The Case Files

Abstract

A ruptured dermoid can have many presentations, making it hard to diagnoseFigureFigureA 45-year-old man presented after a sudden transient loss of consciousness followed by excessive crying. He was conscious and oriented upon arrival. He had no fever, and his blood pressure was 130/80 mm Hg, heart rate was 90 bpm, respiratory rate was 20 bpm, oxygen saturation level was 100 percent, and blood sugar level was 103 mg/dL. No neurological deficit was found on examination. The patient had a sinus tract on his lower back at L2-L3. The rest of the exam was normal. The patient had no significant medical history and was not taking any medication. Neuroimaging, CT, and a brain MRI revealed disseminated lipid tissue in the frontal horn of the lateral, third, and fourth ventricles. Similar extra-axial fat intensities were also found in the frontal region and left sylvian, interpeduncular, and right CP angle cisterns. Two differential diagnoses were considered: ruptured dermoid tumor and traumatic pelvic or spinal fracture. Spinal MRI suggested an intramedullary mass lesion with lobulated margin (1.6 cm by 1.1 cm by 6.8 cm) in the conus medullaris and cauda equina, extending from the L1 to L3 vertebrae. The lesion appeared hyperintense on T2W and T1W images, which were suppressed on saturated T1 images. Evidence of intramedullary T1 and T2 hyperintense multiple foci adherent to the dorso-lumbar spinal cord suggested a ruptured dermoid. A dorsal dermal sinus tract at L2 to L3 vertebrae was noted. Rupture of a spinal dermoid cyst into the central spinal canal is rare. An intradural dermoid cyst may rupture with subsequent subarachnoid dissemination of lipid droplets. Dermoid cysts are benign tumor-like lesions comprising approximately one percent of intracranial and spinal tumors and occur slightly more often in men. Their high incidence occurs in the lumbosacral region involving the conus and cauda equina. Upper thoracic (10%) and cervical (5%) lesions are rare. Dermoids are associated with a dermal sinus in 20 percent of cases. The rupture of a dermoid cyst is a well-known phenomenon and can be spontaneous, iatrogenic, or traumatic in origin. A ruptured dermoid may have myriad presentations. Chemical and aseptic meningitis are the most common features after a rupture because of the irritating effects of the disseminated cholesterol debris. The patient may be asymptomatic or experience headache, vomiting, seizures, coma, infarct, and rarely death. A headache might occur because of the compression of adjacent structures, chemical meningitis, or hydrocephalus due to obstruction of cerebrospinal fluid pathways by lipid droplet. The mean age at presentation of such lesions is 40.6, and all cases have been reported in men. Treatment includes steroids, analgesics, antibiotics, and surgical resection of the spinal lesion.