Pulmonary extramedullary haematopoiesis managed by radiation therapy: A case report and review of literature.

Extramedullary haematopoiesis is a very rare non-oncologic entity, occurring in multiple blood disorders. It refers to haematopoiesis occurring outside the bone marrow. Here we report a patient with an extramedullary haematopoiesis lung mass managed by radiation therapy delivering 20Gy in ten fractions. To the best of our knowledge, this is the first case managed with this scheme. A 54-year-old man was referred for acute hypercapnic respiratory failure. A computed tomography scan (CT-scan) had demonstrated 16 years ago bilateral pulmonary masses. The patient was diagnosed with extramedullary haematopoiesis based on concordant haematological history and typical paravertebral masses. The patient had a previous history of clear cell carcinoma of the right kidney, managed by surgery 5 years ago (pT1aN0M0 on histologic examination). The acute hypercapnic respiratory failure was suggested to be secondary to his pulmonary extramedullary haematopoiesis lesions. After multidisciplinary board discussion, radiation therapy was decided to treat the right extramedullary haematopoiesis lung mass, delivering 20Gy in ten fractions. At 3 months, the patient experienced excellent tolerance with a significant improvement in respiratory symptoms. Tramadol and non-invasive ventilation could be stopped. CT-imaging at 6 months was consistent with partial response and decrease in arteriovenous circulation within the right mass. At 12-months follow-up, patient presented with no thoracic symptoms. Pulmonary extramedullary haematopoiesis is a very rare entity. Its diagnosis should not be underestimated. Radiation therapy delivering 20Gy in ten fractions is a reasonable and safe therapeutic option.