Germinal Membrane Research Articles

Letters to the Editor Choledochal or hydatid cyst: a clinical pitfall

Letters to the Editor Choledochal or hydatid cyst: a clinical pitfall

A Primary Giant Hydatid Cyst of the Ovary

Dear Editor, A 38-year-old female patient was admitted with right lower abdominal pain of 4 months duration. On her clinical examination, right lower abdominal tenderness was noted. Complete blood count including the numbers of eosinophils (80/mm3) was normal. Biochemistry was normal. An abdominal MRI showed an 11 × 9 × 5.5 cm sized cystic lesion in the right ovary surrounded by loculated fluid collection with septations (Figure 1). Echinococcal serology was positive (hydatid cyst antibodies by ELISA and indirect hemagglutination test dilutions up to 1/1280 were positive). Pathological examination of the material had a cuticle and germinative membrane of the hydatid cyst and around it chronic nonspecific inflammation leading to the formation of lymphoid follicles was seen. No other organ involvement was detected. Albendazole (10mg/kg/day) was prescribed. The cyst was removed surgically on the 30th day of albendazole treatment. Pathological examination of the cyst was compatible with hydatid cyst. The patient had regular follow-ups, with no recurrence of the cyst. Echinococcal disease is endemic in many countries (1). It involves multiple organs particularly the liver (50-70%) and the lung (20-30%), while primary involvement of the ovary is very rare (2). The liver and spleen cysts can rupture into the peritoneal cavity which is the way of secondary involvement (3). In our case, there were no cysts in other organs. Although ovarian cysts are usually single, this case showed multilocular cysts the treatment is surgical removal and albendazole is recommended before surgery. Figure 1 Pelvic MRI revealed a septated, lobulated and contrast enhancing cystic mass that is hyperintense on T2 and hypointense on T1 FLAIR sequences.

Acute coenurosis of dairy sheep from 11 flocks in Greece

CASE HISTORY: A syndrome of acute neurological dysfunction with increased mortality was observed in lambs of 10 dairy sheep flocks and adult animals in one flock in Central and Northern Greece. Each farmer completed a questionnaire regarding the management and feeding of their flocks. In seven of the 11 flocks the affected animals were grazing pasture, while in the remaining four flocks (5, 8, 9, 10) the animals were fed alfalfa hay (Medicago sativa) and concentrates indoors. A follow-up study of the affected flocks was conducted during the next 12 months. CLINICAL FINDINGS: Of 42 sheep with acute coenurosis that were examined, the most prominent neurological abnormalities were ataxia, depression, blindness, scoliosis, coma and dysmetria. Except for the four sheep that were comatose, all other animals had normal body temperatures and their appetites remained normal or were slightly decreased. Haematological findings of 15 examined sheep were within normal limits. The affected sheep were subject to euthanasia. A histopathological examination was performed in 13 cases. Faecal samples from dogs associated with these flocks were negative for taeniid infections. During the following 12 months cases of chronic coenurosis in these flocks were observed. PATHOLOGICAL FINDINGS: In the 42 animals that were necropsied, the main gross findings were cystic formations between 0.5–1 cm in diameter with translucent walls that were seen lying free on the leptomeninges or partly penetrating the brain tissue, sterile microabscecess and brain necrosis. Histopathological evaluation of tissue sections of 13 brains showed multifocal purulent or pyogranulomatous meningoencephalitis, accompanied by eosinophilic infiltrations. No bacteria were isolated following bacterial culture of brain tissue Parasitological examination of the cysts from five cases revealed whitish specks on the transparent cyst wall and germination membrane representing the scolices. DIAGNOSIS: Acute coenurosis was diagnosed in all cases studied. CLINICAL RELEVANCE: Acute coenurosis can be one of the causes of acute encephalopathy mainly in lambs, but also in adult sheep. This condition is incurable, but can be controlled by changing the feeding regime. Cases of chronic coenurosis may be seen a few months later in the same flock.

Invited Commentary

Invited Commentary

Primary Hydatid Cyst of the Chest Wall

A 69-year-old female was examined in the emergency room for abdominal pain that had recurred during the preceding 4 years. During the physical evaluation no pathology was determined, except for sensitivity to deep palpations in the upper right quadrant of the abdomen. On the chest roentgenogram, a nonhomogeneous dense area with calcific foci was observed adjacent to the right costophrenic sinus (Fig. 1). The thorax tomography revealed a mass lesion of 5 9 6 cm with calcification, which was located in the chest wall of the lower outer region of the right hemithorax (Fig. 2). Abdominal ultrasonography showed a mass that was pressuring the right lobe of the liver from the outside. The acid-fast bacillus test was negative and other laboratory tests were within normal limits. The results of the transthoracic fine-needle aspiration biopsy indicated the presence of necrotic tissue material containing calcifications. The patient was admitted for surgery with the prediagnosis of chest wall tumor. The mass was completely removed by excisional biopsy (Fig. 3). A 7 9 7 cm defect caused by the en bloc chest wall resection was reconstructed using the M. serratus anterior muscle flap. During the histopathological examination, germinative and cuticular membranes showed dystrophic calcification and chronic inflammation, and a hydatid cyst was diagnosed (Fig. 4a, b). The patient was discharged without any complications. Albendazol 15 mg/kg/day was prescribed for 3 months. Upon completion of the 1 year of follow-up, the patient was still asymptomatic and no recurrence was observed, either clinically or radiologically. A hydatid cyst is a parasitic disease caused by Echinococcus granulosus. It is endemic in countries where sheep and cattle farming is prevalent, such as the Middle East, New Zealand, South Africa, and South America. Although hydatid cyst is frequently seen in the liver and lungs, it can lead to disease in any part of the body [1]. Hydatid cysts can be located in the chest wall through to the sternum, ribs, and regional soft tissues. Yilmaz Avci et al. [2] reported that hydatid cysts in the chest wall might form due to either the rupturing of lung hydatid cysts into the pleural space or inoculation. Currently, the primary treatment for hydatid cyst disease is surgery in which all of the parasitic material is removed. Even though the roentgenographic findings are frequently diagnostic for hydatid cyst, in cases where a definite preoperative diagnosis of lesions cannot be reached, a final diagnosis can be made histopathologically through surgical intervention. Thus, the surgical treatment of these patients S. Karapolat Department of Thoracic Surgery, Duzce University School of Medicine, Duzce, Turkey

Primary echinococcal cyst in the axillary region

Human hydatid disease is a parasitic infection caused by the larval form of Echinococcus granulosus. It has worldwide distribution and is endemic in many countries, especially the Mediterranean region. It most commonly affects the liver and lungs although multi-organ involvement has been observed in 20-30% of patients. A 45-year-old woman presented to a gynaecologist because of a mass in the axillary region. Her mother and her two sisters were undergoing treatment for breast cancer. In her examination, a hard, semi-mobile, painless mass was found that was approximately 3 cm in diameter. Axillary ultrasonography showed lymphadenopathy. No abnormality was found in mammographic examination of either breast, or in abdominal ultrasonography and chest X-ray. Occult breast cancer was suspected but when the mass was excised for pathological examination the biopsy showed a hydatid cyst with germinative membranes. Subsequent lung, abdomen and brain tomography scans, whole body bone scintigraphy and hydatid serology, including indirect haemagglutination and enzyme-linked immunosorbent assay, were negative. For these reasons an isolated axillary hydatid cyst was diagnosed. Parasitic cysts should be considered in endemic areas in patients presenting with a soft tissue mass in the axillary region. Imaging methods should be planned to include this possibility.

Primary Hydatid Disease of the Pancreas Mimicking Pancreatic Pseudo-Cyst in a Child: Case Report and Review of the Literature

Primary hydatid disease of the pancreas is very rare. We report the case of a 7-year-old girl who presented with abdominal pain and an epigastric mass. The Casoni and indirect hemagglutination test for hydatid disease were negative. A diagnosis of a pancreatic pseudocyst was established by ultrasonography (US) and computed tomography scan before surgery. Ultrasound guided percutaneous drainage was planned as treatment. During the procedure, the cyst was perforated and as germinative membrane was seen by US, we arranged surgery. Hydatid disease should be considered in the differential diagnosis of all cystic masses in the pancreas, even if Casoni and indirect hemagglutination tests negative, especially in geographic regions like Turkey, where the disease is endemic.

Comparative Pathology of Pulmonary Hydatid Cysts in Macropods and Sheep

The development and appearance of hydatid cysts of Echinococcus granulosus in experimentally infected tammar wallabies (Macropus eugenii) and sheep during the period 9-17 months post-infection (mpi) were studied. Cysts of unknown age were also examined from mature, naturally infected sheep. The cysts grew more rapidly and became fertile within a shorter period in wallabies compared with sheep. Cysts from the wallabies were larger in absolute size and were larger relative to the size of the lungs. Microscopical examination revealed that wallaby hydatid cysts developed in small bronchioles. Hydatid cysts in the wallabies had a thicker germinal membrane, with more nuclei and a thicker laminated layer (LL), than hydatid cysts of similar age found in sheep. In contrast, the adventitial layer was thicker in the ovine cysts, comprising a hyalinized layer of degenerate collagen and necrotic cellular debris surrounded by a layer of granulation tissue that was largely absent from lesions in the wallabies. Multilocular cysts were present in sheep, but not in wallabies. The greater thickness of the germinal membrane in wallaby cysts suggests greater parasite activity, which may explain the more rapid growth rate in this host, whereas the thicker adventitial layer in sheep cysts may be restrictive to growth while simultaneously protecting the hydatid from the host immune response. These differences in the parasite-host relationship between macropods and sheep may reflect the relatively recent introduction of the parasite into Australia.

Splenic hydatic cyst as a cause of sinistral portal hypertension and isolated gastric variceal bleeding

A 60-year-old male, living in a rural area, presented with recurrent upper gastrointestinal bleeding. Isolated fundal varices were seen on endoscopy. A lesion similar to cyst hydatid was seen in the spleen on abdominal ultrasonography and computerized tomography scanning. Also, sinistral (left-sided) portal hypertension and collaterals were seen due to the compression of the splenic vein by the cyst. Indirect hemagglutination antibody test for Echinococcus granulosus was positive. By screening, no other cyst was found in any other site of the body. The patient underwent open abdominal surgery, and the anterior wall of the cyst was resected partially; within it were multiple daughter cysts and hydatid fluid. After decontamination of the daughter cysts and hydatid fluid, germinative membrane omentoplasty was performed with a part of the omentum. However, the patient suffered from recurrent gastrointestinal bleeding postoperatively and he was re-evaluated. Later, splenectomy was performed in order to relieve left-sided portal hypertension. The patient did not experience further bleeding and gastric varices disappeared following splenectomy.

Cystic Echinococcosis Due to Echinococcus Equinus in a Horse from Southern Germany

In Europe, cystic echinococcosis is rare in horses and is mostly diagnosed at slaughter or postmortem examination. Equine cystic echinococcosis can be caused by various Echinococcus taxa, but only Echinococcus equinus (the "horse strain") is known to produce fertile cysts. In Europe, E. equinus appears to be endemic in Great Britain, Ireland, Spain, and Italy and has sporadically been reported in Belgium and Switzerland. The present report describes the first case of a molecularly confirmed E. equinus infection in a horse foaled and raised in Germany. The 19-year-old mare was presented for examination of inappetence, emaciation, and respiratory symptoms. X-ray radiographs of the thorax showed 2 well-circumscribed tumor-like masses, each approximately 10 cm in diameter in the caudal lung field. The horse was euthanized as its condition rapidly deteriorated. Necropsy revealed 2 thick-walled hydatid cysts, each 7-8 cm in diameter in the lung. The tri-layered cyst walls consisted of an outer adventitial layer, a laminated acellular intermediate layer, and an inner germinal membrane. Grossly, the cysts contained a clear, amber liquid with hydatid sand. Light microscopy of the hydatid sand revealed free protoscoleces, intact and ruptured brood capsules, calcareous corpuscles, and debris. Samples of protoscoleces underwent molecular characterization, and the diagnosis of E. equinus was confirmed by restriction fragment length polymorphism-polymerase chain reaction and sequence analysis of the complete mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene.

Relative expression of antigen B coding gene of bubaline isolates of Echinococcus granulosus in fertile and sterile cysts

This article communicates the relative quantification of five isoforms of antigen B (AgB) of Echinococcus granulosus. Relative expression of the AgB was quantified in active and inactive cysts. Cysts with germinal membrane, clear cyst fluid and protoscoleces showed uniform expression of the five isoforms and were utilized as control. Relative expression of AgB1 was the highest in cysts, where calcification has initiated. AgB2 and AgB4 were expressed more in fertile cysts irrespective of the condition of germinal membrane. The lowest expression of AgB3 was seen in calcified cysts. The relative expression of AgB5 could not be correlated with respect to the condition of the cyst because AgB5 is typically expressed by the adult stage of the parasite.

Left ventricular apical cystic thrombus mimicking a hydatid cyst

A 69-year-old man was admitted to the emergency department with dyspnea. His medical history was remarkable for smoking (75 pack-years), chronic obstructive pulmonary disease and ischemic cardiomyopathy. On physical examination, his blood pressure was 100/80 mmHg, his pulse rate was 104 beats/min and he had bilateral moderate pretibial edema. Cardiac auscultation revealed a 2/6 systolic murmur at the apex with distant heart sounds. Auscultation of the lungs revealed bilateral rales with diffuse rhonchi in the lower lobes. On a 12-lead electrocardiogram, poor progression of the pre-cordial R wave and P mitrale were noticed. Two-dimensional echocardiography displayed diffuse left ventricular hypokinesia with an estimated ejection fraction of 15%. A cystic thrombus that did not have a germinative membrane was found at the apex of the left ventricle (Figure 1). Pulmonary computed tomography angiography showed a filling defect in the left ventricle. Tests for Echinococcus granulosus were negative. Heparin, warfarin and heart failure treatment were started. One week later, echocardiography showed that the size of the thrombus had decreased by 25%. The patient did not have any complication related to the thrombus. Figure 1) Left ventricular apical cystic thrombus Left ventricular thrombus is a common complication of severe heart failure. Therapeutic options for such thrombi include anti-thrombotics, anticoagulant therapy, thrombolysis or surgical removal of the thrombus. Clinicians should also consider hydatid cysts in the differential diagnosis, when history and laboratory tests could be used to confirm the diagnosis. But overall, until the diagnosis is established, treatment should also be initiated for a probable diagnosis of thrombus (1,2).

A simplified method of DNA extraction from Germinal Membrane of Bladder worm stage of Echinococcus granulosus and its application in disease detection

Cystic echinococcosis infection in man and animals are acquired after ingestion of eggs of Echinococcus granulosus. Unilocular fully developed cysts contain protoscoleces within a fluid-filled cavity surrounded by germinal membrane and laminar layers. The cysts are of two types sterile and fertile. In general protoscoleces are used for molecular characterization of strains isolated from fertile cysts. In the present investigation a simple procedure for extraction of DNA from germinal membrane has been described. Further, mitochondrial and nuclear sequence information was compared with the existing sequence information present in the public database.

A young woman with multiple cardiac mass lesions

A 22-year-old woman presented with breathlessness, weight loss and anorexia of 6 months’ duration. Clinical examination was suggestive of mild to moderate cardiomegaly with systolic murmur. Routine laboratory investigations revealed normal cardiac enzymes. An electrocardiogram revealed T-wave inversion in lead II, III, aVF and I, aVL and V4–6. A chest radiograph showed widened mediastinal shadow with minimally multilobulated rightand left-sided margins of cardiac and mediastinal silhouette. No obvious calcifications or altered density difference was seen in this region. Twodimensional echo cardiography (not shown) revealed

Efficacy of Chlorhexidine Gluconate During Surgery for Hydatid Cyst

Dissemination of protoscolices-rich fluid during surgery for hydatid cyst disease is a major cause of recurrence. Instillation of a scolicidal agent into a hepatic hydatid cyst before opening is the most commonly employed measure to prevent this serious complication. In this clinical study, the efficacy of 0.04% chlorhexidine gluconate (Chx-Glu) during hydatid cyst surgery was tested, and early-term results were evaluated. A total of 30 consecutive patients with 45 liver cysts were studied. Only type I and type II cysts were included. Cysts were punctured, and fluid was aspirated. The viability of protoscolices in this fluid was determined. Chx-Glu 0.04% was instilled into the cyst cavity. After 5 minutes of exposure, the cyst fluid was reaspirated and evaluated for the viability of protoscolices. Imprints of the germinative membranes were determined for protoscolices viability. All protoscolices in 45 cysts evaluated were killed by 5 minutes of exposure to 0.04% Chx-Glu. The whole of the germinative membrane imprints contained dead protoscolices. Chx-Glu 0.04% did not cause any adverse effect on biliary tracts in communication with cysts. There was no recurrence during the 2-year follow-up period. There were also no mortality and no cavity-related complications. This study shows that intracystic injection of 0.04% Chx-Glu is an effective measure against the dissemination of viable protoscolices. In addition, Chx-Glu is the most convenient scolicidal agent as per the criteria defined by the World Health Organization. Therefore, it can be used safely during hydatid cyst surgery. However, there remains the need to perform advanced comparative clinical studies on the efficacy of Chx-Glu and other scolicidal agents.

Necrosis in Human Cystic Echinococcosis: An Underrecognized Tissue Reaction Possibly Related to Host Response

Aim: As Echinococcosis stands out worldwide as an important zoonotic cestode infection caused by various Echinococcus species, histopathological features of the disease are worthy of in-depth study. Materials and Methods: Histopathological changes in adjacent parenchymal tissue in patients with cystic echinococcosis (CE) were evaluated. The study included 91 patients 4-80 years of age (mean age: 36.24 years). Results: The histopathological findings of 83 specimens were as follows: fibrosis: 77.11%; mono-nucleated cells: 71.08%; necrosis: 67.47%; eosinophils: 51.80%; giant cells: 31.33%; neutrophils: 8.43%. Fibrosis, eosinophils, neutrophils, and giant cell infiltration were observed significantly more often than mono-nucleated cell infiltration, germinal membranes, and protoscolex existence (P < 0.01). Necrosis was noted adjacent to the acellular laminated layer in host parenchymal tissue. Liver and kidneys were significantly more prone to necrosis than other localizations (P < 0.01). Necrosis was seen significantly more often in patients with higher IHA titration positivity (P < 0.01). Conclusions: As necrosis has not been previously considered in CE, histopathological examination in necrosis-dominant cyst walls should be evaluated for a differential diagnosis. One possible explanation for necrosis as a histopathological finding in CE could be that it occurs as a natural course of its immunopathogenesis.

Impossibility of the treatment of inoperable liver multicystic echinococcosis due to adverse reactions to antihelminitics

In some cases of multicystic forms of liver echinococcal disease, the advanced method for treatment of cystic echinococcosis faces great problems relating to the final outcome of the treatment. In May 2005, a computerized tomography of the abdomen obtained in a 27-year-old female patient with abdominal pain revealed more than 20 echinococcal cysts measuring up to 6.7 cm in both lobes of the liver. Laboratory analyses found the value of eosinophils 6.8%, gamma globulins 29.9%, immunoglobulin E 29 600 IU/mL and the indirect hemagglutination for echinococcosis 1:8,196. The treatment started in December that year with the continuous administration of a daily dose of 800 mg (14.5 mg/kg body weight) of albendazole, but it was terminated two months later due to high serum transaminases values. By the end of 2006, the largest cyst detected in the left lobe of the liver had a diameter of 5.7 cm and the one in the right lobe of the liver measured 4.1 cm. There were lesions of germinative membrane found on both cysts. Six months later, praziquantel at daily dose of 2,500 mg (45.3 mg/kg body waight) was introduced into the therapy, but the treatment was terminated after eight days because of the development of exanthema. The computerized tomography of the abdomen obtained in February 2008 revealed the presence of a large number of echinococcal cysts in the liver. The largest among those cysts measured 3.5 cm while calcifications of the cyst walls were observed on some of them. None of the remaining therapeutic options for further treatmetnt of echinococcal disease could be applied. The presented case confirms medical therapy as the only option for the treatment of some forms of cystic echinococcosis. Benzimidazole carbamates (albendazole, mebendazole) and praziquantel are only efficacious antihelminitics currently available, and when they have to be withdrawn due to serious adverse affects, futher treatment of a patient with liver multicystic echinococcosis is impossible. Because of that there is a need to search for new and more efficient drugs for the treatment of ehinococcal disease.

Echinococcus granulosus: Protoscolicidal effect of high intensity focused ultrasound

High intensity focused ultrasound (HIFU) is a new non-invasive technique which can cause cell death and tissue necrosis by focusing high-energy ultrasonic waves on a single location. The aim of our work is to investigate the damaging effect of HIFU on Echinococcus granulosus protoscolices, as well as its inhibitory effect on growth of hydatid cysts derived from protoscolices. The damaging effect of HIFU on protoscolices was investigated by following parasite mortality after irradiation, while the inhibitory effect was investigated by infection experiments in vivo. The results demonstrated that HIFU was able to damage protoscolices and the protoscolicidal effect was dose-dependent and showed late-onset. The growth of protoscolices that survived the exposure to HIFU was obviously suppressed in vitro, and the mean weight of hydatid cysts resulting from such protoscolices in the experimental group was less than that in controls. Evidences including the protoscolicidal effect, fragmentized protoscolices and low post exposure temperatures, suggest that cavitation may contribute to the protoscolicidal effect of HIFU. In addition, the structure of the germinal membrane in cysts developing from the irradiated protoscolices was not as normal or intact as that from non-irradiated ones, and morphological changes related to degeneration were observed, suggesting that HIFU could prevent protoscolices from developing normal germinal membrane and consequently stop the proliferation of secondary hydatid cysts. HIFU demonstrated damaging effect on protoscolices, inhibited the growth of protoscolices in vitro and in vivo, and could be a possible therapeutic option for cystic echinococcosis.

Subcutaneous hydatid cysts occurring in the palm and the thigh: two case reports

IntroductionHydatid cyst disease is common in some regions of the world and is usually located in the liver and lungs. This report presents two cases of primary hydatid cysts located subcutaneously: one in the medial thigh and one in the left palm between the index and middle fingers.Case presentationsA 64-year-old male farmer visited our hospital because a swelling on the right medial thigh had grown during the last year. Superficial ultrasound and computed tomography revealed a lesion resembling a hydatid cyst. A germinative membrane was encountered during surgical excision. Pathological examination was compatible with a hydatid cyst. The second case involved a 67-year-old male farmer who complained of a swelling that had grown in his left palm in the last year. The preliminary diagnosis was a lipoma. However, a hydatid cyst was diagnosed during surgical excision and after the pathological examination. The patient did not have a history of hydatid cyst disease and hydatid cysts were not detected in other organs. There has been no disease recurrence after following both patients for 3 years.ConclusionA hydatid cyst should be considered in the differential diagnosis of subcutaneous cystic lesions in regions where hydatid cysts are endemic, and should be excised totally, with an intact wall, to avoid recurrence.

Spontaneous expulsion of intact germinative membrane of liver hydatid cyst in a child

A 10-year-old girl presented with an acute abdomen because of spontaneous rupture of a liver hydatid cyst (HC) and associated pelvic cystic mass. The pelvic cyst was found to be an intact germinative membrane of the ruptured HC of the liver at operation. This is the first pediatric case presenting with expulsion of an intact germinative membrane of a spontaneously ruptured HC. Intact germinative membrane should be included in the differential diagnosis of intraabdominal and pelvic cystic masses in children. The liver should be evaluated for ruptured cyst, and the lungs should also be evaluated to detect accompanying pulmonary hydatid disease (HD) especially in children living in countries in which the HD is endemic.