Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH)—An uncommon precursor of a common cancer?

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare, likely under recognized entity. We report on six cases of DIPNECH that were seen in Saskatoon, SK. The cases largely have the characteristics of the typical patient profile thus far described in the literature, consistent with the limited information reported to date. Furthermore, one case had co-existing squamous cell carcinoma, which has not been previously described, and one case had concomitant adenocarcinoma. In this context, we explore the hypothesis of whether DIPNECH could play a role as an uncommon precursor in pulmonary tumorigenesis. We also propose improved diagnostic criteria for DIPNECH, which are currently ill-defined.