Simultaneous Bilateral Secondary Pneumothorax

Simultaneous bilateral pneumothorax is a very rarely condition that is mainly seen in patients with underlying metastatic disease or lung cancer. It is estimated that < 1% of all cases of spontaneous pneumothorax are tumor-associated and most commonly due to the metastatic osteogenic or soft tissue sarcomas .


INTRODUCTION
Spontaneous pneumothorax is a rarely occurence of primary lung cancer or metastasis.All cases of spontaneous pneumothorax are tumor-associated and metastatic osteogenic or soft-tissue sarcomas are associated most commonly with pneumothorax significiantly in the setting of cytotoxic chemotherapy or radiotherapy.Pneumothorax after chemotherapy has been reported only in cases with osteogenic sarcoma, synovial sarcoma, fibrosarcoma, germinal tumors, and lymphoma with lung metastasis (1)(2)(3)(4).

CASE
11-year-old boy had osteogenic sarcoma of left distal femur (Figure 1).Although the patient was scheduled for amputation of the primary tumors, the parents re-fused the operation and go ahead the adjuvant chemotherapy.About 12 months after the chemotherapy, he presented with acute onset of dyspnea.Physical examination revealed extreme agitation, and tachypnea.Bilateral hyperresonant percussion notes and diminished breath sounds were detected on auscultation.An x-ray film of the chest was taken and it showed bilateral pneumothorax (Figure 2).Computed tomography of the thorax demonstrated peripheral pulmonary nodules and bilateral pnuemothorax (Figure 3).The patient was transferred to the operation room, where bilateral chest drains were inserted promptly.This led to a dramatic clinical and radiological recovery(Figure 4).The patient discharged from the hospital after pull out the drain.Removal of the primary tumor and bilateral metastectomy via video-assited thoracoscopy were recommended to the parents.

DISCUSSION
Osteosarcoma lung metastasis are commonlly occured and spread of disease include symptomatic complaints, cough, dyspnea, chest pain and pnuemothrax (1).pneumothorax caused by metastasis represents less than 2% of whole spontaneous pneumothorax cases.Approximately 80% of secondary spontan pnuemothorax cases are associated with metastatic osteogenic sarcoma Patients with metastatic osteosarcoma in the lung have a higher risk of spontaneous pneumothorax than patients with other carcinomas (2,5).Bilateral pneumothorax may require extended hospital stay and could result in death.Tube drainage is necessary and effective for most cases of bilateral pneumothorax improvement.(5)(Figure 4).There are several mechanisms underlying pneumothorax.Firstly including tumor tissue rupture at the lung periphery, a check valve mechanism due to bronchiolar obstruction by tumor tissue, and secondly direct metastasis to a pulmonary cystic lesion (2).Treatment of pneumothorax is urgent if it is simulataneus and bilateral.Some reports have suggested that chemotherapy could increase the relative risk, due to necrotic changes, from 14%, and the period from chemotherapy initiation to pneumothorax onset ranged between first and seventh days (6).In our advice for the thoracic surgeons, firstly controlled of the primary tumor and also resec-    tion of the lung metastasis.A spontaneous pneumothorax in a patient with a malignant disease should raise the suspicion of occult pulmonary metastases.The lung is the most frequent site for metastasis of osteosarcoma.Moreover, pulmonary metastasis has a major factor on the prognosis of those patients.The 5-year overall survival rate for patients who underwent a first pulmonary metastasectomy for Ostesarcom was as high as 40% in several reports.Complete surgery is an essential component of curative second-line therapy.Chemotherapy, particularly chemotherapy with more than one agent, may contribute to limited improvements in outcome (6).It is necessary to follow patients with osteosarcoma for their life threating pulmonary complication such as simultaneous bilateral pneumothorax and keep metastases in mind when pulmonary nodules are investigated.Chest computed tomography detects minimally pneumothorax or subpleural lung metastasis an emergency situation and early diagnosis and management can improve prognosis and quality of life of the patient.

Figure 1 .
Figure 1.Magnetic resonance imaging is showing diffuse osteolysis of the left distal femur.Biopsy revealed osteosarcoma.

Figure 3 .
Figure 3. Chest computed tomographic image is showing pulmonary metastases.

Figure 4 .
Figure 4. Posterior-anterior chest x-ray is showing lung expansion after tube drainage.