In recent years, interest in the management of anterior skull base tumors has been fostered by the introduction and subsequent rapid expansion of indications of transnasal endoscopic techniques. In parallel, extraordinary progress has been made in all the other disciplines which are involved in the complex process of managing anterior skull base tumors, leading to substantial improvements in diagnosis and treatment. The anterior skull base can be involved in a large variety of tumors of a varying nature and histology, which in the majority of cases originate from adjacent anatomic sites. In fact, primary lesions of the anterior skull base mainly include osteoma and other tumors originating from bone and cartilage. Tumors involving the anterior skull base have their origin prevalently in the sinonasal tract, but lesions developing on the intracranial site, such as meningiomas, may also extend caudally to encroach upon this area. All these lesions are rare, which means that the pertinent literature does not include prospective studies or treatment guidelines based on a high level of evidence. In view of the extreme histological variability of lesions involving the anterior skull base, much emphasis has been placed on addressing the different nuances of treatment in relation to histology, especially for malignant tumors. The chapters focusing on surgery provide divergent views on selection criteria for a specific surgical technique, which is the aim of this publication.

Prelims
I	Preliminary Pages Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp I–VI (DOI:10.1159/000505414) Free Access

Preface
VII	Preface Nicolai P. · Bradley P.J. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp VII–VII (DOI:10.1159/000505104) Free Access

1	Macroscopic and Endoscopic Anatomy of the Anterior Skull Base and Adjacent Structures Ferrari M. · Mattavelli D. · Schreiber A. · Nicolai P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 1–12 (DOI:10.1159/000457921)

13	Pathology and Differential Diagnosis of Anterior Skull Base Tumours Williams M.D. · El-Naggar A.K. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 13–27 (DOI:10.1159/000457922)

28	The Role of Morphologic and Functional Imaging in Pretreatment Assessment Maroldi R. · Borghesi A. · Ravanelli M. · Golemi S. · Farina D. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 28–45 (DOI:10.1159/000457923)

46	Transnasal Endoscopic Surgery: Surgical Techniques and Complications Battaglia P. · Lambertoni A. · Castelnuovo P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 46–55 (DOI:10.1159/000457924)

56	Anterior Skull Base Surgery in the 21st Century: The Role of Open Approaches Abu-Ghanem S. · Shilo S. · Yehuda M. · Abergel A. · Safadi A. · Fliss D.M. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 56–67 (DOI:10.1159/000457925)

68	Update of Radiation Techniques Using Photons for Anterior Skull Base Tumors Foster C.C. · Kim J.K. · Melotek J.M. · Lee N.Y. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 68–77 (DOI:10.1159/000457926)

78	The Evolving Role of Systemic Therapy in the Primary Treatment of Sinonasal Cancer Licitra L. · Resteghini C. · Bossi P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 78–86 (DOI:10.1159/000457927)

87	Particle Therapy: Protons and Heavy Ions Jensen A.D. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 87–105 (DOI:10.1159/000457929)

106	Benign Tumors of the Anterior Cranial Base Snyderman C.H. · Lavigne P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 106–113 (DOI:10.1159/000457930)

114	Endoscopic Endonasal Approaches for Anterior Skull Base Meningiomas Todeschini A.B. · Beer-Furlan A. · Otto B. · Prevedello D.M. · Carrau R.L. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 114–123 (DOI:10.1159/000457931)

124	Squamous Cell Carcinoma and Its Variants Mani N. · Shah J.P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 124–136 (DOI:10.1159/000457932)

137	A Comprehensive Update on Intestinal- and Non-Intestinal-Type Adenocarcinomas Vander Poorten V. · Jorissen M. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 137–153 (DOI:10.1159/000457934)

154	Olfactory Neuroblastoma Veyrat M. · Vérillaud B. · Fiaux-Camous D. · Froelich S. · Bresson D. · Nicolai P. · Herman P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 154–167 (DOI:10.1159/000457935)

168	Neuroendocrine Carcinoma and Sinonasal Undifferentiated Carcinoma Abdelmeguid A.S. · Bell D. · Hanna E.Y. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 168–184 (DOI:10.1159/000457936)

185	Sinonasal Malignant Melanoma Lund V.J. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 185–196 (DOI:10.1159/000457937)

197	Adenoid Cystic Carcinoma Castelnuovo P. · Turri-Zanoni M. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 197–209 (DOI:10.1159/000457939)

210	Other Rare Sinonasal Malignant Tumours Involving the Anterior Skull Base Naga R. · Pai P.S. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 210–217 (DOI:10.1159/000457940)

218	Posttreatment Imaging Surveillance Farina D. · Zorza I. · Golemi S. · Lombardi D. · Borghesi A. · Maroldi R. · Ravanelli M. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 218–230 (DOI:10.1159/000457941)

231	Treatment Options for Recurrent Anterior Skull Base Tumors Orlandi E. · Iacovelli N.A. · Ingargiola R. · Resteghini C. · Bossi P. · Licitra L. · Ferrari M. · Nicolai P. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 231–245 (DOI:10.1159/000457942)

246	Future Perspectives in the Management of Tumors of the Anterior Skull Base Nicolai P. · Bradley P.J. · Bossi P. · Ferrari M. Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 246–250 (DOI:10.1159/000457943)

251	Author Index Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 251 (DOI:10.1159/000505415) Free Access

252	Subject Index Nicolai P, Bradley PJ (eds): Anterior Skull Base Tumors. Adv Otorhinolaryngol. Basel, Karger, 2020, vol 84, pp 252–256 (DOI:10.1159/000505416) Free Access