Presentation
A remote history of gastrointestinal stromal tumor (GIST) was treated with partial gastrectomy and splenectomy. An indeterminate mass is seen along the proximal stomach.
Patient Data
Rotating MIP of the Tc-99m SPECT data shows normal moderate-intensity radiotracer activity in the liver and normal mild-intensity radiotracer activity in the bone marrow. The spleen is not seen, consistent with the history of splenectomy.
There is an indeterminate focus of radiotracer activity in the left upper quadrant. Fused SPECT-CT shows that this activity corresponds to the indeterminate soft tissue mass adjacent to the proximal stomach, which is diagnostic of splenosis.
Case Discussion
Abdominal splenosis is seen after abdominal trauma or splenectomy. It is due to the seeding of small deposits of splenic tissue in the peritoneal cavity along the serosal and peritoneal surfaces. When the diagnosis is unclear, as in this case, a Tc-99m sulfur colloid or heat-damaged RBC scan can be used to prove the presence of splenic tissue. While heat-damaged RBC scintigraphy is considered the ‘gold standard', the need to handle blood products and their inherent risks makes sulfur colloid the frequent first choice.