INTRODUCTION: Lung cancer is known to be associated with idiopathic interstitial pneumonia, eosinophilia, and eosinophilic pleural effusion, among other described paraneoplastic syndromes. We present a case of adenocarcinoma of the lung that presented with concomitant occurrence of all these three paraneoplastic syndromes. Only a few such cases have been reported in English literature.
CASE PRESENTATION: A 46 year-old African-American woman presented to emergency department with history of shortness of breath, productive cough, and pleuritic chest pain of 3 weeks duration. Past medical history was significant for sickle cell trait and untreated latent tuberculosis infection. She was a current smoker with 10 pack years smoking history. She denied recent travel, or sick contacts. Physical examination revealed an anxious woman, febrile, tachypneic, with oxygen saturation of 90% on room air. Bibasilar rales were heard on auscultation of the lungs. Cardiac examination was unremarkable. Laboratory investigations revealed normal leukocyte count, 6% eosinophils, and compensated respiratory alkalosis. Chest x-ray showed bilateral multifocal alveolar opacities with right hilar enlargement. Computed tomography (CT) scan of the chest showed bilateral patchy consolidation, worse in bases, with right paratracheal, subcarinal, and hilar lymphadenopathy, and bilateral moderate pleural effusions. The patient was hospitalized to intensive care unit, and initiated on empirical antibiotics for community acquired pneumonia. Blood cultures, and sputum samples for gram stain, culture, smear for acid fast bacilli (AFB), and cytology were negative. The clinical, and radiographic condition worsened despite appropriate antibiotic therapy. Pleural fluid analysis following thoracentesis revealed exudative pleural fluid, with 34% eosinophils consistent with eosinophilic pleural effusion. Bronchoscopy with bronchoalveolar lavage (BAL) was planned, but the patient denied. Antibiotics were discontinued, and prednisone initiated for a diagnosis of eosinophilic pneumonia. This was followed by a significant clinical, and radiographic improvement. The patient was discharged home on a steroid taper with close follow-up. Patient had a CT-Positron Emission Tomography (PET) scan done 6 months later that showed hypermetabolic right upper lobe nodule, with mediastinal, and right hilar hypermetabolic lymphadenopathy. Biopsy of adjacent hilar node revealed well differentiated adenocarcinoma.
DISCUSSIONS: The presenting symptoms of lung cancer result from central, or peripheral growth of primary tumor, local spread, metastatic disease, or paraneoplastic syndromes. Eosinophilia as a paraneoplastic manifestation of non-small-cell lung cancer occurs secondary to production of granulocyte-monocyte colony-stimulating factor by tumor cells (1). In a review of English literature from 1974-2007, only 20 cases of non-small-cell adenocarcinoma with peripheral eosinophilia were found (2). Eosinophilic pleural effusions account for 5-8 % of exudative pleural effusions, and are as likely to be malignant as are non-eosinophilic ones. The differential diagnoses in our patient included infectious pneumonia, parasitic infestation, tuberculosis, drug reaction, allergic bronchopulmonary aspergillosis, Loeffler’s syndrome, Churg Strauss syndrome, tropical pulmonary eosinophilia, and malignancy. Our patient was diagnosed with adenocarcinoma of the right upper lobe, TNM stage T3N1M0, six months following her initial presentation as eosinophilic pneumonia. The patient is currently on adjuvant chemotherapy, and radiotherapy.
CONCLUSION: Eosinophilic pneumonia with peripheral eosinophilia, and eosinophilic pleural effusion are rare paraneoplastic manifestations of adenocarcinoma of lung. In such patients, malignancy should be considered among the differential diagnoses, and must always be excluded.
DISCLOSURE: Ankur Kalra, No Financial Disclosure Information; No Product/Research Disclosure Information