Case Studies in the Skull Base Amy C Tsai, MD Neuroradiology Fellow Department of Radiology and Imaging Sciences University of Utah Health Sciences Center Salt Lake City, Utah, USA No disclosures related to this presentation Living Room Trail DDx Based on Anatomy Anterior Skull Base Common: Meningioma Sinonasal Mucocele Fibrous Dysplasia Sinonasal Osteoma Metastasis DDx Based on Anatomy Anterior Skull Base Less common: Squamous Cell Ca NHL SNUC Melanoma Nerve Sheath Tumor Esthesioneuroblastoma DDx Based on Anatomy Anterior Skull Base Rare: Cephalocele Hemangiopericytoma Nasal Dermal Sinus DDx Based on Anatomy Central Skull Base Common: Fibrous Dysplasia Meningioma Multiple Myeloma Metastasis NHL Pituitary Adenoma Arachnoid Granulation 1
DDx Based on Anatomy Central Skull Base Less common: Chordoma Chondrosarcoma Paget Disease DDx Based on Anatomy Central Skull Base Rare: Cephalocele Ecchordosis Physaliphora Aneurysm Langerhans Histiocytosis Fossa navicularis DDx Based on Anatomy Posterior Skull Base Common: Meningioma Metastasis Jugular Foramen Mass Paraganglioma Schwannoma Meningioma Arachnoid Granulation DDx Based on Anatomy Posterior Skull Base Less common: Dural Sinus Thrombosis Chordoma Dural A-V Fistula DDx Based on Anatomy Posterior Skull Base Rare: Chondrosarcoma Plasmacytoma Giant Cell Tumor Case 1 Antelope Island 2
Case 1 Sagittal T1 Sagittal T1 Post FS Case 1 DDx Ossifying Fibroma Benign Fatty Skull Base Lesion Osteosarcoma Skull Base Metastasis Fibrous Dysplasia Paget Disease Case 1 DDx: Paget Disease Case 1 DDx: Fibrous dysplasia Coronal CTA Coronal CT Case 1 DDx: Fibrous dysplasia Case 1 DDx: Metastatic atypical pleomorphic adenocarcinoma of right submandibular gland Coronal T2 Axial T1 Post Axial T1 Pre Axial T1 Post 3
Case 1 DDx: Intraosseous Meningioma Case 1 Diagnosis Benign Fatty Skull Base Lesion Well-corticated, fat containing, intrinsic skull base lesion Axial T1 Post FS Arrested pneumatization Osseous septations and/or coarse trabeculation Hyperintense areas on pre T1 imaging which saturate on fat sat sequences, variable enhancement Incidental, leave me alone lesion Case 1 Diagnosis Benign Fatty Skull Base Lesion Well-corticated, fat containing, intrinsic skull base lesion Arrested pneumatization Osseous septations and/or coarse trabeculation Hyperintense areas on pre T1 imaging which saturate on fat sat sequences, variable enhancement Incidental, leave me alone lesion Case 1 Diagnosis Benign Fatty Skull Base Lesion Well-corticated, fat containing, intrinsic skull base lesion Arrested pneumatization Osseous septations and/or coarse trabeculation Hyperintense areas on pre T1 imaging which saturate on fat sat sequences, variable enhancement Incidental, leave me alone lesion Case 1 Diagnosis Benign Fatty Skull Base Lesion Well-corticated, fat containing, intrinsic skull base lesion Arrested pneumatization Osseous septations and/or coarse trabeculation Hyperintense areas on pre T1 imaging which saturate on fat sat sequences, variable enhancement Incidental, leave me alone lesion Case 1 Diagnosis Benign Fatty Skull Base Lesion Well-corticated, fat containing, intrinsic skull base lesion Arrested pneumatization Osseous septations and/or coarse trabeculation Hyperintense areas on pre T1 imaging which saturate on fat sat sequences, variable enhancement Incidental, leave me alone lesion 4
Case 1 Diagnosis Benign Fatty Skull Base Lesion Well-corticated, fat containing, intrinsic skull base lesion Arrested pneumatization Osseous septations and/or coarse trabeculation Hyperintense areas on pre T1 imaging which saturate on fat sat sequences, variable enhancement Incidental, leave me alone lesion Uintas at Ruth Lake Coronal CT Coronal STIR Coronal T1 Post FS Axial T1 Post FS DDx: Anterior Skull Base Lesions With Bone Destruction Sinonasal Squamous Cell Carcinoma Esthesioneuroblastoma Fungal Sinusitis Sarcoidosis Osteosarcoma Non-Hodgkin Lymphoma Sinonasal Melanoma Langerhans Histiocytosis Skull Base Metastasis Meningioma Sinonasal Undifferentiated Carcinoma DDx: Melanoma DDx: Melanoma Coronal CT Coronal T1 Post FS 5
DDx: Melanoma (companion case) DDx: Invasive Fungal Sinusitis Axial CT Axial T1 Axial T1 Post FS Coronal CT Coronal T2 Coronal T1 Post FS Coronal T1 Coronal T1 Post FS Coronal STIR DDx: Sinonasal Atypical Neuroendocrine or SCC DDx: JNA Coronal T2 Coronal T1 Post FS Axial T1 Pre Coronal T1 Pre Coronal T1 Post FS DDx: Meningioma Diagnosis Esthesioneuroblastoma Malignant neuroectodermal tumor arising from olfactory mucosa in superior nasal cavity Bimodal distribution, 2 nd and 6 th decades Peripheral tumor cysts at intracranial tumor-brain margin is highly suggestive Sagittal T1 Pre Sagittal CT bone Coronal T1 Post Dumbbell-shaped mass with waist at the cribriform plate Coronal T1 Post 6
Diagnosis Diagnosis Esthesioneuroblastoma Esthesioneuroblastoma Malignant neuroectodermal tumor arising from olfactory mucosa in superior nasal cavity Malignant neuroectodermal tumor arising from olfactory mucosa in superior nasal cavity Bimodal distribution, 2 nd and 6 th decades Bimodal distribution, 2 nd and 6 th decades Peripheral tumor cysts at intracranial tumor-brain margin is highly suggestive Peripheral tumor cysts at intracranial tumor-brain margin is highly suggestive Dumbbell-shaped mass with waist at the cribriform plate Coronal T1 Post Dumbbell-shaped mass with waist at the cribriform plate Coronal T1 Post Diagnosis Diagnosis Esthesioneuroblastoma Esthesioneuroblastoma Malignant neuroectodermal tumor arising from olfactory mucosa in superior nasal cavity Malignant neuroectodermal tumor arising from olfactory mucosa in superior nasal cavity Bimodal distribution, 2 nd and 6 th decades Bimodal distribution, 2 nd and 6 th decades Peripheral tumor cysts at intracranial tumor-brain margin is highly suggestive Peripheral tumor cysts at intracranial tumor-brain margin is highly suggestive Dumbbell-shaped mass with waist at the cribriform plate Coronal STIR Dumbbell-shaped mass with waist at the cribriform plate Coronal T1 Post Sag T1 Sag T1 Post Antelope Island 7
DDx: Intrinsic Central Skull Base Lesion Chordoma Chondrosarcoma Myeloma Ecchordosis Physaliphora Fossa Navicularis Magna Lymphoma Skull base metastatic disease DDx: Ecchordosis Physaliphora DDx: Ecchordosis Physaliphora Sagittal T2 Axial T1 Post FS DDx: Chondrosarcoma DDx: Lymphoma Coronal T1 Post Axial T1 Post 8
DDx: Lymphoma DDx: Multiple Myeloma Axial DWI Axial ADC /PET DDx: Multiple Myeloma DDx: Fossa Navicularis Axial T1 Pre Axial T1 Post FS Sag CT Diagnosis Chordoma Sphenoccipital synchondrosis, can occur anywhere along primitive notochord Most common in 30-50 years, M=F Destructive, expansile, midline, T2 hyperintense Tumor thumbs the pons Diagnosis Chordoma Sphenoccipital synchondrosis, can occur anywhere along primitive notochord Most common in 30-50 years, M=F Destructive, expansile, midline, T2 hyperintense Tumor thumbs the pons 9
Diagnosis Chordoma Sphenoccipital synchondrosis, can occur anywhere along primitive notochord Most common in 30-50 years, M=F Destructive, expansile, midline, T2 hyperintense Tumor thumbs the pons Diagnosis Chordoma Sphenoccipital synchondrosis, can occur anywhere along primitive notochord Most common in 30-50 years, M=F Destructive, expansile, midline, T2 hyperintense Tumor thumbs the pons Diagnosis Case 4 Chordoma Sphenoccipital synchondrosis, can occur anywhere along primitive notochord Most common in 30-50 years, M=F Destructive, expansile, midline, T2 hyperintense Tumor thumbs the pons Salt Lake City courtesy of Eric Ward Case 4 Case 4 DDx: Invasive Central Skull Base Lesion Axial T1 Axial T1 Post FS FS Sag T1 Post Nasopharyngeal Carcinoma (Posterior Spread) Invasive Pituitary Macroadenoma (Inferior Spread) Meningioma Perineural Tumor Spread Osteomyelitis Chondrosarcoma (arises off midline) Osteosarcoma 10
Case 4 DDx: Invasive Pituitary Macroadenoma Case 4 DDx: Meningioma Sagittal T1 Coronal T1 Coronal T1 Post FS Axial T1 Post FS Case 4 DDx: Perineural spread of malignancy Case 4 DDx: Chondrosarcoma Sag T1 Pre Axial T1 Pre Axial T1 Post FS Case 4 Diagnosis Nasopharyngeal Carcinoma with posterior invasion Mucosal tumor arising in the lateral pharyngeal recess (Fossa of Rosenmüller) Divided into keratinizing and nonkeratinizing NPC, nonkeratinizing is strongly associated with EBV infection Peak incidence 40-60 years, males>females Case 4 Diagnosis Nasopharyngeal Carcinoma with posterior invasion Mucosal tumor arising in the lateral pharyngeal recess (Fossa of Rosenmüller) Divided into keratinizing and nonkeratinizing NPC, nonkeratinizing is strongly associated with EBV infection Peak incidence 40-60 years, males>females Parapharyngeal fat invasion (T2), skull base invasion (T3), perineural tumor spread (T4) FS Parapharyngeal fat invasion (T2), skull base invasion (T3), perineural tumor spread (T4) FS 11
Case 4 Diagnosis Nasopharyngeal Carcinoma with posterior invasion Mucosal tumor arising in the lateral pharyngeal recess (Fossa of Rosenmüller) Divided into keratinizing and nonkeratinizing NPC, nonkeratinizing is strongly associated with EBV infection Peak incidence 40-60 years, males>females Case 4 Diagnosis Nasopharyngeal Carcinoma with posterior invasion Mucosal tumor arising in the lateral pharyngeal recess (Fossa of Rosenmüller) Divided into keratinizing and nonkeratinizing NPC, nonkeratinizing is strongly associated with EBV infection Peak incidence 40-60 years, males>females Parapharyngeal fat invasion (T2), skull base invasion (T3), perineural tumor spread (T4) FS Parapharyngeal fat invasion (T2), skull base invasion (T3), perineural tumor spread (T4) FS Case 4 Diagnosis Case 4 Nasopharyngeal Carcinoma with posterior invasion Mucosal tumor arising in the lateral pharyngeal recess (Fossa of Rosenmüller) Divided into keratinizing and nonkeratinizing NPC, nonkeratinizing is strongly associated with EBV infection Peak incidence 40-60 years, males>females Parapharyngeal fat invasion (T2), skull base invasion (T3), perineural tumor spread (T4) FS Nasopharyngeal Carcinoma with posterior invasion Imaging Pearls: Does this arise from the pituitary? Look for contiguous soft tissue into the sella Case 5 Case 5 Coronal T2 Coronal T1 Pre Coronal T1 Post FS Angels Landing Hike at Zion National Park 12
Case 5 Case 5 DDx: Jugular Foramen Lesions Schwannoma Meningioma Paraganglioma Pseudolesion Dehiscent Jugular Bulb Jugular bulb diverticulum bone Coronal CT bone Case 5 DDx: Paraganglioma / Glomus jugulare Case 5 DDx: Paraganglioma / Glomus jugulare Axial T1 Pre Axial T1 Post Post Conventional Angio Lateral projection Case 5 Case 5 DDx: Meningioma DDx: Meningioma Post Axial T1 Post FS Sagittal CT Post Coronal T1 Post FS 13
Case 5 Case 5 DDx: Dehiscent jugular bulb DDx: Jugular bulb diverticulum Coronal CT Coronal 3D Post Coronal CT Case 5 Diagnosis Case 5 Diagnosis Jugular Foramen Schwannoma Benign tumor of differentiated Schwann cells wrapping around cranial nerves IX, X, XI Jugular Foramen Schwannoma Benign tumor of differentiated Schwann cells wrapping around cranial nerves IX, X, XI May present clinically like a vestibular schwannoma (hearing loss) May present clinically like a vestibular schwannoma (hearing loss) Smooth expansile osseous remodeling, superomedial vector of spread Smooth expansile osseous remodeling, superomedial vector of spread Main vascular supply = ascending pharyngeal Main vascular supply = ascending pharyngeal Bone CT and contrast enhanced study to distinguish between other JF lesions Bone CT and contrast enhanced study to distinguish between other JF lesions Case 5 Diagnosis Case 5 Diagnosis Jugular Foramen Schwannoma Benign tumor of differentiated Schwann cells wrapping around cranial nerves IX, X, XI Jugular Foramen Schwannoma Benign tumor of differentiated Schwann cells wrapping around cranial nerves IX, X, XI May present clinically like a vestibular schwannoma (hearing loss) May present clinically like a vestibular schwannoma (hearing loss) Smooth expansile osseous remodeling, superomedial vector of spread Smooth expansile osseous remodeling, superomedial vector of spread Main vascular supply = ascending pharyngeal Main vascular supply = ascending pharyngeal Bone CT and contrast enhanced study to distinguish between other JF lesions Bone CT and contrast enhanced study to distinguish between other JF lesions 14
Case 5 Diagnosis Jugular Foramen Schwannoma Benign tumor of differentiated Schwann cells wrapping around cranial nerves IX, X, XI May present clinically like a vestibular schwannoma (hearing loss) Smooth expansile osseous remodeling, superomedial vector of spread Main vascular supply = ascending pharyngeal Bone CT and contrast enhanced study to distinguish between other JF lesions Case 5 Diagnosis Jugular Foramen Schwannoma Benign tumor of differentiated Schwann cells wrapping around cranial nerves IX, X, XI May present clinically like a vestibular schwannoma (hearing loss) Smooth expansile osseous remodeling, superomedial vector of spread Main vascular supply = ascending pharyngeal Bone CT and contrast enhanced study to distinguish between other JF lesions Summary Often a long DDx for skull base lesions Much of the pathology overlaps regions Intrinsic vs. Invasive lesions Location, location, location where lesion is centered MRI and CT complement each other Enhanced MRI: Soft tissue characteriztion Non-enhanced CT: Bony margin delineation Summary Often a long DDx for skull base lesions Much of the pathology overlaps regions Intrinsic vs. Invasive lesions Location, location, location where lesion is centered MRI and CT complement each other Enhanced MRI: Soft tissue characteriztion Non-enhanced CT: Bony margin delineation Summary Often a long DDx for skull base lesions Much of the pathology overlaps regions Intrinsic vs. Invasive lesions Location, location, location where lesion is centered MRI and CT complement each other Enhanced MRI: Soft tissue characteriztion Non-enhanced CT: Bony margin delineation Summary Often a long DDx for skull base lesions Much of the pathology overlaps regions Intrinsic vs. Invasive lesions Location, location, location where lesion is centered MRI and CT complement each other Enhanced MRI: Soft tissue characteriztion Non-enhanced CT: Bony margin delineation 15
Summary Often a long DDx for skull base lesions Much of the pathology overlaps regions Intrinsic vs. Invasive lesions Location, location, location where lesion is centered MRI and CT complement each other Enhanced MRI: Soft tissue characteriztion Non-enhanced CT: Bony margin delineation THANK YOU 16