Neuroendocrine cell hyperplasia of infancy: diagnosis with high-resolution CT

Abstract

Objective: Neuroendocrine cell hyperplasia of infancy is a form of childhood interstitial lung disease originally reported as persistent tachypnea of infancy. Reports of small series of cases and anecdotal experience have suggested that this disorder may have a consistent CT pattern. The purpose of this study was to review the CT findings in children with neuroendocrine cell hyperplasia of infancy to determine the findings at high-resolution CT, the diagnostic accuracy of CT compared with biopsy, and interrater reliability.

Materials and methods: Images from 23 CT examinations of children with biopsy-proven neuroendocrine cell hyperplasia of infancy and six CT examinations of children with other childhood interstitial lung diseases were reviewed by two pediatric radiologists with special expertise in thoracic imaging. Identifying digital data were removed, and images were reviewed without clinical data. A CT assessment form was completed for each patient.

Results: Ground-glass opacification was the most common finding in patients with neuroendocrine cell hyperplasia of infancy. The right middle lobe and lingula were most commonly involved. Air trapping with a mosaic pattern was the second most common finding. Interrater reliability was very good with a kappa value of 0.93. The sensitivity and specificity of CT in the diagnosis of neuroendocrine cell hyperplasia of infancy were at least 78% and 100%.

Conclusion: Neuroendocrine cell hyperplasia of infancy can have a characteristic appearance on high-resolution CT scans, the imaging findings being useful in differentiating neuroendocrine cell hyperplasia of infancy from other types of childhood interstitial lung disease. The appearance aids radiologists in suggesting a specific diagnosis but does not exclude this diagnosis; in 17-22% of cases, the readers in this study did not suggest the diagnosis of neuroendocrine cell hyperplasia of infancy when it was present.

Fig. 1

6-month-old boy with neuroendocrine cell hyperplasia of infancy. Photomicrograph obtained after immunostaining with bombesin shows increased number of neuroendocrine cells within bronchiole and large neuroepithelial bodies (inset). (bombesin, ×200; inset, bombesin, ×400)

Fig. 2

5-month-old boy with biopsy-proven neuroendocrine cell hyperplasia of infancy. Neither reader considered neuroendocrine cell hyperplasia of infancy present. A–C, Inspiratory high-resolution CT scans show abnormalities are most marked in upper (A) and middle (B) portions of lungs, sparing lower parts (C). Ground-glass opacification (asterisk, B) is evident, as are areas of volume loss (arrows, B) and architectural distortion (arrow, A). D–F, Expiratory high-resolution CT scans show hyperlucent areas indicating air trapping is most marked in upper portion of lungs (A, E) with no air trapping in lung bases.

Fig. 3

40-month-old girl with typical appearance of neuroendocrine cell hyperplasia of infancy. A–C, Inspiratory high-resolution CT scans show sharply defined areas of ground-glass opacification along mediastinal borders, peripherally, and most prominently in right middle lobe and lingula (asterisks, C). D–F, Expiratory high-resolution CT scans show only mild increase in attenuation in all areas of lung, consistent with air trapping involving both areas with ground-glass opacification and areas with normal attenuation.