Long standing lumbosacral dermoid tumor and intracranial fat droplet dissemination: A case report.

BACKGROUND: Dermoid tumors are slow growing, benign CNS lesions. CASE DESCRIPTION: This case study concerns a 29-year-old female with a 6-year history of lower extremity paresthesias attributed to magnetic resonance (MR)/computed tomography (CT) documented intradural dermoid tumor that extended from L1 to S1. On MR, it was hypointense on T1, hyperintense on T2, and did not enhance with gadolinium. CT showed hyperdensity at the L1-L2 levels. The craniocervical MR imaging showed small hyperintense foci in the cisternal space favoring "fat dissemination." L1-S2 laminectomy revealed an intradural lesion characterized by "a solid and firm component compatible with fat tissue adherent to the conus medullaris and a solid-soft component within the cauda equina;" there were also "multiple fragments of white-creamy soft tissue with hair." Following tumor resection, the brain CT scan demonstrated fat dissemination within the intraventricular and cisternal space. Histopathologic examination confirmed the diagnosis of a dermoid tumor.
CONCLUSION: Dermoid tumors should be considered among the differential diagnosis of intradural lesions in young patients even without any other congenital abnormality.

INTRODUCTION

Dermoid tumors, attributed to superficial ectoderm dysembriogenesis occurring during the gastrulation phase of fetal development, are slow growing, benign tumors occasionally found within the nervous system.[56] They constitute only 0.7–1.1% of all spinal tumors.[3] Here, we present a 29-year-old patient with an L1-S2 intradural dermoid tumor.

CASE DESCRIPTION

A 29-year-old female complained of low back pain and lower limbs paresthesias for 6 years; symptoms had exacerbated for the last 1.5 years. She also had urinary urge incontinence, sacral hypoesthesia, and 4/5 lower extremity weakness. The lumbosacral magnetic resonance (MR) imaging showed an intradural lesion filling the canal from L1 to S1; it was hypointense on T1, hyperintense on T1, and showed no enhancement with gadolinium injection [Figure 1]. The spinal computed tomography (CT) scan showed only a small focus of hyperdensity within the spinal canal. The craniocervical MR showed small foci of hyperintensity in the cisterns consistent with diffuse fat dissemination.

Figure 1

Magnetic resonance imaging sequences: (a) T1 and (b) T2 images sequences

Surgery

The L1-S2 laminectomy revealed an intradural lesion that filled the spinal canal. There were fragments of white-to-creamy soft tissue with tufts of hair [Figure 2], accompanied by a solid-firm component consistent with fat adherent to the conus medullaris and cauda equina. The fat could only be subtotally resected due to adherence to neural structures, while the remainder of the lesion was fully excised. Postoperatively, the patient was intact except for increased urinary incontinence. When she complained of headache, a brain CT scan showed increased fat dissemination in the intraventricular space consistent with postoperative chemical meningitis; this was successfully treated with corticosteroid. The patient's histopathologic examination confirmed the diagnosis of a dermoid tumor.

Figure 2

Intraoperative photography of the tumor

DISCUSSION

Dermoid tumors are rare benign tumors that are more common in the brain than the spine.[3] Intradural dermoid tumors most commonly involve the lumbosacral region, and are typically associated with the other congenital anomalies (e.g., bone abnormalities, meningocele, and dermal sinus tracts).[25] They have two distinct components, consisting of fat or a solid or liquid element, containing ectodermal or mesodermal tissues (e.g., hair, bone, and teeth).[2] Because they are slow growing, they become symptomatic in the second and third decade of life.[7] Symptoms are caused by compression of the spinal cord, conus medullaris, and cauda equina.[7] Two major complications may include chemical meningitis or obstructive hydrocephalus attributed to cephalad migration of fat droplets into the ventricular system and cisternal spaces.[6] Table 1 presents demographic and clinical finding of some studies reporting dermoid tumor.

Table 1

Demographic and clinical features of some studies

CONCLUSION

Dermoid tumors should be considered amongst the differential diagnoses of intradural spinal lesions in younger patients even without accompanying congenital abnormalities.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.