Abstract: Pyoderma gangrenosum (PG) is a rare chronic ulcerative dermatosis, while multiple myeloma (MM) is a hematological malignancy with relatively high incidence. The concurrent occurrence of these two diseases is clinically rare, and their underlying association remains unclear. This paper reports a case of bullous PG complicating MM during lenalidomide maintenance therapy. The patient achieved complete resolution of skin lesions following treatment with methylprednisolone combined with cyclosporine A and doxycycline for 11 months, but MM recurrence was noted at 6-month follow-up and was treated with multiple therapentic regimens, such as VPd (pomalidomide+bortezomib+dexamethasone). Additionally, we reviewed 14 domestic and international articles on PG complicated with MM, summarized the clinical characteristics of the cases, and explored the potential relationship between the two diseases. These findings suggest that clinicians should be alert to the concurrent occurrence of PG and MM in clinical practice, and attach importance to hematological parameter detection in PG patients and skin symptom monitoring in MM patients.

Key words: bullous pyoderma gangrenosum, multiple myeloma, lenalidomide