Benign splenosis mimicking peritoneal seeding in a bladder cancer patient: a case report

Abstract

Introduction: Splenosis is a post-traumatic autotrasplantation and proliferation of splenic tissue in ectopic sites. These implants may mimic malignancy in healthy patients or peritoneal metastases in cancer patients. When a previous history of splenic injury is known, the finding of soft tissue nodules in many thoracic and abdominal locations might raise the suspicion of the benign condition of splenosis, in order to avoid unnecessary surgery or chemotherapy.

Case presentation: A 56-year-old man with history of persistent hematuria from bladder cancer was referred to our Institution for suspected peritoneal carcinosis. For staging purposes he underwent abdominal computed tomography and ultrasound. The integration of patient's history and imaging results led to the diagnosis of peritoneal splenosis. The patient therefore underwent regular Trans Urethral Resection of Bladder for the known malignancy; while no treatment was necessary for splenosis. Two years follow-up was negative for metastases.

Conclusion: Splenosis is a benign condition after traumatic splenectomy which should be taken into account in the differential diagnosis with peritoneal seeding of malignancy because its appearance may resemble malignancy.

Figure 1

Abdominal CT scan of a splenic nodule before and after contrast medium injection. This 28 mm peritoneal nodule located in the right paracolic space showed slight hypodensity during the pre-contrast phase, (a) inhomogeneous contrast-enhancement during the arterial phase (b), slightly iso-hypodenity during the portal (c) and equilibrium phase (d).

Figure 2

Second-look ultrasound of the nodule in figure 1. US shows homogeneous splenic-like echogenicity of the nodule in the paracolic space, thus confirming its splenic origin.