Cho Ah Ra, Cha Young Joo, Kim Hye Ryoun, Park Eun Kyung, Cha Eun Jong
Department of Laboratory Medicine, Chung-Ang University, Seoul, Korea.
Korean J Lab Med. 2010 Jun;30(3):244-8. doi: 10.3343/kjlm.2010.30.3.244.
The association of thymoma with pure red cell aplasia has been well documented, but amegakaryocytic thrombocytopenia is not a recognized paraneoplastic syndrome complicating thymoma. We report a case of thymoma-complicated pure red cell aplasia and amegakaryocytic thrombocytopenia in a 73-yr-old woman. Pure red cell aplasia was diagnosed seven months after the detection of thymoma. One year after the diagnosis of pure red cell aplasia and seven months after thymectomy, bone marrow aspiration and biopsy showed an absence of megakaryocytes, marked erythroid hypoplasia with normal myeloid series. A diagnosis of amegakaryocytic thrombocytopenia and pure red cell aplasia was made. Oral steroid maintenance therapy resulted in recovery of platelet count. She has still transfusion-dependent anemia but platelet and neutrophil counts had been maintained in normal range for more than five months, until the last follow-up. We think that autoreactive T cells may induce a clinical autoimmune response even after eradication of thymoma, and aplastic anemia as a late complication following thymectomy was described in previous cases. This patient also has to be under a close observation because of the possibility to evolve into aplastic anemia.
胸腺瘤与纯红细胞再生障碍性贫血的关联已有充分文献记载，但无巨核细胞性血小板减少症并非胸腺瘤并发的一种公认的副肿瘤综合征。我们报告一例73岁女性患者，其胸腺瘤并发纯红细胞再生障碍性贫血和无巨核细胞性血小板减少症。在发现胸腺瘤七个月后诊断为纯红细胞再生障碍性贫血。在诊断纯红细胞再生障碍性贫血一年后且胸腺切除术后七个月，骨髓穿刺和活检显示无巨核细胞，红系显著发育不全而髓系正常。诊断为无巨核细胞性血小板减少症和纯红细胞再生障碍性贫血。口服类固醇维持治疗使血小板计数恢复。她仍依赖输血治疗贫血，但直至最后一次随访，血小板和中性粒细胞计数已维持在正常范围超过五个月。我们认为自身反应性T细胞即使在胸腺瘤切除后仍可能引发临床自身免疫反应，且此前病例中有胸腺切除术后再生障碍性贫血作为晚期并发症的描述。由于有发展为再生障碍性贫血的可能性，该患者也必须密切观察。
