Coexistent hairy cell leukaemia and hepatosplenic t-cell lymphoma: a case report

BACKGROUND: Hairy cell leukaemia (HCL) is a chronic B-cell leukaemia characterized by expansion of neoplastic cells in the spleen, bone marrow and blood. Symptoms of HCL are related to pancytopenia and immune deficiency. Patients with HCL have an increased risk of second malignancy either in a form of synchronous disease or in a form of an increased incidence of a second neoplasm after the treatment of HCL. Hepatosplenic T-cell lymphoma (HSTCL) is a rare form of aggressive extranodal T-cell lymphoma. Its pathogenesis is connected to a chronic immune deficiency status and its coexistence with other neoplasms is practically non-existent. CASE: We present a case of a 53-year-old female patient suffering from hepatosplenomegaly, peripheral lymphadenopathy and related B symptoms. An excisional biopsy of the enlarged axillary lymph node revealed partial infiltration with CD3+/CD56+/TIA + T cell lymphoma. Bone marrow trephine biopsy and flow cytometric immunophenotypization of bone marrow cells and peripheral blood showed presence of two types of neoplastic cells in the peripheral blood and in the bone marrow (composite lymphoma). One of them showed typical morphologic characteristics and immunohistochemical features of HCL, while another one was morphologically and immunophenotypically consistent with the diagnosis of HSTCL, respectively. The patient was treated with multivalent chemotherapy including rituximab but all treatments turned out to be only partially effective. While HCL responded to the treatment, HSTCL was refractory to the chemotherapy and the patient died 7 months after the initial diagnosis because of haematemesis induced by Mallory-Weiss syndrome. CONCLUSION: This is the first recorded case of coexistent HCL and HSTCL in the same patient. A multidisciplinary approach, encompassing careful morphology interpretation, immunophenotypic, cytogenetic and molecular analyses, is mandatory to obtain an accurate diagnosis of composite lymphoma. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9354870531161685.