Author Parevi Majmudar D.O (Pediatric Pulmonary Fellow) Nadia Krupp, M.D. (Assistant Professor of Clinical Pediatrics) Kevin Albright M.D. (Pediatric Pathology) Indiana University School of Medicine, Indianapolis, IN
Case
Intro
This is a 1 year old adopted Chinese male with trisomy 21 and
progressive hypoxemia. He had persistent bilateral infiltrates on chest
x-ray over a period of 2 months and ultimately a lung biopsy was
performed. A milky white substance was noted to be oozing from the
biopsy site. Pathology reveals the following image.
H&E stain with 10x magnificationChest radiograph
Question
Which diffuse lung disease of infancy is this pathology image classic for?
A. Pulmonary interstitial glycogenosis B. Pulmonary alveolar proteinosis C. Acinar dysplasia D. Neuroendocrine hyperplasia of infancy (NEHI)
Answer
B- Pulmonary alveolar proteinosis
Discussion
This patient was adopted from China at one year of age and was noted
to be hypoxemic. A chest x-ray showed bilateral infiltrates which
persisted over time. He had hypoxemia that ultimately required
admission to the pediatric intensive care unit. A lung biopsy was
performed and H&E stained slides showed distended alveoli,
eosinophilic proteinaceous material and chronic inflammation which was
consistent with the diagnosis of pulmonary alveolar proteinosis (PAP).
The slides also demonstrated simplified epithelium consistent with
alveolar simplification, which can be seen in Down syndrome.
PAP is a broad term that describes the accumulation of surfactant in
the alveolar spaces, which impairs gas exchange. The etiology of PAP
includes dysfunction of surfactant metabolism (overproduction or
impaired removal), GM-CSF mutations, hematologic disorders and
malignancy, autoimmune disease, immunodeficiency, infections and dust
exposure.
Clinical clues to diagnosis include persistent respiratory distress
in the neonate or worsening dyspnea with diffuse infiltrates on chest
radiograph in infants and older children. Genetic testing can be
performed to look for surfactant mutations.
Treatment involves identifying and treating the etiology of the PAP. Whole lung lavages can be therapeutic.
References
Armes, Jane E., William Mifsud, and Michael Ashworth. "Diffuse lung
disease of infancy: a pattern-based, algorithmic approach to
histological diagnosis." Journal of clinical pathology (2014): jclinpath-2014.
