Figure 5

(a and b). Radiotherapy-related Sweet's syndrome skin lesions in a woman with malignancy-associated Sweet's syndrome. Radiotherapy associated-exacerbated Sweet's syndrome in a patient with chronic lymphocytic leukemia and cutaneous squamous cell carcinoma. This biopsy-confirmed culture-negative, erythematous-based hemorrhagic, and vesicular-appearing Sweet's syndrome lesion extends from the dorsal (a) to the palmar (b) surface of the radial side of the right index finger and involves the skin between the metacarpal-phalangeal joint and the proximal interphalangeal joint of a 77-year-old woman. She has a prior medical history of hypothyroidism for which she receives daily Synthroid. Twenty-four months earlier, she had been diagnosed with chronic lymphocytic leukemia, which is adequately being managed with 2 mg of Myleran each day; her current white blood cell count of 51,800 cells/mm³ consists of 79% neutrophils, 15% bands, and 2% lymphocytes. More recently (3 months previously), a biopsy confirmed (at both initial microscopic evaluation and subsequent consultation pathology review) cutaneous squamous cell carcinoma involving the left index finger. She was started on an oral antibiotic (ciprofloxaxin), and radiotherapy (in fractionated doses over a period of 3 weeks) to the left index finger tumor was performed; during this treatment, a clinically similar-appearing lesion whose "presentation was suspicious for squamous cell carcinoma" began to develop on her right index finger. Based only on the lesion's morphologic characteristics, a single treatment with radiotherapy was also given; promptly thereafter, the right index finger lesion rapidly increased in size. Within a week, the lesion on the right index finger (as shown in a and b) had grown to a 4- × 4-cm pseudovesicular nodule that nearly involved the entire circumference of the digit and she was referred to the dermatology clinic. The lesion was painful and her leukocyte count was markedly elevated; however, she was (and had been) afebrile. Lesional biopsies for microscopic and culture evaluation were performed. Because the diagnosis of Sweet's syndrome was suspected, daily oral corticosteroid therapy with 60 mg prednisone was started. Oral cephalexin (250 mg 4 times each day for 7 days) and topical 2% mupirocin ointment (3 times each day) were also given. After a week of therapy, the lesion was greatly improved: it was no longer tender and it had decreased in size. Subsequently, the lesion completely resolved. The dose of prednisone was tapered during the next 5 weeks and then discontinued. (From [23] Cohen PR, Kurzrock R: Sweet's syndrome: a neutrophilic dermatosis classically associated with acute onset and fever. Clin Dermatol 2000;18:265–282. Copyright 2000, Reprinted with permission from Elsevier Ltd, Oxford, United Kingdom.)