The Indian Journal of Chest Diseases and Allied Sciences
Volume 65 | Issue 1 | Year 2023

Pulmonary Hydatid without Liver Involvement: A Case Series

Ashish K Prakash1, Roopanshi Jain2, Bornali Datta3, Satinder Kumar Jain4, Nikhil Rane5, Bhushan Thombare6, Ali Zamir Khan7, Anand Jaiswal8

1–3,8Department of Respiratory and Sleep Medicine, Medanta – The Medicity, Gurugram, Haryana, India

4–7Department of Thoracic Surgery, Medanta – The Medicity, Gurugram, Haryana, India

Corresponding Author: Ashish K Prakash, Department of Respiratory and Sleep Medicine, Medanta – The Medicity, Gurugram, Haryana, India, Phone: +91 9968014661, e-mail:

How to cite this article: Prakash AK, Jain R, Datta B, et al. Pulmonary Hydatid without Liver Involvement: A Case Series. Indian J Chest Dis Allied Sci 2023;65(1):1–5.

Source of support: Nil

Conflict of interest: None

Received on: 28 May 2021; Accepted on: 12 April 2022; Published on: 29 June 2023


Pulmonary hydatid is not a rare disease. But raising a suspicion for its diagnosis is limited. There are limited approaches for the diagnosis and treatment of the same. We present here four cases of pulmonary hydatid, without liver involvement, with emphasis on how it was misdiagnosed and received multiple treatment and landed into complications. Most of our cases presented with cough, sputum and hemoptysis. For these nonspecific signs and symptoms, patient is generally treated on a different line of diagnosis. Two of the cases were already treated for abscess and fungal infection. One of the patients was on antitubercular treatment. One of our cases was secondarily infected with aspergilloma. One of the cases was referred to oncologist to start chemotherapy. Interestingly, to raise a suspicion, none of our cases had liver involvement. A detailed history revealed expectoration of white salty material in sputum, living with sheep and dog and expectorating grape-like vesicles in sputum. History helped us to put hydatid as one of our differentials. Echinococcal serology was positive in three cases. Only three cases had on-table appearance of hydatid cyst. All four cases underwent surgical management for complete cure.

There is need for strong suspicion and a detailed history and proper set of investigations help in timely diagnosis and management of pulmonary hydatid disease.

Keywords: Albendazole, Echinococcus, Hydatid, Liver cyst, Pericyst, Pulmonary hydatid, Water lily sign.


ATT = Antitubercular treatment; CECT = Contrast-enhanced computed tomography; FNAC = Fine needle aspiration cytology; HRCT = High resolution; IVC = Inferior vena cava.


Pulmonary hydatid is one of the most misdiagnosed diseases. Lack of suspicion, nonspecific radiological sign, nonspecific symptoms are the major causes of misdiagnosis/delayed treatment course. We present here case series of four patients (Table 1) who came to us after being treated for a considerable period of time but with worsening of clinicoradiological features. None of them had liver involvement.

Table 1: Summary of all four cases
CASE 1 2 3 4
Clinical presentation Hemoptysis, cough, and sputum Hemoptysis, cough, and sputum Hemoptysis, cough, and sputum Cough
Chest pain
Differential diagnosis Fungal infection
Lung abscess
Bronchiogenic cyst
Important clues for diagnosis Expectoration of grape-like vesicles in sputum Old CT – water-lily sign
Dog and sheep living in neighborhood
Expectorating whitish salty material in sputum MRI details
Echinococcus serology
(u/mL of IgG)
126.38 >200 20.94 Not done
Surgery done Lobectomy Cystectomy with repair of bronchioles Cystectomy with ligation of vessels Cystectomy with bronchopleural fistula closure bronchoplasty
Macroscopic appearance Multiple hydatid cyst with daughter cysts Multiple hydatid cysts with daughter cysts Single cyst resembling bronchogenic cyst with abundant vasculature Infected hydatid
Histopathology Hydatid cyst with aspergilloma Hydatid cyst Hydatid cyst Hydatid cyst


Case 1

A 57-year-old male presented in our OPD with fever, cough and purulent sputum for 3 days. He had one episode of minimal hemoptysis 5 days back. He also gave history of dry cough and recurrent chest pain in last 3 months. At the time of presentation, he had already taken two courses of antibiotics and was on antifungals, started based on his chest X-ray findings. Chest X-ray findings showed multiple, well-defined, nonhomogeneous opacities (Fig. 1). The patient was hemodynamically stable. He was admitted and all relevant investigations were done. The sputum examination showed budding yeast cells with pseudohyphae. The CECT chest showed large consolidation with areas of necrosis, cavitation, and air locules in the left upper lobe and multiple necrotic nodules in both lungs (Fig. 2). Bronchoscopy was done which showed whitish, membrane-like material in the left upper lobe bronchus. Cryobiopsy was done with a bronchoscope in the same settings. Macroscopic appearance of the cryobiopsy specimen hinted toward the hydatid cyst. A detailed history of the patient was re-explored. The patient gave a history of expectorating grape-like vesicles in sputum few months back. Under strong suspicion, Enterococcus serology test was done. The left lobectomy and macroscopic appearance of surgical specimen were similar to hydatid cyst. Histopathology of both the surgical specimen and cryobiopsy specimen was conclusive of hydatid lung disease, and surprisingly, it was filled with Aspergillus fungus (Fig. 3). The echinococcal serology test was highly positive (>126.38 /u/mL of IgG). The patient was started on albendazole and was discharged. On follow-up, good clinical improvement was witnessed.

Fig. 1: Chest X-ray showing multiple well-defined, nonhomogeneous opacities

Figs 2A and B: (A – lung window, B – mediastinal window), large consolidation with areas of necrosis, cavitation, and air locules in the left upper lobe and multiple necrotic nodules in both lungs

Figs 3A and B: (A) PAP-stained smear-fungal filaments with parallel walls and acute angle branching compatible with aspergilloma; (B) GMS stain showing lamellated acellular tissue compatible with hydatid cyst wall, with few adherent fungal filaments

Case 2

A 26-year-old female, resident of Afghanistan presented in our emergency with fever, cough and purulent sputum for 15 days, and 2–3 episodes of minimal hemoptysis in last 15 days. She had complaints of chest pain for the last 1 year and had consulted nearly three physicians before. She had taken around four courses of different higher antibiotics in the last 1 year based on the working diagnosis of a lung abscess. She had already completed 2 months of antitubercular treatment (ATT). There was no history of epistaxis, hematuria or gastrointestinal bleeding. The patient had a CT chest scan done 6 months back which was very typical for hydatid “Water-Lily sign” (Fig. 4). Most of the infective parameters were stable. Sputum and bronchoscopic examinations were inconclusive. Suspicion of a hydatid cyst was raised and her history was re-explored. In addition, the patient gave a history of a dog and sheep living nearby and a culture of eating outdoors in storms. Under strong suspicion, Enterococcus serology was performed. Thoracic surgeons explored many thick-walled infected cysts with daughter cysts in the left upper lobe. Many varying-sized hydatid cysts were present in the rest of the lung parenchyma that was incised along with the pericyst. A cystectomy was done. Bronchial communication at the base was repaired using 3-0 prolene-pledgeted sutures (Fig. 5). The patient was started on albendazole post-op. Histopathology of biopsy was conclusive of hydatid lung disease. The echinococcal serology test was strongly positive (with >200 u/mL of IgG). In the follow-up visits, echinococcal serology monitoring was done, which showed a gradual decline with good clinical response.

Fig. 4: HRCT chest with water-lily sign

Figs 5A to C: (A) On-table appearance; (B) Hydatid membrane with pericyst; (C) Surgically resected specimen with multiple varying-sized hydatid cysts with pericyst

Case 3

A 34-year-old male resident of Nepal presented in our OPD with 4–5 episodes of minimal hemoptysis in the last 10 days. He had complaints of chest pain with 1 bout of minimal hemoptysis 8 years back. He was diagnosed of having a lung cyst, but due to personal constraints, the patient did not undergo any treatment. The patient had one episode of expectorating some salty fluid a year back. He was advised of investigation and treatment but the patient did not undergo either of them again. His chest X-ray showed nonhomogeneous opacity in the right lower lobe. He was started on conservative management. The patient had a massive bout of hemoptysis, and an urgent bronchoscopy was done which revealed fresh blood oozing out from the right lower lobe bronchus. An urgent angioembolization was done and the patient was stabilized. No hemoptysis was observed for the next 24 hours. The CT angiography of the chest revealed thick-walled cavitating lesions with air-fluid levels with multiple small pseudoaneurysms in the right lower lobe (Fig. 6). Meanwhile, enterococcal serology was done. Thoracic surgeons planned immediate surgery. A grossly infected cavity with no viable cyst membrane was seen. Necrotic slough was excised. Aneurysmal vessels in the wall were ligated and oversewn. Bronchial communications were closed. On-table macroscopic appearance of the lesion was of a bronchogenic cyst. The post-op patient was hemodynamically stable. Histopathology of lobectomy specimen revealed a hydatid lung cyst. The patient was started on albendazole post-op. The echinococcal serology report came out to be positive (with >20.94 u/mL of IgG).

Figs 6A to C: CT angio chest revealed thick-walled cavitating lesions with air-fluid levels

Case 4

A 35-year-old male, resident of Jhansi presented with complaints of right-sided chest pain. He was a smoker for the last 17 years. He was evaluated outside and had a CT scan done 1 year back, which showed a mass-like lesion in the right upper and middle lobe. And FNAC was done from the same twice. While one was inconclusive, the other showed some atypical cells. Because of strong smoking history, malignancy was thought of and the patient was referred to the medical oncology department. A chest X-ray was done in our ER which showed a well-defined opacity in the right middle zone. On examination, HRCT chest reported a soft tissue lesion in the right upper lobe with another nodular lesion in the adjacent parenchyma, extending into the right middle lobe. An MRI was conducted which revealed the presence of “hydatid cyst with intact membrane.” Calcified nodules were seen in the left lower lobe. Thoracic surgeons performed a cystectomy with bronchopleural fistula closure and bronchoplasty. His histopathology reports stated the presence of an eosinophilic laminated membrane with areas of necrosis and hemorrhage compatible with a hydatid cyst. Post-op chest X-ray was stable.


Echinococcosis is a zoonotic disease caused by the larval stage (metacestode) of the parasite of the genus Echinococcus. Four species are identified, out of which only two such as Echinococcus granulosus and Echinococcus multilocularis are responsible for most of the pulmonary cases.1,2 Adult worm resides in a definitive host, such as small intestine of dogs, wolf, fox, and jackal. The larval form resides in an intermediate host, including cattle, sheep, goat, pig, and horse. Dogs and sheep are the most common hosts. Man Is The Dead End Host.38

Hydatid fluid is a colorless/pale yellow, odorless, sterile fluid. Its electrolyte level and pH are similar to that of human serum and is slightly acidic.9 It contains sodium chloride/sulfate/phosphate and sodium and calcium salts of succinic acid. Hydatid fluid is antigenic; thus, it can cause an anaphylactic reaction when the cyst ruptures.

The rate of growth of a hydatid cyst depends on the softness of the organ and the elasticity of the surrounding tissue.1013 Hydatid involves both the liver (more commonly) and the lung. Due to softer consistency, lung cysts grow faster as compared with the liver hydatid. Negative pleural pressure may aid in accelerating the growth rate of cysts.14 Hydatid is seen in the liver and lungs with respective frequencies of 60% and 20–30% of all cases15 Most frequently, the site involved is the right lower lobe, posterior segment.1618

It has been reported that lung hydatid without liver involvement has a better prognosis,19 as seen in our cases. Hydatid disease involves the lungs by various mechanisms:9

Fig. 7: Bloodstream

Clinical features of lung hydatid depend on the site, size, and number of the cysts. Cough and hemoptysis are the most common clinical features of the disease.15 If left untreated, the patient can also develop features of secondary infections. Generally, the patient comes to a clinician once features of secondary infection sets in, as all our patients did. They can also give a history of expectorating a grape-like vesicle (the cyst) as our case 1 or salty fluid (the hydatid fluid) as seen in case 3. Some may give a history of living with sheep and dogs as noted in case 2. History and strong suspicion are the most useful diagnostic tools. Rarely, anaphylaxis can be the first symptom of the disease itself.18 Radiological signs in hydatid disease have always been fascinating as well as a diagnostic clue. Common radiological signs include (1) meniscus/double arch/moon/crescent sign: – air crescent in the upper most part of cyst; (2) onion peel/combo sign: – air-fluid level inside the endocyst; (3) serpent sign: – collapsed membranes inside the cyst outlined by air; (4) water-lily sign: – completely collapsed cyst floating on cystic fluid; (5) cavity: – all contents of the cysts break out via communicating bronchus.19 Surgery is the definitive treatment of choice and also helps in confirming the diagnosis of pulmonary hydatid cyst and all four cases underwent surgery.

Most patients have raised blood eosinophilia. Serum IgG levels can be raised. Some of the specific radiological signs may aid in diagnosing, for example, the classical water-lily sign that was seen in our second case. Bronchoscopy is not routinely advised in these patients. The diagnostic yield is up to 20.5%.2023 It is mainly helpful in taking a biopsy (as in case 1) or to verify hooklets in lavage, if any.22 Definitive diagnosis however lies in tissue specimen only. Most of our cases presented with cough, sputum, and hemoptysis. For the nonspecific signs and symptoms, the patient is generally treated on the wrong line of diagnosis. Two of the cases discussed were already treated for abscess and fungal infections. One of the patients was also on ATT. One of our cases was secondarily infected with aspergilloma. One of the cases was referred to oncology to receive chemotherapy. Interestingly, to raise a suspicion, none of our cases had liver involvement. Echinococcal serology was positive in three cases.

Lung hydatid has only one definitive treatment – surgical24 to which all our cases were subjected. The role of albendazole (400 mg BD) in the post-op period is not much recognized, however, recommended.25 Praziquantel/Mebendazole also seem to have a role but are not used routinely. Long-term follow-up with repeated chest X-rays and regular serum IgG monitoring21 is suggested.

History taking and management of secondary infection hold the mainstay in medical management; however, surgery is the definitive treatment of choice for pulmonary hydatid cysts.


Hydatid disease of the lung is not a rare entity. However, by the time it is diagnosed, it is mostly, secondarily infected. Patients generally present with features of rupture or infection. Keeping a high degree of suspicion in cases with mostly a non-resolving lung abscess can help diagnose and treat the cases in the early stage itself. Proper exploration of the history and management of secondary infection holds the mainstay in these cases.


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