Granular cell tumors of the sellar region: what should be done after subtotal resection? A systematic review.

PURPOSE: Granular cell tumors (GCT) are highly vascularized and adherent to adjacent structures, and so, complete resection represents a challenge. Adjuvant therapy decisions for residual GCTs currently relies on individual clinician decisions due to a paucity of systematic literature data. We present a comprehensive analysis about the impact of adjuvant therapy in reported cases of patients with incomplete GCT resection. METHODS: One database (PubMed) and crossed references were queried for GCT with incomplete resection or biopsy from 1962 to 2020. Literature review was performed according to the PRISMA guidelines. Also, two patients with residual GCT from our institutions are added to the analysis. Data regarding clinical presentation, surgical approach, use of adjuvant therapy, Ki-67 labeling, and follow up assessments were extracted and analyzed from selected publications. RESULTS: Thirty-three studies met the predetermined inclusion criteria and 53 patients were selected (including our two reported cases). The median of age was 49 [IQR, 39-60 years], with a slight male predominance (1.2:1). Among the surgical procedures, seven (13%) were biopsies alone. Adjuvant therapy was used in 18 patients (radiotherapy, 94.5%; chemotherapy, 5.5%) but there is no statistical correlation with adjuvant therapy and the progression of the remnant tumor (p = 0.33). Our institutions' patients did not receive adjuvant therapy and did not show tumor progression on MRI. CONCLUSION: Our systematic literature review suggests there is a limited role for chemo and/or radiotherapy in the management of incomplete GCT resection. It may be reasonable recommending close clinical follow up in patients with incomplete resection.

Craniovertebral junction 360°: A combined microscopic and endoscopic anatomical study.

OBJECTIVES: Craniovertebral junction (CVJ) can be approached from various corridors depending on the location and extent of disease. A three-dimensional understanding of anatomy of CVJ is paramount for safe surgery in this region. Aim of this cadaveric study is to elucidate combined microscopic and endoscopic anatomy of critical neurovascular structures in this area in relation to bony and muscular landmarks. MATERIALS AND METHODS: Eight fresh-frozen cadaveric heads injected with color silicon were used for this study. A stepwise dissection was done from anterior, posterior, and lateral sides with reference to bony and muscular landmarks. Anterior approach was done endonasal endoscopically. Posterior and lateral approaches were done with a microscope. In two specimens, both anterior and posterior approaches were done to delineate the course of vertebral artery and lower cranial nerves from ventral and dorsal aspects. RESULTS: CVJ can be accessed through three corridors, namely, anterior, posterior, and lateral. Access to clivus, foreman magnum, occipital cervical joint, odontoid, and atlantoaxial joint was studied anteriorly with an endoscope. Superior and inferior clival lines, supracondylar groove, hypoglossal canal, arch of atlas and body of axis, and occipitocervical joint act as useful bony landmarks whereas longus capitis and rectus capitis anterior are related muscles to this approach. In posterior approach, spinous process of axis, arch of atlas, C2 ganglion, and transverse process of atlas and axis are bony landmarks. Rectus capitis posterior major, superior oblique, inferior oblique, and rectus capitis lateralis (RCLa) are muscles related to this approach. Occipital condyles, transverse process of atlas, and jugular tubercle are main bony landmarks in lateral corridor whereas RCLa and posterior belly of digastric muscle are the main muscular landmarks. CONCLUSION: With advances in endoscopic and microscopic techniques, access to lesions and bony anomalies around CVJ is becoming easier and straightforward. A combination of microscopic and endoscopic techniques is more useful to understand this anatomy and may aid in the development of future combined approaches.