Neuroradiology #34

54-year-old woman:
– Known breast cancer
– Arm paresis and soft-tissue lump

What are the salient findings?

Left: NECT, bone algorithm. Aggressive-like bone lesion with permeative pattern and hair on end periosteal reaction

Right: MRI T1 post-Gd. Associated trans-diploic soft-tissue mass with extracranial and intracranial-extraaxial components. Solid, homogeneous and avidly enhancing. Contiguous dural thickening and enhancement.

What is the differential diagnosis?

1- Metastasis
2 – Myeloma/Plasmocytoma
3 – Lymphoma
4 – Primary Bone Tumour (Osteosarcoma)
5 – Dural Lesion (Meningioma+++, Hemangiopericytoma)


– Always consider in older patients
– Multiplicity and known primary

Varies depending on tumor type and aggressiveness

– Lytic: Most tumor types
– Permeative: Highly cellular and small-round cell tumors (PNET, small cell lung, lymphoma)
– Sclerotic/mixed: Prostate, breast. Less frequently: Transitional cell, neuroendocrine, PNET
– Hypervascular: Renal cell, melanoma, thyroid, hepatocarcinoma, lung, neuroendocrine

Possible soft-tissue components



– Affects older patients (median 68-70 years). Very rare under 40 years (<10%) Imaging
MM 4 patterns of bone involvement
– Diffuse lytic bone infiltration simulating osteopenia
– Multiple focal lytic well-defined lesions
– Solitary plasmacytoma
– Sclerotic bone lesions (exclusively associated with POEMS sd)

Solitary plasmacytoma in the skull: lytic, aggressive trans-diploic, soft tissues, and hypervascular aspect


– 7% of all bone malignancy; 5% of extranodal lymphoma
– All ages; predominates in adults (peak 50-60 years); men/women 1.5:1
– Secondary dissemination >>> primary bone lymphoma
– Imaging characteristics of a hypercellular small round cell tumour

– Trans-diploic permeative bone pattern and abundant of tissue components (small round blue cells spread through Haversian canals conditioning a striking relatively little bone destruction in comparison to important soft-tissue lesions)
Hyperdensity on NECT, T2 hypodensity and striking diffusion restriction on DWI (all signs related to hypercellularity)
– Homogenous enhancement
– No or little necrosis


– Most common primary high-grade bone sarcoma
– Bimodal distribution: 10-14 and >40 years old
Extremely rare in the skull in adults, and much more frequently arising from coexisting Paget’s disease> >previously irradiated bone> or bone infarction
– Clinically, quickly growing painful mass

– Destructive, aggressive lesion, with periosteal reaction, soft tissue-mixed lytic-blastic component. May show “fluffy”, “cloud-like” osteoid matrix.

Secondary osteosarcoma arising in a Pagetic skull. See the globally aggressive pattern and the deep hypointensities inside the soft-tissue components probably transducing osteoid matrix (usually easily depicted on CT, non-available in this case)


– Most common brain tumor (36% of all brain tumors)
– Predilection for middle-aged females
– Can produce neurologic symptoms due to compression
– Most do not infiltrate bone, but when they do it, the hyperostosis is very specific, virtually pathognomonic
– Intra-diploic or trans-diploic meningiomas are less frequent

Key signs:
“Dural tail” and extra-axial semiology
Hyperostosis (very specific)
– Hypervascular with intense homogenous enhancement

*Even the great specificity of the hyperostosis, bone involvement can be VERY VARIABLE including aggressive-like lysis and periosteal reactions that do not exclude or go against the diagnostic

Ddx: Hemangiopericytoma (Solitary Fibrous Tumor New WHO 2016 classification). Younger, frequently male patients. Osteolysis possible, but NO hyperostosis. NO calcifications. The rest of imaging features identical to meningioma, differentiation is very difficult and challenging


With all the information mentioned above:

Could meningiomas condition aggress periosteal reaction? Does it go against its diagnosis

Meningiomas are very frequent, specially in middle-aged woman, if all or the vast majority of features favour this diagnosis, a relatively atypical bone affectation (lysis, periosteal reaction instead of the virtually pathognomonic hyperostosis) may not change the diagnostic orientation.

Bonus clues and some advance imaging pearls

Diffusion: Striking restriction in lymphomas
Perfusion: Striking high rCBV in meningiomas
Spectroscopy: Alanine (and GLX) in meningiomas. Striking high Cho in lymphoma and plasmacytoma. Striking high lipids in metastases

Back to the case:




– Very frequent, specially middle-aged women
– Important to know the classic characteristic features, some of them are very specific; but recognize the great polymorphism/many faces of this entity
– Advanced imaging can be helpful
– Not all the lesions in a neoplastic patient are metastases

Head and Neck #5

66-year-old female:
– Feels a lump in the neck when swallowing

In what space houses this lesion?

Mass in the right parapharyngeal space or deep part of parotid space. No parapharyngeal fat is visible, so either the lesion displaces the fat or it arises from it. It is certainly not from the carotid space, since the carotid arteries are displaced posteriorly. It is also not from the mucosal space since it compresses the lateral oropharyngeal wall, instead of arising from it.

Do you want further imaging to make a diagnosis and what?

MRI will provide you more details in head and neck lesions where the lesion arises from exactly, and what the origin is. MRI is made with T1, T2, and T1 with Gad and fat suppression.


What is your differential diagnosis?

Origin from deep parotid lobe, so DD benign or malignant salivary gland tumor, such as pleiomorphic adenoma, adenoid cystic of mucoepidermoid cell carcinoma. Radiologists are not good in differentiating benign from malignant lesions on MRI. Histopathology has to be done. DWI will help you a little, in that, malignant lesions have often lower ADC values, but also Wharthin tumors do so. DD rare schwannoma arises from V3 (mandibular nerve) in the true parapharyngeal space.

We performed ultrasound and cytologic punction. This turned out to be a fairly rare acinic cell carcinoma.

Teaching point:

Malignant tumors of the salivary glands are well delineated and do not have to present as ill-defined lesions, nor have to have lymph node metastasis or perineural spread

Musculoskeletal #11

68-year-old male:
* 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.

Abdominal #8 – Long case

76-year-old male.
* Presents with acute abdominal pain, enlarged abdomen and no defaecation since a few days.

What do you see?

Abdominal CT scan shows dilated colon loops with a calibre change in the sigmoid. Whirl of mesenterial vessels.

Differential diagnosis is Sigmoid volvulus. This was confirmed on OR.

Sigmoid volvulus is differentiated from a cecal volvulus by its ahaustral wall and the lower end pointing to the pelvis.

Abdominal radiographs will show a large, dilated loop of the colon, often with a few gas-fluid levels. Specific signs include coffee bean sign and absent rectal gas.

CT scan will show large gas-filled loop lacking haustra, forming a closed-loop obstruction. Specific signs include:
– whirl sign: twisting of the mesentery and mesenteric vessels
– bird’s beak sign: if rectal contrast has been administered
– X-marks-the-spot sign: crossing loops of bowel at the site of the transition
– split wall sign: mesenteric fat seen indenting or invaginating the wall of the bowel

Rectal tube insertion for treatment is successful in treating 90% of cases. Occasionally patients suffer from recurrent sigmoid volvulus, for which a surgeon may consider sigmoid colopexy (surgical fixation of the sigmoid colon), or in the surgically unfit, a percutaneous endoscopic colostomy (PEC) might be performed. The mortality rate of sigmoid volvulus is 20-25%. The most serious complication is bowel ischemia, not blow-out perforation as you might expect.

Musculoskeletal #8 – Flash card

What do you see on the following images?

CT scout view

CT soft tissue window

CT bone window

Click here to see the answer

Skull eosinophilic granuloma
Well defined lytic lesion with scalloped edges. It involves both the inner and outer table. Narrow zone of transition, no cortical breakthrough and no soft tissue component.

Abdominal #2 – Long case

We present the case of a 31-year-old woman with:
* Nausea and vomiting since three days
* Unable to eat or drink without vomiting
* Epigastric pain after eating
* Feels weak

* No prior trauma or illness
* No fever, no diarreha, no hematemesis or bloody stools
* No other family members ill

See below the laboratory findings:

What do you think?

Click here to see the answer

Signs of dehydration with secondary acute renal impairment and electrolyte disorders

Abdominals X-Ray were performed:

What do you see on the X-Rays?

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Apparent elevation of the right hemidiaphragm with obscuration of the right cardiac border

Air – fluid level at the right upper quadrant: free air?
Absense of gastric air and fluid-air level
Colonic air at the right upper quadrant (Chilaiditi)

Apparent soft tissue mass at the right upper quadrant

Elongated right liver lobe (Riedel lobe)
Instability of the symphysis pubis


* Apparent elevation of the right hemidiaphragm with obscuration of the right cardiac border
* Air – fluid level at the right upper quadrant: free air?
* Colonic air at the right upper quadrant (Chilaiditi)
* Apparent soft tissue mass at the right upper quadrant

* No apparent dilated bowel loops
* Elongated right liver lobe (Riedel lobe)
* Instability of the symphysis pubis

Differential diagnosis of a large amount of air in the RUQ

* Pneumoperitoneum
* Subphrenic abscess
* Hepatic abscess
* Anterior interposition of colon to the liver

* Loculated pneumothorax (mimick)
* Situs inversus – gastric air (mimick)
* Pneumobilia, portal venous gas (smaller amount)

Images from an abdominal CT-scan:

What do you see on the CT images?

Click here to see the answer
Anterior defect in the right hemidiaphragm

Partial herniation of stomach (blue arrow) and transverse colon (green arrow)

Gastric outlet obstruction due to compression of the pyloric region (red arrow),with secundary dilatation with fluid (blue arrows)

Normal position of the gastro-esophageal junction and hiatus

Collapse of the right middle lobe (green arrow) and partial collapse of the right lower lobe (blue arrow).


* Anterior defect in the right hemidiaphragm
* Partial herniation of stomach and transverse colon
* Gastric outlet obstruction due to compression of the pyloric region of the stomach, with secundary dilatation with fluid
* Normal position of the gastro-esophageal junction and hiatus
* No signs of ischemia
* Collapse of the right middle lobe and partial collapse of the right lower lobe.

What is the most likely diagnosis?

Click here to see the answer

Morgagni hernia of the diaphragm

Patient had a laparoscopic reduction of the hernia with mesh closure of the defect. No signs of ischemia at surgery.
Uneventful recovery with resolution of pain and normal intake the day after.

Morgagni hernia

* Rare congenital diaphragmatic hernia (<5% of all CDH)
* Anterior (retrosternal)
* Right-sided (90%)
* Usually small
* +/- 30% symptomatic: respiratory distress (newborn), recurrent chest infections, abdominal symptoms
* Contents: omental fat, transverse colon (60%), stomach (12%)

* Treatment: surgical repair
> In symptomatic cases, some say also in asymptomatic cases: prevention of strangulation of hernia contents
*Prognosis: good

* Differential diagnosis:
> Traumatic diaphragmatic rupture
> Diaphragmatic eventration / weakness / paralysis (abnormal contour / position of the dome)
> Cardiophrenic angle lesions ( pericardial fat pad, cyst, lipomatosis, tumor)

Emergency #11 – Long case

23-year-old male:
* Macroscopic hematuria and blood at urine meatus

What is the most likely diagnosis? What should we do next?

Click here to see the answer

 X-ray: Bilateral pelvis fractures discontinuity iliopectineal line most clearly left-sided

CT: Bilateral ramus superior/anterior iliac bone and ramus inferior pubic bone
Avulsion fracture symphysis pubis
Fracture sacrum on the right

Look also in soft-tissue setting!

Large hematoma posterior of symphysis pubis around urethra and perineum, lateral around the pelvic floor obturator internus muscles and cranially in the retroperitoneal Retzius space anterior of the bladder

Do a RUG: Retrograde Urethrogram. If intact, followed by CT Cystography

RUG shows contrast extravasation and complete rupture of anterior bulbous part of urethra, grade V isolated anterior injury. However, the rupture might be at the anatomic weak point, the bulbomembranous junction, meaning avulsion of the puboprostatic ligament and stretching of the membranous urethra. There is no contrast above the urogenital diaphragm (level of symphysis pubis). Contrast in the bladder is a residue from the IV contrast given for earlier total body CT.

Goldman classification urethral injury

Anterior urethra = Penile and bulbous part
Posterior urethra = Membranous and prostatic part

  • Type I: stretching the posterior urethra due to disruption of puboprostatic ligaments and hematoma, but urethra is intact
  • Type II: posterior urethral injury above urogenital diaphragm (between ischiopubic rami)
  • Type III: injury to membranous urethra, extending into the proximal bulbous urethra (i.e. with laceration of the urogenital diaphragm), thus contrast extravasation below diaphragm
  • Type IV: bladder base injury involving bladder neck and proximal urethrainternal sphincter is injured, hence the potential for incontinence
  • Type IVa: bladder base injury, not involving bladder neck (cannot be differentiated from type IV radiologically)
  • Type V: anterior urethral injury (isolated)

* In this case, no CT cystography was performed
* Patient was treated conservatively

Neuroradiology #11 – Long case

47-year-old male:
* Presented with epistaxis

Axial & coronal CT+C

Where is the lesion?

The bulk of the tumour is within the ethmoid sinuses extending inferiorly into the nasal cavity and superiorly into the intracranial cavity through the cribriform plates

What is the lesion like?

Enhancing soft-tissue tumor expanding the ethmoid sinuses and nasal cavity

T2, T1 and T1+C

What are the MRI signal characteristics?

Mixed signal intensity on T2, low signal on T1, and intense enhancement on post-contrast images

What is the differential diagnosis of paranasal sinus tumour?

* Olfactory neuroblastoma:  involves the ethmoid sinuses  and extends through the cribriform plate into the anterior cranial fossa. Usually, shows intense enhancement and may show calcifications. They are slow growing with sinus expansion

* Juvenile angiofibroma: benign locally aggressive vascular  tumor that affects adolescents. It is usually lobulated and expands the sphenopalatine foramen. Intense enhancement on post-contrast images

* Sinonasal carcinoma: heterogeneously enhancing mass that erodes the bone and may extend into the orbits or intracranially

* Lymphoma: low T2 signal with intense contrast enhancement and usually expands the bone

Diagnosis:Olfactory neuroblastoma