INTRODUCTION:Thymomas are known to have paraneoplastic syndromes with significant morbidity resulting from immune dysregulation. Two rare conditions include Good’s syndrome and Evans’ Syndrome, not yet reported with thymoma.
CASE PRESENTATION:A 64 year-old woman demonstrated an anterior mediastinal mass (Figure 1) Needle aspiration biopsy revealed thymoma. She developed recurrent respiratory infections and sepsis. Immunologic evaluation revealed hypogammaglobulinemia. Bone marrow aspirate revealed low CD4+ lymphocytes and a reduced CD4:CD8 ratio, with undetectable B-cells. These findings, in the setting of thymoma, constitute Good’s Syndrome –an uncommon cause of B and T cell immunodeficiency. The patient received immunoglobulin replacement with temporary improvement.Several months later the patient developed fatigue, pallor, and petechiae of the extremities. Studies revealed a hemoglobin of 3.3g/dL, hematocrit of 8.4%, and platelet count of 4,000. Indirect bilirubin and LDH were elevated, haptoglobin was <35mg/dL, and direct Coombs test was positive, indicating autoimmune hemolytic anemia with thrombocytopenia. This represents Evans Syndrome, a rare immune-mediated condition. Methylprednisolone, IV immune globulin, radiation therapy and splenectomy were attempted. She continued to have recurrent hemolytic anemia, thrombocytopenia, and respiratory infections until she expired six months later.
DISCUSSIONS:Hypogammaglobulinemia with thymoma was first described by Robert Good in 1954.(1) It is uncommon, occurring in 3-6% of patients. Features include hypogammaglobulinemia, reduced or absent B-cells, and CD 4+ T-cell dysfunction.(1)The hallmark is recurrent sinopulmonary infection, along with opportunistic infections caused by T-cell impairment. The etiology is unclear; one possible explanation is abnormal cytokine influence over T- and B-cell growth and differentiation. Another theory suggests that autoantibodies directly hinder immunoglobulin production. (1)Management of Good’s syndrome consists of treating underlying thymoma with surgical resection, chemotherapy and/or radiation. Immunoglobulin replacement can help reduce recurrent infections. Responses are variable, and symptoms can persist despite surgical resection and medical therapy.(1)Robert Evans first described an association between idiopathic thrombocytopenic purpura and autoimmune hemolytic anemia in 1951.(2) He hypothesized that autoantibodies directed against red blood cells were also present against platelets.(2) The syndrome is rare and sporadically reported, making the exact frequency of Evans’ syndrome unknown.It appears that an underlying deficiency in humoral and cell-mediated immunity may be a causative factor in Evan’s syndrome. Quantitative abnormalities in T-cells and immunoglobulins are common.(2) This suggests that defective immune control may result in autoimmune cytopenias and abnormal lymphoproliferation. Concomitant conditions of immune dysfunction such as diabetes mellitus, rheumatoid arthritis, HIV, and organ transplantation are often present in case reports of Evan’s syndrome.(2)The course of Evans syndrome is chronic and relapsing. Steroids, immunoglobulin therapy, cytotoxic medications, and splenectomy may palliate the process, but are not curative, and a poor prognosis often results.
CONCLUSION:Thymomas are the most common tumor of the anterior mediastinum, with paraneoplastic syndromes that cause significant morbidity due to immune dysfunction. Good’s syndrome is well-described but uncommmon. Evans’ syndrome has been described with other immunocompromised states, but this case represents the first to be reported with thymoma. Comprehensive testing of immune function is recommended at the time of diagnosis with thymoma.(1) Early detection of immune dysfunction is crucial, as immune replacement and targeted antimicrobial therapy may reduce the morbidity and complications associated with chronic infections and immunodeficiency.
DISCLOSURE:Carrie Samiec, None.