COVID-19-induced pulmonary sarcoid: A case report and review of the literature

Background: The COVID-19 pandemic has resulted in dramatic loss of life worldwide, but as the large number of acutely ill patients subsides, the emerging group of "COVID-19 long-haulers" present a clinical challenge. Studies have shown that many of these patients suffer long-term pulmonary disease related to residual fibrosis. Prior studies have shown that while many patients have non-specific findings of fibrotic-like changes, others develop specific patterns of interstitial lung disease.Case report: Here, we present the first case of a patient developing pulmonary sarcoidosis one year after critical illness from COVID-19. He developed numerous non-necrotizing and well-formed granulomas in mediastinal lymph nodes and pulmonary nodules, compatible radiographically and pathologically with sarcoid.Conclusions: While the pathophysiology of sarcoid is incompletely understood, inflammation is mediated through the dysregulation of a number of different cytokines (IFN gamma, IL-2, IL-12, IL-17, IL-22). This case provides valuable clues for better understanding of the shared pathophysiology of cytokine dysregulation seen in COVID-19 and other interstitial lung diseases such as sarcoidosis.