B-Cell Acute Lymphoblastic Leukemia Presenting as a Hidradenitis Suppurativa Flare

Summary: Hidradenitis suppurativa (HS) is a chronic inflammatory condition characterized by recurrent painful nodules, abscesses, and fistulas of hair-bearing regions1. Chronic inflammation can promote DNA damage, immune dysregulation, and cell proliferation1. Emerging reports suggest a possible association with hematologic cancers2-3. We present a case of leukemia cutis presenting as an HS flare in a patient newly diagnosed with B-cell acute lymphoblastic leukemia (B-ALL). A previously healthy 26-year-old male was admitted for B-ALL chemotherapy induction. Dermatology was consulted for possible leukemia cutis of the lower abdomen due to nodular skin thickening and subcutaneous nodules detected on CT scan. On exam, the patient had Hurley stage II HS of the lower pannus and bilateral axillae. He reported one month of worsening skin lesions with no prior HS diagnosis. Biopsy of the lower abdominal plaque showed diffuse dermal infiltrate of large cells with hyperchromatic nuclei expressing CD45, TdT, CD10, CD19, CD34, and CD22 consistent with B-ALL. A diagnosis of leukemia cutis presenting as HS flare was made. This case adds to the few reports of HS concurrent with hematologic malignancy2-3. HS flare was a presenting symptom of B-ALL in our patient. However, further research is needed to understand the relationship between HS and B-ALL.