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Tun Orthop 2008, Vol 1, N° 2Kandara H et al.Xanthomatosis is a widespread disorder in whichlipid depositing in the containing cells appear inthe skin and visceral organs. They may representa localized cutaneous phenomenon or signify asystemic hyperlipidemia with abnormal lipid metabolism[1, 2].Xanthelasma palpebrum is the most commoncutaneous xanthoma [2]. Tuberous xanthoma israre in both children and adults. It is predominatelylocated on the trunk and extremities. We describein this paper a boy with normolipemic multipletuberous cutaneous xanthomas. This case isbeing reported because of its rare occurrence.i. Case reportA 12-year-old boy, born of a consanguineousmarriage, presented to the paediatric orthopaedicdepartment with a history of multiple asymptomaticskin tumors since age 2 years. These tumorswere located on both elbows and knees and hadincreased progressively in number and size tobecome large. No family member had any suchlesions. Physical examination revealed multipleyellowish skin tuberous and nodular xanthomason both elbows and knees. All of these tumorswere firm, painless, well delimitated and of varyingsizes from 2 to 6cm of long axis (Fig 1).Figure 1: Multiple skin xanthomas on both elbows and knees varyingin sizeExcept for these skin lesions the physical examinationwas normal. Biological investigations weredone in a paediatrics department. Lipid profilewas normal and serum protein electrophoresisshowed a normal pattern. Biopsy of a tumour ofthe elbow was consistent with a xanthomatous lesionshowing histiocytes with foamy vacuolatedcytoplasm (Fig 2). Repeat lipid profile after severalmonths was also normal. The child was operatedand surgical excision was done for all xanthomasin the same time. At 3 years follow-up, there wereno recurrences.ii. disCussionXanthomas are tumours characterised by collectionsof foamy histiocytes (lipid-laden macrophages).They can be a reflection of altered lipidmetabolism or a result of local cell dysfunction.Often secondary to hyperlipoproteinemias, especiallyhypercholesterolemia, xanthomas result inthe accumulation of cholesterol in various tissues[1]. However, normolipemic patients had beenrarely described with different types of xanthomas[3]. It has been suggested that 3 pathogeneticprocesses could be responsible for normolipemicxanthomatosis. The first group includes disorderswith accumulation of unusual lipids other thancholesterol such as cholestanol or plant sterols. Inthe second group planar xanthomas may be seenin patients with lymphoproliferative diseases suchas multiple myeloma or lymphomas. Xanthomaformation may be due to cutaneous lymphoreticularhyperplasia with secondary xanthomatisation.The third group comprises patients in whomlocal abnormalities in the skin are thought to playa role. This includes xanthomas following distinctdiseases such as erythroderma and epidermolysisbullosa dystrophica [3]. Based on their clinicalappearance they are classified into five principaltypes: eruptive, tuberous, tendinous, planar andxanthelasma [3]. The latter is the most commonof the xanthomas and presents as asymptomatic,usually bilaterally symmetric soft, velvety, yellow,flat, polygonal papules around the eyelids. Peripheraltuberous xanthomas are rare nodular, firm,painless subcutaneous swellings that developin those areas which are subjected to repeatedtrauma such as elbows, knees, and buttocks. Theymay arise as single or multiple and vary in sizefrom pea sized to lemon/mango sized. Usually,the lesions evolve for several months and enlargeslowly. Sometimes and like in our case, they maycoalesce to form large tumorous swelling. Histologically,they are characterized by foamy cellsand Touton giant cells [4]. Some normolipemicxanthomatosis are found to be associated witheither a systemic disease or malignancy [5, 6, 7,8]. Our case showed multiple tuberous xanthomasbut without any lipid disorder, associatedsystemic disease, or malignancy. Although spontaneousinvolution had been reported in papularxanthomas [1], in our case the tuberous lesionswere persistent for 10 years and the aim of surgerywas essentially cosmetic and esthetical. Therewere not functional problems.200Figure 2: Histiocytes with foamy vacuolated cytoplasmiii. reFerenCes1) Caputo R., Monti M., Berti E., Gasparini G. Normolipemiceruptive cutaneous xanthomatosis Arch Dermatol1986; 122:1294-97.