Elbow Metastasis From Primary Lung Adenocarcinoma: A Case Report.

Background: Lung cancer is a leading cause of cancer-related death worldwide, with bone metastasis frequently seen in advanced stages and often located in the axial skeleton or proximal long bones. Metastasis to the elbow is extremely rare and poses diagnostic and therapeutic challenges. Case Presentation: We report the case of a 39-year-old male with a history of smoking and recent occupational exposure, presenting with an 8-month history of progressive pain, swelling, and limited mobility in the left elbow. Imaging revealed an osteolytic lesion in the distal humerus, prompting further evaluation. A biopsy confirmed metastatic adenocarcinoma from a primary lung tumor. Following diagnosis, the patient underwent a targeted treatment regimen, including chemotherapy, immunotherapy, and localized radiotherapy for elbow metastasis. After 2 years of treatment, the patient achieved complete oncological remission. Conclusion: This case underscores the potential for positive outcomes in rare presentations of metastatic lung cancer to atypical sites such as the distal humerus. Although bone metastasis in lung cancer usually signals poor prognosis and limited therapeutic options, a personalized, multimodal treatment approach can substantially improve outcomes, even in advanced-stage lung cancer with unusual metastasis.