LAUSR

A 41-year-old Vietnamese woman presented with a platelet count of 23 × 10/L and gum bleeding. On presentation, the remainder of the full blood count was normal with a haemoglobin level of 128 g/L and a white cell count of 6.9 × 10/L. Her blood film demonstrated normal morphology of red cells, white cells and platelets. She was diagnosed with immune thrombocytopenia and commenced on prednisone. She partially responded to prednisone and required high doses of 25–50 mg daily to maintain a platelet count greater than 30 × 10/L. One month later, she developed bilateral deep vein thromboses while thrombocytopenic with a platelet count of 37 × 10/L, necessitating the use of intravenous immunoglobulin (IVIG) to increase her platelet count prior to commencing therapeutic anticoagulation. An inferior vena cava filter was inserted as her response to IVIG was short-lived and her platelet count remained below 50 × 10/L despite 50 mg of prednisone daily (Fig. 1). A bone marrow biopsy was consistent with peripheral platelet destruction, with no evidence of lymphoma on flow cytometry. A thrombophilia screen was negative. Malignancy screening with computed tomography of the chest/abdomen/pelvis demonstrated bilateral dermoid cysts (8 × 10 × 6.5 cm and 4 × 3 × 4 cm) without compression of the lower limb venous supply. Tumour markers, including CA19.9, CA125, CA15.3, CEA and beta-human chorionic gonadotropin, were normal. The dermoid cysts were removed and shown by histopathology to be mature cystic teratomas with no malignant components (Fig. 2). There was a lymphocytic infiltrate, which was a mixture of B and T cells. Cytology of peritoneal washings was negative for malignancy. Her platelet count increased to 209 × 10/L 1 week after the operation. Her inferior vena cava filter was removed and anticoagulation was ceased after 6 months. She has not experienced any recurrence of thrombocytopenia or venous thrombosis. Immune thrombocytopenia is a paraneoplastic phenomenon seen in many solid malignancies including lung, breast, renal cell carcinoma and ovarian carcinoma; however, it has never been described in benign ovarian dermoid cysts. The aetiology of paraneoplastic thrombocytopenia is thought to be immune dysregulation. There is a known association between ovarian dermoid cysts and autoimmune haemolytic anaemia (AIHA). In previous cases, some patients responded to high-dose steroids whereas others required splenectomy with temporary improvement of anaemia. Cyst removal always