Malignant tumors of the skull base

Role of craniofacial surgery in oral and maxillofacial tumors involving the skull base: A retrospective analysis of 126 patients

OBJECTIVES

Oral and maxillofacial tumors involving the skull base (SB) are rare and complex, making treatment difficult and controversial. The purpose of the present study was to evaluate the treatment efficacy of craniofacial surgery (CFS).

STUDY DESIGN

Patients who underwent CFS for these tumors between May 2000 and November 2017 were retrospectively analyzed. Clinicopathologic and treatment modality data were collected and follow-up was recorded. Kaplan-Meier and log-rank tests and Cox-regression model were used for survival analysis.

RESULTS

In total, 126 patients were enrolled (70 males and 56 females; 97 malignant tumors). Squamous cell carcinoma accounted for the majority of tumors. The lip-submandibular-neck approach was most frequently applied. Through-and-through SB bone or partial dura resection was performed in 42 cases. A pathologic positive margin was found in 18 cases. Of the included patients, 80 underwent simultaneous craniofacial reconstruction. The postoperative complications rate was 11.1%. Estimated 1-year, 3-year, and 5-year overall survival rates were 78.8%, 68.2%, and 54.4% respectively; and the 1-year, 3-year, and 5-year recurrence-free survival rates were 77.4%, 66.8%, and 63.8%, respectively. Multivariate analysis indicated postoperative complications, radiotherapy, recurrence, and metastasis status had a negative impact on survival (P < .05).

CONCLUSIONS

Although tumors involving the SB had various clinicopathologic characteristics, with interdisciplinary cooperation, CFS is an optimal option.

A retrospective study of skull base neoplasia in 42 dogs

This study describes the prevalence and distribution of 42 cases of skull base neoplasia in dogs between 2000 and 2014. The average age of affected individuals was 9.5 years, and there was no sex or breed predisposition. The most common skull base neoplasms were meningioma (25 cases) and pituitary adenoma (9 cases). Less common tumors included craniopharyngioma (2 cases), nerve sheath tumor (2 cases), and 1 case each of pituitary carcinoma, meningeal oligodendrogliomatosis, presumed nasal or sinonasal carcinoma, and multilobular tumor of bone. All neoplasms caused some degree of compression of adjacent structures. The distribution of the tumors was greatest in the sellar region ( n = 18), followed by the paranasal region ( n = 12), caudal cranial fossa ( n = 10), central cranial fossa ( n = 1), and rostral cranial fossa ( n = 1).

Celebrating the golden anniversary of anterior skull base surgery: reflections on the past 50 years and its historical evolution

With its inception nearly half a century ago through the pioneering work of Dandy, McLean, and Smith, anterior skull base (ASB) surgery is a relatively young discipline. It became a distinct entity in 1963 when Ketcham popularized the combined transcranial transfacial approach for en bloc resection of tumors of the paranasal sinuses extending into the anterior cranial fossa. However, because these procedures resulted in major morbidities and mortalities, alternative modes of treatment were sought. Since the 1970s, the introduction and promotion of the surgical endoscope by Messerklinger, Stammberger, and Kennedy, commenced the era of endoscopic sinus surgery. Thaler and colleagues described the utility of the endoscope for ASB surgery at the turn of the century. This allowed direct visualization and safer, more accurate removal of tumors. In 2001, Casiano reported the first purely endoscopic endonasal ASB resection, a novel technique that has been adopted by major skull base centers. The success of ASB surgery can be attributed to both the development of the skull base team as well as improvements in surgical techniques, instrumentation, and visualization technology. In this article, we review the historical evolution of ASB surgery as we approach the 50th anniversary since its recognition as a distinct entity.

Craniofacial resection of midline anterior skull base malignancies: a reassessment of outcomes in the modern era

OBJECTIVE

Craniofacial resection has been considered the gold standard in the management of malignancies involving the anterior skull base, where the goal of surgery is negative margins with minimal morbidity. In recent years, there has been growing enthusiasm for purely endoscopic techniques for craniofacial malignancies. Given recent advancements in open surgical approaches, there is a need to review the technique of open craniofacial resection in the modern surgical era.

METHODS

We review our experience of open craniofacial resection of midline anterior cranial fossa malignancies in the modern era.

RESULTS

Between 1995 and 2009, 41 patients underwent bifrontal craniotomy/craniofacial resection for malignancy. A subset of patients had undergone previous treatment, i.e., transfacial resection (34%), chemotherapy (5%), and radiation therapy (10%). Esthesioneuroblastoma (29%) was the most common pathology, followed by squamous cell carcinoma (27%) and the remaining patients presented with various histologic subtypes. All tumors invaded the cribriform plate; tumors invaded dura in 51%, parenchyma in 17% and orbit in 54% of patients. Negative margins were obtained in 85% of the cohort. Postoperative complications included seizure (one patient), cerebrospinal leak (one patient), and symptomatic pneumocephalus (two patients).

CONCLUSION

Since its introduction more than 50 years ago, craniofacial resection has undergone several important technical advancements concurrent to the introduction of endoscopy. With these improvements, our results indicate good oncologic disease control with minimal morbidity for extensive malignancies invading the intracranial cavity. With improvements in both open and endoscopic techniques, there is a need to reassess outcomes to determine relative indications.

Anterior craniofacial resection - for paranasal sinus tumors involving anterior skull base

Management of anterior skull base tumors is complex due to the anatomic detail of the region and the variety of tumors that occur in this area. Currently, the "gold standard" for surgery is the anterior craniofacial approach. Craniofacial resection represents a major advance in the surgical treatment of tumors of the paranasal sinuses involving anterior skull base. It allows wide exposure of the complex anatomical structures at the base of skull permitting monobloc tumor resection. This study presents a series of 18 patients with anterior skull base tumors, treated by a team of head-neck surgeons and neurosurgeons. The series included 15 malignant tumors of the nose and paranasal sinuses and 3 extensive benign lesions. All tumors were resected by a combined bi-frontal craniotomy and rhinotomy. The skull base was closed with a pediculated pericranial flap and a split-thickness free skin graft underneath. There were no postoperative problems of wound infection, cerebrospinal fluid-leakage or meningitis. Recurrent tumor growth or systemic metastasis occurred in 3 out of 15 patients with malignant tumors, 6 months to 2 years postoperatively. Craniofacial resection was thus found to give excellent results with low morbidity in malignant lesions and can also be adapted for benign tumors of anterior skull base.

Anterior and middle cranial fossa skull base reconstruction using microvascular free tissue techniques: surgical complications and functional outcomes

Surgical ablation for oncologic disease requiring skull base resection can result in both facial disfigurement and a complex wound defect with exposed orbital content, oral cavity, bone, and dural lining. Inadequate reconstruction can result in brain abscesses, meningitis, osteomyelitis, visual disturbances, speech impairment, and altered oral intake. This study assesses the functional outcomes of patients who undergo anterior and middle cranial fossa skull base reconstruction using microsurgical free tissue transfer techniques. Using a prospectively maintained database, a 10-year, single institution retrospective chart review was performed on patients who had surgery for anterior and middle cranial base tumor resections. The type of resection, reconstruction method, complication rate, and functional outcomes were reviewed. From 1992 to 2003, 70 patients (49 men, 21 women) with a mean age of 54 (age 6-78) underwent anterior and middle cranial skull base tumor resection and reconstruction. The patients were divided into the following groups: maxillectomy with orbital content preservation (n = 21), orbitomaxillectomy with palatal preservation (n = 26), and orbitomaxillectomy with palatal resection (n = 23). The average length of hospital stay was 12.6 days. The vertical rectus abdominis myocutaneous flap was used in the majority of cases to correct midface defects. Two flaps required emergent re-exploration; however, there were no flap failures. Early and late postoperative complications were investigated. Cerebrospinal fluid was observed infrequently (7%) and did not require additional surgical intervention. Intracranial abscesses were encountered rarely (1.4%). Patients who had maxillectomy with orbital preservation and reconstruction had minor ophthalmologic eyelid changes that occurred frequently. Patients who required palatal reconstruction had a normal or intelligible speech (93%) and unrestricted or soft diet (88%). Using a multidisciplinary surgical team approach, there is an increasing role for reconstruction of complex oncologic midface resection defects using microvascular surgical techniques. Early/late complications and functional problems after anterior cranial base resections are uncommon when free tissue transfer is used concomitantly.