Foreign Body Granuloma
Demographical and clinical details: 53 years old male, tender mass of left-hand that develops 2 months after woody foreign body penetrating injury.
Image Details: Photograph(a) shows the tender mass on the dorsal surface of hand. US images (b-d) shows the linear echogenicity with acoustic shadowing consistent with foreign body. You can also note surrounding hypoechoic soft tissue of foreign body that is consistent with foreign body granuloma (FBG). White arrows indicate metacarpal bone; red arrows indicate the echogenic foreign body. Post-operative photograph (e) shows granulation tissue and 2 woody foreign body (red arrow)
FBG which develops as a tissue of granulomatous reaction to retained foreign body generally presents as a tender mass.
As in our case, foreign bodies are seen as echogenic focus with posterior acoustic shadowing. Granulation tissue that surrounds the foreign body is called as foreign body granuloma.
In my experience, US is important for diagnosis of FBG especially in patient with history of penetrating foreign body injury.