Be careful with lentils! About a forensic observation

The discovery of exogenous particles in the broncho-pulmonary tree is frequently described in forensic literature, especially in lung samples, in the context of aspirated gastric content during the death agony period or during resuscitation. We report an original observation of a multi-visceral dispersion of exogenous particles detected, in an 8-year-old boy, who allegedly fell from a 2-m high brick-wall. The autopsy found major liver fracture and diaphragm rupture with massive internal hemorrhage without gastric wall rupture. The histological analyses have identified round to oval bodies in the lung bronchi, alveoli, and, rarely, in vascular sections, and also on the surface of several samples. These particles stained strongly pink by the periodic acid Schiff method, evoking dried vegetables. Two hypotheses were invoked: aspirated vegetable particles into the bronchial tree or parasitic infection, like pinworm larva. In order to characterize the nature of these particles, different legumes were cooked, embedded in paraffin wax, and examined under light microscope. Simultaneously, morphological comparison between the gastric content and pinworm larva and lentils was made and a PCR analysis was performed on gastric fluid sample. The DNA sequencing showed a Fabaceae plant family, Lens culinaris. The possibility of a hematogenous dissemination of the starch grains during a perimortem aspiration of gastric content seems unlikely, and a contamination from the gastric content of the organs samples during the autopsy or the pathologic macroscopic and microscopic processes seems to be the principal hypothesis. The formal identification of such particles is important to avoid the misdiagnosis of a potential parasitic infection. The risk of confusion can be detrimental in some circumstances.

Keywords: Aspiration of gastric content; Contamination; Exogenous particles; Pinworm larva; Starch grains.