2012 Radiology Exam - Abdomen Case 2

Observation

• Soft tissue opacity mass in the right central ventral abdomen caudal to the liver, and dorsal to the tail of the spleen.
• This mass is associated with a moderately/markedly distended (2X height of L2) segment of small intestine that extends caudally from the mass.
• Heterogenous, granular soft tissue, gas and mineral (small amount) opacity material is seen within the lumen of this small intestinal segment, representing a gravel sign/sentinel foreign material.
• A focal loss of serosal detail surrounds the mass and the cranial aspect of the abnormal loop of intestine.

Synthesis

• Cranial ventral abdominal mass causing partial mechanical obstruction of the small intestine.
• Differential diagnoses for the mass are neoplasia (adenocarcinoma, lymphoma, leiomyoma/sarcoma), a soft tissue opacity intraluminal foreign body or, less likely, a granulomatous mural lesion (fungal, pythiosis).
• Focal abdominal effusion and/or steatitis (possible rupture) or neoplastic infiltrate (carcinomatosis).

Case Management

• Ultrasound exam to confirm the location and nature of the intestinal mass, regional lymph node involvement and guide tissue sampling if warranted.
• Because there is a mechanical obstruction, surgical intervention is also required. 

Most candidates identified the mass and focal loss of serosal detail, but several did not identify the abnormal segment of small intestine and its association with the mass. Some did not clearly conclude that this segment of intestine represented a mechanical obstruction or did not qualify the obstruction as chronic/partial. Differential diagnoses for the focal loss of detail often did not include mesenteric neoplastic infiltrate or possible rupture.