A Case of Lung Cancer with Persistent Anorexia and Weight Loss after COVID-19 Infection

Post-acute COVID-19 syndrome is characterized by complaints of malnutrition, reduced fat mass, and low-level inflammation that occur after infection with coronavirus disease 2019 (COVID-19), and continuous functional decline such as fatigue and loss of appetite can occur.A 77-year-old male patient visited the Department of Family Medicine of a national university hospital complaining of unintentional weight loss of more than 5% and anorexia for two months.After he was diagnosed with COVID-19 two months prior, the symptoms began, and he had been receiving treatment at a primary clinic for suspected post-acute COVID-19 syndrome.Physical examination revealed pain in multiple areas, including the right chest, shoulder, and lumbar region, and decreased respiratory sounds in the left upper lung region.In blood tests, mild elevations of alkaline phosphatase and gamma glutamyl peptidase and severe elevations of carcinoembryonic antigen and carbohydrate antigen 19-9 were observed.Chest radiographs showed a focal opacity in the upper left region.On chest computed tomography, a 3-cm mass was observed in the left upper lobe.Subsequent positron emission tomography and endobronchial ultrasonography using a guide sheath confirmed that it was nonsmall-cell lung cancer with multiple metastases.This case reports anorexia and weight loss after COVID-19 infection and confirmed advanced lung cancer that was misdiagnosed as post-acute COVID-19 syndrome.Key Words: Anorexia, COVID-19, Lung neoplasms, Post-acute COVID-19 syndrome, Weight loss 서 론 코로나바이러스병-19 (coronavirus disease 2019, COVID-19) 는 2023년 3월 29일 현재 국내 누적 감염자수는 30,798,723명, 사망자수는 34,245명에 이르며, 특히 60세 이상의 확진 환자 수는 6,142,007명에 이른다[1].COVID-19 환자는 유의한 체 중감소를 가질 위험성이 증가하는 것으로 알려져 있다[2].만성 코로나19증후군(long-COVID or post-acute COVID-19 syndrome)은 영양부족, 제지방감소, 낮은 수준의 염증 등을 특징으로 하며, 피로, 근육약화, 식욕저하, 미각/후각 감각 이 상 등의 지속적인 기능저하가 나타날 수 있다[3].따라서 적 절한 영양상태 및 전반적인 건강상태의 평가가 COVID-19