Background: In the pediatric population, dermoid cysts are among the most frequent lesions of the scalp and skull. Imaging plays a key role in characterizing scalp and skull lesions in order to narrow the differential diagnoses. In general, dermoids are described as heterogeneous T1-/T2-hypo- to hyperintense lesions on magnetic resonance imaging.
Methods: The goal of this retrospective study is to evaluate the diffusion weighted imaging findings while reviewing the conventional T1-/T2-/T1+C-weighted MR characteristics in a pathology-proven series of 14 dermoids of the pediatric scalp and skull.
Results: In our pediatric cohort (eight boys, six girls, age range 3-95 months), half of the dermoids were homogeneous T1-hypointense and homogeneous T2-hyperintense. We found a mixture of restricted (45.5%) and increased diffusion (54.5%) in dermoids. The vast majority of dermoids (91.7%) showed rim enhancement. Most dermoids (57.1%) were located at the midline and adjacent to one of its sutures.
Conclusions: This study suggests that dermoids may have more variable imaging appearances than hitherto assumed and are frequently seen in close proximity or adjacent to the anterior fontanelle.
Keywords: apparent diffusion coefficient; dermoid; diffusion weighted imaging; magnetic resonance imaging; pediatric; scalp; skull.