Week 4 - Cases 11-20

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Case 11: What is the most likely diagnosis?

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Wegener’s Granulomatosis of Temporal Bone

Case 11: What is the most likely diagnosis?

Wegener’s Granulomatosis is considered to be an autoimmune disease mediated by either cellular immune mechanisms or by immune complex deposition. Wegener’s granulomatosis is also characterized by necrotizing granulomatous inflammation of small vessel walls, resulting in areas of necrosis surrounded by hemorrhage, small abscesses and granulomata. The histopathologic hallmark of Wegener’s granulomatosis is the presence of both granulomas and necrotizing vasculitis. Involvement of the inner ear will result in profound loss of auditory and vestibular function. 19 to 38% of patients with Wegener’s granulomatosis have otologic involvement, possibly extension from the nasopharynx. Local granulomatosis may have similar radiologic appearance as the skull base (red arrow). Tissue opacification can be seen on CT, often accompanied by bone erosion. Wegener’s can be distinguished from other vasculitis by further criteria: oral/nasal inflammation with ulcers, purulent or bloody nasal discharge, and presence of nodules (blue arrow).

DDx: Wegener’s Granulomatosis 1.

Cholesteatoma

2.

Langerhans cell histiocytosis

3.

Metastasis

4.

Coalescent mastoiditis

5.

PTLD

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DDx


Coalescent Mastoiditis

Case 12: What is the most likely diagnosis?

Coalescent mastoiditis is the progressive resorption and demineralization of the thin intercellular septa of the mastoid cells due to osteomyelitis. Destruction of the trabeculae and development of an empyema often follows (red arrows). Presentation often includes deep facial pain along the course of the trigeminal nerve, abducens palsy and purulent ear discharge. Radiologic examination will reveal opacification of the mastoid cells with resorption of intercellular walls and thickening of perimastoid soft tissues. Fluid may also be seen within the middle ear. Coalescent mastoiditis is best detected with CT. Treatment is typically mastoidectomy as antibiotics are usually ineffective. Complications include subperiosteal abscess, epidural/subdural empyema, dural sinus thrombosis, cerebritis/ parenchymal abscess, meningitis, neck abscess, or jugular vein thrombosis.

DDx: Coalescent Mastoiditis 1.

Acute mastoiditis

2.

Chronic suppurative otitis media

3.

Cholesteatoma

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DDx


Fenestral Otosclerosis

Case 13: What is the most likely diagnosis?

The clinical findings of fenestral otosclerosis are quite characteristic; patients present with conductive hearing loss, a normal tympanic membrane, and no evidence of middle ear inflammation. The most common early manifestation seen radiographically is demineralization of the fissula ante fenestram; the bone just anterior to the oval. On CT, the oval window should be examined for either subtle lucent areas or otosclerotic foci (red arrows). Early disease is spongiotic and visualized as a small, demineralized focus anterior to the oval window. This represents the abnormal “spongiotic” bone replacing the normal dense otic capsule. Late phase disease is sclerotic and these changes are not typically well seen by CT, but one may see narrowing of the oval window, thickening of the stapes footplate, and small decreased density lesions in the lateral wall of the labyrinth. Paget’s disease has a similar histologic appearance.

DDx: Fenestral Otosclerosis 1.

Osteogenesis Imperfecta

2.

Fibrous Dysplasia

3.

Paget’s Disease

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DDx


Prussak’s Space Cholesteatoma

Case 14: What is the most likely diagnosis?

Pars flaccida cholesteatoma is the most common acquired (secondary) cholesteatoma. It is a soft-tissue mass found in the epitympanum lateral to the ossicles in Prussak’s space. It typically presents with erosion of the scutum and lateral epitympanic wall (red arrows). Prussak’s space cholesteatoma results from ingrowth of squamous epithelium through the eardrum due to either a marginal perforation or invagination of a retraction pocket. Erosion or demineralization of the ossicles is not uncommon. Erosion of the bony covering of the lateral SCC may lead to canal dehiscence and a perilymphatic fistula (more commonly seen with a pars tensa cholesteatoma). Patient’s typically present with painless otorrhea and conductive hearing loss. Clinically a pearly white mass is seen in the middle ear.

DDx: Prussak’s Space Cholesteatoma 1. 2. 3. 4. 5.

Chronic inflammatory otitis media Tuberculosis Paraganglioma Squamous cell Carcinoma Langerhans cell histiocytosis

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DDx


Case 15: What is the most likely diagnosis?

Malleus Fixation in Down’s Syndrome Patient Numerous congenital disorders present with symptoms of ossicular fixation. Most commonly, the malleus fuses with the incus head to the epitympanic wall by a fibrous band or a bar of bone (red arrows) resulting in conductive hearing loss. Rarely, the malleus handle is fixed to the posterior tympanic wall by a bony bar. In Down’s syndrome, abnormal ossicle formation is also seen, most commonly in the stapes. Most ossicular ankyloses and abnormalities can be treated surgically. It is presumed that the mesenchyme behind the malleus handle is incompletely absorbed in development and this persistent mesenchymal tissue differentiates into osseous tissue. Fixation is often resultant of malformations during this process.

DDx: Malleus Fixation in Down’s Syndrome 1. 2.

Tympanosclerosis Chronic Otitis Media

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DDx


External Auditory Canal Atresia

Case 16: What is the most likely diagnosis?

Congenital atresia of the external auditory canal is caused by a failure of canalization of the epithelial plug portion of the first branchial arch. 1:10000 births. Right ear greater than left is affected. More commonly involves the fibrocartilaginous portion than bony portion of the EAC. Can be syndromic or sporadic. Atresia can be bony or membranous, complete or incomplete. It is graded as mild, moderate, or severe based on degree of involvement of the EAC, auricle, ossicles (esp malleus and incus), middle ear cavity, and seventh nerve. A classification system exists by location and severity. Type A (meatal), B (partial), C (total), D (hypopneumatic total). This case demonstates a complete bony atresia with hypopneumatized MEC and ossicular agenesis. (red arrows).

DDx: External Auditory Canal Atresia 1. 2. 3. 4.

Cleft Lip and Palate Crouzon Syndrome Microtia Osteogenesis Imperfecta

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DDx


Case 17: What is the most likely diagnosis?

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Case 17: What is the most likely diagnosis?

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Persistent Stapedial Artery, Bilateral Enlarged Stapedial and Case 17: What is the most likely diagnosis? Jacobson The stapedial artery is transiently present during fetal development and normally involutes in the 3 rd fetal month. Failure of its involution leads to a persistent stapedial artery which originates from the vertical petrous ICA. MR or CT angiogram is useful for demonstrating the persistent stapedial artery (red arrows). It continues on to form the middle meningeal artery; ipsilateral foramen spinosum will be absent. It is a rare vascular anomaly and may be associated with an aberrent internal carotid artery and other middle ear abnormalities, especially involving the stapes and facial nerve. Typically, patients are often asymptomatic and the condition is detected as an incidental finding on imaging. Patients can also present with symptoms of pulsatile tinnitus and conductive hearing loss. Persistent stapedial artery is known to complicate stapedectomy and cholesteatoma resection, and can prevent cochlea implantation.

DDx: Persistent Stapedial Artery 1. 2. 3.

Facial Nerve Schwannoma Aberrant internal carotid artery Aberrant facial nerve

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DDx


Case 18: What is the most likely diagnosis?

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MERSA Acute Mastoiditis and Subperiosteal Abscess overlying Case 19: What Mastoid is the most likely diagnosis? Process MRSA (methicillin-resistant staphylococcus aureus) is a nosocomial infection typically acquired by inpatients exposed to a clonal isolate. Infections resulting from community-acquried MRSA have been increasingly reported in otolaryngology. Skin and soft tissue infections including cellulitis, abscesses, impetigo, folliculitis, and furunculosis can all be caused by this infection. Beginning in the 1990’s, outbreaks of MRSA were recognized among healthy individuals lacking traditional risk factors, such as exposure to the health care system. Cases of MRSA infection have also continued to rise in pediatric patients. If a subperiosteal abscess is encountered, it should be aspirated and the pus cultured.

DDx: MRSA Subperiosteal Abscess 1. 2. 3.

Pseudotumor Cellulitis Other Bacterial Infections

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DDx


Case 20: What is the most likely diagnosis?

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Case 20: What is the most likely diagnosis?

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Case 20: What is the most likely diagnosis?

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DDx: Temporal Bone Fracture-Ossicular Dislocation 1. 2. 3.

Case 20: What is the most likely diagnosis?

Transverse or mixed fracture Normal fissure or suture Vascular channel

Longitudinal TB Fracture- Incudomalleolar and Incudostapedial Dislocation- Sigmoid Sinus Thrombosis Longitudinal temporal bone fractures are oriented along the long axis of the petrous bone. They represent ~70% of temporal bone fractures. They are typically the result of a lateral blow and are a/w squamosal fractures (red arrows). They are often accompanied by ossicular injury ipsilateral side to the trauma with resultant conductive hearing loss. Up to 50% of temporal bone fractures are associated with ossicular injury (blue arrow). They don’t typically involve the otic capsule. Other complcations include 7th and 6th CN injuries.

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DDx


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