Migrating foreign material mimicking metastatic soft tissue sarcoma in a patient with history of synthol injection.

Injecting substances like Synthol for cosmetic muscle enhancement is known, but its potential for causing severe systemic complications is less documented. This case highlights the risks of foreign material migration, initially presenting as a suspected malignancy. A 47-year-old male presented with dyspnea and bilateral diffuse airspace opacities on chest X-ray, initially raising suspicions for metastatic disease. The patient's medical history was unremarkable until further detailed questioning revealed the use of Synthol injections. Initial imaging suggested metastatic soft tissue sarcoma with bilateral lung and various soft tissue masses detected on PET-CT scans. However, subsequent detailed examinations, including a CT-guided biopsy of the lung lesions, revealed no evidence of malignancy but instead chronic inflammation and fibrosis indicative of a reaction to foreign material. This finding prompted a re-evaluation of the initial diagnosis, leading to the identification of Synthol migration as the underlying cause of the patient's symptoms. This case underscores the importance of considering foreign substance migration in the differential diagnosis for patients presenting with unexplained tissue masses and emphasizes the need for thorough history-taking in elucidating the etiology of atypical radiologic findings. Early detection and accurate diagnosis can prevent unnecessary invasive procedures and facilitate appropriate management.