Ashley R Jones, Harry C Kellermier, Matthew P Doepker
Introduction: Incidental findings are identified on 35% to 45% of trauma CT scans. Most commonly, they are found on CT scans of the abdomen/pelvis in female patients older than age 60. Multiple studies show that the majority of these findings are benign and do not require urgent intervention. Many patients are discharged without notification of their findings or sufficient follow-up care.
Case description: A 28-year-old male presented as a trauma alert after a rollover motor vehicle collision. He was assessed according to ATLS protocol and underwent CT scans of his head, neck, chest, abdomen, and pelvis. Imaging showed a fracture of his C1 vertebrae, so the patient was placed in an Aspen collar by neurosurgery and admitted to the hospital. The CT scan also showed an incidental 11 cm × 9.5 cm × 12.6 cm solid mass containing areas of calcification and hemorrhage displacing the bladder and the right external iliac vein. A CT guided biopsy of this mass was preformed and sent for pathological evaluation. Results returned as a spindle cell lesion, positive for S-100 and negative for desmin and vimentin. Decision was made to respect the mass based on its large size and potential for obstructive or compressive symptoms. Pathology was positive for a schwannoma.
Discussion and Conclusion: Our case describes a rare benign neoplasm found incidentally after a work-up for trauma. Schwannomas account for 5% of benign soft tissue neoplasms, occurring primarily as solitary, slow-growing lesions in patients 20 to 40 years of age. They are rarely symptomatic unless their size results in compression of surrounding structures. They appear as heterogenous encapsulated masses with degenerative and cystic cavitations on imaging. They will routinely stain positive for S-100 on histological examination.