Radiological diagnostics in nasal dermoids: Pitfalls, predictive values and literature analysis

Imaging Yield and Surgical Outcomes of Nasal, Medial Brow, Forehead, and Scalp Dermoid Cysts

OBJECTIVE

Dermoid cyst (DC) is a congenital cyst with the potential to have intracranial extension (ICE). This study aims to evaluate the imaging yield and surgical outcomes of nasal, medial brow, forehead, and scalp DCs.

DESIGN

Retrospective review of craniofacial DCs treated at our institution between 1992 and 2024.

RESULTS

A total of 117 patients (57 females) were included. The median age at cyst detection and removal were 4.8 months (IQR 3.6-9.6) and 1.8 years (IQR 0.9-5.3), respectively. In 42 patients, parents have noticed the presence of the cyst immediately after birth. Cyst wall rupture during surgical removal was reported in 15.4%. The median follow-up time was 1.3 months (IQR 0.5-12.2). Three patients experienced recurrence. No postoperative complication was reported. The regions with the highest prevalence of ICE were the forehead, frontotemporal scalp, and nasal region. The lateral frontal/temporal scalp had a 33.3% rate of ICE. Midline forehead/scalp lesions demonstrated a higher risk of ICE compared to their lateral equivalents (54.5% vs 17.5%, P = .03). The sensitivity and specificity of magnetic resonance imaging (MRI) were 100% and 95.7%, while for computed tomography (CT scans) were 72.7% and 96.5%. The Area Under the Curve for MRI was 0.978, and for CT was 0.846. The sensitivity and specificity of ultrasound were 50% and 100%.

CONCLUSIONS

Midline forehead/scalp DCs are more prone to extend intracranially than lateral DCs. MRI had a higher sensitivity and specificity than CT scans in detecting ICE. Routine screening imaging should be considered in midline forehead/scalp, lateral frontal/temporal, and nasal DCs.

Transnasal Endoscopic Approach for Excision of Intracranial Nasal Dermoid Sinus Cysts

OBJECTIVE

Nasal dermoid sinus cysts (NDSCs) with intracranial extension in the form of dermal sinus tracts require careful and complete resection to prevent recurrence. Resection techniques necessitate adequate intracranial exposure, but morbidity associated with historical resection approaches has presented unique multidisciplinary challenges for surgeons treating cysts with intracranial extension.

METHODS

The authors primarily employed a transnasal approach through a midline nasal incision, utilizing endoscopic or microscopic access between the lateral cartilages for resection of NDSCs with intracranial extension. A retrospective review was completed for patients treated for NDSCs at the authors' pediatric quaternary referral center from 2017 to 2023. Data collection included demographics, comorbidities, perioperative data, pre and postoperative imaging, surgical outcomes, and complications.

RESULTS

Eighteen patients with NDSCs with possible or confirmed intracranial extension were surgically treated from 2017 to 2023. Fifteen were treated with resection performed through a midline transnasal approach with endoscopic assistance, achieving successful total resection while avoiding nasal osteotomy or frontal craniotomy. One patient had a slow cerebrospinal fluid leak from an operative durotomy, successfully treated with a lumbar drain. No other complications occurred. No patients required transfusion. Incision length and postoperative scar burden were less than approaches that used osteotomies or craniotomies and demonstrated excellent cosmetic results. No patients have had cyst recurrence or required reoperation.

CONCLUSIONS

A transnasal approach through a midline incision with endoscopic assistance is an effective approach for resection of NDSC with intracranial extension, but utility may vary with cyst size and complexity. This approach leverages appropriate exposure for resection with decreased morbidity and decreased incision length through avoidance of osteotomies.

Pädiatrische Rhinologie

The following review article highlights key topics in pediatric rhinology that are currently the focus in research and at conferences as well as in the interdisciplinary discussion between otorhinolaryngologists and pediatricians. In particular, congenital malformations such as choanal atresia or nasal dermoid cysts are discussed, followed by statements on the current procedures for sinogenic orbital complications as well as on the diagnosis and therapy of chronic rhinosinusitis in children. Furthermore, updates on the role of the ENT specialist in the care for children with cystic fibrosis and primary ciliary dyskinesia are provided.

Preoperative Imaging and Surgical Findings in Pediatric Frontonasal Dermoids

OBJECTIVE

To review cases of congenital frontonasal dermoids to gain insight into the accuracy of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) in predicting intracranial extension.

METHODS

This retrospective study included all patients who underwent primary excision of frontonasal dermoids at an academic children's hospital over a 23-year period. Preoperative presentation, imaging, and operative findings were reviewed. Receiver operating characteristic (ROC) statistics were generated to determine CT and MRI accuracy in detecting intracranial extension.

RESULTS

Search queries yielded 129 patients who underwent surgical removal of frontonasal dermoids over the study period with an average age of presentation of 12 months. Preoperative imaging was performed on 122 patients, with 19 patients receiving both CT and MRI. CT and MRI were concordant in the prediction of intracranial extension in 18 out of 19 patients. Intraoperatively, intracranial extension requiring craniotomy was seen in 11 patients (8.5%). CT was 87.5% sensitive and 97.4% specific for predicting intracranial extension with an ROC of 0.925 (95% CI [0.801, 1]), whereas MRI was 60.0% sensitive and 97.8% specific with an ROC of 0.789 (95% CI [0.627, 0.950]).

CONCLUSION

This is the largest case series in the literature describing a single institution's experience with frontonasal dermoids. Intracranial extension is rare and few patients required craniotomy in our series. CT and MRI have comparable accuracy at detecting intracranial extension. Single-modality imaging is recommended preoperatively in the absence of other clinical indications.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1961-1966, 2024.

The Differential Diagnosis of Congenital Developmental Midline Nasal Masses: Histopathological, Clinical, and Radiological Aspects

Developmental midline nasal masses including nasal dermoids (NDs), encephaloceles (EPHCs), and nasal glial heterotopias (NGHs) are a consequence of disrupted embryonal developmental processes in the frontonasal region. Surgery is the only method of treatment in order to prevent local and intracranial inflammatory complications as well as distant deformities of the facial skeleton. Due to their rarity, similar location, and clinical and radiological symptoms, meticulous preoperative differential diagnostics is mandatory. The aim of this thorough literature review was to present and discuss all clinical, histopathological, and radiological aspects of NDs, NGHs, and EPHCs that are crucial for their differential diagnosis.

Congenital midline upper lip sinuses with intracranial extension - A variant of nasal dermoid? An embryology-based concept

OBJECTIVE

The study aimed to present the comparative analysis of midline congenital upper lip sinuses (MCULS) and nasal dermoids (NDs). The clinical similarity of congenital midline pathologies of the midface was interesting subject for further studies. Therefore, histopathological, and embryological background were also analyzed to verify a hypothesis that NDs and MCULSs are the different variants of the same entity.

MATERIAL AND METHODS

The study group included 27 surgically treated pediatric cases with the congenital midline sinus of the nose (n = 25) or upper lip (n = 2). Seven children presented intraoperatively confirmed intracranial extension of the abnormality, 6 in NDs group and 1 in MCULS group. Apart from clinical characteristics also histopathological results were compared in both groups. An analysis of the literature concerning the proposed theories of origin of NDs as well as the current classification systems of MCULSs and NDs were conducted.

RESULTS

The analysis revealed that MCULSs present the same clinical characteristics as NDs. No differences were noticed in the histopathological results. The embryological theories presented so far are insufficient to convincingly explain the precise process of origin of abnormalities such as ND and MCULS. Nevertheless, the developmental embryological processes of the midface shed a new light on the common origin of NDs and MCULSs. The proposal of an update of the existing classification of midline congenital midface sinuses was presented.

CONCLUSIONS

The comparative analysis of clinical, histopathological, and embryological characteristics confirms that NDs and MCULSs are different forms of the same entity. Embryological implications result in the possibility of intracranial extension in each case of MCULS. Therefore, CT and MR imaging which provide irreplaceable information are recommended for all patients with MCULS. The updated classification of midline congenital midface sinuses should be taken into consideration.