Pralsetinib-induced interstitial pneumonitis in a patient with metastatic pulmonary sarcomatoid carcinoma harboring RET fusion: a case report

Background

Pulmonary sarcomatoid carcinoma (PSC), an exceptionally rare subtype of non-small cell lung cancer (NSCLC), remains poorly characterized in terms of molecular alterations, rendering targeted therapy a promising option. RET gene fusions act as oncogenic drivers across multiple tumor types, and the emergence of selective RET tyrosine kinase inhibitors (TKIs) like pralsetinib has transformed the treatment of RET-fusion positive malignancies. However, their expanding clinical use underscores the need to better understand adverse event (AE) profiles, particularly severe toxicities.