Coexistence of follicular lymphoma and an unclassifiable myeloproliferative neoplasm in a treatment-naïve patient: A case report

Use of Next Generation Sequencing to Define the Origin of Primary Myelofibrosis

Primary myelofibrosis (PMF) is a chronic myeloproliferative neoplasm (MPN) characterized by progressive bone marrow sclerosis, extra-medullary hematopoiesis, and possible transformation to acute leukemia. In the last decade, the molecular pathogenesis of the disease has been largely uncovered. Particularly, genetic and genomic studies have provided evidence of deregulated oncogenes in PMF as well as in other MPNs. However, the mechanisms through which transformation to either the myeloid or lymphoid blastic phase remain obscure. Particularly, it is still debated whether the disease has origins in a multi-potent hematopoietic stem cells or instead in a commissioned myeloid progenitor. In this study, we aimed to shed light upon this issue by using next generation sequencing (NGS) to study both myeloid and lymphoid cells as well as matched non-neoplastic DNA of PMF patients. Whole exome sequencing revealed that most somatic mutations were the same between myeloid and lymphoid cells, such findings being confirmed by Sanger sequencing. Particularly, we found 126/146 SNVs to be the e same (including JAK2V617F), indicating that most genetic events likely to contribute to disease pathogenesis occurred in a non-commissioned precursor. In contrast, only 9/27 InDels were similar, suggesting that this type of lesion contributed instead to disease progression, occurring at more differentiated stages, or maybe just represented “passenger” lesions, not contributing at all to disease pathogenesis. In conclusion, we showed for the first time that genetic lesions characteristic of PMF occur at an early stage of hematopoietic stem cell differentiation, this being in line with the possible transformation of the disease in either myeloid or lymphoid acute leukemia.

Polycythaemia following treatment of lymphoplasmacytic lymphoma

A 61-year-old man presented to the department of clinical haematology in February 2016 with symptomatic anaemia, generalised lymphadenopathy and hepatomegaly. Routine investigations showed severe anaemia with the presence of lymphoplasmacytoid cells in the peripheral smear, and bone marrow examination with IHC and serum protein electrophoresis confirmed diagnosis of lymphoplasmacytic lymphoma. The patient received supportive transfusion therapy and combination chemotherapy. After VI cycles, the patient had a complete haematological response with marrow in remission. Maintenance rituximab was planned every 3 months for 2 years. At the time of first dose of maintenance rituximab, his haemoglobin (Hb) was 189 g/L with low normal erythropoietin level. During the last 3 years follow-up, his Hb ranged between 16.5 and 20.1 g/dL. All causes of secondary polycythaemia were ruled out. Workup for polycythAemia vera (PV), including JAK-2 and bone marrow, was not suggestive of PV. We labelled it as a case of polycythaemia due to undetermined aetiology.

Clinical significance and epidemiological evolution of epitrochlear lymphadenopathy in pre- and post-highly active antiretroviral therapy era: A systematic review of the literature

Epitrochlear lymphadenopathy is believed to be associated with distinct etiologies, however the evidence for the same is lacking. We systematically reviewed the reported causes of an enlarged epitrochlear lymph node and compared them over different time periods. Epitrochlear lymphadenopathy was encountered in a wide range of diseases, and we found no association with any particular disease.