Covert pneumatosis cystoides intestinalis in ascending colon, successfully observed by CT and colonoscopy in an asymptomatic patient

A 62-year-old woman presented for a follow-up colonoscopy after a previous polypectomy. Colonoscopy revealed a cluster of raised lesions in the ascending colon. The lesions were covered by normal mucosa with a smooth and slightly reddened surface (A, B). Subsequent CT to explore the submucosal structures revealed a cystic lesion with air-dense gas accumulation in the inner wall of the ascending colon (C, abdomen; D, lung window). A diagnosis of pneumatosis cystoides intestinalis (PCI) was made. Although various causes of PCI have been suspected, exposure to organic solvents is a major candidate. In this regard, the patient was a nursery school teacher and began disinfecting her facility frequently and for long periods of time when the COVID-19 pandemic began. Because the disinfectant contained high concentrations of ethanol, she was exposed to such a volatile substance for extended periods of time. She was instructed to wear a high-filtration mask and to work with adequate ventilation. The lesion remained under observation in the hope that the intracystic gas would be absorbed spontaneously, and we considered following up the lesion after 6 months or 1 year later. So far the patient’s symptoms have not recurred. With infectious diseases occurring worldwide, situations like hers are not uncommon. This may be contributing to the potential increase of this elusive disease.