Urinary bladder trauma can be broadly classified as blunt or penetrating with blunt injury being the most common type. Penetrating injury to the bladder is relatively rare and accounts for 14–49%. Clinical presentation of bladder injury includes suprapubic pain, inability to pass urine, hematuria and peritoneal sign and symptoms in case of intraperitoneal injury [6]. The index case is unique as there was no reported sign and symptoms suggestive of bladder injury.

Port of entry can either be abdomen, perineum, rectum, buttocks or pelvis with upper inner thigh as the port of entry being a very rare presentation [1, 6]. Our case was diagnosed with penetrating bladder injury after a year and six months because of the unusual presentation of both symptoms and signs and the entry point. Complications of bladder injury includes persistent hematuria, infection (sepsis) and urine incontinence (fistula formation) [6, 7]. Pererira et al. also state in their literature that penetrating trauma to the lower abdomen, thighs or perineum is sensitive to bladder injuries [2]. Common cause of penetrating bladder injury is gunshot wounds (GSW) accounting for 80% versus 20% from stab wounds. One cannot predict the trajectory of a gunshot wound whereas stab wounds can be predicted with relatively little damage to surrounding tissues compared to GSW [8]. Other causes include pelvic fractures and isolated bladder injuries from iatrogenic injury, though are uncommon [8].

Diagnostic modalities for urinary bladder injuries can be X-ray cystography but CT-cystography is recommended if there is suspicion for other viscera injuries, provides a 3D image for evaluation, whereas on the contrary has exposure to more radiation [8]. Acute bladder injuries should be graded according to the Organ Injury Scale developed by the American Association of Surgery for Trauma (AAST) but this was not possible in the index case due to the chronicity of the injury and process of healing [8].

Thigh abscess associated with a fistula due to abdominal pathology has been reported in literature. VCF presenting as a thigh abscess can have various aetiologies such as extensive pelvic fracture, pelvic abscess, post pelvic radiation giant bladder calculus, IBD and post operative cases such as hip arthroplasty [9]. It is evident that VCF occur due to reaction from a foreign body as mentioned by Apul Goel et al. and Raghavendran et al. [10, 11]. Urinary fistula especially long standing can cause considerable physical and psychological stress, such as in the index case where she had to miss school due to recurrent thigh abscess. This is more likely where the cause cannot be ascertained and often misdiagnosed as in the index report [4].

Vesicocutaneous fistulas rarely communicate to the thigh but commonly exit the perineum, scrotum, buttocks or hypogastrium [12]. The time for the fistula to develop can be variable but usually precede an abscess [12]. We believe our patient did not leak urine because the fistula tract was blocked by the foreign body. For simple fistula a micturating cystourethrogram can be sufficient but in cases where the history is prolonged and fistula is complex a CT or an MRI are needed as evident in our case where the history was long and presentation was rather uncommon [13].

Management depends on the presenting symptoms, the complexity of the fistula and the underlying cause [14]. Urinary diversion to reduce the hydrostatic pressure of the bladder is vital therefore urethral catheter was kept for 21 days in our case. However, fistula excision surgery was not needed as the tract healed spontaneously after removal of the foreign object (causal agent) [3, 9]. VCF can also be managed surgically by fistulectomy with vacuum-assisted closure or larger and complex fistulas may require musculocutaneous flap surgery [15].