Abstract
Introduction
Lung adenocarcinoma represents the most frequent histopathological variant of bronchopulmonary neoplasm, but the invasive mucinous subtype is rarely encountered, difficult to diagnose, has a poor prognosis, with rapid progression and poor treatment response.
Case Description
A 78-year-old female patient, non-smoker, without exposure to respiratory irritants, presented with dry cough, dyspnea on minimal exertion, and loss of appetite. Thoracic computed tomography (CT) and blood analysis suggested an infectious etiology. Thoracentesis and bronchoscopy were performed, and the results of the bronchial aspirate and bronchoalveolar lavage initially supported the hypothesis of bronchopneumonia. Following antibiotic treatment, the patient’s condition initially improved, but she returned to the emergency department with aggravated symptoms and imaging progression. A CT-guided lung punch biopsy was performed, and the histopathological examination revealed the presence of an invasive mucinous adenocarcinoma. The evolution was unfavorable, followed by death.
Discussion
The initial imaging appearance, weakly suggestive of a proliferative pathology, posed difficulties in early diagnosis and initiation of specific treatment. The biological samples contributed to delaying the oncological diagnosis by supporting the hypothesis of an infectious pathology.
Conclusions
This case highlights the importance of heightened clinical suspicion and thorough evaluation in situations with atypical evolution and insufficient response to antibiotic treatment.