some hematologic dyscrasias have been associated with thymoma . about 5% of patients with thymoma develop pure red cell aplasia ( prca ) . other hematologic complications occur far less frequently and include autoimmune hemolytic anemia , pernicious anemia , peripheral neutropenia , agranulocytosis , thrombocytopenia and hypogamma - globulinemia . prca disappear after thymectomy but reappear after a latency period even without recurrence of thymoma . aplastic anemia is a rare complication of thymoma and is properly documented in only a few cases . as thymoma - associated hematologic dyscrasias are likewise supposed to be of immunologic origin , we report here a case of very severe aplastic anemia following thymectomy , which was successfully treated with immunosuppressants such as cyclosporine a and g - csf . a 60-year - old woman who complained of cough and dyspnea visited the pulmonary department in april 2000 . chest radiography and computed tomography ( ct ) showed a large mass in the anterior mediastinum , compatible with a thymoma ( figure 1 ) . about sixteen months after the operation , a non - productive cough and high fever developed . a routine hematologic feature was as follows ; hb 5.9 g / dl ; hct 16.9% ; wbc 0.810/l , absolute neutrophil count 0.210/l ; platelets 8610/l . there was no recent antecedent exposure to chemicals and drugs , and serology for hepatitis a , b , c , parvovirus and hiv infection was negative . cytomegalovirus and epstein - barr virus serology was consistent with previous viral exposure . with a high suspicion of aplastic anemia , multiple bone marrow aspirations and biopsy histopathological examination of the bone marrow disclosed extremely low marrow cellularity with increased fatty areas . the patient received transfusions of platelet concentrate and empiric antibiotic therapy for fever and neutropenia during her hospital course . after her neutropenic fever subsided , oral cyclosporine a ( 5 mg / kg / day ) was administered . three months after this treatment , she is clinically stable with no transfusion requirement and without any signs of infection . peripheral blood counts were as follows : hb 10.3 g / dl ; hct 30.2% ; wbc 3.510/l , absolute neutrophil count 1.910/l ; platelets 16410/l . from then to march , 2002 , the patient remained in complete remission with low doses of cyclosporine alone . thymoma is the most common tumor of the anterior mediastinum and is often associated with autoimmune diseases , including myasthenia gravis , polymyositis , hypogammaglobulinemia and various cytopenia . in fact , the overall long - term survival of patients with thymoma is poor once cytopenias occur . although thymectomy is indicated in thymomas with blood dyscrasia , a permanent hematologic remission can be expected in less than 30% of patients with thymoma - associated prca . often , the immunoassociated symptoms like prca disappear after thymectomy but reappear after a latency period , even without recurrence of thymoma , and there is no codified therapy for surgically resistant or relapse cases . in aplastic anemia , thymectomy may fail to resolve aplastic cytopenias as in the case presented by liozon et al . pl et al presented a patient with aplastic cytopenia - associated thymoma in whom complete remission was achieved with surgical removal of the thymoma . alg and cyclosporin , often successful in primary as well as secondary prca and idiopathic aa , should be proposed in unresponsive cases . reported that the combination of octreotide and prednisone produced a complete clinical response in a patient with malignant thymoma and pure red cell aplasia . aplastic anemia is a rare complication of thymoma and is extremely infrequent after thymectomy . in large series , the incidence of aa with thymoma is 01.4% to our knowledge , this is the fourth report of aplastic anemia following thymectomy many pathogenetic mechanisms have been suggested to explain the bone marrow failure seen in aplastic anemia . especially , the role of suppressor t lymphocytes is considered important in the development of aplastic anemia . similarly , thymoma associated with aplastic anemia seems to be caused by the suppression of the bone marrow due to an unbalanced regulation and the inhibitory effects of t lymphocytes on bfu - e and cfu - e as demonstrated in previous reports . because immune mechanisms appear to play an important part in the maintenance and/or progression of thymoma - associated aplastic anemia , this is the rationale for the use of immunosuppressive therapy as one option in the treatment of the disease . cyclosporine a has been associated with good responses in cases of thymoma - associated prca and aplastic anemia , so we decided to treat the patient with cyclosporine a and g - csf . thus , our case seems to be an example for the development of very severe aa , following surgical removal of a thymoma , in which an immunosuppressive agent like cyclosporine a has been efficient .