Torcular pseudomass in a 14-month-old child: illustrative case

Abstract

Background: "Torcular pseudomass," or redundant soft tissue in the torcular region, is not an infrequent incidental finding on advanced imaging of the brain in infants and young children. It was recently codified among pediatric neuroradiologists; however, its report in the pediatric neurosurgical community has not previously been elucidated.

Observations: The authors present a case of a 14-month-old child who presented with fever and a first-time seizure. Computed tomography of the head suggested an epidural abscess; however, magnetic resonance imaging characteristics of the lesion were consistent with torcular pseudomass, a normal variant. At the 3-month follow-up, the child was continuing to do well and had not had another seizure. There have been no indications for surgical intervention or additional radiographic surveillance.

Lessons: The differential diagnosis for torcular pseudomass includes dural venous sinus thrombosis, dermoid cysts, occipital encephalocele, eosinophilic granuloma, and primary and metastatic tumors, such as neuroblastoma. The management of each of these disorders in the differential diagnosis may be much more invasive than continued observation in the case of torcular pseudomass. Therefore, it is important for pediatric neurosurgeons to become familiar with this developmental anomaly of the dura and occipital skull.

Keywords: endovascular; incidental; pediatric neurosurgery; torcular pseudomass.

FIG. 1.

Noncontrast axial (left) and sagittal (right) CT images showed a hypodense mass compared with the brain parenchyma straddling the transverse sinuses and situated between the torcula and inner table of the occipital bone. The mass has a slightly higher density than the cerebrospinal fluid.

FIG. 2.

Redundant soft tissue presented in the epidural space without compression on the surrounding brain structures on axial (A–F) and sagittal (G) imaging. MRI showed facilitated diffusion on diffusion-weighted imaging (A) and apparent diffusion coefficient map (B), T2 hyperintensity (C), T2-weighted fluid-attenuated inversion recovery hyperintensity (D), T1 isointensity (E), and minimal contrast enhancement on T1-weighted images with gadolinium (F). The transverse sinuses showed normal signal voids. A sagittal T1-weighted three-dimensional turbo field echo image (G) confirmed minimal contrast enhancement.