Simultaneous bilateral spontaneous pneumothorax as the first manifestation of primary pulmonary MALT lymphoma

Primary pulmonary lymphoma is a rare entity. Furthermore, simultaneous bilateral spontaneous pneumothorax (SBSP) is a very rare condition which is often related to therapeutic complications. We present, to the best of our knowledge, the first case of primary pulmonary mucosa associated lymphoid tissue (MALT) lymphoma revealed by SBSP. A 50-year-old female was diagnosed with organizing pneumonia. One month later, she presented with sudden chest pain and shortness of breath due to SBSP. Bilateral chest tubes were inserted. A scan- guided right lung biopsy led to the diagnosis of primary pulmonary MALT lymphoma. The patient was treated with R-CHOP chemotherapy. The association between lymphoma and pneumothorax is extremely rare, often related to therapeutic toxicity. We report the case of SBSP as the first manifestation of primary pulmonary MALT lymphoma.


Introduction
Primary pulmonary lymphoma is a rare entity, which accounts for less than 1% of Non-Hodgkin´s lymphoma (NHL) and only 0.5 to 1% of primary pulmonary malignancies [1]. Primary pulmonary mucosa associated lymphoid tissue (MALT) lymphoma is the most common sub type of low grade primary pulmonary lymphoma [2]. Simultaneous bilateral spontaneous pneumothorax (SBSP) is usually due to an underlying lung disease which is rarely neoplastic (0.05%) dominated by sarcoma [3]. To the best of our knowledge, no cases of SBSP as the first manifestation of NHL have been reported. In this report, we present an unusual presentation of primary pulmonary MALT lymphoma revealed by SBSP.

Patient and observation
A 50-year-old non-smoker woman followed for bipolar disorder treated with Depakote and Prazepam for 7 months was, a month ago, diagnosed with organizing pneumonia. The diagnosis was based on the presence of a dry cough with stage 2 dyspnea on exertion and unexplained weight loss. Chest computed tomography (CT) scan showed bilateral and peripheral alveolar condensations with 2 left posterior basal air cysts. Laboratory tests did not objectify inflammatory syndrome. A compete blood count revealed lymphopenia. Serum protein electrophoresis, liver and renal function tests were unremarkable. Lactate dehydrogenase test and calcium levels were normal. Immunological assessment and the infectious disease tests were negative. No significant improvement was noted after antibiotherapy with levofloxacin. Divalproex Sodium induced organizing pneumonia was suspected and the treatment was stopped. In the presence of severe restriction in spirometry and hypoxemia on exertion, steroids were prescribed.
Bronchoalveolar lavage was not carried out due to significant respiratory repercussions. A slight improvement was noted under corticotherapy. One month later, she presented with sudden chest pain and shortness of breath due to SBSP ( Figure 1, Figure 2). Immediately after diagnosis, bilateral chest tubes were inserted. The right one was removed after 24 hours and the left one after 48 hours when no air leak was evident. A scanguided right lung biopsy was performed before the ablation of the drain, which led to the diagnosis of primary pulmonary MALT lymphoma. On immunohistochemistry, the tumor cells expressed CD20 (strong membrane positivity). They were immunonegative for CD3, CD5, CD10, CD23 and Cyclin D1 (Figure 3, Figure 4). Left pneumothorax recurred 7 days after. Left chest tube was inserted followed by pleurodesis by left pleural abrasion with partial thoracoscopic pleurectomy. The cervical and abdomino-pelvic CT scan did not show any other ganglionic or extra ganglionic lesions and the bone marrow biopsy was negative. The patient was treated with R-CHOP chemotherapy.

Discussion
In this report, we present a case of SBSP as the first manifestation of primary pulmonary MALT lymphoma. SBSP is a very rare condition which often occurs on a pathological lung [4]. Underlying lung disease is rarely neoplastic. The association between lymphoma and spontaneous pneumothorax is extremely rare. The appearance of the pneumothorax is often related to therapeutic complications  [2]. Thus, organizing pneumonia may be a preneoplastic condition of lymphoma in our case.

Conclusion
The association between lymphoma and pneumothorax is extremely rare, often related to therapeutic toxicity. We report the case of SBSP as the first manifestation of primary pulmonary MALT lymphoma.