What is the cause of this patients abdominal pain?
Intussusception of the small bowel, located in the left upper quadrant.
What is the likely cause of this intussusception?
At the most distal point of the intussusception a soft tissue mass is present as the lead point. This is most likely due to malignancy, based on widespread pulmonary and retroperitoneal and soft tissue metastases.
What are the most common primary lesions would you consider given the widespread metastases to mesentery, subcutaneous and retroperitoneal tissues and lung?
Many end stage malignancies can be widespread, however malignant melanoma, breast cancer, lung cancer and gastrointestinal stromal tumour (GIST) should be considered in this instance.
Proximal jejunal intussusception over approximately 9cm segment. No significant contrast passage past this point, however bowel loops proximal to the intussusception are not overtly dilated. The stomach is distended with contrast. No free intraabdominal gas or fluid.
Enlarged left coeliac axis lymph node measures 20mm in short axis. Several bilateral retroperitoneal soft tissue deposits - the largest nodules are seen adjacent to the left psoas muscle at the level of the renal hilum and in the left paracolic gutter at the level of the iliac crest. Smaller subcentimeter nodules are seen in the pararenal spaces bilaterally.
Well defined low density right lower pole renal lesion is most likely a simple cyst. The liver, spleen, pancreas , adrenals and kidneys are otherwise within normal limits. IDC in situ.
Multiple pulmonary soft tissue masses scattered through both lungs. Expansile lytic left anterior 6th rib lesion. No further bone lesions identified. Soft tissue deposit in the subcutaneous fat overlying the right iliac crest.