Heterotopic Splenic Tissue Mimicking Metastases on Magnetic Resonance Imaging.

Background: Heterotopic splenic tissue can occur following splenectomy and is typically asymptomatic, often discovered incidentally during imaging for other conditions. This benign condition may mimic malignant processes, posing diagnostic challenges especially in patients with a history of cancer or concurrent malignancy. Case description: We report the case of a 60-year-old male with a history of well-controlled hypertension and a splenectomy following a traumatic injury at age 7. The patient underwent routine screening which revealed elevated prostate-specific antigen (PSA) levels. Subsequent magnetic resonance imaging (MRI) identified suspicious lesions in the prostate and a left lower quadrant mass. Prostate biopsy confirmed an adenocarcinoma with a Gleason score of 6, while biopsy of the abdominal mass revealed heterotopic splenic tissue. The management strategy included active surveillance for prostate cancer, considering the tumour's low aggressiveness and the benign nature of the splenic tissue. Conclusions: This case highlights the importance of considering heterotopic splenic tissue in differential diagnosis when evaluating abdominal masses in patients with a history of splenectomy. Accurate diagnosis through careful imaging and biopsy is crucial to avoid misdiagnosis and unnecessary treatments, particularly in patients with concurrent malignancies. LEARNING POINTS: In patients who have had a prior splenectomy for trauma, heterotopic splenic tissue may be mistaken for metastases on MRI.