CASE REPORT
A 6-year-old boy with Neurofibromatosis type-1 (NF-1), presented with
symptoms of progressive pallor, fever and muco-cutaneous bleeding. He
was diagnosed to have acute myeloid leukaemia (AML) after bone marrow
aspiration, flow cytometry based immunophenotyping and cytogenetic
evaluation. The patient was treated with standard multidrug intensive
chemotherapy (MRC-15 AML Protocol3), following which
the child was in remission. Both the parents had genetic disease, NF1 in
father and skeletal dysplasia (hereditary multiple exostosis) in mother.
Sixteen months from initial diagnosis, the child presented with
prolonged fever and diffuse erythematous papules distributed over arms,
legs, face, trunk and neck. Investigations revealed leucocytosis,
thrombocytopenia and circulating blasts in peripheral smear. A bone
marrow aspiration and biopsy confirmed relapse of the AML with the
immunophenotype and cytogenetics similar to the primary disease. The
child was hence planned for salvage chemotherapy followed by
consolidation with hematopoietic stem cell transplantation (HSCT). The
skin lesions were assumed to be leukemic deposits and hence were not
biopsied upfront for histological evaluation.
The child received first cycle of chemotherapy (Azacytidine based),
following which there was clinical improvement in terms of disappearance
of circulating blasts and defervescence of fever. Contrary to the
clinical expectation, the skin lesions however, continued to progress
with crops of blotchy papules with increased tenderness (Fig 1A). A
biopsy of the skin lesion was hence pursued which showed dense
neutrophilic infiltration in the dermis suggestive of acute neutrophilic
dermatosis also termed, Sweet’s syndrome (Fig 1B). The patient was
initiated on oral steroids (prednisolone 2mg/kg for a week followed by
tapering doses over next 2 weeks) following which there was remarkable
response. After 2 weeks, on tapering steroids, there was recurrence or
flare of skin lesions. Oral colchicine was hence added as a steroid
sparing agent following which there was complete response. The steroids
could be tapered and stopped in next 1 week. Oral colchicine was used
for a total of 4 weeks. The child received 3 cycles of salvage
chemotherapy (Azacytidine followed by Fludarabine and high dose
cytarabine) following which the disease was in morphological remission
(minimal residual disease 1.7%). He underwent a haplo-identical stem
cell transplantation with mother as the stem cell donor. He remains
disease free and well at 24 months from HSCT.