Cystic mucinous tumors of the lung are recently described neoplasms whose h
istology is different from most lung adenocarcinomas, and represent a spect
rum of malignant potential. Little is known of the behavior of the more mal
ignant subtype. We present a cystic mucinous tumor of borderline malignancy
that recurred locally following initial limited resection, and was treated
with lobectomy. (C) 2001 by The Society of Thoracic Surgeons.