CHEST WALL MASS IN A PATIENT WITH RECURRENT PLEURAL EFFUSION

Abstract

SESSION TITLE: Chest Infections 4 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Recurrent exudative pleural effusion often presents a diagnostic challenge. Undetected malignancy and indolent infections should be considered in the differential. We present one such case. CASE PRESENTATION: A 62 year old Caucasian male with severe COPD (FEV1 1.54 L or 49% predicted) presents for evaluation of dyspnea and productive cough. Further history is notable for 44 pack year smoking, cats at home, poor dental hygiene, and occupation as a truck driver.CXR is positive for left pleural effusion, with CT demonstrating moderate non-loculated pleural effusion. Thoracentesis reveals exudative fluid, negative cytology, stains, and culture including AFB/ fungal.At eight months follow up, he presents with a palpable, firm, left posterior chest wall mass. MRI demonstrates the palpable mass to be a lipoma. MRI also reveals an invasive 9x7x3 cm pleural based tissue mass in the left costophrenic sulcus infiltrating through the pleural space into the posterior chest wall. Chest CT done next day confirms large left sided pleural effusion with lingular and left lower lobe atelectasis. An irregular mass showing some central low density attenuation in the left paraspinous area measuring 33 x 40 mm was detected. PET/CT reveals large lobulated intense uptake abnormality in the same area with SUV of 8.7. Differential diagnoses included mesothelioma, pleural metastasis, and soft tissue sarcoma.Additional workup included CT guided needle aspiration and core biopsy of the lesion. Aspirate reveals acute and prominent histiocytic inflammation. Core biopsy demonstrates conspicuous sulfur granules displaying prominent Splendore-Hoeppli phenomenon. Tissue gram stain reveals numerous thin beaded, branching filamentous bacteria within these sulfur granules.He underwent thoracotomy with decortication and left pleurectomy. Loculated fluid collection demonstrated benign cytology with colonies of Gram positive and GMS positive filamentous bacteria morphologically consistent with Actinomycosis. No readily identifiable communication tract was found between the chest and the chest wall abscess.He was treated with penicillin for protracted period with CT chest showing complete resolution of pleural effusion 16 months later. DISCUSSION: This case highlights the fact that in cases of recurrent exudative pleural effusion in a setting of poor dental hygiene and COPD, Actinomycosis should be in the differential diagnosis. Penicillins remain the mainstay for treatment with protracted course needed for complete resolution. CONCLUSIONS: Indolent infections should be considered in the differential diagnosis of recurrent pleural effusion. Cutaneous masses/lump in the chest wall in association with pleural effusion should raise suspicion of Actinomycosis/Empyema necessitans. Reference #1: Choi H, Lee H, Jeong SH, Um S-W, Kown OJ, Kim H. Pulmonary actinomycosis mimicking lung cancer on positron emission tomography. Annals of Thoracic Medicine. 2017;12(2):121-124. https://doi.org/10.4103/1817-1737.203752. DISCLOSURES: No relevant relationships by Riju Dasgupta, source=Web Response No relevant relationships by Asok Dasgupta, source=Web Response No relevant relationships by Paresh Timbadia, source=Web Response No relevant relationships by James Uhlenbrock, source=Web Response