Torcular Pseudomass

In 2011, a neonate with a complex cardiac malformation underwent neuroimaging as part of a comprehensive preoperative evaluation. Magnetic resonance imaging (MRI) revealed normal anatomy, but the interpretation of a “mass” posterior to the torcula (torcular herophili, confluence of superior sagittal, straight, and transverse sinuses) was uncertain ([Fig. 1A] and [B]). Developmental milestones were appropriate. Repeated MRI at 2 years and 3 months showed adequate myelination and a marked reduction in the “mass” ([Fig. 1C] and [D]). Recent re-evaluation of the imaging allowed a diagnosis of a “torcular pseudomass,” a term coined by Sampaio et al in 2017.[1] Subsequently, we have identified additional cases.

Fig. 1 (A and C) Midsagittal and (B and D) axial T2 magnetic resonance imaging of the patient at 10 days (A and B) and at 2 years and 3 months (C and D). Note the large “torcular pseudomass” in the upper row, and the subtotal involution in the second row (arrows point to “torcular pseudomass”).

Sampaio et al[1] observed an incidental extra-axial midline rounded pseudomass between the torcula and the occipital squama in a large proportion (12.7%) of 2,283 children younger than 3 years. MRI features were homogeneous T1 isointensity and T2 hyperintensity to the cerebral cortex, contrast enhancement, and normal signal intensity of the dural venous sinuses. On follow-up MRI (available in 34.7% of children, median follow-up time 18 months), 35.6% had total, 52.5% had partial involution, and 4.1% showed stability of the pseudomass.

Recognition of “torcular pseudomass” as an “incidental” finding is relevant to avoid unnecessary anxiety and further investigations.

• Reference

• 1 Sampaio L, Morana G, Severino M, Tortora D, Leão M, Rossi A. Torcular pseudomass: a potential diagnostic pitfall in infants and young children. Pediatr Radiol 2017; 47 (02) 227-234