Case Series
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Unusual Presentation of Echinococcosis Causing Diagnostic Dilemma by Mimicking Neoplasm Clinically: A Case Series |
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Mangesh Machindra Londhe, Tushar Vitthalrao Patil, Kishor Hiraman Suryawanshi,Grishma Satishrao Digraskar
1. Assistant Professor, Department of Pathology, PCMC's PGIYCMH, Pimpri, Pune, Maharashtra, India. 2. Professor, Department of Pathology, PCMC's PGIYCMH, PIMPRI, Pune, Maharashtra, India. 3. Professor, Department of Pathology, PCMC's PGIYCMH, PIMPRI, Pune, Maharashtra, India. 4. Junior Resident- 2, Department of Pathology, PCMC's PGIYCMH, Pimpri, Pune, Maharashtra, India. |
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Correspondence
Address : Dr. Grishma Satishrao Digraskar, Opposite Balaji Mandir, Sailu, Parbhani, Maharashtra, India. E-mail: grishmasdigraskar@gmail.com |
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ABSTRACT | |||||||||||||||||||||||||||||||
Echinococcosis (hydatid disease) is caused by the cestode parasite belonging to genus Echinococcus (tapeworm). It is found frequently in rural areas where domestic livestock-raising is common. Globally, it is endemic in Middle East, Africa, South America, New Zealand, Australia, Turkey and Southern Europe including India. Even though echinococcosis can occur in any organ, it is very rare to see the disease at the sites reported in this article. Even at common sites, the way of presentation might be unusual causing diagnostic dilemma. Hence, current study was undertaken to evaluate the different unusual presentations of echinococcosis and to emphasise that it should be suspected in cystic lesions, especially in endemic areas. A series of six cases of echinococcosis over the period of three years (January 2017-December 2019) has been reported here. The correlation of clinical features, radiological with intraoperative findings (frozen section) wherever available and confirmatory diagnosis given on histopathology was attempted. All six cases which were suspected as neoplasm based on clinical and radiological findings turned out to be echinococcosis on cytopathology and histopathology. The sites involved were breast, brain, ovary, lung single case each followed by two cases in liver. Multisystem involvement was seen in only one case. Thus, the study conclude that echinococcosis can mimic cystic neoplasm clinico-radiologically and hence, should be considered as a differential diagnosis of cystic lesions irrespective of its endemicity, site and clinical presentation. | |||||||||||||||||||||||||||||||
Keywords : Brain, Breast, Hydatid disease, Lung, Liver, Ovary | |||||||||||||||||||||||||||||||
INTRODUCTION | |||||||||||||||||||||||||||||||
Echinococcosis was described by Hippocrates more than 2000 years ago who had used the term 'liver filled with water’ (1). Two forms of echinococcosis have been described: cystic (hydatidosis) and alveolar caused by E. granulosus and E. multilocularis respectively (2). Today, despite of advances in its management, it still prevails a major public health problem. It is endemic globally in the Middle East, Africa, South America, New Zealand, Australia, Turkey and Southern Europe including India (3). In endemic regions, human incidence rates for cystic echinococcosis can reach more than 50 per 100000 person-years, and prevalence levels as high as 5%-10% may occur (2). The highest prevalence in India is found in the Saurashtra (now includes the state of Gujarat and Maharashtra), Andhra Pradesh, Tamil Nadu (4). It is found frequently in rural areas where domestic livestock-raising is common causing serious health problems. The 2015 World Health Organization (WHO) Foodborne Disease Burden Epidemiology Reference Group (FERG) estimated echinococcosis to be the cause of 19300 deaths and around 871000 Disability-Adjusted Life-Years (DALYs) globally each year (2). As the institute where these cases are reported is located in semi-urban area of Maharashtra, findings of cystic echinococcosis at unusual sites and with unusual presentations provoked us to undertake this study. | |||||||||||||||||||||||||||||||
CASE REPORT | |||||||||||||||||||||||||||||||
Six cases of echinococcosis at various sites observed in the tertiary care hospital situated in Pune over the period of three years (January 2017-December 2019) are being discussed. Clinical features & radiological findings were taken from case record forms of these patients. Each and every case was suspected to be neoplastic based on clinic-radiological findings, the suspicion being cystic meningioma in brain, ovarian neoplasm for mass in peritoneum, pseudotumour appearance in liver, cystic neoplasm of unknown origin with metastasis for multisystemic involvement, cystic neoplasm of lung and solid-cystic mass suspicious of malignancy in breast. The gross findings of each case revealed multiple cysts with whitish, translucent ‘tender coconut’ appearance (Table/Fig 1)a-f. In all the six cases, the study performed cytological examination of wet mount and smears prepared from centrifuged deposits of fluid aspirated from cystic lesion followed by histopathological examination of formalin-fixed tissue sections stained with Haematoxylin and Eosin (H&E). In one case in addition to this, fluid aspirated from cystic lesion received intraoperatively was centrifuged and wet mount smears of the same were examined. Clinical and radiological comparison was done in each case individually and then histopathology confirmed the diagnosis of echinococcosis. Details of each case are presented in tabulated form (Table/Fig 2). The wet mount as well as smears prepared from centrifuged deposits of fluid in each case mentioned above were stained with Leishman’s and H&E stain, the microscopy of which revealed typical hooklets with scolices (Table/Fig 3)a,b. The histopathological examination of tissue sections from cyst wall was followed by, which in all cases revealed cyst wall with an outer fibrous laminated layer and an inner germinative layer. The cyst cavity revealed numerous scolices and hooklets (Table/Fig 4)a,b. The surrounding host tissue showed infiltration of chronic inflammatory cells, including lymphocytes and eosinophils. In addition, only the third case revealed foci of calcification within the cyst wall. None of the cases revealed malignancy. The patients were in the age range of 20-65 years, the mean age being 44.5 years. Marked female predominance was noted with male: female ratio of 1:5. None of the cases were clinically suspicious of echinococcosis, instead radiologically were suspected of neoplastic aetiology. However, histopathological examination revealed diagnosis of echinococcosis. Thus, none of the cases showed concordance between clinico-radiologically and histopathological diagnosis. In one case (4th case), intraoperative cytological diagnosis avoided the further exploration of patient followed by conservative management. | |||||||||||||||||||||||||||||||
DISCUSSION | |||||||||||||||||||||||||||||||
Human echinococcosis is a zoonotic infection with incidence in endemic areas ranging from 1-220 cases per lac (5),(6). Humans are occasionally accidently infected by oral ingestion of tapeworm eggs with contaminated food or water or direct contact with host (7). The sites most frequently affected by echinococcosis in humans is liver (65%) followed by the lungs (25%) and the remaining 10% occur in muscle, spleen, bones, kidneys, brain, eye, heart, pancreas, peritoneum and breast (8). The unusual clinical presentation even at the expected sites of involvement creates a diagnostic dilemma. In this case series, the diagnosis of echinococcosis was made on examination of wet mount smears and cytology which enabled immediate diagnosis without the time lag that is required for histopathological diagnosis. In literature available, there are rarely any case series highlighting the significance of cytological examination of fluid for diagnosing echinococcosis, thus emphasising the need of the same in all the cystic lesions despite of clinical suspicion. This cytological examination was also found helpful in making correct diagnosis of echinococcosis intraoperatively in frozen section which further highlights the use of cytology especilally in resource limited facilities where cryostat is not available for processing of frozen section. There are just a few published reports of separate cases on echinococcosis of brain based on radiological examination (6). Yet, to the best of the knowledge, the study did not find any case of cerebral echinococcosis mimicking as cystic meningioma as was suspected in present case. Primary peritoneal involvement is seen only in 2% of all abdominal hydatid disease and its clinical presentation as suspicious of neoplasm is even rarer (9),(10). In the current study, the isolated peritoneal cystic mass was considered to be neoplastic with possibly ovarian origin and turned out to be echinococcosis on histopathological examination. In liver, it can mimic neoplasm clinically as reported by Petrakis IE et al., which was similar to the finding in present case (11). However, in case of cystic mass of liver with large dimensions without any additional symptoms, echinococcosis must be first ruled out. Mesenteric involvement by hydatid disease is very rare with this case being the third case reported in the literature so far. Multisystem involvement has been described and reported but simultaneous involvement of liver, lesser sac and ovary raising the suspicion of metastatic malignancy is very unusual. In case of echinococcosis of lungs, De Wilde C et al., has highlighted the presentation of complicated hydatid cyst mimicking neoplasm clinically leading to a diagnostic trap. Similar scenario was seen in present case where patient underwent surgical exploration and was diagnosed postoperatively (12). Breast as a site of infestation for echinococcosis is very rare with only few single case reports being found in literature till date (13). The rarity at this site makes it very less likely to consider the diagnosis of echinococcosis clinically, thus making it clinically suspicious of neoplasm (14). Clinical details including patient’s occupation, residence along with radiological findings of cyst with egg shell calcification, water lily sign and serpent sign should be looked for, to rule out echinococcosis, in cases of cystic lesions at any location. However, histopathology still remains gold standard diagnosis for echinococcosis. However in present study, the cytological examination of fluid in all cases revealed the diagnosis of echinococcosis immediately and was even used in frozen section to give stat report even before the histopathological examination. Thus, the study recommend the use of cytological examination of fluid aspirated from any cystic lesions, be it suspicious of neoplasm or not, to give rapid and confirmatory diagnosis. As this is reported within short period of time, it can help the treating physician to take appropriate decision for further management of the patient. | |||||||||||||||||||||||||||||||
CONCLUSION | |||||||||||||||||||||||||||||||
Echinococcosis should be considered in the differential diagnosis of cystic lesions at any site in endemic as well as non-endemic areas as it is curable with anti-helminthic drugs. The confirmatory diagnosis at early stage will prevent complications and unnecessary surgical exploration of the patients, thus reducing the morbidity and mortality of the disease. The cytological examination of fluids aspirated from cystic lesions should be mandatory as it confirms the diagnosis even prior to the histopathological examination. | |||||||||||||||||||||||||||||||
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TABLES AND FIGURES | |||||||||||||||||||||||||||||||