Myeloproliferative and lymphoproliferative malignancies occurring in the same patient: a nationwide discovery cohort.

Myeloid and lymphoid malignancies are postulated to have distinct pathogenetic mechanisms. The recent observation that patients with a myeloproliferative neoplasm have an increased risk of developing lymphoproliferative malignancy has challenged this assumption. We collected a nationwide cohort of patients with both malignancies. Patients diagnosed in 1990-2015 were identified through the national Danish Pathology Registry. We identified 599 patients with myeloproliferative neoplasm and a concomitant or subsequent diagnosis of lymphoma. Histopathological review of the diagnostic samples from each patient led to a final cohort of 97 individuals with confirmed dual diagnoses of myeloproliferative neoplasm and lymphoma. The age range at diagnosis was 19-94 years (median: 71 years). To avoid the inclusion of cases of therapy-induced myeloproliferative neoplasm occurring in patients previously treated for lymphoma, only patients with myeloproliferative neoplasm diagnosed unequivocally before the development of lymphoma were included. The average time interval between the diagnoses of the two malignancies was 1.5 years. In the majority of patients (90%) both diagnoses were established within 5 years from each other. Among the lymphoma entities, the frequency of peripheral T-cell lymphomas was markedly increased. Interestingly, all but one of the T-cell lymphomas were of angioimmunoblastic type. These findings suggest that myeloproliferative neoplasm and lymphoproliferative malignancy developing in the same patient may have common pathogenetic events, possibly already at progenitor level. We believe that the molecular characterization of the newly developed biorepository will help to highlight the mechanisms driving the genesis and clonal evolution of these hematopoietic malignancies.

Two cases of tick-borne transmitted tularemia on Southern Zealand, Denmark.

Francisella tularensis is a zoonotic bacterium which causes the infection tularemia. It colonizes invertebrates and vertebrates, counting wildlife animals and rodents. Humans can become infected through several pathways including contaminated food, water, and handling animals and due to bites from vectors. Ticks are known to cause tularemia in humans, though their role as a disease transferring vector is not well understood. We describe two case reports of tularemia transferred by ticks on Southern Zealand, Denmark. Case 1: A 49-year-old woman presented with lymphadenopathy and an unhealed sifting wound after a tick bite. Serology tests for F. tularensis were initially negative but turned positive five weeks after symptom onset, when abscess drainage was performed. Gentamicin and ciprofloxacin treatment improved the patient's clinical condition, and she completely recovered. Case 2: A 74-year-old man presented with malaise, fever, and an abdominal ulcer allegedly caused after a vector bite. CRP and leukocytes were increased, while serology tests for F. tularensis were negative. Doxycycline treatment improved the patient's clinical condition, and he completely recovered. Three weeks after symptom onset, renewed serology tests for F. tularensis were positive.