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Structural/Congenital
Staphyloma
Outward bulging of the posterior globe on the temporal side of optic nerve
Coloboma
Congenital defect in any ocular structure
Astrocytic glial hamartomas
Can be seen in TS, NF, and vHL
Calcifications on retina
DiffDx: retinoblastoma
Ocular infection
Toxocara canis
Ocular lesions
Retinoblastoma
Calcifications in the posterior portion of the globe with extension into vitreous
Moderately bright on T1WI and dark on T2WI
Persistent hyperplastic primary vitreous
Funneled shaped mass (Cloquet canal) between back of the lens and head of optic nerve
Microphthalmia
Does not calcify
Coats disease
Telangiectatic vessels leaking serum and protein into retina and subretinal space
High density of the vitreous due to exudate
Bright on T1WI and bright on T2WI
DiffDx: retinoblastoma (dark on T2WI)
Toxocara canis
Retrolental fibroplasia => result of prolonged oxygen therapy in premature infants
Increased density of posteior portion of the globe
Melanoma
Hyperdense
Bright on T1WI, dark on T2WI
Choroidal hemangioma
Medulloepithelioma
Metastases
Choroidal osteoma
Intraconal
Optic nerve lesions
Glioma, meningioma, schwannoma, hemangioblastoma, neuritis, sarcoid
Devic disease => optic neuritis associated with transverse myelitis
Tolosa-Hunt syndrome => painful ophthalmoplegia caused by nonspecific inflammation of the cavernous sinus or superior orbital fissure.
Optic nerve glioma
Radiographically, can not be separated from the nerve
Arachnoidal granulamatosis (perineural glial proliferation) => a feature of optic gliomas in neurofibromatosis
Optic nerve sheath meningioma
Nerve may be visualized
Cavernous/capillary hemangioma
Orbital venous anomalies
Orbital varix
Lymphangioma
Carotid-cavernous fistula
Dural vascular malformation
Conal
Thyroid ophthalmopathy
Inferior and medial rectus are most commonly affected
Most common single pattern is enlargement of all muscles
Orbital pseudotumor (Tolosa-Hunt syndrome)
Sarcoidosis
Wegener’s granulomatosis
Homogenously enhancing mass with associated sinus disease and bone destruction
Kimura disease
Similar to orbital pseudotumor but with skin findings in young Asian males
Orbital lymphoma
Molds around the orbit
DiffDx: pseudotumor
Posttransplantation lymphoproliferative disorder
Can destroy bone
Extraconal lesions
Infection
Lacrimal sac lesions
Dacryocystitis
Papilloma – has malignant degeneration potential
Lacrimal gland lesions
Mikulitz syndrome => non-specific swelling of lacrimal and salivary glands associated with sarcoid, TB and leukemia.
Sjogren’s syndrome => lymphocytic infiltration of lacrimal and salivary glands associated with connective tissue disorders
Lymphoid tumors (usually does not produce bony erosion)
Epithelial tumors (generally involve bone)
Pleomorphic adenomas
Malignant adenoid cystic carcinoma
Transitional cell carcinoma
Dermoids
Orbital rhabdomyosarcoma
Lymphangioma
Fibrous histiocytoma
Metastasis
Scirrhous breast carcinoma => infiltrative retrobulbar mass with enophthalmos from desmoplastic reaction
Sphenoid wing meningioma
DiffDx: fibrosseous lesions such as ossifying fibroma, osteoma, sclerotic metastases such as prostate metastases, fibrous dysplasia
Bone lesions
Fibrous dysplasia
Paget’s
EG
Fibroosseous lesions
Osteoma
Ossifying fibroma
Osteoblastoma
Osteosarcoma
Osteoclastoma
Brown tumor of hyperparathyoidism
ABC
Giant cell reparative granuloma
Probably a reaction to intraosseous hemorrhage
May contain fluid levels
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Prenasal mass
Dermoid/epidermoid cyst
Encephalocele
Hemangioma
Glial heterotopia
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Cystic masses
Odontogenic cysts
Radicular cyst
Dentigerous cyst
Formed by excessive accumulation of fluid between enamel and dental capsule
Well corticated pericoronal radiolucency
Odontogenic keratocyst
Aggressive cystic jaw lesion
Perforation of bone cortex
Scalloped corticated border
Large size
Associated with basal nevus syndrome
Botryoid cyst => developmental lateral periodontal cyst
Non-odontogenic cyst
Solitary simple hemorrhagic bone cyst
Static bone cavity => Stafne cyst
Benign tumors
Ameloblastoma
Odontoma
Fibromyxoma
Cementoma
Malignant tumors
Odontogenic
Odontogenic carcinoma
Odontogenic sarcoma
Non-odontogenic
Osteosarcoma
Chondrosarcoma
Ewing’s sarcoma
Multiple myeloma
Metastases
Carcinoma (breast, lung, renal)
Sarcoma
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- Middle Ear
- Anatomy
- Malleus
- Manubrium
- Neck
- Anterior process
- Head
- Incus
- Body
- Long process
- Lenticular process
- Short process
- Stapes
- Head
- Neck
- Anterior crus
- Posterior crus
- Footplate
- Developmental
- Bony bars
- Oval window atresia
- Fenestral otospongiosis
- Inflammatory
- Cholesteatoma
- Acquired from perforation of tympanic membrane
- Congenital from epidermoid formation
- Tympanosclerosis
- Resorptive osteitis
- Masses
- Benign
- Hemangioma – most common benign mass in pediatric patients
- Facial nerve neuroma
- Paraganglioma – most common benign mass in adult patients
- Cholesterol granuloma
- Malignant
- Squamous cell carcinoma
- Trauma
- Fractures
- Dislocations
- Incus is most common
CPA
Schwannoma
Arachnoid cyst
Meningioma
Epidermoid
Petrous Apex
Mucocele
Cholesterol granuloma
Multiple myeloma
Metastasis
Schwannoma
Enchondroma/Chondrosarcoma
Apical petrositis
Xanthoma
- Middle Ear
Types of orbital resections
Procedure Indications Removed Not removed Evisceration Painful blind eye with no malignancy, chronic endophthalmitis Internal globe Scleral coat, optic nerve, EOM Enucleation IO malignancy, granulomatous uveitis, traumatic globe rupture Globe and sclera, portion of optic nerve Teno capsule, EOM Exenteration Agressive malignancies All orbital contents Ref: T.J. Greenwood and M.S. Parsons, Imaging Characteristics of Common Postoperative Orbital Devices, Neurographics 2016 Types of neck dissections
Radical neck dissection
LN I-V
SM gland
SCM
IJV
CN XI
Modified neck dissection
RND with preservation of one or more of:
SCM
IJV
CN XI
Selective neck dissection
Preserves SCM, IJV, CN XI
Individual LN
Supraomohyoid neck dissection
SM gland
I
II
III
Lateral neck dissection
II
III
IV