[Development of severe aplastic anemia in a girl with Hashimoto's thyroiditis and papillary thyroid carcinoma].

A 14-year-old girl was admitted because of general fatigue and cervical lymphadenopathy. She showed bilateral struma (IInd degree) and enlargement of her left cervical lymph nodes. Laboratory data revealed neutropenia (219/microliter) and thrombocytopenia (Plt 5.1 x 10(4)/microliter) with mild anemia (Hb 11.1 g/dl), and the bone marrow aspirate and biopsy specimens showed hypocellularity. In addition, auto-antibodies against thyroid peroxidase (TPO) and thyroglobulin (TG) were highly elevated. Computed tomography of the neck showed a nodule in the left thyroid lobe with marked lymphadenopathy, and fine needle aspiration biopsy demonstrated papillary thyroid carcinoma with Hashimoto's thyroiditis and metastasis to the lymph nodes. One month after left thyroid lobectomy and cervical lymphadenectomy, the patient's condition progressed to very severe aplastic anemia, and she received immunosuppressive therapy consisting of cyclosporin A and anti-thymocyte globulin. Hematologically, partial and complete responses were obtained three and six months later, respectively. Of interest, anti-TPO and TG antibody titers remarkably decreased after immunosuppressive therapy. The patient had HLA-DR 2(DRB 11501) and DR 8(DRB 10802). The former is frequently found in patients with cyclosporin A-dependent aplastic anemia, and the latter is frequently found in Asian patients with Hashimoto's thyroiditis, suggesting an underlying autoimmune background for the simultaneous outbreak of aplastic anemia and Hashimoto's thyroiditis complicated by thyroid carcinoma.