Giant intrathoracic extrapulmonary hydatid cyst manifested as unilateral pectus carinatum.

ABSTRACT

HYDATID DISEASE most commonly affects liver and lung, but it can also be seen elsewhere in the body. (1-3) Many hydatid cysts are asymptomatic and are incidentally diagnosed clinically or radiologically. (4) Extrapulmonary intrathoracic location of the disease is rare. (1)

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Liver and lung are the most common sites of hydatid disease, but it can also be seen elsewhere in the body. Extrapulmonary intrathoracic location of the disease is rare. This case of giant intrathoracic extrapulmonary hydatid cyst manifested as unilateral pectus carinatum serves to illustrate that hydatid disease can produce various symptoms and that it may also exist in locations apart from lung and liver.

CASE REPORT

An 8-year-old female patient was brought to the department of thoracic surgery of our hospital because of gradually increasing bulging in the anterior wall of the right hemithorax. The patient and her parents had noticed it for the first time 6 months earlier. On physical examination, the right hemithorax was slightly more prominent than the left. History included pulmonary infection treated with antibiotics, but no thoracic pain, fever, weight loss, or trauma. Chest radiograph showed homogeneous opacity in the right hemithorax (Fig 1). Thoracic ultrasonography and computed tomography showed the cystic mass established in the right hemithorax, causing thoracic wall asymmetry (Fig 2). Ultrasonography showed no lesions in the abdomen.

At operation via right posterolateral thoracotomy, white membrane was found protruding from the thoracotomy opening, and the cystic mass almost completely filled the right hemithorax. As suspended sutures were placed, the cyst was ruptured, cystic fluid was aspirated, and the cystic membrane was removed. Upper and middle lobes of the lung were compressed. The lower lobe was not seen. After decortication, expansion of the upper and middle lobes was secured. Decortication of the lower lobe, which had collapsed totally into the posterior costophrenic sinus, was also done, followed by reexpansion. The thorax was closed after 26F and 28F chest tubes were placed in pleural space. Hydatid disease was diagnosed when the membrane removed was examined pathologically. Chest radiograph 1 month after operation showed a totally aerated right lung (Fig 3).

DISCUSSION

In adults, intrathoracic masses compress intrathoracic organs, whereas in children such masses can expand the diameter of the chest because of the chest wall flexibility in children. Imaging modalities can determine the cause of such an expansion.

Pectus carinatum is the term most frequently used to describe protrusion deformities of the chest. The condition is not a single entity but a spectrum of abnormal thoracic development. The most frequent type consists of anterior displacement of the body of the sternum with symmetric concavity of the costal cartilages. Less frequent are the asymmetric deformities with anterior displacement of the costal cartilages on one side and normally positioned sternum, and normal or concave contralateral cartilages. In almost half of the patients, deformity was not identified until after age 11. (5) Pleural cysts are the most frequent types among extrapulmonary intrathoracic hydatid cysts (72.9%). Among these, the cyst is in the fissure in 54.6%, and in the pleural space in 18.3%. Other locations of the cysts include the chest wall, the diaphragm, the mediastinum, and the heart. (1)

We found no previously reported case of giant solitary intrathoracic extrapulmonary hydatid cyst manifested as unilateral pectus carinatum in the literature. In children, the cause of chest protrusion should be searched for by imaging modalities. Hydatid disease can produce various symptoms and may exist in locations apart from lung and liver.

References

(1.) Oguzkaya F, Akcali Y, Kahraman C, et al: Unusually located hydatid cyst: intrathoracic but extrapulmonary. Ann Thorac Surg 1997; 64:334-337

(2.) Nazaroglu H, Ozates M, Bilici A, et al: Multilocular cerebral hydatid disease with extracalvarial extension. AJR 1999; 172:1455-1456

(3.) Ozdemir N, Akal M, Kuday H, et al: Chest wall echinococcosis. Chest 1994; 105:1277-1279

(4.) Haliloglu M, Saatci I, Akhan O, et al: Spectrum of imaging findings in pediatric hydatid disease. AJR 1997; 169:1627-1631

(5.) Shamberger RC, Welch KJ: Surgical correction of pectus carinatum. J Pediatr Surg 1987; 22:48-53

RELATED ARTICLE: KEY POINTS

* Extrapulmonary intrathoracic location of hydatid disease is rare.

* Intrathoracic masses can expand the diameter of the ches because of the chest wall flexibility in children.

* In children, the cause of chest protrusion should be searched for by imaging modalities.

From the Departments of Radiology and Thoracic Surgery, Faculty of Medicine, University of Dicle, Diyarbakir, Turkey.

Reprint requests to Hasan Nazaroglu, MD, Department of Radiology, Faculty of Medicine, University of Dicle, 21280 Diyarbakir, Turkey.