Iron pill aspiration: Cytologic and histologic findings of a potential life-threatening airway injury. A Case report and literature review.

Iron pill-induced injury of bronchial mucosa is a complication following accidental aspiration of an iron tablet. Oral iron supplementation is a common therapy, particularly among advanced-age patients, who are more prone to aspiration. However, iron pill aspiration has been rarely reported in the literature, usually under the format of short case reports, with only 32 cases published in the literature. The cytologic features suspicious for this rare but potentially lethal entity have been seldom described. We report a case of a patient diagnosed with iron pill-induced bronchial injury, after oral ferrous sulfate has been prescribed during a hospital admission for pneumonia. In the bronchial washing specimen, a background of necrotic cell debris and acute inflammation involving extracellular golden-brown fibrils positive for iron stains was seen, along with the yeast forms, which, in this clinical context could confirm the iron pill aspiration. Our aim is to highlight the cytology features associated with iron pill aspiration bronchitis, and to review the literature for the histologic, clinical, bronchoscopy, and treatment aspects.