Abstract
INTRODUCTION AND IMPORTANCE: Basaloid squamous cell carcinoma (BSQCC) of the lung is a rare and aggressive subtype of squamous cell carcinoma. It predominantly affects individuals over 60 with a history of tobacco use. This case report highlights the unique presentation of BSQCC in a young, non-smoking patient, emphasizing the need for early and accurate diagnosis. CASE PRESENTATION: A 32-year-old male presented with a 1-month history of productive cough and dyspnea. Imaging revealed a right middle lobe mass with bronchial wall thickening. Immunohistochemistry confirmed BSQCC (p63 positive, TTF-1 negative). Molecular analysis identified a TP53 mutation and ZMYND8::FOXO1 transcription, which has not been previously described in BSQCC. Despite chemotherapy with carboplatin-paclitaxel followed by a second-line regimen, rapid disease progression ensued, leading to pleural effusion, cardiac tamponade, and fatal cardiac arrest within 2 months. CLINICAL DISCUSSION: This case highlights diagnostic challenges posed by BSQCC, particularly in atypical presentations without standard risk factors. Molecular findings suggest genetic diversity in BSQCC and underscore the potential for novel markers in diagnosis and prognosis. The advanced stage and rapid progression in this patient limited treatment options, demonstrating the critical need for early molecular testing and multidisciplinary care. CONCLUSION: BSQCC is an aggressive carcinoma requiring prompt diagnosis and treatment. This case underscores the importance of heightened awareness, molecular profiling, and further research to improve outcomes in rare lung cancers.