Odontoid infiltration and spinal compression in Farber Disease: reversal by haematopoietic stem cell transplantation.

Farber disease (FD) is a lysosomal storage disorder caused by accumulation of ceramide in various organs and tissues, most notably the central nervous system, subcutaneous tissues and respiratory tract. We report a girl who developed major destructive bone involvement, which affected the odontoid process and produced spinal compression at 9 years of age. Bone involvement was proven histologically but resolved, as assessed by serial MRI scanning, following matched unrelated donor haematopoietic stem cell transplantation. This transplant resulted in only partial donor chimerism (less than 10 % donor cells in peripheral blood), yet this was sufficient to almost normalize acid ceramidase levels in leukocytes and to produce dramatic improvements in subcutaneous nodules and joint mobility as well as the beneficial effect on the involved bone. Unfortunately, the transplant was rejected after 2 years but the patient was rescued from an aplastic state by successful haploidentical peripheral blood stem cell transplantation and remained a full donor chimera without recurrence of the bone involvement and with steadily improving mobility at the age of 17 years. We describe an FD patient who presented with severe destruction of the odontoid by inflammatory tissue which was reversed after long-term control achieved by allogeneic hematopoietic stem cell transplantation. After extensive literature search, we believe that this is the first report of bony involvement in Farber disease.