Objective: To study the clinical and pathological features of pulmonary neuroendocrine cell hyperplasia and tumorlets with bronchiectasis.
Methods: Both the clinicopathologic changes and immunohistochemical findings were examined with microscopy and EnVision method in 22 cases of pulmonary neuroendocrine cell hyperplasia and tumorlets.
Results: The average age of the 22 patients was 53 years, with a male to female ratio of 9:13. On macroscopic examination the lungs showed bronchiectasis; one case was accompanied by gray-white, soft nodules (diameter < 5 mm). Microscopy of the HE sections showed the basic pathologic change was bronchiectasis, accompanied by neuroendocrine cell hyperplasia and tumorlet formation in the pulmonary parenchyma surrounding the bronchioles, presenting as single nodule (10 patients), or multifocal nodules (12 patients), with average size of 1.6 mm in diameter. No tumor cells were identified in the lymph nodes. Sixteen of 22 patients were disease-free after an average follow-up period of 58 months (17 - 117 months); one patient died suddenly after surgery; and five were loss of follow up. Immunohistologically, the tumor cells were positive for CgA (18/18), Syn (16/16), AE1/AE3 (16/16) , TTF-1 (14/15), and CD56 (14/14), and Ki-67 index was < 2% in 12 cases.
Conclusions: Immunohistological staining for CgA, Syn, CD56, TTF-1 and AE1/AE3 can confirm the diagnosis. Early detection, pulmonary resection and follow-up help prevent the progression of these diseases.