* Presents with a mass around knee which has been present for seven years and has been enlarging since then
What do you see?
A sclerotic ill-defined soft tissue mass around the knee was present on radiographs.
The mass is located in the soft tissue around the knee with no apparent bone destruction.
Coronal fat-suppressed T2 WI (a) shows a hyperintense lobulated mass which was hypointense on T1 WI (b) and has peripheral heterogeneous enhancement on postcontrast T1 WI (c); cortical bone is preserved.
The mass encircles a pedunculated lesion which continues with cortical and medullary bone (arrows), consistent with an osteochondroma.
Histopathologic diagnosis of the mass is chondrosarcoma.
* Osteochondromas are developmental lesions rather than true neoplasms and are often referred to as an osteocartilaginous exostosis (or simply exostosis).
* An osteochondroma is composed of cortical and medullary bone protruding from and continuous with the underlying bone; cortical and medullary continuity between the osteochondroma and parent bone is well depicted on MRI.
* Malignant transformation, almost invariably due to chondrosarcoma arising in the cartilage cap of the lesion, occurs in approximately 1% of solitary osteochondromas.
* Lesions that grow or cause pain after skeletal maturity should be suspected of malignant transformation since osteochondromas only rarely enlarge after this time.
A 21-year-old male:
* Collapse twice
* Loss of strength of right arm
* Trouble finding words
What are the CT Findings?
* No abnormalities were seen.
* No bleeding.
* No signs of recent ischemia.
Patient develops fever. Cannot bend his neck properly. When asked, he has been traveling recently to Thailand
What further imaging could help us?
What are the MRI findings?
* Two areas left frontal and left parietal with T2/FLAIR hyperintense swelling/edema of cortex and subcortical white matter, with diffusion restriction and patchy, gyriform cortical enhancement
* Diffusely leptomeningeal enhancement
* No ring-enhancing lesions. No white matter vasogenic or cytotoxic edema
What is the most likely diagnosis?
Cerebritis (precursor of abscess) and meningitis. Not yet an abscess
Note: Encephalitis means inflammation of PARENCHYMA
Differential diagnosis of meningitis:
* Leptomeningeal carcinomatosis
* Sarcoidosis and other granulomatous diseases
* Connective tissue diseases
Viral inflammatory cause for symptoms was confirmed with lumbar puncture and patient was treated with IV anti-viral treatment.
29-year-old long-distance athlete presenting with 3 weeks of sciatica associated with an increase of running training loads
What do you see?
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Unilateral sacral bone edema T2W, STIR hyperintensity associated with hypointense fracture line
Fatigue stress fracture
The sacrum is a frequent site for stress fractures
They can be related to overload occurring in a healthy bone as in this case, or related to osteoporosis (insufficiency stress fractures) in which cases they tend to be bilateral and “h- shaped”
There is a small lucency anterior to the vestibule, just lateral to the basal turn of the cochlea. Consistent with fenestral otosclerosis.
There are two types of otosclerosis:
1- Fenestral: is the most common type. It involves the bone anterior to the oval window and causes conductive hearing loss.
2- Retro-fenestral: involves the cochlear capsule and causes sensorineural hearing loss.
The two types can occur simultaneously.