Successful treatment of pulmonary lymphomatoid granulomatosis with PD-1 inhibitor-based regimen: A Case Report and Literature Review

Pulmonary lymphomatoid granulomatosis (PLG) is a rare and aggressively progressive tumor characterized by atypical clinical manifestations and pathological features. This condition is notably susceptible to misdiagnosis and underdiagnosis. The absence of standardized treatment regimens has led to various recommendations in the literature, predominantly favoring, Rituximab-based regimens. However, the prognosis for these patients has been consistently poor, with a median survival time of only 14 months. Recently, we encountered a case of PLG exhibiting PD-1/PD-L1 and P53 expression. We administered a programmed cell death-1 (PD-1) inhibitor-based regimen. Remarkably, the patient had an overall survival (OS) of 40 months as of the most recent follow-up, without disease progression. This case stands as a notable observation, particularly, because the utilization of a PD-1 inhibitor-based regimen has not been previously reported for PLG treatment. We hope this case could contribute significantly to enhancing physicians' comprehension of PLG and provide new potential treatment strategy.