Torcular pseudomass: a potential diagnostic pitfall in infants and young children

Torcular pseudomass is frequently detected on fetal magnetic resonance imaging and reduces with gestational age

BACKGROUND

The torcular pseudomass is an incidental extra-axial midline mass located between the venous sinuses and the occipital squama in the pediatric population. Although this structure is presumed to be a developmental feature, it has not been characterized on fetal MRI.

OBJECTIVE

To determine the frequency, imaging features and longitudinal in utero evolution of torcular pseudomass using fetal MRI.

MATERIALS AND METHODS

We present a single-center retrospective study of fetal MRI performed at a tertiary hospital. Two independent reviewers first ordinally scored torcular pseudomass as absent, focal, crescentic or bulky based on morphology. We reviewed available follow-up fetal and postnatal MRI and further classified torcular pseudomass as stable, involuted or progressive. We also collected clinical and demographic data from electronic charts and compared them among categories, corrected for multiple comparisons.

RESULTS

This study included a total of 219 fetuses with median gestational age of 28 weeks (interquartile range [IQR]: 23-32 weeks). Torcular pseudomass was absent in 8% (n=17) and present as a focal mass in 15% (n=33), crescentic in 45% (n=98) and bulky in 32% (n=71) of the cases. Median gestational age was statistically different among torcular pseudomass categories and inversely associated with size. Follow-up fetal MRI was available in 9.6% (n=21) of cases (median interval 4 weeks; IQR: 2-9 weeks) and torcular pseudomass in these cases was classified as stable in 67% (n=14), involuted in 29% (n=6) and progressive in 5% (n=1). Postnatal MRI was available in 5% (n=12) of fetuses (median interval 11.5 months, IQR: 3-17 months), and among these cases torcular pseudomass was classified as stable in 33% (n=4) and involuted in 67% (n=8).

CONCLUSION

Torcular pseudomass is highly prevalent in the fetal population and shows a natural tendency to involute, even in utero, although it sometimes persists during early infanthood.

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

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.

Torcular Dural Sinus Malformation: Fetal and Postnatal Imaging Findings and Their Associations With Clinical Outcomes

BACKGROUND

Torcular dural sinus malformations (tDSMs) are rare vascular malformations that present in fetuses and infants. Existing data on prognostic imaging features, as well as the associated morbidity and mortality, are limited and variable. We therefore reviewed cases of tDSMs diagnosed on fetal magnetic resonance imaging (MRI) at our referral center to identify pre- and postnatal MRI imaging features associated with long-term outcomes.

METHODS

We searched our imaging database for fetal and postnatal MRI reports of tDSM cases. The electronic medical record was then reviewed for pre- and postnatal clinical data, including follow-up imaging. Neurological outcomes were characterized using the previously reported scale based on the Bicêtre Score. Imaging features association with outcome scores were compared using the Fisher exact test.

RESULTS

Sixteen cases of tDMS diagnosed by fetal MRI with postnatal clinical follow-up were identified, 11 of whom underwent postnatal MRI. The majority of cases of tDSM (73%) decreased in size or resolved on postnatal follow-up study without treatment. Restricted diffusion and parenchymal hemorrhage on fetal MRI were the only imaging features identified significantly associated with unfavorable neurological outcome or death, present in two patients with poor outcomes (two of two) and only one with a normal outcome (one of 14) (P = 0.025).

CONCLUSIONS

Findings of tDSM on fetal MRI most often regress and/or resolve with normal or mild neurological outcomes, with the most significant predictor of poor outcome being the presence of parenchymal injury on fetal MRI. In addition, a subset will present with venolymphatic malformations.

Torcular pseudomass in newborns and its association with delivery: follow up or leave it alone?

PURPOSE

The cranial epidural space (ES) is a potential space and is not generally recognized unless there is underlying pathology. With MRI in newborns, we have frequently observed T2 hyperintense thickening of the ES posterior to the confluence of sinuses, also referred to as "torcular pseudomass" (TP). We aim to identify the frequency of TP and possible associations with delivery.

METHODS

Retrospectively, brain MRIs of 194 neonates obtained within the first 2 weeks of life were evaluated. If TP was present, imaging characteristics and thickness were assessed by two observers, using fat-suppressed T2WI/FLAIR, T1WI, and SWI. Exclusion criteria were motion artifact, lack of sagittal T2WI, and lack of clinical data. Medical records were evaluated for demographic and clinical data. Follow-up exams were evaluated if available. Patients with TP and without were compared using Student t and chi-square tests.

RESULTS

TP was present in 64/158 (40%). No difference was found between the groups regarding sex, gestational age, birth weight, delivery type, fetal presentation during delivery, birth difficulty, and neurological sequelae (p > 0.05). Eight patients with TP underwent follow-up imaging, and in 6/8, TP completely resolved. Two patients showed persistent TP, improving from 3.2 to 1 mm in one child and from 3.2 to 2.8 mm in the other within a week.

CONCLUSION

TP frequently occurs in early newborns. TP does not appear to be associated with factors related to delivery, shows complete resolution in most cases with a follow-up, and is likely of no clinical importance.

Spontaneous Resolution of Congenital Dural Venous Sinus Ectasia Associated With Polymicrogyria-Case Report

Dural venous sinus ectasia belongs to a rare group of venous sinus malformations of unknown origin and uncertain prognosis. We report the first patient with idiopathic congenital ectasia of the confluence of sinuses with thrombosis associated with bilateral polymicrogyria. It may highlight the causative relation between ischemia within the central nervous system due to torcular herophili ectasia with thrombosis in early pregnancy and the development of cortical malformations in neonates. We also highlight the role of MR neuroimaging in the diagnosis of these entities.

Venous pathologies in paediatric neuroradiology: from foetal to adolescent life

The interpretation of cerebral venous pathologies in paediatric practice is challenging as there are several normal anatomical variants, and the pathologies are diverse, involving the venous system through direct and indirect mechanisms. This paper aims to provide a comprehensive review of these entities, as their awareness can avoid potential diagnostic pitfalls. We also propose a practical classification system of paediatric cerebral venous pathologies, which will enable more accurate reporting of the neuroimaging findings, as relevant to the underlying pathogenesis of these conditions. The proposed classification system comprises of the following main groups: arterio-venous shunting-related disorders, primary venous malformations and veno-occlusive disorders. A multimodal imaging approach has been included in the relevant subsections, with a brief overview of the modality-specific pitfalls that can also limit interpretation of the neuroimaging. The article also summarises the current literature and international practices in terms of management options and outcomes in specific disease entities.