1909 A Case of Severe Pseudomelanosis Duodeni

Abstract

INTRODUCTION: Melanosis in the gastrointestinal tract consists of black pigmentation of the mucosa. It is generally seen in colon, and extracolonic melanosis is rare. Duodenal Melanosis is a rare benign condition caused by idiosyncratic metabolism of benzene-ring-containing drugs resulting in the accumulation of pigment in the duodenal mucosa. It is thought to be related to folate deficiency, gastric ulcer, intestinal bleeding, hypertension, chronic heart failure, chronic renal failure, consumption of sulfur-containing antihypertensive agents, drugs containing cyclic compounds, anthracene laxatives, and ferrous sulfate. CASE DESCRIPTION/METHODS: 80-year-old man with history of hypertension, chronic heart failure, chronic renal failure, and chronic anemia on iron supplementation, presented to the hospital with weakness, palpitations, and melena. He was found to have acute blood loss anemia. The patient had normal folate level of 16 ng/ml. Gastroduodenoscopy revealed 2 cm gastric ulcer with no active bleeding, and melanosis of duodenum. Pathology confirmed aggregates of macrophages in the lamina propria with CD 68 positive immunostaining, contain black granular material consistent with Pseudomelanosis Duodeni (PD). Iron stain and Melan-A were both negative. DISCUSSION: Pseudomelanosis Duodeni was first described in 1976. Although there has been increased reports of this condition, its pathogenesis and clinical significance are not yet known. It is postulated that iron deposition secondary to intramucosal hemorrhage or impaired intramucosal iron transport after oral ferrous sulfate supplementation, or impaired macrophage metabolism of drugs is to be blamed. PD does not require any specific treatment or recommended follow-up; However, in our patient a 1 year follow up showed the progression of his melanosis.