Resection of a colloid adenocarcinoma of the lung: A case report

Colloid adenocarcinoma of the lung is a rare subtype of lung adenocarcinoma, accounting for only about 0.24% of lung cancers. Because of its rarity, long‐term postoperative prognostic reports are limited. In this report, we describe a case of colloid adenocarcinoma of the lung with a 5‐year recurrence‐free follow‐up. The patient is a 66‐year‐old woman. During postoperative follow‐up for ovarian cancer, chest CT showed a 45 × 30 mm sized mass in the left lung with mixed low‐absorption areas inside that were suspicious of cystic lesion. We suspected metastatic lung tumour, and performed lower lobectomy. Pathological examination revealed pale tumour cells forming a glandular lumen with internal mucus production. Based on the results of immunostaining we diagnosed colloid adenocarcinoma of the lung. She received postoperative adjuvant chemotherapy and is alive 4 years postoperatively without recurrence. Colloid adenocarcinoma of the lung, even if large, may have a good prognosis if completely resected.