with oncospheres rather than metastasis.

Fatal Liver and Lung Alveolar Echinococcosis with Newly Developed Neurologic Symptoms due to the Brain Involvement

The fox tapeworm Echinococcus multilocularis causes human alveolar echinococcosis, commonly affecting the liver. However, in ∼1% of cases, systematic spread of the disease involves the brain as well. A patient had a 6-year history of liver and lung alveolar echinococcosis that was considered not suitable for surgery, and treatment with albendazole was introduced. After the appearance of neurologic disturbances, an intracranial mass lesion was demonstrated by radiologic imaging. The lesion was surgically removed, and histologic analysis revealed metacestode tissue of E. multilocularis . Despite the surgical resection of the lesion, the patient died of progression of systemic alveolar echinococcosis. The authors highly recommend implementing neurologic monitoring to the follow-up algorithm for patients with systemically disseminated alveolar echinococcosis. When neurologic symptoms occur, radiologic imaging of the brain should be obtained immediately. Surgery should be considered for all intracranial echinococcal lesions, unless the lesion is located in the eloquent brain area.

Parasitoses of the human central nervous system

Cerebral involvement in parasitoses is an important clinical manifestation of most of the human parasitoses. Parasites that have been described to affect the central nervous system (CNS), either as the dominant or as a collateral feature, include cestodes (Taenia solium (neurocysticerciasis), Echinococcus granulosus (cerebral cystic echinococcosis), E. multilocularis (cerebral alveolar echinococcosis), Spirometra mansoni (neurosparganosis)), nematodes (Toxocara canis and T. cati (neurotoxocariasis), Trichinella spiralis (neurotrichinelliasis), Angiostrongylus cantonensis and A. costaricensis (neuroangiostrongyliasis), Gnathostoma spinigerum (gnathostomiasis)), trematodes (Schistosoma mansoni (cerebral bilharziosis), Paragonimus westermani (neuroparagonimiasis)), or protozoa (Toxoplasma gondii (neurotoxoplasmosis), Acanthamoeba spp. or Balamuthia mandrillaris (granulomatous amoebic encephalitis), Naegleria (primary amoebic meningo-encephalitis), Entamoeba histolytica (brain abscess), Plasmodium falciparum (cerebral malaria), Trypanosoma brucei gambiense/rhodesiense (sleeping sickness) or Trypanosoma cruzi (cerebral Chagas disease)). Adults or larvae of helminths or protozoa enter the CNS and cause meningitis, encephalitis, ventriculitis, myelitis, ischaemic stroke, bleeding, venous thrombosis or cerebral abscess, clinically manifesting as headache, epilepsy, weakness, cognitive decline, impaired consciousness, confusion, coma or focal neurological deficits. Diagnosis of cerebral parasitoses is dependent on the causative agent. Available diagnostic tools include clinical presentation, blood tests (eosinophilia, plasmodia in blood smear, antibodies against the parasite), cerebrospinal fluid (CSF) investigations, imaging findings and occasionally cerebral biopsy. Treatment relies on drugs and sometimes surgery. Outcome of cerebral parasitoses is highly variable, depending on the effect of drugs, whether they are self-limiting (e.g. Angiostrongylus costaricensis) or whether they remain undetected or asymptomatic, like 25% of neurocysticerciasis cases.