Foreign Body Mimicking Sacral Tumour: Gauze Retained After the Lumbar Disc Surgery Performed 31 Years Ago

It is quite rare for foreign bodies retained after surgery to display tumour-like clinical and radiological findings. A 60 year-old female patient presented to the clinic with low-back and left hip pain. She had undergone lumbar disc surgery 31 years ago. She had pain in her low-back and left hip for 3 months. The patient’s CT and MRI showed a well-defined mass lesion at left posterior S2-S3, measuring 3.5 to 4 cm, with circumferential scattered contrast enhancement, which extended to the canal and caused bone erosion. Only when the mass was completely resected with its circumference, it was found out that it was the gauze retained after the surgical procedure. Our case is the oldest one in the neurosurgery and spinal surgery literature, which showed clinical findings 31 years after the lumbar disc surgery.