Hidden Fetus in Fetu in a Male Adult

We present unusual retained remnants of hidden conjoined twin of possible abdominal pagus after 21 years who presented with abdomenpain and incidentally have found his forbidden conjoined twin. He presented for many years with a palpable epigastric mass, and recent abdominal pain, early satiety, nausea and vomiting. The mass was a like deformed fetus weighing 815 gr who was anencephalic and deprived of viscera but there was a distinct vascular connection through the right limb. Microscopic examination revealed a normal epidermis with melanocytes overlying dermis with mature adnexa. The fetus plain film after surgery showed a rather complete skeletal system. All above findings were in favor of fetus in fetus, a rare congenital entity in which a nonviable parasitic fetus grows within the body of its twin.