Bullous Pyoderma Gangrenosum Associated with Hairy Cell Leukemia and Its Complete Response to Cladribine Therapy

Pure Bullous Pyoderma Gangrenosum, a Challenging Clinico-Pathological Diagnosis: Critical Literature Review with Emphasis on Diagnostic Criteria

Pyoderma gangrenosum (PG) is an uncommon, idiopathic, neutrophilic dermatosis characterised by large necrotic ulcers. Occasionally, patients develop atypical presentations, including pustular, bullous, and vegetative lesions. Bullous pyoderma gangrenosum (BPG) is considered an extremely rare form. We describe a case of BPG in a 76-year-old man, with active oncological history, including a recent diagnosis of hairy cell leukemia. Diagnosis of PG was delayed because of atypical clinical presentation that mimicked necrotising fasciitis. The patient was treated with diverse intravenous antibiotics and several surgical procedures. The suspicion of neutrophilic dermatosis arose from the histopathological studies. In the setting of mandatory clinico-pathological correlation, the aim of this report is to point out the morphological characteristics that allow recognition of this uncommon variant of pyoderma gangrenosum.

Skin changes in hairy cell leukemia

Skin lesions have been reported in about 10–12% of hairy cell leukemia (HCL) patients. Most are etiologically related to autoimmune or infectious processes, although secondary cutaneous neoplasms and drug-induced lesions are also reported. However, leukemia cutis with the direct infiltration of the skin by leukemic cells is extremely rare in HCL patients. This paper reviews the epidemiology, pathogenesis, clinical symptoms, diagnosis, and approach to treating skin lesions in HCL. A literature review of the MEDLINE database for articles in English concerning hairy cell leukemia, skin lesions, leukemia cutis, adverse events, infectious, cutaneous, drug reactions, neutrophilic dermatoses, secondary neoplasms, and vasculitis was conducted via PubMed. Publications from January 1980 to September 2020 were scrutinized. Additional relevant publications were obtained by reviewing the references from the chosen articles.

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.