#00065792

A 41-year-old female presented with left upper quadrant pain for 3 months. There was no history of trauma. On contrast enhanced computed tomography (CECT) found to have splenic cyst which was measuring 7.5x7.4x7.0 cm in size with well demarcated fluid lesion and no peripheral enhancement noted (Figure A). Splenectomy was done and on gross examination showed well defined uniloculated cyst at one pole (Figure B). Cut surface revealed serous fluid. Histopathological findings show splenic parenchyma with congestion of red pulp and it showed cyst wall lined by single layered flat cuboidal epithelium (Figure C). No atypia or mitosis or necrosis seen. On immunohistochemistry lining epithelium showed positivity for WT-1 (Figure D). Final diagnosis of mesothelial cyst was done. Non parasitic cysts are uncommon and usually will be asymptomatic. It is derived from mesothelial lining of splenic capsule.

Figure legends:

A: Contrast enhanced computed tomography (CECT) shows 7.2 x 7 cm cystic lesion in the spleen (red arrow). B: Gross image of splenectomy specimen with uniloculated cyst in the upper pole. C: Part of spleen with cyst wall (H&E, 400x). D: WT-1 DAB IHC (diaminobenzidine immunohistochemistry) shows nuclear positivity in the lining epithelium of the cyst (DAB IHC, 400x)