Pyoderma gangrenosum in hematologic malignancies: A systematic review

Background: Pyoderma gangrenosum (PG) is a devastating neutrophilic dermatosis that may be associated with trauma or systemic diseases. The associations, characteristics, and temporal relationship of PG with hematologic malignancies are not well understood. Objective: We performed a systematic review of PG associated with hematologic malignancies using data from case reports, case series, and retrospective studies. Methods: We searched MEDLINE, EMBASE, Scopus, and Web of Science from each database's inception to December 12, 2018. Two reviewers independently selected studies and extracted data. Results: Two hundred seventy-nine publications met the inclusion criteria (340 cases). Myelodysplastic syndrome (MDS) was the most commonly reported hematologic malignancy associated with PG, followed by monoclonal gammopathy of undetermined significance and acute myeloid leukemia. The mean age of patients was 56.5 years, with males being more common. There was a predominance of the ulcerative PG subtype and multifocal distributions across all hematologic malignancies. The majority of MDS cases preceded PG, which was reversed for MGUS. Limitations: The data were limited by reporting bias because PG subtypes rely on the rendered diagnosis reported. In addition, the classification for hematologic malignancies has evolved since 1978. Conclusion: Patients with PG should be evaluated for hematologic malignancies, with MDS being the most common.