Fibro-Osseous Lesions of the Skull Base in the Pediatric Population

Pediatric Orbital and Skull Base Pathology

Pediatric orbital and skull base pathologies encompass a spectrum of inflammatory, sporadic, syndromic, and neoplastic processes that require a broad and complex clinical approach for both medical and surgical treatment. Given their complexity and often multicompartment involvement, a multidisciplinary approach for diagnosis, patient and family counseling, and ultimately treatment provides the best patient satisfaction and clinical outcomes. Advances in minimally invasive surgical approaches, including endoscopic endonasal and transorbital approaches allows for more targeted surgical approaches through smaller corridors beyond more classic transcranial or transracial approaches.

Giant fronto-spheno-orbitary juvenile psammomatoid ossifying fibroma: Case report and literature review

Juvenile psammomatoid ossifying fibroma (JPOF) is an osteofibrous neoplasm that originates in the craniofacial skeleton typically during the first three decades of life. JPOFs usually involve the orbit, paranasal sinuses or the jaws. Extensive involvement of the anterior cranial base with compromised visual function is a rare phenomenon. In such clinical context, a definite diagnosis can only be made on the basis of histopathological findings, given the absence of pathognomonic radiological features. Despite being considered a benign entity, JPOFs present a locally aggressive behavior. Therefore, these neoplasms must be included in the differential diagnosis in every patient harboring a skull base osteofibrous lesion, and, once diagnosed, gross total surgical removal should be attempted. In this study, we present our experience in the diagnosis and treatment of a patient diagnosed with a giant JPOF involving the cranial base.

Ossifying fibroma of the ethmoid and sphenoid sinuses: A report of a rare case and literature review

Background

Fibro-osseous lesions include a variety of bone lesions with different clinical and histopathological features.

Case Description

We report a case of cemento-ossifying lesion involving the left ethmoid and sphenoid sinus in a 17-year-old male patient. Computed tomography showed an expansile hyperdense lesion with sclerosed peripheral mantle epicentered on the left ethmoid and sphenoid sinus and extending into the left nasal cavity. Magnetic resonance imaging was done for preoperative planning. Transnasal endoscopic resection was performed and histopathological examination confirmed the diagnosis of ossifying fibroma (OF).

Conclusion

Involvement of the ethmoid sinus with OF is a rare condition; therefore, we examined the literature for similar cases to highlight the possible clinical presentation and management. Endoscopic management is a safe, effective approach with a low rate of complications.

Pediatric Benign Fibro-Osseous Lesions of the Nose and Paranasal Sinuses: A Tertiary Hospital Experience

Background

Pediatric benign fibro-osseous lesions of the nose and paranasal sinuses are considered rare neoplastic entities. These fibro-osseous lesions are difficult to accomplish owing to the multifaceted anatomy of the skull base in addition to the closeness to neurovascular configurations.

Objective

The study aimed to study different clinical presentations, radiological manifestations, surgical management, and consequences of different benign fibro-osseous lesions in the pediatric age groups. Methods and Settings. This is a case series study of a single-center experience.

Results

Four different cases were presented and discussed (osteoma, fibrous dysplasia, and ossifying fibroma.

Conclusion

We reported four different cases of osteoma, ossifying fibroma, and fibrous dysplasia. All of these cases were managed endoscopically with no postoperative complications. Endoscopic management is considered highly effective with reduced morbidity. Preoperative radiographic studies are highly essential for diagnosis and operative planning.

Frontal osteoplastic flap without frontal sinus obliteration for orbital roof decompression

Purpose: We describe a novel surgical approach for bilateral orbital roof decompression using a frontal osteoplastic flap without frontal sinus obliteration. This technique utilizes a combined external and endonasal endoscopic approach for wide exposure to the orbital roof bilaterally. We demonstrate this technique for the resection of a massive frontal fibrous dysplasia lesion in a healthy male with bilateral orbital roof involvement. The endonasal endoscopic portion of the technique includes a Draf III frontal sinusotomy (endoscopic modified Lothrop procedure) which precludes the need for frontal sinus obliteration, restores normal frontal sinus function, and allows for postoperative endoscopic surveillance. Methods: Report of novel surgical technique with video demonstration. Results: This technique for orbital roof decompression allows for removal of a frontal lesion, wide decompression of the bilateral orbital roof, and post-operative endonasal endoscopic surveillance of the cavity. The patient in whom we demonstrate this technique had complete resolution of his orbital symptoms and minimal residual fibrous dysplasia postoperatively. Conclusion: Bilateral orbital roof decompression for frontal lesions can be performed safely and effectively with a frontal osteoplastic flap without frontal sinus obliteration, restoring normal orbital and sinus function.

Pediatric sinonasal and skull base lesions

Pediatric skull base lesions are complex and challenging disorders. Safe and comprehensive management of this diverse group of disorders requires the expertise of an experienced multidisciplinary skull base team. Adult endoscopic skull base surgery has evolved due to technologic and surgical advancements, multidisciplinary team approaches, and continued innovation. Similar principles continue to advance the care delivered to the pediatric population. The approach and management of these lesions varies considerably based on tumor anatomy, pathology, and surgical goals. An understanding of the nuances of skull base reconstruction unique to the pediatric population is critical for successful outcomes.

The expanded endonasal approach in pediatric skull base surgery: A review

OBJECTIVE

Surgery of the pediatric skull base has multiple unique challenges and has seen recent rapid advances. The objective of this review is to assess key issues in pediatric skull base surgery (SBS), including anatomic limitations, surgical approaches, reconstruction techniques, postoperative care, complications, and outcomes.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of the literature was conducted to assess the challenges, recent advances, and reported outcomes in pediatric SBS.

RESULTS

The pediatric skull base presents multiple anatomic challenges, including variable patterns of pneumatization, narrow piriform aperture width, and narrow intercarotid distance at the level of the cavernous sinus but not the superior clivus. These issues may be particularly challenging in patients less than 2 years of age. Endoscopic endonasal approaches in the sagittal and coronal plane have been applied to the pediatric skull base while open approaches may still be necessary in the setting of extensive intracranial or orbital disease, as well as disease lateral to critical neurovascular structures. While the nasoseptal flap was initially called into question for pediatric cases, it has been shown through multiple reports to be a feasible and robust reconstructive option. Complications and outcomes often depend upon the pathology. In children, response to noxious stimuli, ability to avoid Valsalva, and adherence to nasal precautions is variable. The use of lumbar drains is more common in pediatric than adult patients.

CONCLUSION

While the pediatric skull base presents unique challenges, outcomes data support that endoscopic endonasal approaches are a pertinent surgical technique in appropriately selected patients.

LEVEL OF EVIDENCE

3a.

Utilization of contrast-enhanced ultrasound in the evaluation of craniofacial osseous lesions: A case report

A 14-year-old boy undergoing brain MRI had an incidental avidly enhancing lobulated lesion in the left superolateral orbital rim with associated cortical erosion. Apart from Contrast-enhanced Magnetic Resonance Imaging (MRI), and Computed Tomography (CT), Contrast-Enhanced Ultrasound (CEUS) was obtained prior to a biopsy. It provided additional information about the microvasculature and an orbital biopsy was subsequently performed through an upper eyelid crease incision with minimal blood loss and no postoperative complications. Histopathological examination revealed features which were compatible with the diagnosis of LCH. The authors propose that CEUS may be considered as an adjunct and possibly alternative imaging modality for the evaluation of craniofacial osseous lesions, especially in the orbital region (due to the known radio-sensitivity of the eyes) and in pediatric patients, to minimize the risk of ionizing-radiation exposure.

Next-Generation Sequencing in the Diagnosis of Rare Pediatric Sinonasal Tumors

The diagnosis of desmoid fibromatosis or other spindle cell tumors in the sinonasal region is very rare in children and needs to be thoroughly confirmed with immunohistochemical and/or molecular tests. We report 2 patients with such rare tumors and describe the use of next-generation sequencing in their evaluation. A 3-year-old female had a 4.4-cm midline nasal cavity mass involving the bony septum and extending into the base of the skull bilaterally. The moderate cellular fibroblastic proliferation revealed areas of thick keloid-like collagen bands and other areas with myxoid edematous stroma. Deep targeted sequencing identified a novel G34V mutation in the CTNNB1 gene consistent with desmoid fibromatosis. An 11-month-old male infant presented with a right nasal mass that extended through the cribriform plate into the anterior cranial fossa and involved the right ethmoid sinus and adjacent right orbit. Histology revealed an infiltrative atypical fibrous proliferation with focal calcifications that was negative for CTNNB1 and GNAS mutations. A novel RET E511K variant was identified in the tumor and later was also found in the germline and hence rendered of unknown significance. Both cases highlight the utility of next-generation sequencing in the evaluation of pediatric sinonasal spindle cell tumors that may have overlapping pathologic features. Reporting of rare or novel variants in tumor-only sequencing should be cautiously evaluated in children and pairing with germline sequencing may be needed to avoid the pitfall of assigning uncommon variants.