Abstract
<jats:p>Introduction. Hairy-cell leukemia is a rare chronic B-cell lymphoproliferative disorder that most often affects the bone marrow and spleen. Hairy-cell leukemia is characterized by leukopenia with neutropenia and monocytopenia, as well as by anemia and thrombocytopenia. Clinical symptoms of (one-, two-, or three-lineage) cytopenia depend on its severity; in general, anemia remains compensated for a long time, while thrombocytopenia is often asymptomatic or shows a mild hemorrhagic syndrome. Differential diagnosis of hairy-cell leukemia should include all conditions associated with cytopenia, lymphocytosis, and splenomegaly. Aim. To present a clinical case of hairy-cell leukemia complicated by thrombosis of the left common iliac vein and inferior vena cava, and to demonstrate its differential diagnosis from systemic lupus erythematosus. Materials and Methods. A clinical case of hairy-cell leukemia is described. A 54-year-old female patient consulted infectious disease specialists, rheumatologists, hematologists, and oncologists due to rash, fever, and bicytopenia. Thrombosis was diagnosed in her left common iliac vein and inferior vena cava. Bone marrow trephine biopsy and immunophenotyping were performed, revealing hairy cells and B-lymphocytes expressing CD19, CD20, CD22, CD11c, and CD103 markers. Results and Discussion. The patient was admitted with complaints of general weakness, fever up to 38.5°С, and widespread skin rash. Examination revealed leukopenia (1.5×109/L), anemia (80 g/L), the presence of IgG antibodies to ribosomal protein P, splenomegaly, and thrombosis of the left common iliac vein and inferior vena cava, as confirmed by abdominal computed tomography. Thrombectomy of the inferior vena cava and the lymph node biopsy were performed. Based on negative immunological tests (ANA, anti-dsDNA antibodies), rheumatologists excluded the presence of an autoimmune disease. Following immunohistochemical analysis of the lymph node biopsy, oncologists ruled out the PEComa. The findings from the trephine biopsy and immunophenotyping were consistent with bone marrow involvement typical of hairy-cell leukemia. Conclusions. An extensive diagnostic workup involving the multidisciplinary approach was conducted to confirm the diagnosis of hairy-cell leukemia.</jats:p>