Picture of the Month Quiz
An 8-year-old boy was born with a vascular mass involving the left axilla. The affected skin showed a violaceous purpuric plaquelike lesion with induration and telangiectasia (Figure). His blood cell count was notable for severe thrombocytopenia (platelet count of 17 x 103/μL; to convert to x109/L, multiply by 1). Hemoglobin level, white blood cell count, prothrombin time/international normalized ratio, partial thromboplastin time, fibrinogen level, and D-dimer level were normal.
Treatment with oral corticosteroids for 1 year showed variable response. At the age of 14 months, treatment with vincristine sulfate was initiated. This resulted in normalization of the platelet count and a decrease in the mass size. On the last clinic visit 6 years after discontinuing vincristine treatment, the platelet count was 343 x 103/μL and the lesion continued to shrink. However, clinical examination showed atrophy of the muscles and soft tissue of the left axilla and chest wall with some limitation of range of motion of the left shoulder.
What is your diagnosis?
For a complete discussion of this month's case, read next month's Picture of the Month—Quiz Case. -For a complete discussion of last month's case, read this month's Picture of the