Cerebellitis

Findings and interpretation:

• There is symmetrical FLAIR and T2 signal hyperintensity occupying the cerebellar hemispheres bilaterally, corresponding with T1 hypointensity.
• The cerebellum is enlarged and swollen, causing effacement of the pre-pontine cistern and the 4^th
• The mastoid air cells bilaterally show high T2 and FLAIR signal, indicating fluid contents within the air cells.

Pertinent negative findings:

• There is no diffusion restriction or enhancement in the affected regions of the cerebellum.
• No evidence of meningitis.
• No obstructive hydrocephalus.

Incidental:

• There is thickening of the mucosal lining in the right maxillary and frontal paranasal sinuses, indicating sinusitis.

The findings represent acute inflammation of the cerebellum, which may have spread from an adjacent mastoiditis.

Principal diagnosis:

Acute cerebellitis.

Differential diagnosis:

• Cerebellar lymphoma (this is usually seen in elderly patients).
• Lhermitte Duclos disease (usually asymmetrical).

Management:

Alert referring physician of findings.

Chondroblastoma

Findings and interpretation:

• The patient is skeletally immature.
• There is a lesion in the distal femoral epiphysis showing heterogeneous high T2/PD and low T1 signal intensity. It contains cystic spaces within.
• The lesion is well defined with a surrounding thin rim of hypointense compact (sclerotic) bone.
• The lesion is causing expansion of the femoral condyle with thinning of the cortex, and is bulging caudally into the knee joint at the intercondylar space.
• There is mild fluid sensitive signal hyperintensity in the surrounding bone marrow which corresponds with low T1 signal intensity, indicating bone marrow oedema.
• The post contrast sequence demonstrates enhancement of the solid components of the lesion.
• There is a mild knee joint effusion.

Pertinent negative findings:

• The lesion does not involve or cross the growth plate.
• There is no surrounding periosteal reaction.
• There is no associated pathological fracture.

The findings represent a bony lesion with a narrow zone of transition and non-aggressive features. However, it is causing surrounding inflammation.  

Principal diagnosis:

Chondroblastoma.

Differential diagnosis:

• Osteomyelitis (Brodie’s abscess) however, this does not respect the growth plate
• Giant cell tumour (this is seen in patients with a closed physis)
• Aneurysmal bone cyst (however, the spaces are not blood filled)

Management:

Alert referring physician of findings.

Discussion at orthopaedic MDT. These lesions are usually treated by curettage and packing.  

Hepatoblastoma

Findings and interpretation:

• There are multiple heterogeneous T2 hyperintense masses arising from and within the liver, which appear mostly hypointense on T1. One of these masses is quite large and extends far beyond the confines of the liver caudally into the abdomen, causing displacement of the bowel and other abdominal contents by mass effect.
• The largest mass appears to be lobulated with locules of higher T2 hyperintensity, some of which show T1 hyperintensity / hyperintense rims. This indicates haemorrhagic areas within the mass.
• The masses are heterogeneously bright on the DWI sequence with corresponding low ADC values indicating restricted diffusion.
• On the post-contrast images there is heterogeneous enhancement of the masses, with the individual lobules showing rim enhancement and hypo-enhancing centres. These likely correspond with areas of necrosis.

Pertinent negative findings:

• The mass does not show filling in with contrast on the delayed phase post-contrast images.
• There is no portal vein thrombosis.

The findings represent an aggressive neoplasm in the liver with local metastases which is likely malignant.

Principal diagnosis:

Hepatoblastoma

Differential diagnosis:

• Hepatic mesenchymal hamartoma
• Hepatic metastases from unknown primary
• Infantile haemangioendothelioma (however, the pattern of enhancement does not fit with this diagnosis)

Management:

Alert referring physician of findings.

Recommend image guided biopsy for histopathological diagnosis.

Refer to paediatric surgery MDT for discussion regarding further management.

Pulmonary tuberculosis and tuberculous peritonitis

Findings and interpretation:

Abdomen and pelvis:

• There is a large amount of intraperitoneal free fluid in the abdomen. The peritoneal lining is smoothly thickened and enhancing.
• There is thickening and soft tissue infiltration of the greater omentum, giving the appearance of omental caking. This is also seen at the lesser sac.

Chest:

• There are clusters of branching nodules, some of which show a tree-in-bud appearance in both apices and the right middle lobe.
• There are bilateral marked pleural effusions.

Pertinent negative findings:

• There are no adnexal masses.
• No evidence of bony / spine involvement.

The findings represent an infectious peritonitis in the abdomen. The multi-system disease is also involving the lungs with endobronchial spread of disease.  

Principal diagnosis:

Multi-system tuberculosis with tuberculous peritonitis and re-activation pulmonary tuberculosis.

Differential diagnosis:

• Metastatic spread to the peritoneum and omental deposits from an ovarian / unknown primary.

Management:

Contact referring physician and inform of findings; recommend placing the patient in isolation, screening close contacts and testing sputum for acid-fast bacilli.

Recommend image guided biopsy of the omental mass.

Cavitating pneumonia with mycotic aneurysm on a background of NSIP

Findings and interpretation:

• There is a thick walled cavity in the left upper lobe associated with an element of consolidation caudally. Surrounding this lesion are clusters of centrilobular nodules.
• There is generalised, bilaterally symmetric, basal and lower lobe pre-dominant ground glass opacification, reticular opacities, septal thickening and traction bronchiectasis.
• On the pulmonary arterial phase images, there is focal dilatation of a pulmonary artery which abuts the wall of the cavity.
• There are enlarged mediastinal lymph nodes, mostly pre-vascular at the aortic arch.
• There is a central line with the tip in adequate position at the SVC / right atrial junction.

Pertinent negative findings:

• No pleural effusions.
• No pulmonary embolism.

The findings represent an acute infectious disease in the lungs on a background of a chronic interstitial fibrotic pulmonary disease. The pulmonary artery aneurysm is caused by the adjacent inflammatory process.

Principal Diagnosis:

Cavitating pneumonia with mycotic aneurysm on a background of non-specific interstitial pneumonia (NSIP).

Differential diagnosis:

• Rasmussen aneurysm with re-activation pulmonary tuberculosis.

Management:

• Urgently contact referring physician and inform of findings.
• Recommend interventional radiology opinion with regards to endovascular management of the aneurysm.
• Sputum cultures may be obtained for culture and sensitivity.

Lymphoma

Findings and interpretation:

MRI abdomen:

• The left kidney is enlarged in size with multiple infiltrative masses within, some of which appear nodular. The masses are iso-intense on T2.
• The pancreas is also almost uniformly enlarged, and again is infiltrated by nodular masses of the same appearance.
• There are multiple enlarged para-aortic and aortocaval lymph nodes, showing the same signal intensity.
• There is dilatation of the intra-hepatic and extra-hepatic bile ducts, down to the level of the CBD.

MRCP:

• Marked bile duct dilatation is confirmed on MRCP, with a smoothly tapering segment of CBD leading to the point of obstruction.
• The main pancreatic duct is obstructed at the head and dilated distal to this point.

The findings represent a diffuse, neoplastic, infiltrative disease involving the lymph nodes as well as solid organs with replacement of normal parenchyma by the disease process. The deposits in the pancreatic head are causing biliary and pancreatic duct obstruction and subsequent dilatation.

Principal diagnosis:

Multi-systemic abdominal lymphoma (Burkitt’s) with kidney and pancreatic involvement.

Differential diagnosis:

Metastatic disease from a kidney or pancreatic primary carcinoma.

Management:

Alert referring physician of findings.

Complete imaging of the neck, chest and abdomen for staging purposes.

Recommend image guided biopsy for tissue diagnosis.