LETTER TO THE EDITOR
Year : 2008 | Volume
: 19 | Issue : 4 | Page : 645--646
Pseudomelanosis Duodeni in a Child with Chronic Renal Failure
Maryam Monajemzadeh1, Niloufar Tayari1, Mehri Najafi2, Abbas Madani3, Fatemeh Mahjoub1, Seyed Taher Esfahani3, Neamatollah Ataei3, Mohammad Taghi Hagghi Ashtiani1, Parvin Mohseni3, Sedighe Shams1,
1 Department of Pathology, Children Medical Center Hospital, Tehran University of Medical Sciences, Keshavarz Boulevard, Tehran, Iran
2 Department of Pediatric Gastroenterology, Children Medical Center Hospital, Tehran University of Medical Sciences, Keshavarz Boulevard, Tehran, Iran
3 Department of Pediatric Nephrology, Children Medical Center Hospital, Tehran University of Medical Sciences, Keshavarz Boulevard, Tehran, Iran
Department of Pathology, Children Medical Center Hospital, Tehran University of Medical Sciences, Keshavarz Boulevard, Tehran
|How to cite this article:|
Monajemzadeh M, Tayari N, Najafi M, Madani A, Mahjoub F, Esfahani ST, Ataei N, Ashtiani MT, Mohseni P, Shams S. Pseudomelanosis Duodeni in a Child with Chronic Renal Failure.Saudi J Kidney Dis Transpl 2008;19:645-646
|How to cite this URL:|
Monajemzadeh M, Tayari N, Najafi M, Madani A, Mahjoub F, Esfahani ST, Ataei N, Ashtiani MT, Mohseni P, Shams S. Pseudomelanosis Duodeni in a Child with Chronic Renal Failure. Saudi J Kidney Dis Transpl [serial online] 2008 [cited 2021 Apr 16 ];19:645-646
Available from: https://www.sjkdt.org/text.asp?2008/19/4/645/41330
To the Editor,
The presence of a spotty brownish or blackish pigmentation in the duodenal mucosa at endoscopy, termed duodenal melanosis or pseudomelanosis is a rare benign condition. Histochemically, the pigment appeared to contain either iron, melanin like substances or both. Pseudomelanosis duodeni is very rarely seen in children. 
In 1976, Bisordi and Kleinman reported an unusual patient with patchy, 'peppered', pigmentation in the second part of the duodenum and since that time, few similar cases have been reported in the medical literature but most of them are in adult patients. ,
Its pathogenesis and significance, however, remain obscure.  With electron microscopy and electron-probe energy dispersive X-ray analysis, the pigment has been shown to consist largely of iron sulphide in angular crystalline plates. This is in contrast with melanosis coli where the pigment is lipofuscin. 
We present herein the endoscopic, microscopic, and histochemical studies of an eight year-old girl with this condition.
The child was referred because of abdominal discomfort and convulsion. She was a known case of polycystic kidney disease and the nephrotic syndrome diagnosed at eight months of age, who developed endstage renal disease when she was twoyears old, and underwent kidney transplant three years later (at the age of 5 years). The transplanted kidney was rejected one month after surgery; she was placed on maintenance hemodialysis with anti-hypertensive drugs including hydralazine, clonidine, amilodipine and oral iron supplements as well as anti convulsant drugs (phenytoin).
Gasteroesophageal endoscopic examination show tiny superficial erosions proximal to the Z line with hiatal hernia, normal gastric mucosa and profuse black spots in the second part of duodenum. Biopsy was taken from the duodenum. Microscopic examination showed some cells filled with black- brown coarse granules scattered in the lamina propria [Figure 1].
The pigment was positive by both the Masson-Fontana method and the Perls' stain. This patient had been treated with hydralazine, a drug that contains a sulphur group  which together with possible intra-mucosal hemorrhagic events due to stress, medication, hemodialysis and/or renal failure itself compounded by oral iron intake could have resulted in accumulation of iron and sulphur in the lamina propria.
The question is why every patient with chronic renal failure and use of these drugs does not develop these lesions. It seems that the quantity of iron deposited presumably determined whether or not the pigment was macroscopically visible. The staining characteristics of the pigment on the other hand might be related to the amount of sulphur present in the pigment. ,
Our results indicate that hypertension; gastrointestinal hemorrhage, renal insufficiency and anemia are factors involved in pigmentation of the duodenum and it can occur in children like adult patients especially if there is longstanding disease like our case (about 8 years).
Awareness of this condition among gastroenterologists, pathologists, and other clinicians can aid in better identification of such patients and also aid in evaluation of other possible variables in its pathogenesis.
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