Abstract
Primary pulmonary colloid adenocarcinoma (PPCA) is a rare variant of lung adenocarcinoma characterized by abundant extracellular mucin production, often posing diagnostic challenges due to its slow growth and nonspecific imaging findings. We present the case of a 77-year-old male with a medical history of coronary artery disease (CAD) and congestive heart failure (CHF), who exhibited a gradually enlarging right lower lobe lung mass over eight years. Initial imaging and biopsy results were inconclusive, but a subsequent biopsy following surgical resection confirmed the diagnosis of PPCA. This case highlights the clinical challenges, pathological features, and diagnostic complexities for elderly patients with this rare type of lung carcinoma. It emphasizes the crucial role of surgical resection in its management.