Musculoskeletal #4 – Long case

Regarding the following X-Ray:

Frontal x-ray of the right hand

Where is the lesion?

Metaphysis of the base of the fourth middle phalanx.

What are the radiological characteristics/findings?

Expansile lytic lesion (bubbly appearance) with narrow zone of transition, no cortical break through, and no soft-tissue component.

What is the differential diagnosis?

Enchondroma: Enchondromas have variable imaging appearances but are typically lytic lesions with non-aggressive features. They could show chondroid calcifications (rings and arcs calcification). But in the hands and feet they are typically purely lytic with no matrix.
Eosinophilic granuloma: It mainly involves the diaphysis and does not cross the growth plates. It appears as punched out lytic lesions without sclerotic rim.  Imaging appearance in the long bones depends on the phase of the disease which is imaged. It can look aggressive in the initial phase. In the healing phase it can show solid benign periosteal reaction.
Fibrous dysplasia.Usually shows ground-glass matrix but may be completely lucent or sclerotic. Well-circumscribed lesions with no periosteal reaction may lead to premature fusion of growth plates leading to short stature in the lower limbs and bowing deformities (Shepherd’s Crook deformity of the femoral neck)

What is the most likely diagnosis?

Diagnosis: Enchondroma

Regarding the diagnosis…

What are the associated syndromes with multiple enchondromas?

Ollier disease: multiple enchondromas are usually  confined to one side of the body and limited to the limbs. There is increased risk of chondrosarcoma 

Maffucci syndrome: multiple enchondromas with soft-tissue haemangiomas

Emergency #14 – Flashcard

18-years-old male:
* Rigid abdomen and generalised tenderness
* Pain lower abdomen
* CRP 250

What do you see? Perforated appendicitis? What is your diagnosis?

Diagnosis Perforated sigmoid diverticulitis (Hinchey 3 or 4, peritonitis)

> Mesenterial fatty infiltration, free air bubbled outside bowel lumen.
> Also subdiaphragmal free air and free fluid.
> Notice enlarged reactive lymph nodes and peritoneal thickening and enhancement, indicative of peritonitis.
> Patient was operated, free faeces was found in the abdomen.

Hinchey classification of acute diverticulitis:
* Stage 1a: phlegmon
* Stage 1b: diverticulitis with pericolic or mesenteric abscess
* Stage 2: diverticulitis with walled off pelvic abscess
* Stage 3: diverticulitis with generalised purulent peritonitis
* Stage 4: diverticulitis with generalised faecal peritonitis

Abdominal #3 – Long case

A 70-year-old male presents to the Emergency Room with abdominal pain and distention. The patient has a history stage IV non-small cell lung cancer, chronic obstructive pulmonary disease, hypertension, severe dementia and recent deep venous thrombosis. He presents secondary to 2 days of poor appetite, diffuse abdominal pain, abdominal distention, and increasing dyspnea. He reports no bowel movements in last 2 days.

The decision was made to proceed with a CT of the abdomen and pelvis with intravenous and oral contrast. The following study was obtained.

Whats is the most likely diagnosis?

Diagnosis: High-grade small bowel obstruction due to internal hernia with small bowel pneumatosis and small volume pneumoperitoneum.

In cases with bowel obstruction, the radiologist should aim to identify the cause of the obstruction as early surgical reversal may be curative for the patient. One of the uncommon causes of small bowel obstruction includes internal hernias. This is a difficult diagnosis to make, and a few signs are may be useful to help identify it. Firstly, it is important to look at the overall distribution of the bowel loops. In this case, the distended bowel loops are abnormal in position, as they are within the pelvis as well as positioned anterior to the large bowel.

In this case, the duodenojejunal junction and ligament of Treitz are seen to the right of midline and are positioned inferiorly and posteriorly deep pelvis along the peritoneal reflection. In this case, the low position of the bowel loops may be due to a defect in the sigmoid mesocolon which would make the rare diagnosis of a sigmoid mesocolon hernia.

Most importantly are the ancillary features which make this case a surgical emergency. Firstly, pneumatosis intestinalis is seen within the small bowel wall:

Using the lung window, we are also able to notice subtle pneumoperitoneum:

In cases with suspected bowel ischemia, it is important to additionally look for gas within the portal venous system, which in this case was not present.

Due to multiple comorbidities, and upon further consultation with family and the patient, the decision was made not to operate and undergo conservative management.

Musculoskeletal #3 – Long case

Axial CT abdomen bone window

Axial CT abdomen soft tissue window

Where is the lesion?

Left iliac bone

What are the radiological characteristics/findings?

Large lytic lesion with wide zone of transition, cortical destruction, and large soft tissue component.
No specific matrix.

What is the differential diagnosis of an aggressive iliac bone lesion?

* Metastasis
* Plasmacytoma: solitary plasma cell tumor expansile lytic lesion with bone destruction and soft tissue component. Usually shows low signal intensity on T2 with variable post contrast enhancement. 
* Chondrosarcoma: malignant cartilage tumor destructive lytic lesion with intralesional rings and arcs calcification (chondroid matrix). High signal intensity on T2. 

What is the most likely diagnosis?