LUNG MASSES OF SURPRISING ETIOLOGIES MIMICKING MALIGNANCY

TYPE: Case Report TOPIC: Lung Pathology INTRODUCTION: Lung masses may pose a difficult differential diagnosis. The malignant etiology is the most feared. CASE PRESENTATION: Case 1: 51-y-old female, complainig of persistent cough with several months of evolution, which led to the performance of a chest x-ray that revealed an opacity in the right upper lobe (RUL). Chest computed tomography (CT) showed a round and homogeneous mass in the RUL (48x50mm), with discreet enhancement after contrast administration. The patient was submitted to surgical ressection of the reffered lesion and the histopathological examination revealed a Schwannoma. Case 2: 55-y-old man, smoker, admitted in the emergency room for hemoptysis. Chest x-ray showed a left para-hilar mass; chest CT revealed a solid, irregular mass in the left upper lobe (83x37mm), connecting to the hilum. The lesion showed increased uptake on PET-CT. Transthoracic biopsy and bronchoscopy were performed, which were inconclusive. As a malignant tumor could not be definitively ruled out, a lobectomy was performed, and the histopathological examination showed alterations suggestive of organizing pneumonia, as well as the presence of a foreign-body. DISCUSSION: Schwannomas are benign, typically slow-growing and often discovered incidentally. Organizing pneumonia consists of granulation tissue with chronic inflammatory cell infiltrate. In the described cases, given the high suspicion of malignancy, it was decided to remove the lesions surgically and the diagnosis was obtained post-operatively. CONCLUSIONS: It is important to raise awareness to the pathologies that can mimic lung cancer, and to know its main characteristics, in order to narrow the differential diagnosis and initiate the appropriate treatment. DISCLOSURE: Nothing to declare. KEYWORD: Lung mass; Schwannoma; Organizing pneumonia.