Case of pyoderma gangrenosum showing oral and genital ulcers, misdiagnosed as Behcet's disease at first medical examination.

It is occasionally difficult to distinguish between Behcet's disease (BD) and pyoderma gangrenous (PG). Our case showed ulcers of the oral, vaginal and perineal areas, and in the ileum, thus resulting in our initial diagnosis of BD. However, the patient showed a continued leukopenia, and she was subsequently diagnosed by bone marrow biopsy as having a myelodysplastic syndrome, which will sometimes accompany PG. In addition, following a hysterectomy, the ulcers of the stump in the vagina and the perineum showed the characteristic findings of a PG-like destructive ulceration. Based on these findings, we finally diagnosed our case to have PG.