Atypical Sweet Syndrome As a Contemporaneous Presentation of Relapsed Hairy Cell Leukemia (Hcl)

Case Presentation:

53 year‐old Caucasian male with history of hairy cell leukemia, diagnosed in 1997 with three relapses, now in remission, diabetes mellitus, obesity, hypothyroidism, COPD, hyperlipidemia, and hypertension presented with worsening generalized pain, high‐grade fevers (T=103F), night sweats, and a worsening rash for one month. The patient had a bone marrow biopsy one month ago, which showed residual hairy cell leukemia (10% cellularity). Review of system was significant for weight loss, arthritis, myalgia, and weakness. On physical examination, he had scattered red papules and nodules 5‐10mm in size on his upper back, bilateral upper extremities, and left shoulder.

During the hospitalization, he spike a fever daily and the nodular papular rash spread from his upper extremities and back to his abdomen and lower extremities. Infectious (bacterial, viral, fungal, and mycobacterium) and rheumatological causes were ruled out. CT imaging was negative for abscesses or solid tumors. Skin biopsy showed a focal perivascular infiltrate of neutrophils with nuclear dust and a mild perivascular infiltrate of lymphocytes. Despite the lack of diffuse neutrophilic infiltration in dermis on the biopsy, the skin lesions otherwise appeared to be consistent with Sweet syndrome and the patient was started on prednisone. He became afebrile and the rash resolved after two days, and was discharged home.

Ten days later, the patient returned with persistent high‐grade fever for three days. Despite administering higher doses of prednisone, the patient continued to spike high‐grade fever. Laboratory value was significant for development of pancytopenia. At this time, the suspicion for relapse of hairy cell leukemia recurrence was raised and bone marrow biopsy was repeated. The biopsy showed recurrent hairy cell leukemia and the patient received chemotherapy.

Discussion:

Our patient does not strictly fulfill the diagnostic criteria for Sweet Syndrome; the patient meets one out of two major criteria and all four minor criteria. Our explanation for the lack of diffuse neutrophilic infiltrate is that the patient had a sluggish bone marrow from the hairy cell leukemia and the neutrophils did not penetrate the full layer of dermis. Due to these reasons, we started the patient on prednisone and he responded well initially. However, when the patient returned with refractory high‐grade fever, repeat bone marrow biopsy confirmed overt HCL relapse.

Conclusions:

For patients with a past medical history of leukemia, recurrence can manifest as Sweet syndrome. In our case, the patient had an atypical presentation of Sweet syndrome with limited neutrophilic infiltration on skin biopsy. We suggest lower thresholds for serial bone marrow biopsies to rule out recurrent malignancy in patients who meet criteria for Sweet Syndrome even in cases when the pathological criteria of diffuse neutrophilic infiltrate is not present, especially in patients with prolonged durable remission.