A rare presentation of primary lung adenocarcinoma mimicking bilateral interstitial infiltration: A case report and literature review.

Background: Primary lung adenocarcinoma can sometimes present atypically, mimicking interstitial lung disease (ILD), and posing significant diagnostic challenges. Such presentations often lead to misdiagnoses, delaying appropriate treatment.

Case Presentation: A 35-year-old female non-smoker presented with a six-month history of progressive cough, mild hemoptysis, fatigue, and exertional dyspnea, with no associated weight loss. Imaging studies revealed diffuse ground-glass opacities and interstitial infiltrates, while pulmonary function tests were consistent with interstitial lung disease. Despite these findings, bronchoscopy results were normal. A definitive diagnosis was ultimately made through a biopsy, which identified a moderately to poorly differentiated adenocarcinoma with acinar and micropapillary features.

Discussion: This case highlights the diagnostic complexity when lung adenocarcinoma presents atypically, mimicking ILD. Conventional diagnostic tools, such as imaging and pulmonary function tests, may overlap with ILD findings, leading to misdiagnoses. Early consideration of malignancy and the use of invasive diagnostic procedures, such as biopsy, are essential for distinguishing between ILD and malignancy in atypical cases.

Conclusion: This case underscores the importance of maintaining a high index of suspicion for malignancy in atypical ILD presentations. Early invasive diagnostic techniques are crucial for achieving a timely and accurate diagnosis, ultimately improving patient outcomes.