LAUSR

A 36-year-old woman was referred for unexplained pancytopenia (Hb: 90 g/L, platelets: 127 (cid:1) 10 9 /L, neutrophils: 0.2 (cid:1) 10 9 /L) of sudden onset. This patient was followed for chronic hyperalgesia of the hip and stump secondary to an amputation of the left lower limb in the setting of Klippel-Trenaunay syndrome (KTS) requiring multimodal analgesic treatment. Due to the intensification of pain, inhaled analgesic therapy with equimolar mixture of nitrous oxide and oxygen was added 2 weeks before. Bone marrow examination (May-Grünwald-Giemsa, original magnification (cid:1) 100) showed hyperplastic erythropoi-esis with megaloblasts (Image 1A) and late erythroblasts with nuclear budding (Image 1B). Giant metamyelocytes (Image 1C) and multinucleated megakaryocytes ( Image 1D) were also present. Despite normal MCV (92.6 fL), serum vitamin B12 (313 pg/mL)