Makis et al. Journal of Medical Case Reports 2010, 4:281 http://www.jmedicalcasereports.com/content/4/1/281 Page 4 of 6 Figure 3 Almost confluent ulcers on the buttocks. treatment with corticosteroids the diagnosis of Sweet’s syndrome was established (Appendix). The vesicobullous features of the rash, which are not common presenta- tions in Sweet’s syndrome, led the differential diagnosis to a superficial bullous variant of pyoderma gangrenosum, probably associated with an emerging hematological malignancy [3]. Therefore, a screening for a concomitant malignancy (bone marrow aspirate and trephine, chest X-ray and an abdominal ultrasound) was performed with no abnormal findings. Figure 4 Histopathology of a skin lesion. Spongiotic epidermis and exocytosis of neutrophils with focally confluence into microabcesses. Intense edema of the upper dermis and a dense neutrophilic inflammatory infiltrate of the lower dermis. (Hematoxylin-Eosin, × 100).