Dumbbell-Shaped Intradiploic Epidermoid Cyst Involving the Dura Mater and Cerebellum -Case Report-

Abstract

A 55-year-old woman presented with an epidermoid cyst extending to the cerebellum manifesting as headaches and pain in the left eye. Magnetic resonance imaging showed an intradiploic part with ring enhancement and an intracerebellar part. Intraoperative inspection revealed erosion of the occipital bone and defective dura mater. The tumor was located both epidurally and subdurally and the cyst consisted of pearly white keratin. The tumor was totally removed and the patient was discharged with no neurological deficit. The intradiploic part of the tumor formed the body and the intracerebellar part was caused by inflammatory reaction, which resulted in the atypical enhancement of the intradiploic part.

Clinical characteristics and diagnostic imaging of epidermoid tumors

“…27 Intradiploic lesions account for 25% of epidermoids and 3% of these expand to include the subdural space. 28,29 Less common locations of development include the middle cranial fossa, thalamus, spinal canal, corpus callosum, lateral ventricles, parietal lobe and occipital lobe. 3,9,11,14,30 Epidermoid cysts completely encompassed by brain parenchyma account for 1.5% of all intracranial epidermoids, with 80% involving the frontal and temporal lobes.…”

“…28,54,55 On T1-weighted MRI, epidermoid cysts generally appear hypointense, whereas T2-weighted MRI demonstrates a hyperintense lesion. 3,28 However, this presentation has been shown to be somewhat variable depending upon the cystic contents. Typically, cholesterol inclusions are in a solid state and appear hypointense on T1-weighted MRI.…”

“…24 As such, diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) imaging should be utilized, as epidermoids appear characteristically hyperintense on both of these sequences. 1,3,9,28,60 However, FLAIR images have been demonstrated to reduce image quality due to artifacts of cerebrospinal fluid (CSF) inflow when visualizing lesions of the prepontine and basal cisterns, foramen of Monro, and 4th ventricle. 26 This innate impairment may prove detrimental to the detection of small lesions in these locations.…”

Traumatic intradiploic epidermoid cyst manifest as scalp papule

“…Four cases to date have demonstrated association between intradiploic epidermoid cysts and trauma,2 10 12 13 however, this is the first association between cutaneous stigmata and underlying calvarial lesions of this nature.

Learning points

Intradiploic epidermoid cysts may be associated with scalp trauma.

Cutaneous stigmata may be a sign of underlying calvarial lesions.

Further work up is warranted in a patient presenting with cutaneous stigmata after head injury, especially in the setting of headaches or other neurologically-related clinical signs.

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A swelling on the fore head- the tip of the iceberg

“…3,4 Bony epidermoid cysts which nearly form 25 percent of epidermoid cyst are mainly located in the skull, although other locations, including the mandible, maxilla, temporomandibular joint, distal phalanges, tibia and femur, have been described. 5 The presentation and clinical symptoms of these tumours vary depending on size and location. These are rare, slow growing tumours that can present in many different ways, including a painless lump, tenderness, headache and rarely with focal neurological signs.…”