Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 19 2 2024 06 09 273 277 Brahmansh Singh Department of Respiratory Medicine, Dr D Y Patil Medical College, Hospital & Research Centre, Pune, India Kundan Mehta Department of Respiratory Medicine, Dr D Y Patil Medical College, Hospital & Research Centre, Pune, India 2023 10 19 2024 02 17 Hydatid disease can virtually involve any organs, liver being the most common followed by lungs. Pleural effusion as a complication of pulmonary hydatid cyst is exceptionally rare and its diagnosis and treatment pose significant challenges. We present an intriguing case managed in Dr D Y Patil medical college and Hospital in west India in June 2023 involving a 70-year-old female who presented with symptoms of right-sided chest pain and acute-onset dyspnoea. Referred from a local hospital, a chest radiograph revealed the presence of right pleural effusion. Subsequent radiological investigations including a contrast enhanced CT at our centre exposed two large, well-defined hypodense lesions with fluid density, encased by thick enhancing walls, along with right-sided pleural effusion and hence a diagnosis of lung abscess with right pleural effusion (right parapneumonic effusion) was established. Despite ongoing care, clinical improvement eluded us. Thoracocentesis yielded a surprising revelation – the pleural fluid was transudative with visible hooklets and protoscolices, indicating a ruptured pulmonary hydatid cyst. The patient began albendazole treatment and received a CVTS consultation. They recommended a right lower lobe lobectomy, now scheduled for the near future. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/4066 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/4066/1366