[Abdominal wall skin nodules revealing xanthogranulomatous pylonephritis]. / Des nodules cutanés de la paroi abdominale révélant une pyelonéphrite xanthogranulomateuse.

INTRODUCTION: Xanthogranulomatous pyelonephritis is a chronic pyelonephritis characterized by an inflammatory granulomatous reaction that destroys the renal parenchyma. It is an uncommon entity. Diffuse inflammation has the potential to spread to nearby organs, especially the skin. OBSERVATION: A 73-year-old patient presented with a three-year history of painful and fistulized nodules on the abdominal wall. The results of abdominal computed tomography and magnetic resonance imaging revealed xanthogranulomatous pyelonephritis with extension to the skin, colon, and psoas muscle. The skin lesions were improved by a double antibiotic therapy. The patient was advised to have a radical left nephrectomy, but he refused surgery and was then lost to follow-up. CONCLUSION: We report an uncommon case of xanthogranulomatous pyelonephritis revealed by cutaneous nodules of the abdominal wall, with an extension toward the skin, the colon and the psoas muscle.

[Yellowish psoriasis revealing dermal lipomatous metaplasia]. / Lésions jaunâtres de psoriasis révélant une métaplasie lipomateuse dermique.

INTRODUCTION: Dermal lipomatous metaplasia is a particular histological presentation characterized by the presence of mature fat cells in the dermis. It is found in the tissue stroma of certain skin tumours and in a single reported case of psoriasis, imparting an orange-yellow tint. Herein we report a second case of this type. PATIENTS AND METHODS: An 82-year-old woman was consulting for an extensive, rapidly spreading psoriasis flare-up that had appeared 3 months earlier. Her psoriasis had been present for 30 years and had rarely been treated. The clinical examination revealed orange-yellow patches, either alone or mixed with psoriasis plaques. The laboratory lipid balance was without abnormalities. Protein electrophoresis revealed chronic inflammation. Histopathology and immunohistochemistry findings supported the diagnosis of dermal lipomatous metaplasia. Acitretin 20mg/day produced marked improvement in the rash within one month. CONCLUSION: Dermal lipomatous metaplasia is a highly specific and rare entity that should be considered where orange-yellow lesions are seen.