Disseminated juvenile xanthogranuloma occurring after treatment of Langerhans cell histiocytosis: a case report.

CASE PRESENTATION: An 11-year-old boy presented with a complaint of a painful temporal mass. Brain magnetic resonance imaging (MRI) showed a 3-cm-sized, homogeneously enhancing mass in the greater wing of the left sphenoid bone, which was diagnosed as Langerhans cell histiocytosis (LCH). Chemotherapy with vincristine and prednisolone was performed for 1 year. After 1 year and 11 months off treatment, he developed symptoms such as polydipsia and polyuria. Brain MRI showed thickening of the pituitary stalk with enhancement, suggestive of LCH involvement, and no recurrence in the sphenoid bone. After 4 years and 4 months off treatment, he developed multiple, subcutaneous, asymptomatic, and yellowish variable-sized papules on his face, posterior neck, and back, which were pathologically diagnosed as juvenile xanthogranuloma (JXG). Brain MRI revealed multifocal enhancing skull lesions in the left parietal, right frontal, and left occipital bones, which were also diagnosed as JXG. After 5 years and 8 months off treatment, the number of variable-sized skin lesions was increased without changes in the lesions in the skull and pituitary stalk. CONCLUSION: We report a case of disseminated JXG occurring after treatment of LCH. These clinical co-presentations suggested a close relationship between their pathogenesis.

An aggressive systemic juvenile xanthogranuloma clonally related to a preceding T-cell acute lymphoblastic leukemia.

Juvenile xanthogranuloma (JXG) is a disorder of disputed origin thought to be related to the dermal/interstitial macrophage. A 5-year-old female presented with an aggressive systemic JXG that developed 5 months after the diagnosis of T-cell acute lymphoblastic leukemia (T-ALL). Examination of the T-cell receptor gamma (TCR-γ) rearrangement in T-ALL blasts, JXG infiltrated lymph node biopsies and micro-dissected JXG histiocytes revealed an identical bi-allelic TCR-γ rearrangement in all samples, thus providing evidence for a clonal relationship between T-ALL and JXG in this case.

Xanthogranulomatosis in an adult: lipid analysis of xanthomas and plasma.

Xanthomatosis in the absence of hyperlipidemia is unusual but has been associated with compositional abnormalities of lipoprotein particles. An adult who developed juvenile xanthogranulomatosis in association with oral contraceptive ingestion is reported. Plasma lipids and lipoprotein electrophoresis were normal, as in a few other patients reported with this disorder. However, analysis of cutaneous xanthoma and plasma by thin-layer and gas-liquid chromatography revealed that cholesterol was the principal lipid in xanthoma and that there were no unusual sterols in plasma or tissue. Possible mechanisms of xanthoma formation are discussed. Thus juvenile xanthogranulomatosis should be considered in adults with normolipemic xanthomatosis.

PIP: This article reports the case of a 23-year-old woman with juvenile xanthogranulomatosis, an unusual normolipemic xanthomatosis most often seen in young children. Chromatographic techniques were used to analyze this patient's plasma and xanthomatous tissue for beta-sitosterol, cholestanol, and other sterols that might be present in unusual quantities. The woman had normal fasting levels of plasma cholesterol and triglyceride. The lipoprotein electrophoresis was also normal, and levels of unusual sterols, such as cholestanol and beta-sitosterol, were not increased in plasma or in the xanthomas. Analysis of xanthoma tissue revealed that the predominant lipid was cholesterol. The only medication this patient reported using was a combination oral contraceptive (OC) containing 1 mg of norethindrone and 0.035 mg of ethinyl estradiol. OC use was initiated 1 month before the onset of cutaneous symptoms. The patient refused to discontinue OC use. Since it was not possible to withdraw the drug and observe the patient for regression of the lesions, a causal association of juvenile xanthogranulomatosis with OC use can not be asserted. This case suggests that juvenile xanthogranulomatosis should be considered in adults with normolipemic xanthomatosis. Possible mechanisms for cutaneous xanthoma formation include a defect in local lipid synthesis, an abnormality in local tissue uptake and degradation of lipoproteins that may or may not be coupled with an abnormality in circulating lipoproteins, or local invasion of histiocytes that then accumulate large amounts of cholesterol because of an intrinsic cellular abnormality.