Pseudomelanosis Duodeni of Undetermined Etiology

Abstract

Pseudomelanosis duodeni is a rare, benign condition of unknown etiology. It is characterized by collection of pigment-laden macrophages in the tips of duodenal villi. The pigment, originally interpreted as melanin, pseudomelanin, lipomelanin or hemosiderin, has now been demonstrated to be mostly ferrous sulfide. There is a strong association with chronic renal failure, arterial hypertension, diabetes mellitus and the use of medications such as ferrous sulfate, hydralazine, propranolol, hydrochlorothiazide and furosemide. We reported a case of a 48 years old female who only had dyspeptic symptoms and no history of hypertension or drug history. Laboratory tests showed normal serum electrolytes and renal function. On endoscopy we found multiple tiny brownish-black pigmentation throughout proximal duodenum. Histopathological examination showed mild inflammation in lamina propria with haemosiderin-laden macrophages. Stain for iron was positive and that for melanin was negative.