The occurrence of juvenile myelomonocytic leukemia (JMML), juvenile xanthogranuloma (JXG), and neurofibromatosis type 1 (NF1) together is relatively rare. Approximately only 20 cases have been reported in the literature. It is debated whether children with NF1 and JXG are at higher risk of developing JMML than children with NF1 alone. We present the case of a boy primarily diagnosed with NF1 with coexisting JXG who developed JMML at the age of 22 months. The clinical course from initial presentation to final diagnosis is detailed and the genetic features and hematologic characteristics are discussed. We report this case to underscore the importance of close monitoring of blood count and strict clinical follow-up in children presenting with concurrent NF1 and JXG and provide a possible explanation for this association.

Scleromyxedema is a rare progressive cutaneous mucinosis, usually associated with a systemic involvement and paraproteinemia. Its aetiology remains unknown. The therapeutic options include numerous treatment modalities, however, no standard treatment exists as the rarity of this disease prevents the execution of controlled therapeutic trials. This paper reports a case of a 38-year-old male with progressive scleromyxedema associated with gammopathy. Initially, the patient was treated with prednisolone and later etretinate was added to the therapeutic schedule with quite good clinical improvement. However, after 6 months of treatment, several adverse effects were observed: hypercholesterolemia, hypertriglyceridaemia and cataract of the right eye. The patient was consulted by dermatologists in Warsaw and Gdansk as well as by a haematologist. The patient was excluded from oncological treatment. Melphalan therapy was not recommended as it is associated with very toxic side effects. IVIG treatment (intravenous immunoglobulin) was not initiated because of financial issues. As the disease progressed, treatment with plasmapheresis was introduced. The patient received 4 cycles of the therapy. It was well-tolerated by the patient and gave satisfactory, but temporary results. In order to obtain long-lasting improvement the patient was treated with IVIG (21.0 g/dose for 5 consecutive days). This treatment modality seems to have resulted in a more stable improvement.