Subcentimeter large cell neuroendocrine carcinoma of the lung.

To our knowledge, no report exists of a subcentimeter size large cell neuroendocrine carcinoma (LCNEC) of the lung. A 75-year-old man participating in a low-dose CT screening program for lung cancer was found incidentally to have a partly-solid nodule in the right upper lung. After treatment with antibiotics, a repeat CT showed resolution of the nodule, but a new solid nodule measuring 9 x 9 mm was detected in the left lower lobe. The lesion showed marked enhancement on dynamic contrast-enhanced MRI. Video-assisted thoracic surgery and frozen section biopsy was suggestive of malignant lesion, resulting in extension of surgery to lobectomy with nodal dissection. The final diagnosis was stage IA-LCNEC. The estimated volume doubling time of the tumor was 30.1 days. These aggressive tumors may rarely have doubling times that overlap with benign processes.