Intradiploic epidermoid cyst

What is it about?

We report a 45‑year‑old female, who presented with localized occipital headache and a tender occipital swelling, gradually increasing in size.Whole skull and brain imaging revealed a well‑demarcated expansile lytic lesion in the right occipital bone, which was hypointense on T1‑weighted and hyperintense on both T2‑weighted imaging and diffusion‑weighted imaging without any contrast enhancement. The patient underwent a right occipital craniotomy and total excision of the intradiploic space occupying lesion. Histopathological examination confirmed the lytic bone lesion over occipital bone as intradiploic epidermoid cyst.

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Why is it important?

Atypical epidermoids are very rare lesions with atypical imaging features including reversal of the typical T1 and T2 signal, as well as a lack of restricted diffusion. In spite of their slow growth, they can erode and invade adjacent structures and hence requiring meticulous neurosurgical intervention.