The Clinical Course of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia

Pulmonary Neuroendocrine Cell Hyperplasia Associated With Surfactant Protein C Gene Mutation

“…His CT of chest finding revealed emphysema, ground-glass opacities, multiple lung cysts, septal thickening, and subpleural honeycombing, which have all been reported to be associated with SFTPC mutations. In addition, there was some evidence of air-trapping and mosaic attenuation, which are well-described radiographic findings in DIPNECH [23,33].…”

“…The unexpected finding in this case was the presence of diffuse neuroendocrine cell hyperplasia and carcinoid tumorlets. The number of PNEC and carcinoid tumorlets were numerous and theoretically met the diagnostic criteria of DIPNECH proposed by previous studies as mentioned above [23,28,29]. In addition, the quantity of PNEC would also have met proposed criteria for NEHI [24].…”

“…PNEC hyperplasia without an underlying pulmonary disease is known as neuroendocrine cell hyperplasia of infancy (NEHI) in children and in adult counterpart is known as diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH). It has been increasingly recognized but still remains a relatively rare entity [23]. There was no formal criterion for defining excess of pulmonary neuroendocrine cells, but it was proposed in previous study [24] that finding of PNEC within 70% of bronchioles in the lung biopsy specimen and >10% in an individual airway is consistent with diagnosis of NEHI in appropriate clinical setting.…”

“…A study by Marchevsky et al attempted to provide diagnostic criteria for DIPNECH and concluded that the presence of 5 or more neuroendocrine cells, singly or in clusters located within the basement membrane of bronchiolar epithelium of at least 3 bronchioles, combined with 3 or more carcinoid tumorlets can be used consistently to diagnose DIPNECH [28]. Another study proposed combination of clinical, radiographic, histologic, and serum markers for diagnosis, but of note, they found 100% of DIPNECH patients had presence of carcinoid tumorlets in biopsy sample [23]. DIPNECH has radiographic findings of ground-glass opacity, air-trapping, mosaic attenuation, and histology commonly showing constrictive bronchiolitis [23].…”

“…Another study proposed combination of clinical, radiographic, histologic, and serum markers for diagnosis, but of note, they found 100% of DIPNECH patients had presence of carcinoid tumorlets in biopsy sample [23]. DIPNECH has radiographic findings of ground-glass opacity, air-trapping, mosaic attenuation, and histology commonly showing constrictive bronchiolitis [23]. Besides an underlying condition, there are no clear histologic differences between reactive PNEC and DIPNECH [28].…”