Retroperitoneal Accessory Spleen Presented As Metastatic Suprarenal Tumour- A Diagnostic Dilemma

Accessory spleen may be formed during defective embryonic development. The retroperitoneal accessory spleen is a rare clinical entity and metastasis of renal carcinoma into this entity is extremely rare. We are presenting a case of a 50-year-old male patient who was admitted with complaints of left lower abdominal lump and pain. The computed tomography revealed a 7×4 cm mass at upper pole of left kidney. To rule out malignancy, we planned for surgical exploration. Suprarenal mass was densely adherent to left kidney so left nephouroureterectomy with suprarenal mass was performed. On histopathology examination left kidney showed transitional cell carcinoma with metastasis into suprarenal mass that was found to be an accessory spleen. Diagnosis was made retrospectively by histopathological observation. So this case highlights the difficulty in differentiation of these masses from malignant adrenal tumours.