Myelodysplastic syndrome presenting as generalized granulomatous dermatitis.

Background: Granulomatous dermatitis has rarely been reported as a manifestation of leukemia or myelodysplastic syndrome (MDS). We describe a case of widespread granulomatous dermatitis that preceded the diagnosis of MDS by 2 years.

Observations: A 71-year-old man developed a generalized, mildly pruritic eruption that slowly progressed over a 2-year period. Punch biopsy specimens demonstrated interstitial dermal granulomatous inflammation. A complete blood cell count with differential showed marked monocytosis, and the findings of a subsequent biopsy of the bone marrow confirmed MDS. Lenalidomide therapy was initiated, and the patient's skin condition improved after 6 weeks of treatment; however, his MDS progressed to acute myeloid leukemia, and he died shortly thereafter.

Conclusions: There is a paucity of literature documenting the occurrence of granulomatous dermatitis as a manifestation of an underlying hematologic disorder. This case illustrates a striking example of widespread granulomatous dermatitis heralding the onset of MDS. It is imperative that the dermatologic community recognize the rare association of granulomatous dermatitis with myelodysplasia, because the cutaneous manifestations may be the presenting finding and can precede the development of leukemia by several years.