Histopathology
Most of our cohort were diagnosed via chest imaging and with a history
of known sJIA. Four patients underwent bronchoscopy and three of the
four also underwent lung biopsy for further confirmation of suspected
diagnosis (Table 4). Pathological findings from bronchoalveolar lavage
(BAL) were mixed. Two patients showed neutrophil predominance while the
remaining two patients showed macrophage/monocyte predominance. Two
patients showed hemosiderin-laden macrophages and two patients showed
lipid-laden macrophages on BAL. All patients were negative for
bacterial, fungal, and pneumocystis-like organisms on BAL. Regarding
lung biopsies, all 3 cases showed findings of mixed neutrophilic,
lymphocytic, eosinophilic inflammation with cholesterol clefts or lipid
laden macrophages, findings of pulmonary alveolar proteinosis, with no
signs of vasculitis or capillaritis. Two cases showed alveolar and
interstitial inflammatory changes consistent with chronic inflammation
with pulmonary alveolar proteinosis. The third case showed an “acute
patchy to diffuse bronchopneumonia,” with concern for possible lipoid
pneumonia; the interpretation was complicated by an acute inflammatory
process overlapping with mild chronic interstitial changes. In this
patient’s case, there was a bronchoscopy with BAL after lung biopsy
which demonstrated Periodic Acid-Schiff positive staining and an
elevated lipid laden macrophage index concerning for pulmonary alveolar
proteinosis on BAL sample.