Splenosis Mimicking Peritoneal Seeding of Advanced Colon Cancer Can Be Identified by Spleen SPECT/CT and FDG PET/CT

Gastric Fundus Splenosis Mimicking Malignancy on FDG PET/CT

ABSTRACT

A 17-year-old man presented with dull pain in the left upper abdomen for 1 month. Initial CT and gastroscopy revealed a mass in the gastric fundas, protruding into the lumen. Based on findings of a fine-needle biopsy, an inflammatory myofibroblastic tumor was suspected. Subsequent PET/CT showed increased FDG uptake in the gastric fundas as well as hepatogastric ligament, para-aortic region. Eventually, he underwent surgical resection, and histopathologic findings confirmed the diagnosis of splenosis.

Abdominal and pelvic splenosis: atypical findings, pitfalls, and mimics

Splenosis is an acquired form of ectopic splenic tissue that typically arises after trauma or splenectomy. It is often an incidental image finding in an otherwise asymptomatic patient, but the spectrum of symptoms varies based on the site of implantation. Radiologists should be familiar with the imaging features of splenosis to avoid mistaking it for malignancy. Splenosis has identical imaging features to that of the native spleen on US, CT, MRI, and nuclear medicine examinations. Therefore, when the radiologic findings support the diagnosis of splenosis, the patient can be spared invasive procedures for tissue sampling.