RUPTURED HYDATID LUNG CYST IN A CHILD

RUPTURED HYDATID LUNG CYST IN A CHILD: A Diagnostic Dilemma

DHARMENDRA SINGH*, SANGRAM SINGH*, SJ KARMARKAR**
*Resident; **Ass. Prof. and Unit Head, Department of Pediatric Surgery, BJ Wadia Hospital for Children, Parel,Mumbai 400 012.

Hydatid lung disease caused by Echinococcus is often asymptomatic and usually benign. We present a case of a hydatid lung cyst which ruptured following trauma and patient presented with cough, fever and chest pain, X-ray chest revealed hydropneumothorax for which intercostal tube drainage was put suspecting haemopneumothorax, as there was a history of trauma. Even after two weeks of intercostal tube drainage patient’s condition did not improve and instead patient developed empyema due to secondary infection. Patient was investigated for all possible causes of empyema. But as patient continued to have persistent fever, airleak and pneumothorax patient was subjected to surgery and during surgery we found a large ruptured hydatid cyst with empyema. We have d iscussed this case to highlight the diagnostic problems, the presentation and successful surgical management of this patient, with review of pertinent literature.

INTRODUCTION

Hydatid lung cyst in children is unheard of although it is commonly seen in adults. Hydatid lung cysts are seen in many parts of the world, including India. It’s prevalent in areas where the livestock is raised in association with dogs. Hydatid lung disease is caused by the larval form of Echinococcus Granulosus, E. Multilocularis, E. Vogeli, E. Granulosus usually produces unilocular lesion, whereas E. Multilocularis and E. Vogeli produce multilocular lesions which are locally invasive. E. Multilocularis is more common in our country and is also seen in subarctic and arctic regions including Canada, USA, northern Europe and Asia. Dogs are the definite hosts and they pass eggs in their faeces. When the intermediate hosts-sheep, cattle, humans, goat, camels, horses, mice and other rodents ingest the eggs, cysts develop within these hosts. When a dog ingests beef or a lamb containing cysts, the lifecyle is completed. We present a case of hydatid lung cyst, the diagnostic difficulties encountered and the successful surgical outcome is discussed with review of pertinent literature.

CASE REPORT

A 7 year old female child was referred by a private practitioner as a case of non-resolving empyema with intercostal drainage tube in situ. As informed by the father, there was a history of trauma to chest following which patient developed cough, chest pain and fever for which the local doctor was consulted, who got an X-ray chest done which revealed air fluid level and a collapsed lung on the right side of chest (Fig. 1). Suspecting haemopneumothorax he inserted an intercostal drainage tube on the right side of the chest.

As per the referring doctors note the intercostal tube initially drained blood, but as there was persistent airleak intercostal tube could not be removed. After one week purulent fluid started coming through intercostal tube drain, which despite antibiotic therapy and good physiotherapy didn’t resolve and hence patient was referred to us.

On general examination patient was haemodynamically stable and had no respiratory distress. Patient was afebrile and had no cyanosis or pallor. On auscultation breath sounds were absent on the right side of chest, in the subscapular and infra axillary region, whereas on the other side of the chest normal vesicular breath sounds were heard. Patient’s Hb was 11.3 gm%, TLC was 16300/mm³, DLC was P74 L9 M11 E6. ESR was 90 mm of Hg. ABG, serum electrolytes and liver function tests were normal. Pleural fluid for routine microscopy revealed uncountable pus cells, proteins - 2.9 gm%. Pleural fluid for culture grew pseudomonas and klebsiella, which were sensitive to tetracycline, ciprofloxacin, amikacin, and piperacillin. Pleural fluid for ADA was 21 IU/Lit (normal < 36 IU/Lit). Mauntoux test was negative. X-ray-chest was done which revealed pneumothorax and air fluid level. As traumatic diaphragmatic hernia was also thought of, we did a barium meal and it was ruled out. Then considering the air leak and the pyo pneumothorax we thought that perhaps we might be dealing with a major bronchopleural fistula as there was a history of trauma. Subsequently CT scan of chest was done, which revealed a subtotal collapse of right lower lobe and a right pneumothorax (Fig. 1). As airleak and pyopneumothorax persisted despite prolonged intercostal tube drainage surgery was planned. Patient was taken up for thoracotomy. During thoracotomy pus was found sandwiched between the thickened visceral and parietal pleura. There was a large ruptured hydatid cyst in the right lower lobe which was easily enucleated. There was a significant air leak from a site from where the hydatid cyst was enucleated which was stiched with 3-0 catgut. Decortication was done and after confirming no major airleaks on table chest was closed after putting a no 20 portex chest tube connected to underwater seal drainage. Patient made an uneventful postoperative recovery. Intercostal drainage tube was removed on 5th postoperative day and patient was discharged on 10th postoperative day. On discharge X-ray chest revealed good expansion of the right lung with no air or fluid collection (Fig. 3). Histopathological examination revealed classical echinococcal cyst.

Fig. 1: X-ray chest on admission showing air fluid level and a collapsed right lung.

Fig. 2: CT scan showing subtotal collapse of the right lower lobe and a right pneumothrax.

Fig. 3: X-ray chest on discharge showing good expansion of the rigth lung.

DISCUSSION

Hydatid lung disease of children in our country is usually caused by E. Multilocularis. Humans are accidental intermediate host. Slowly enlarging Echinococcal cysts usually remain asymptomatic until their expanding size or their space occupying effect elicits symptoms. The cysts may be discovered as an incidental finding on a routine X-ray chest. Pulmonary hydatid cyst may rupture into pleural cavity, pericardium or the bronchial tree leading to cough, chest pain and haemoptysis. Ruptured hydatid cyst in the pleura can get secondarily infected leading to empyema, which mandates surgery[1-3] to remove the cyst (enucleation), thickened pleura (decortication) and take care of the leak, as we did in our case and we saw that it returns the patient rapidly to good health.

Diagnosis becomes difficult once the pulmonary hydatid cyst ruptures spontaneously or following trauma and gets secondarily infected. One usually thinks of more common causes of empyema (haemothorax getting infected in our case) and secondly as per the natural history of pulmonary hydatid cyst one would not think of it till adolescent or adult age group. As it happened in our case we didn’t investigate for hydatid lung cyst, of course we did get the history of contact with dogs retrospectively. When we looked into the literature, we found out that Lamey et al[4] in their paper did mention that children are more prone to be symptomatic and to develop complitations from rupture of their cysts mainly because of two reasons. Firstly children develop very large cysts in relation to the size of the lung (6-12 cm), due to greater elasticity of the lung and secondly a large residual cavity takes more time to resolve and is then more prone to develop infections. Also, the bronchial tree in children is smaller than in adults and the explusion of membranes and particles is compromised.

Therefore by presenting this case we want to underscore the importance of a good history, especially of contact with dogs in the patients who develop respiratory complaints spontaneously or following trivial trauma to chest and all such patients should be investigated on the lines of pulmonary hydatid cyst so as to avoid unnecessary delay in the diagnosis and inconvenience to the patient.

REFERENCES

1.Zhongxi Q. Thoracic hydatid cysts; A report of 842 cases treated over a thirty year period. Thorac surg 1988; 46 : 342-46.

2.Dogan R, Yuksel M, Guven C, et al. Surgical treatment of hydatid cysts of the lung; report of 1055 patients. Thorax 1989; 44 : 192-99.

3.Novick RJ, Tchervenkov CI, Wilson JA, et al. Surgery for thoracic hydatid disease; North American experience. Ann Thorax Surg 1987; 43 : 681-86.

4.Andre LL, Brain HC, Cameron JG, et al. Giant hydatid lung cysts in the Canadian Northwest: Outcome of conservative treatment in three children. JPS 1993; 28 (9) : 1140-43.

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Fig. 1: X-ray chest on admission showing air fluid level and a collapsed right lung.	Fig. 2: CT scan showing subtotal collapse of the right lower lobe and a right pneumothrax.

Fig. 3: X-ray chest on discharge showing good expansion of the rigth lung.