Low grade chondrosarcoma

Findings and interpretation:

Radiographs:

• There is an ill-defined, large, heterogeneous, mostly lytic lesion involving the distal diaphysis and metaphysis of the femur.
• It contains punctate and ‘ring and arc’ calcifications consistent with a chondroid matrix.
• There is cortical thinning/ scalloping at the distal diaphysis of the femur; cranial to this the cortex appears thickened with mild expansion of the bone.

MRI:

• There is a large, lobulated lesion corresponding to that seen on the radiographs, showing marked heterogeneous T2 hyperintensity with low signal on T1; the chondroid matrix is low signal on all sequences.
• There is mild high STIR signal intensity surrounding the distal femur.
• The lesion extends through parts of the cortex distally, with areas of complete cortical breach and extension of the soft tissue mass beyond the cortex.
• The lesion shows avid heterogeneous post contrast enhancement.

Pertinent negative findings:

• There is no large soft tissue mass.
• There is no aggressive periosteal reaction.

The findings represent a musculoskeletal neoplasm of chondroid origin. This appears to be moderately aggressive.

Principal diagnosis:

Low grade chondrosarcoma.

Differential diagnosis:

• Enchondroma: this is expected to have less cortical scalloping with no cortical break-through, and should not have an extra-osseous soft tissue mass.

Management:

• Alert referring physician.
• Recommend staging CT thorax abdomen and pelvis.
• Recommend discussion at sarcoma MDT regarding biopsy for tissue diagnosis.

Veno-lymphatic malformation

Findings and interpretation:

CT:

• There are multiple masses in the chest wall and soft tissues of the back, made up of serpiginous enhancing structures; some of these structures exhibit calcified round structures representing phleboliths. Some of the masses contain interspersed fatty tissue. The masses are located in the left axilla and breast, left paraspinal region and pleural space, back muscles and subcutaneous tissues of the left flank. 
• The left pleural space mass insinuates into the thoracic spinal canal with one of the disordered vessels entering via one of the intervertebral foramina, causing expansion of the foramen and displacement of the cord at that level. 
• These vascular masses are also found in the abdomen, located in the retroperitoneal space, within the posterior pararenal space bilaterally and within the pelvis.
• There is a solid soft tissue mass at the left breast posteriorly, related to the anterior chest wall. 
• There are multiple large cystic structures with thin, enhancing walls in the retroperitoneum.
• There are multiple cysts of similar size in the spleen.

MRI:

• The pelvis shows serpiginous structures surrounding both adnexae and the uterus, showing fluid-fluid levels on the T2 images and areas of hyperintensity on the T1 fat saturated sequence, indicating the presence of blood products.
• The abdominal cysts demonstrate fluid-fluid levels on the T2 images, indicating presence of blood products.
• The serpiginous structures in the pelvis are enhancing on the post-contrast images.

Pertinent negative findings:

• The ovaries are demonstrated separate from the vascular structures.

The findings represent widespread presence of venous and lymphatic malformations located in the soft tissues as well as the abdomen and pelvis. The splenic lesions are likely haemangiomas / lymphangiomas. Benign appearing left breast / chest wall mass likely represents a haemangioma. 

Principal diagnosis:

Multiple venous and lymphatic malformations and haemangiomas.

Differential diagnosis:

• Proteus syndrome: hemihypertrophy or an overgrown limb would support this diagnosis.
• Klippel Trenaunay Weber syndrome: overgrowth of a limb or part of a limb would support this diagnosis.
• Neurofibromatosis: however, the masses are clearly vascular and vascular malformations are not a feature of this entity.

Management:

• Alert referring physician.
• Recommend discussion at vascular / surgical MDT with regards to further management.

Mycotic aneurysm

Findings and interpretation:

First CT:

• There is ill-defined soft tissue density and fat stranding surrounding a focal segment of the abdominal aorta at the level of the renal arteries. This is surrounded locally by lymph nodes with a reactive appearance, giving a picture of peri-aortic inflammation.
• Within this segment there is a focal interruption of the aortic wall with mild, eccentric luminal expansion.
• A few scattered mural calcifications noted throughout the aorta represent mild atherosclerosis.

Second CT:

• There is much greater luminal expansion at the focal aortic segment with lobular contours, giving the appearance of a saccular aneurysm.
• The peri-aortic soft tissue now appears thicker and better organised, and forms a rind around the aneurysm with rim enhancement with low density centrally.

Negative findings:

• There is no aortic rupture.
• Normal appearance of the adjacent vertebral bodies with no evidence of discitis/osteomyelitis.

The findings represent a rapidly growing aortic aneurysm caused by infection of the aortic wall with peri-aortic abscess formation.

Principal diagnosis:

Mycotic aneurysm

Differential diagnosis:

• Contained aortic rupture: unlikely because there is evidence of peri-aortic inflammation
• Atherosclerotic aneurysm: almost implausible as this entity is slow growing and shows a fusiform shape

Management:

Urgently contact referring physician / vascular surgeon and inform of findings.

Non-accidental injury to the abdomen

Findings and interpretation:

Ultrasound:

• There is free fluid and dilated loops of bowel in the abdomen. The fluid shows homogeneous low level echogenicity, indicating that it is not simple ascites.

CT:

• The proximal small bowel loops are dilated with no clear transition point. There is no passage of oral contrast distal to the proximal jejunum.
• There is a large amount of free fluid in the abdomen; there is also enhancement of the peritoneal lining, suggestive of peritonitis.
• There is a pocket of extraluminal gas centrally in the abdomen, with surrounding loops of small bowel.
• There is irregularity of the posterior border of the left lobe of the liver, as well as adjacent parenchymal heterogeneity. There is also an irregularly linear hypodense lesion oriented along the plane of cleavage of the liver cranial to the falciform ligament.
• The lower ribs demonstrate posterior and anterior fractures with surrounding callus formation, indicating that these are subacute, healing fractures.
• There is bibasal atelectasis with a left sided pleural effusion, which contains a pocket of air.

Pertinent negative findings:

• There is no extra-luminal oral contrast media to indicate bowel perforation at the time of scanning.

The findings reflect blunt trauma to the abdomen and chest with a subacute time-frame. Perforation of small bowel at that time has allowed free fluid to accumulate in the peritoneal cavity and cause peritonitis. Laceration of the liver has occurred, with evidence of healing. Currently, obstruction of the small bowel may be caused by either adhesions or strictures in the bowel as a result of trauma. The healing rib fractures are further evidence of neglected trauma and non-accidental injury. The fact that the findings are incongruent with the history is further evidence of non-accidental injury.

Principal diagnosis:

Non-accidental injury to the abdomen with prior perforation of small bowel, liver lacerations, present peritonitis and small bowel obstruction.

Differential diagnosis:

• Accidental trauma to the abdomen; however, the advanced time after injury at which the child presented and incongruent history make this implausible.

Management:

Keep the child in the radiology department if still there.

Contact referring physician urgently and inform of findings; convey suspicion of non-accidental injury.

Perform skeletal survey and CT brain.

Contact child protection services.

Abdominal tuberculosis

Findings and interpretation:

• There is a moderate amount of free abdominal fluid, located in the perihepatic, subphrenic, perisplenic, both paracolic gutters and extending into the pelvis. There is a rim of thickened, nodular enhancing peritoneum surrounding the fluid. There is thickening, caking and soft tissue infiltration of the greater omentum which shows contrast enhancement. There is also diffuse mesenteric fat stranding. This represents tuberculous peritonitis.
• There is bilateral hydrosalpinx, as well as thickening and enhancement of the fallopian tube walls. There is a large cyst in the left ovary with enhancing walls that are mildly thickened. This likely represents tuberculous salpingo-oophoritis.
• There are multiple, small hypodense nodules of similar size that are distributed diffusely in the spleen.

• There are diffuse centrilobular nodules in the lung bases as well as left sided pleural thickening, representing endobronchial spread of infection.

• There is a large right inguinal lymph.

Pertinent negative findings:

• No evidence of bony / spine involvement.

The findings represent a multi-system granulomatous infection, involving the peritoneum, genital system, spleen and lungs.

Principal diagnosis:

Multi-system tuberculosis

Differential diagnosis:

• Peritoneal carcinomatosis: there is no visualised primary malignancy; also, this does not explain the lung findings.

Management:

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

Refer for discussion at infectious disease MDT with regards to further management / possibility of image guided biopsy of inguinal lymph node.

Venous Mesenteric Ischaemia

Findings and interpretation:

• There are multiple loops of small bowel which show bowel wall thickening. These bowel loops demonstrate a target/halo appearance with a hypodense, non-enhancing, thickened central layer of the bowel wall.
• The superior mesenteric vein is enlarged and non-enhancing on the portal venous phase. Moreover, the intrahepatic portal vein also demonstrates no enhancement in the same phase.
• There is mesenteric oedema and fat stranding caused by transudation of fluid in the mesentery; there is also perihepatic and pelvic free fluid.
• Lymphadenopathy is noted in the root of the small bowel mesentery.

Pertinent negative findings:

• There is no bowel perforation or pneumatosis intestinalis.
• The visceral arteries are normally enhancing and of normal calibre.

Incidental findings:

• Status post gastric bypass surgery with suture material noted at the stomach and bowel anastomotic sites.

The findings represent mural oedema of the small bowel, caused by venous congestion and congestion of the small bowel mesentery. This is a result of superior mesenteric vein thrombosis, causing small bowel ischaemia. The intrahepatic portal vein is also thrombosed.

Principal diagnosis:

Venous small bowel ischaemia caused by superior mesenteric vein thrombosis.

Differential diagnosis:

• Small intestine vasculitis: however, the visceral arteries are normal, and this is not supported by the venous thrombosis.
• Intestinal angioedema: however, this is not supported by venous thrombosis.

Management:

• Immediately contact the referring physician and notify them of the findings.
• Systemic anticoagulation may be urgently administered.
• Emergency laparotomy may be required.
• Following acute management, investigation for causes of hypercoagulable states, such as protein C/S deficiency may be performed.