In evaluating a patient with hemarthrosis, it is customary to consider trauma, neoplasm (1,2), infection, and coagulation abnormalities in the differential diagnosis. Hemorrhagic effusions are also seen with neuropathic joints (3), and recent reports have linked hemarthrosis to the pseudogout syndrome (4), sickle trait (5), and metallic joint prostheses (6). We have just had the opportunity to study 2 patients in whom painful hemarthrosis was the presenting manifestation of a myeloproliferative syndrome.
The purpose of this review is to illustrate the wide range of radiological abnormalities in myelofibrosis. Myelofibrosis, also called myeloid metaplasia, is a myeloproliferative disorder of unknown etiology. The common imaging findings in patients with myelofibrosis are osteosclerosis, hepatosplenomegaly, and lymphadenopathies. In addition, extramedullary hematopoiesis may develop in multiple sites such as chest, abdomen, pelvis, and central nervous system, simulating malignant disease. Selected plain-film, CT, and MR images in patients with myelofibrosis are shown as pictorial essay to allow ready recognition of the most common imaging abnormalities of the disease.
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.