Pathology of Regions Adjacent to Paranasal Sinuses (Anterior skull base/ Middle skull base)

Back To Search

Pathology of Regions Adjacent to Paranasal Sinuses (Anterior skull base/ Middle skull base)

Rhinology
Author Credentials 

Mark Mims, MD

Eric Wang, MD

Associate Professors
Department of Otolaryngology
University of Pittsburgh Medical Center
Pittsburgh, PA

Module Summary

Tumors of the anterior and middle skull base represent a heterogeneous collection of neoplasms and lesions, the most common of these involving the pituitary. Surgery is often the mainstay of treatment with current trends favoring endoscopic, endonasal approaches when possible.

Module Learning Objectives 
  1. Describe the various pathologies affecting the anterior and middle skull base.
  2. Recognize the anatomical landmarks in the sphenoid sinus and anterior skull base.
  3. Explain endoscopic endonasal approaches to the anterior and middle skull base.
  4. Recognize complications associated with endoscopic, endonasal surgical approaches.
  5. Summarize the management of complications after skull base surgery.
  6. Discuss the role of medical and adjuvant therapies in skull base neoplasms.

Embryology

Learning Objectives 
  1. Be familiar with embryologic structures that develop into the skull base.
    1. Parachordal cartilage
    2. Otic capsule
    3. Hypophyseal cartilage
    4. Prechordal cartilages
    5. Trabeculi cranii
    6. Nasal capsule
  2. Differentiate areas of the skull that undergo specific types of ossification
    1. Intramembranous
    2. Endochondrial
References 
  1. Gruber DP, Brockmeyer D. Pediatric skull base surgery. 1. Embryology and developmental anatomy. Pediatr Neurosurg. 2003;38(1):2-8.

Anatomy

Learning Objectives 
  1. Be familiar with the anatomy of the sphenoid bone from multiple perspectives
    1. Sella
    2. Optic Nerve
    3. Internal Carotid Artery
      1. Paraclinoidal
      2. Cavernous
      3. Paraclival
      4. Foramen lacerum
    4. Lateral Opticocarotid Recess
    5. Clival Recess
    6. Planum sphenoidale
    7. Orbital Apex
  2. Recognize the three types of sphenoid sinus pneumatization
    1. Conchal
    2. Presellar
    3. Sellar
  3. Understand the anatomy of the pituitary gland and its substructures
    1. Adenohypophysis (Anterior Pituitary Gland)
      1. Vascularity from superior hypophyseal arteries
    2. Neurohypophysis (Posterior Pituitary Gland and Pituitary Stalk)
      1. Vascularity from inferior hypophyseal arteries
  4. Describe the anatomy and structures contained within the cavernous sinus
    1. Bordered by five walls of dura
    2. Cavernous internal carotid artery
      1. Three segments, two genua (Proximal to Distal)
        • Posterior vertical segment,
        • posterior genu,
        • horizontal segment,
        • anterior genu,
        • anterior vertical (paraclinoidal) segment
      2. Two main branches
        • Meningohypophyseal trunk
        • Inferolateral trunk (artery of the inferior cavernous sinus)
    3. Nerves traversing the cavernous sinus
      1. Oculomotor (CN IIII)
      2. Trochlear (CN IV)
      3. Abducens (CN VI)
      4. Trigeminal – ophthalmic branch (CN V1)
      5. Sympathetic plexus
    4. Venous compartments divided by internal carotid artery
      1. Superior, inferior, posterior, lateral
  5. Describe the suprasellar space
    1. Infrachiasmatic, suprachiasmatic, and retrochiasmatic areas
  6. Understand the anatomy of the clivus
    1. Upper third – sellar clivus
    2. Middle third – sphenoidal clivus
    3. Lower third – nasopharyngeal clivus
  7. Understand the anatomy of the cribiform and ethmoid roof
    1. Anterior and Posterior ethmoid arteries
    2. Crista galli
    3. Lateral lamella and Keros classification
    4. Slope of the skull base anterior to posterior; lateral to medial
References 
  1. Fernandez-Miranda JC, Gardner PA, Rastelli MM Jr., et al. Endoscopic endonasal transcavernous posterior clinoidectomy with interdural pituitary transposition. J Neurosurg. 2014;121(1):91-99.
  2. Patel CR, Fernandez-Miranda JC, Wang WH, Wang EW. Skull base anatomy. Otolaryngol Clin North Am. 2016;49(1):9-20.
  3. Pinheiro-Neto CD, Fernandez-Miranda JC, Wang EW, et al. Anatomical correlates of endonasal surgery for sinonasal malignancies. Clin Anat. 2012;25(1):129-34.

Pathogenesis

Learning Objectives 
  1. Understand visual disturbance is the most common presentation of central skull base tumors
    1. Bitemporal hemianopsia
    2. Abducens and Oculomotor cranial neuropathies from cavernous sinus
  2. Headaches
    1. Classic retro-orbital pain for sellar pathology
  3. Anosmia from tumors of the olfactory cleft.
  4. Common sinonasal complaints such as nasal congestion, drainage, and facial pressure are common in sinonasal malignancies secondary to mass effect and obstruction.
References 
  1. Bresson D, Herman P, Polivka M, Froelich S. Sellar lesions/pathology. Otolaryngol Clin North Am. 2016;49(1):63-93.
  2. Folbe A, Herzallah I, Duvvuri U, et al. Endoscopic endonasal resection of esthesioneuroblastoma: a multicenter study. Am J Rhinol Allergy. 2009;23(1):91-94.

Basic Science

Learning Objectives 
  1. Understand the role of BRAF mutations in papillary craniopharyngiomas.
References 
  1. Brastianos PK, Taylor-Weiner A, Manley PE, et al. Exome sequencing identifies BRAF mutations in papillary craniopharyngiomas. Nat Genet. 2014;46(2):161-165.

Incidence

Learning Objectives 
  1. Recognize the incidence of skull base tumors
    1. Pituitary adenomas: 8.0 per 100,000
    2. Skull Base Meningiomas: 6.0 per 100,000
    3. Clival Chordomas: 0.08 per 100,000
References 
  1. Di Maio S, Ramanathan D, Garcia-Lopez R, et al. Evolution and future skull base surgery: The paradigm of skull base meningiomas. World Neurogsurg. 2012;78(3-4):220-221.
  2. Ezzat S, Asa SL, Couldwell WT, et al. The prevalence of pituitary adenomas: A systematic review. Cancer. 2004;101(3):613-619
  3. Fernandez-Miranda JC, Gardner PA, Snyderman CH, et al. Clival chordomas: A pathological, surgical, and radiotherapeutic review. Head Neck. 2014;36(6):892-906.

Genetics

Learning Objectives 
  1. Recognize hereditary causes of pituitary tumors
    1. MEN1, FIPA
  2. Recognize genetic mutations involved in familial syndromes with pituitary adenomas
    1. MEN1, AIP, PRKAR1A, CDKN1B, SDHD, RET
  3. Understand the mechanism of the most common genetic mutations
    1. MEN1, AIP
References 
  1. Lecoq AL, Kamenicky P, Guiochon-Mantel A, Chanson P. Genetic mutations in sporadic pituitary adenomas – what to screen for? Nat Rev Endocrinol. 2015;11(1):43-54.

Patient Evaluation

Learning Objectives 

​

Understand the various diagnostic tools available to guide clinical decision making with regards to the various types of tumors

  1. Laboratory
  2. Radiologic
    1. CT with contrast for intracranial vasculature
    2. MR for soft tissue characterization
  3. Physical exam
    1. Cranial Neuropathies
    2. Extraocular motion
  4. Nasal endoscopy
References 
  1. Bresson D, Herman P, Polivka M, Froelich S. Sellar lesions/pathology. Otolaryngol Clin North Am. 2016;49(1):63-93.
  2. Hong GK, Payne SC, Jane JA Jr. Anatomy, physiology, and laboratory evaluation of the pituitary gland. Otolaryngol Clin North Am. 2016;49(1):21-32.

Measurement of Functional Status

Learning Objectives 
  1. Understand how skull base pathology affects patient’s quality of life
  2. Recognize various tools available to assess quality of life in skull base patients
    1. Anterior skull base tumors
      1. Skull Base Inventory (SBI)
      2. Previous Skull Base-Quality of Life (ASB-QOL)
    2. Secreting pituitary tumors: Numerous quality of life measures depending principally on the endocrinopathy
      1. Acromegaly Quality of Life (AcroQOL)
      2. Hypopituitarism Quality of Life Satisfaction (QLS-H)
      3. Pituitary Adenoma
      4. Addison Quality of Life (AddiQOL)
      5. Quality of Life-Assessment of Growth Hormone Deficiency in Adults (QOL-AGHDA)
      6. Hormone Deficiency-Dependent Quality of Life (HDQOL)
      7. Cushing QOL
  3. Be familiar with the expected changes in nasal anatomy/function as well as patient issues associated with a nasoseptal flap reconstruction
    1. Nasal obstruction
    2. Crusting
      1. Average duration of crusting: 126 days
      2. Nasoseptal flap may add to crusting at harvest site
References 
  1. De Almeida JR, Vescan AD, Gullane PJ, et al. Development of a disease-specific quality-of-life questionnaire for anterior and central skull base pathology – the skull base inventory. Laryngoscope. 2012;122(9):1933-1942.
  2. De Almeida JR, Witterick IJ, Gullane PJ, et al. Quality of life instruments for skull base pathology: systematic review and methodologic appraisal. Head Neck. 2013;35(9):1221-1231.
  3. Hanson M, Patel PM, Betz C, et al. Sinonasal outcomes following endoscopic anterior skull base surgery with nasoseptal flap reconstruction: a prospective study. J Laryngol Otol. 2015;129:S41-46.
  4. Pant H, Bhatki AM, Snyderman CH, et al. Quality of life following endonasal skull base surgery. Skull Base. 2010;20(1):35-40.

Imaging

Learning Objectives 
  1. Appropriate imaging is critical in the evaluation of the skull base pathology
  2. Recognize the complimentary nature of imaging modalities
    1. High resolution, contrast enhanced CT
      1. Bony architecture
      2. Tumor vascularity
      3. Intracranial vasculature
    2. MRI
      1. Soft tissue definition
      2. Cystic T2 hyperintensity for Rathke’s cleft cyst, craniopharyngioma
      3. T2 hyperintensity for chordoma
  3. Understand the changes that occur on imaging in the postoperative period
    1. Early postoperative period
    2. Late postoperative period
    3. Complications
References 
  1. Nunes RH, Abello AL, Zanation AM, Sasaki-Adams D, Huang BY. Imaging in endoscopic cranial skull base and pituitary surgery. Otolaryngol Clin North Am. 2016;49(1):33-62.

Pathology

Learning Objectives 
  1. Differentiate amongst various types of skull base pathology
    1. Neoplastic
      1. Pituitary
        • Benign
          1. Pituitary adenoma (secreting)
          2. Pituitary macroadenoma
        • Low grade malignancy
          1. Pituicytoma
        • Malignant
          1. Pituitary carcinoma
    2. Non-pituitary
      1. Usually benign
        • Craniopharyngioma
        • Meningioma
        • Schwannoma
        • Lipoma
        • Hemangioblastoma
      2. Low grade malignancy
        • Chordoma
        • Chondrosarcoma
        • Plasmacytoma
        • Langerhan’s histiocytosis
      3. Malignant
        • Sinonasal malignancies
          1. Esthesioneuroblastoma
          2. Squamous cell carcinoma
          3. SNUC (Sinonasal Undifferentiated Carcinoma)
          4. Neuroendocrine carcinoma
          5. Adenocarcinoma
          6. Adenoid Cystic Carcinoma
          7. Hemangiopericytoma
        • Germ cell tumor
        • Lymphoma
        • Metastasis
        • Perineural malignant spread
  2. Non-neoplastic
    1. Developmental lesions
      1. Rathke’s cleft cyst
      2. Epidermoid cyst
      3. Dermoid cyst
      4. Arachnoid cyst
      5. Ecchordosis physaliphora
    2. Infectious
      1. Abscess
      2. Skull base osteomyelitis
    3. Inflammatory
      1. Sarcoidosis
      2. Wegner’s granulomatosis
    4. Vascular lesions
      1. Aneurysms
      2. Carotid-cavernous fistula
      3. Cavernous sinus thrombosis
References 
  1. Bresson D, Herman P, Polivka M, Froelich S. Sellar lesions/pathology. Otolaryngol Clin North Am. 2016;49(1):63-93.
  2. Tsai EC, Santoreneos S, Rutka JT. Tumors of the skull base in children: review of tumor types and management strategies. Neurosurg Focus. 2002;12(5):e1.

Treatment

Learning Objectives 
  1. Be familiar with surgical procedures for the management of skull base tumors
    1. Endoscopic endonasal approach (EEA)
      1. Transellar approach
      2. Tuberculum/ Transplanum approach
      3. Transcribiform approach
      4. Transclival approach
        • Upper transclival
        • Middle transclival
        • Lower transclival
      5. Transpterygoid approach
        • Cavernous sinus
        • Meckel’s cave
      6. Orbital approach
  2. Be familiar with indications for radiation therapy, including stereotactic radiosurgery (Gamma Knife)
    1. Meningiomas
    2. Pituitary adenomas
    3. Clival chordoma
      1. IMRT vs. proton beam RT
    4. Sinonasal maligancies
  3. Recognize the incidence of skull base metastases and its management
    1. Chemotherapy
    2. Radiation therapy
      1. Stereotactic radiosurgery
    3. Surgery
References 
  1. Platta CS, Mackay C, Welsh JS. Pituitary adenoma: a radiotherapeutic perspective. Am J Clin Oncol. 2010;33(4):408-419.
  2. Chamoun RB, DeMonte F. Management of skull base metastases. Neurosurg Clin N Am. 2011;22(1):61-66.
  3. Martin JJ, Niranjan A, Kondziolka D, et al. Radiosurgery for chordomas and chondrosarcomas of the skull base. J Neurosurg. 2007;107(4):758-764.
  4. Starke RM, Przybylowski CJ, Sugoto M, et al. Gamma Knife radiosurgery of large skull base meningiomas. J Neurosurg. 2015;122(2):363-372.
  5. Zwagerman NT, Zenonos G, Lieber S, et al. Endoscopic transnasal skull base surgery: pushing the boundaries. J Neurooncol. 2016;130(2):319-330.

Medical Therapies

Learning Objectives 
  1. Understand the role of medical therapies in skull base tumors
    1. Prolactinoma
      1. Dopamine agonist
  2. Be familiar with the management of hypopituitarism
    1. Growth hormone deficiency
      1. Pediatric versus adult
    2. ACTH deficiency
      1. Hydrocortisone
    3. TSH deficiency
      1. L-thyroxine
    4. Gonadotropin deficiency
      1. Male versus female
    5. Diabetes insipidus
      1. Desmopressin
References 
  1. Higham CE, Johannsson G, Shalet SM. Hypopituitarism. Lancet. 2016;388(10058):2403-2415.
  2. Platta CS, Mackay C, Welsh JS. Pituitary adenoma: a radiotherapeutic perspective. Am J Clin Oncol. 2010;33(4):408-419.

Pharmacology

Learning Objectives 
  1. Understand the presentation, and management, of post-operative endocrinopathies
References 
  1. Ausiello JC, Bruce JN, Freda PU. Postoperative assessment of the patient after transsphenoidal pituitary surgery. Pituitary. 2008;11(4):391-401.

Surgical Therapies

Learning Objectives 
  1. Be familiar with patient positioning pre-operatively
    1. Mayfield head holders
    2. Nasal decongestion
  2. Recognize the benefits of binarial access
    1. Role of posterior septectomy
  3. Review endoscopic approach to the pituitary and sella
    1. Sphenoidotomy
      1. Selective removal of sinus mucosa
      2. Resection of intrasinus septations
        • Intrasinus Septations frequently lead to the ICA
    2. Identification of Key landmarks
      1. Sella tursica
      2. Lateral and Medial OCR,
      3. Paraclinoidal internal carotid artery,
      4. Paraclival ICA
      5. Optic canal
      6. Tuberculum sella
    3. Intrasellar dissection
      1. Anterior and Posterior Pituitary gland
    4. Cavernous sinus extension
      1. Inferior hypophyseal artery
  4. Review expanded approaches
    1. Transtuberculum
    2. Transplanum
    3. Transcribiform
  5. Understand approaches to the paramedian skull base and middle fossa
    1. Transorbital
    2. Transpterygoid
    3. Meckel’s cave
  6. Understand the options for vascularized reconstructive flaps for the skull base
    1. Vascular pedicled nasoseptal flap
    2. Rescue flap: Preservation of the pedicle to the nasoseptal flap
    3. Endoscopic-assisted extracranial pericranial flap
    4. Temporoparietal fascia flap
    5. Inferior turbinate flap/ Lateral nasal wall flap
    6. Nasal floor flap
    7. Middle turbinate flap
    8. Palatal flap
    9. Occipital flap
References 
  1. De Lara D, Ditzel Filho LF, Prevedello DM, et al. Endonasal endoscopic approaches to the paramedian skull base. World Neurosurg. 2014;82(6):S121-129.
  2. Hadad G, Bassagasteguy L, Carrau RL, et al. A novel reconstructive technique after endoscopic expanded endonasal approaches: vascular pedicle nasoseptal flap. Laryngoscope. 2006;116(10):1882-1886.
  3. Kassam AB, Prevedello DM, Carrau RL, et al. The front door to Meckel’s cave: An anteromedial corridor via expanded endoscopic endonasal approach – Technical considerations and clinical series. Neurosurgery. 2009;64(3 Suppl):ons71-ons82
  4. Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL. Ex­panded endonasal approach: the rostrocaudal axis. Part I. Crista galli to the sella turcica. Neurosurg Focus. 2005;19: E3
  5. Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL. Ex­panded endonasal approach: the rostrocaudal axis. Part II. Posteri­or clinoids to the foramen magnum. Neurosurg Focus. 2005;19: E4
  6. Kassam AB, Gardner P, Snyderman C, Mintz A, Carrau R. Ex­panded endonasal approach: fully endoscopic, completely trans­nasal approach to the middle third of the clivus, petrous bone, middle cranial fossa, and infratemporal fossa. Neurosurg Focus. 2005 Jul 15;19(1):E6.
  7. Patel MR, Taylor RJ, Hackman TG, et al. Beyond the nasoseptal flap: outcomes and pearls with secondary flaps in endoscopic endonasal skull base reconstruction. Laryngoscope. 2014;124(4):846-852.
  8. Daraei P, Oyesiku NM, Patel ZM. The nasal floor pedicled flap: a novel technique in skull base reconstruction. Int Forum Allergy Rhinol. 2014 Nov;4(11):937-43.
  9. Zanation AM, Snyderman CH, Carrau RL, et al. Minimally invasive endoscopic pericranial flap: A new method for endonasal skull base reconstruction. Larygnoscope. 2009;119(1):13-8.
  10. http://www.american-rhinologic.org/videos (Surgical dissection videos on the ARS website, for members. ARS membership is FREE for residents.)

Rehabilitation

Learning Objectives 
  1. Understand the difference between high-flow and low-flow CSF leaks in early postoperative care
  2. Understand the role of prophylactic antibiotic regimens
    1. Incidence of infection after endoscopic skull base surgery -1.8%
    2. Presence or absence of nasal packing
  3. Be familiar with postoperative clinical follow up
    1. Debridements
References 
  1. Esposito F, Dusick JR, Fatemi N, Kelly DF. Graded repair of cranial base defects and cerebrospinal fluid leaks in transsphenoidal surgery. Neurosurgery. 2007;60(4):295-303.
  2. Kono Y, Prevedello DM, Snyderman CH, et al. One thousand endoscopic skull base surgical procedures demystifying the infection potential: incidence and description of postoperative meningitis and brain abscesses. Infect Control Hosp Epidemiol. 2011;32(1):77-83.
  3. Tien DA, Stokken JK, Recinos PF, Woodard TD, Sindwani R. Comprehensive postoperative management after endoscopic skull base surgery. Otolaryngol Clin North Am. 2016;49(1)253-263.

Staging

Learning Objectives 
  1. Understand the classifications of skull base tumors
References 
  1. Lloyd RV, Kovacs K, Young WF, Jr., Farrell WE, Asa SL, Trouillas J, et al. Tumours of the pituitary. In: DeLellis RA, Lloyd RV, Heitz PU, editors. Pathology and Genetics. Tumours of Endocrine Tumours. 1 ed. Lyon: International Agency for Research and Cancer (IARC); 2004:9–48.
  2. Louis DN, Ohgaki H, Wiestler OD, et al. The 2007 WHO Classification of Tumours of the Central Nervous System. Acta Neuropathologica. 2007;114(2):97-109. 

Case Studies

  1. A 48-year-old female presents with six months of bilateral retro-orbital headaches and a one-week history of diplopia with leftward gaze. She has no other focal neurological deficits. An MRI shows T1-hypointense, T2-hyperintense clival mass.
    1. What nerve has been compromised and why was this nerve the first involved?
    2. What further imaging should be obtained?
    3. What laboratory workup should this patient receive?
    4. How would you approach the surgical resection of this tumor?
  2. A 57-year-old male who has underwent an EEA with nasoseptal flap reconstruction for a pituitary macroadenoma one year prior presents to clinic for continuous unilateral clear, watery rhinorrhea that worsens when he bends over or Valsalvas.
    1. What laboratory test should be performed?
    2. What worrisome signs/symptoms should he be assessed for?
    3. If a specific source was identified on imaging or exam, how you manage this patient?
References 
  1. Bresson D, Herman P, Polivka M, Froelich S. Sellar lesions/pathology. Otolaryngol Clin North Am. 2016;49(1):63-93.
  2. Ivan ME, Iorqulescu JB, El-Sayed MW, et al. Risk factors for postoperative cerebrospinal fluid leak and meningitis after expanded endoscopic endonasal surgery. J Clin Neurosci. 2015;22(1)48-54.

Complications

Learning Objectives 
  1. Be familiar with potential complications that arise from approaches to, and pathology of, the skull base
    1. CSF leak
    2. Pituitary dysfunction
    3. Blood loss
    4. Neurologic complication
      1. ICH
      2. Cranial nerve deficits
    5. Epistaxis
    6. Nasal morbidity
      1. Crusting
      2. Secondary sinusitis, mucoceles
      3. Septal perforation
  2. Be familiar with complications related to the endoscopic endonasal approach to skull base tumors
    1. Malodor: 19%
    2. Incisor hypoesthesia: 11%
    3. Nasal synechiae: 9%
    4. Palatal hypoesthesia: 7%
    5. Taste disturbance: 7%
    6. Alar sill burn: 5%
    7. Maxillary nerve hypoesthesia: 2%
    8. Serous otitis media: 2%
References 
  1. Ivan ME, Iorqulescu JB, El-Sayed MW, et al. Risk factors for postoperative cerebrospinal fluid leak and meningitis after expanded endoscopic endonasal surgery. J Clin Neurosci. 2015;22(1)48-54.
  2. Kasemsiri P, Carrau RL, Ditzel Filho L, et al. Advantages and limitations of endoscopic endonasal approaches to the skull base. World Neurosurg. 82;6(S12-21).
  3. Pant H, Bhatki AM, Snyderman CH, et al. Quality of life following endonasal skull base surgery. Skull Base. 2010;20(1):35-40.
  4. Villwock JA, Villwock MR, Goyal P, Deshaies EM. Current trends in surgical approach and outcomes following pituitary tumor resection. Laryngoscope. 125(6):1307-1312.

Review

Review Questions 
  1. What are the most common neoplasms of the anterior and middle skull base?
  2. What are the anatomic relationships of the sella and the surroundings structures?
  3. What imaging modality should be used in assessing skull base lesions?
  4. Describe the various surgical approaches to the skull base.
References 
  1. Bresson D, Herman P, Polivka M, Froelich S. Sellar lesions/pathology. Otolaryngol Clin North Am. 2016;49(1):63-93.
  2. Patel CR, Fernandez-Miranda JC, Wang WH, Wang EW. Skull base anatomy. Otolaryngol Clin North Am 2016;49(1):9-20.
  3. See “Surgical Therapies” reference list
Resources 

Learner must Sign In to access AAO-HNSF education activities.

  1. Annual Meeting Webcasts (AMW)
  2. Surgical Videos: