Small Cell Lung Cancer Associated With Cystic Airspace: A Case Report and Literature Review

Cystic airspaces are recognised as a risk factor for lung cancer. Nearly all cancers arising in association with cystic airspaces are non-small cell lung cancers, whereas cases of small cell lung cancer (SCLC) in this setting are rarely reported. A 72-year-old woman with a history of smoking was referred to our hospital for evaluation of an abnormal chest shadow. Computed tomography (CT) revealed a cystic airspace in the left upper lobe, along with a nodular lesion adherent to the cyst wall with polypoid extension into the lumen. Marked uptake of 18F-fluorodeoxyglucose was observed in the nodular lesion on positron emission tomography-CT. Consequently, primary lung cancer was suspected, and surgical resection was performed. Histopathological examination of the resected specimen led to a diagnosis of SCLC. Although rare, SCLC could arise from cystic airspaces. Nodules abutting cystic airspaces, as well as cyst wall thickening, warrant close short-term follow-up.