Microscopic acute lesions after caustic exposure.

Although lesions related to chemical burns have been studied through case reports, clinical analyses and autopsy series, microscopic lesions have not yet been precisely described. Our study analyses the microscopic lesions recorded after caustic exposure in fourteen lethal and four non-lethal cases. We find that microscopic lesions after caustic exposure are various and non-specific. Moreover, the distribution of gastrointestinal lesions is inconsistent. Histological changes affect the digestive mucosa first, with the entire wall suffering damage in some cases. Multiple factors influence the pattern of lesions, including the nature of the caustic substance, the duration of contact, the amount of the substance encountering the tissue and the length of postingestion survival. The assessment of microscopic lesions, especially necrosis, can be limited by post-mortem autolysis, which quickly affects the digestive tract. Chemical pneumonia due to caustic burns is rare and, when present, typically secondary to aspiration. According to the presented findings, macroscopic examination at autopsy under- or overestimates the nature and degree of lesions. Significant complications of caustic ingestion such as chemical pneumonitis can also be found by histological analysis. Microscopic examination can be useful to rule out oesophagitis or other digestive pathologies that can mimic chemical burns.