Wandering projectile, a rare cause of acute urinary retention

BACKGROUND: Urethral obstruction due to retained projectile migrating into the genitourinary system has rarely been reported. The literature describes two main methods of retained projectile removal from the genitourinary system: (1) spontaneous expulsion during voiding and (2) manual extraction due to urethral obstruction causing acute urinary retention. CLINICAL PRESENTATION: We present a case in which a 23-year-old man presented with acute urinary retention four days after suffering a gunshot wound to the right distal posterolateral thigh. A retained projectile eroded through the posterior wall (slightly to the right) of the bulbar urethra at the bulb, migrated through the urethra, and eventually became lodged in the external urethral meatus, causing obstruction and acute urinary retention. Subsequently, the foreign body was removed with manual extraction along with gentle external pressure under sedation and the patient was discharged with a 16 Fr transurethral catheter in situ to be kept for 1 week and removed after a week. CONCLUSION: The absences of signs do not always effectively rule out urethral or bladder injury. Urethral foreign bodies are not commonly encountered when they do the entry is usually the urethral meatus. However, the treating physician must that other mechanisms also exist especially in those with bullet injury to flank, abdomen, pelvis and even the distal thigh like our case. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12894-023-01204-x.