Treatment of juvenile xanthogranuloma.

Juvenile xanthogranuloma (JXG) is generally a benign, self-limited histiocytic disorder of the skin. We report two cases of multisystem JXG presenting with clinical features more commonly seen in Langerhans cell histiocytosis (LCH), including diabetes insipidus and lytic bony lesions. Histologically, the skin lesions demonstrated a histiocytic dermal infiltrate that stained for CD-68, but S-100 and CD1a stains were negative. Treatment according to LCH-based chemotherapy regimens resulted in prompt resolution of symptoms. A literature review of multisystem JXG cases treated with chemotherapy suggests that symptomatic patients can successfully be treated with LCH-based regimens that include both corticosteroids and vinca alkaloids.

Acute Lymphocytic Leukemia with Bilateral Renal Masses Masquerading as Nephroblastomatosis.

Acute lymphoblastic leukemia (ALL) is the most common malignancy in the pediatric patient population. However, renal involvement as the primary manifestation of ALL is rare. We report a case of a 4-year-old boy with bilateral renal lesions resembling nephroblastic rests as the first finding of early stage ALL preceding hematological changes and subsequent classic clinical findings by two weeks. These renal hypodensities completely resolved after one week of induction chemotherapy. This case demonstrates that renal involvement can be the only initial presenting finding of leukemia. Children with lesions resembling nephroblastic rests need appropriate surveillance due to the risk of malignant disease.

N-acetylcysteine renoprotection in methotrexate induced nephrotoxicity and its effects on B-cell lymphoma.

BACKGROUND: Nephrotoxicity is one of the known side effects of methotrexate (MTX) therapy despite the use of conventional protective measures. Our objectives were to evaluate the effects of N-acetylcysteine (NAC) on MTX-induced toxicity in renal tubular cells and to evaluate whether adjunctive use of NAC interferes with MTX antitumor activity in the B-cell lymphoma. METHODS: Kidney Epithelial (Madin-Darby canine kidney [MDCK]) cells were exposed to MTX (10 µM or 100 µM) alone and with NAC (0.2 mM or 0.4 mM). Reactive oxygen species (ROS) generation at 1, 2, 4, and 24 h was measured by flow cytometer. Quantification of total glutathione (GSH) was performed by using GSH assay kit. To measure the impact of NAC on the antitumor activity of MTX, B lymphoma cells were exposed to MTX alone and with NAC. A percentage of apoptosis was measured using fluorescein isothiocyanate in both cell lines. Quantitative data was presented as a means ± standard deviation, and P values were analyzed using the Student's t-test. RESULTS: Apoptosis in MDCK cells were observed after 24 h of incubation with both 10 µM and 100 µM MTX. Maximum ROS generation was observed at 4 h and corresponded to GSH production. Treatment with 0.2 and 0.4 mM of NAC led to decrease percentages of apoptotic MDCK cells. NAC did not change either proliferation or apoptosis of B-cell lymphoma. CONCLUSION: Using NAC for kidney protection may not interfere with the antitumor activity of MTX. Further in vivo studies are warranted to confirm noninterference between MTX and NAC and assess synergistic antitumor effects.

N-acetylcysteine as a novel prophylactic treatment for ifosfamide-induced nephrotoxicity in children: translational pharmacokinetics.

Ifosfamide (IFO), which is used in the treatment of pediatric solid tumors, causes high rates of nephrotoxicity. N-acetylcysteine (NAC), an antidote for acetaminophen overdose, has been shown to prevent IFO-induced renal cell death and nephrotoxicity in both LLCPK-1 cells and a rat model. To facilitate the use of NAC in preventing IFO-induced nephrotoxicity in children, the authors compared the systemic exposure to NAC in children treated for acetaminophen overdose to the systemic exposure of the therapeutically effective rat model. The mean systemic exposure in the rat model was 18.72 mM·h (range, 9.92-30.02 mM·h), compared to the mean systemic exposure found in treated children (14.48 mM·h; range, 6.22-32.96 mM·h). They also report 2 pediatric cases in which NAC-attenuated acute renal failure associated with IFO when given concurrently with their chemotherapy treatment. Systemic exposure to NAC measured in 1 of these cases was comparable to that in the children treated for acetaminophen overdose. These results corroborate NAC's potential to protect against IFO-induced nephrotoxicity in children when used in its clinically approved dose schedule and supports a clinical trial in children.