Orbital pathology

Question 1

How is the orbit divided?

Answer 1

Extraconal
Conal (muscles)
Intraconal

Question 2

Cavernous malformation - Most frequent space

Answer 2

Lateral aspect of the intraconal space

Question 3

Cavernous malformation - Morphology

Answer 3

Well-circumscribed, homogeneous and ovoid

Question 4

Cavernous malformation - Epidemiology

Answer 4

Middle-age adults (43-48 years old)

Female predominance

Question 5

Cavernous malformation - Signal intensity

Answer 5

T1: isointense to muscle
T2: hyperintense uniformly

Question 6

Cavernous malformation - Enhancement pattern

Answer 6

Progressive and slow (complete feeling in 30 minutes)

Question 7

Fibrous solitary tumor/Hemangiopericytoma - Most frequent space

Answer 7

Extraconal

Question 8

Fibrous solitary tumor/Hemangiopericytoma - Morphology

Answer 8

Lobulated and well-circumscribed

Question 9

Fibrous solitary tumor/Hemangiopericytoma - Signal intensity

Answer 9

T1: isointense
T2: hypointense with flow voids

Question 10

Fibrous solitary tumor/Hemangiopericytoma - Enhancement pattern

Answer 10

Vivid and heterogeneous

Question 11

Fibrous solitary tumor/Hemangiopericytoma - Cell origin

Answer 11

Spindle-cell neoplasm that originates from mesenchymal fibroblast-like cells (pericytes)

Question 12

What’s the most common primary lesion of orbit in older adults? What tumor is the most common?

Answer 12

Lymphoproliferative lesion

Lymphoma

Question 13

The majority of lymphoproliferative lesions are unilateral and extraconal (T/F)

Answer 13

True (76%)

Question 14

Main characteristc of lymphoproliferative disease

Answer 14

Mold the orbital structures: globe, optic nerve, orbital wall

Question 15

What happens to the bone surrouding the lesion?

Answer 15

Remodelling

Vary rarely it destroy bone

Question 16

Half of lacrimal gland lesions are malignant and half are benign (T/F)

Answer 16

True

Question 17

How are the lesions of the lacrimal gland divided?

Answer 17

Epithelial and non-epithelial

Question 18

Lacrimal gland - Epithelial lesions

Answer 18

Pleomorphic adenoma

Adenoid cystic carcinoma

Question 19

Lacrimal gland - Nonepithelial lesions

Answer 19

Lymphoproliferative

Question 20

Pleomorphic Adenoma - Epidemiology

Answer 20

Most common benign neoplasm of the lacrimal gland

Slow-growing that manifest in the 4th or 5th decade

Question 21

Pleomorphic Adenoma - Macroscopy

Answer 21

Well-circumscribed
Homogeneously enhacing mass

Bigger lesions may be heterogeneous secondary to cystic degeneration, hemorrhage, serous ou mucous collections or necrosis

Question 22

Pleomorphic Adenoma - Signal

Answer 22

T1: hypointense
T2: hyperintense

Question 23

Adenoid Cystic Carcinoma - Epidemiology

Answer 23

Most common malignancy of the lacrimal gland
Second most common epithelial lesion
4th decade of life

Question 24

Adenoid Cystic Carcinoma - Pattern

Answer 24

Infiltrative

Propensity for perineural spread

Question 25

Adenoid Cystic Carcinoma - Imaging

Answer 25

Irregular borders Distortion of orbital contents Bone erosions and calcification

Question 26

Adenoid Cystic Carcinoma - What nerve is commonly affected?

Answer 26

Lacrimal branch of the ophthalmic nerve

Question 27

Optic Nerve Glioma - Epidemiology

Answer 27

Most common primary tumor of the optic nerve Children less then 8 years of age NF-1

Question 28

Optic Nerve Glioma - What's the most common grade?

Answer 28

Grade I (Pilocytic astrocytoma)

Question 29

Optic Nerve Glioma - Image Pattern

Answer 29

T2 hyperintense lesion with cystic spaces and variable enhancement

Question 30

Optic Nerve Glioma - Apparence of the nerve in NF1 x Non-NF1

Answer 30

Tortuous, kinked and diffusely enlarged x fusiform dilatation

Question 31

Optic Nerve Sheath Meningioma - Epidemiology

Answer 31

2% of all orbital masses More common in women 5th decade of life

Question 32

Optic Nerve Sheath Meningioma - Image pattern

Answer 32

Tram-track with bone remodeling and calcification (20-50%)

Question 33

Schwannoma - Nerves

Answer 33

Mostly trigeminal nerve | May ocur in oculomotor, trochlear and abducens nerve, parasympathetic and sympathetic fibers, and ciliary ganglia

Question 34

Schwannoma - Pattern

Answer 34

Extraconal and at the superior orbit (ophtalmic nerve) | Cone shaped or dumbbell

Question 35

Schwannoma - Signal

Answer 35

T2 hyperintense, heterogeneous (cystic components)

Question 36

Plexiform neurofibroma - Image Pattern

Answer 36

Serpentine soft-tissue mass extraconal with heterogeneous contrast enhancement and fluid-fluid levels T2 hyperintense with a focal inner hypointensity

Question 37

Metastasis - Common sites

Answer 37

Breast (50%) Prostate Melanoma Lung