Rosai-Dorfman Disease: A previously unreported association with Sickle Cell Disease

BACKGROUND: Rosai-Dorfman Disease is an uncommon benign systemic histio-proliferative disease. This is the first time the disease, although more common in people of African descent, is described in association with Sickle cell disease. CASE PRESENTATION: A Nigerian boy born started a complex medical history with post-natal anemia of unknown origin. Subsequently he was diagnosed with Sickle Cell Anemia (Hb SS). At age 3 during a routine review, he was noted to have generalised massive lymphadenopathy. He had further reoccurrences of this lymphadenopathy, but investigations did not reveal the cause until age five. At this point, because of the progressive lymph node enlargement, a biopsy was performed, and he was diagnosed with Rosai-Dorfman Disease. Since that time, the child has had further episodes of intermittent massive lymphadenopathy, particularly associated with Sickle Crisis. His medical history has been further complicated by development of complications from Sickle Cell Disease, cardiomyopathy and an autoimmune hemolytic anemia with multiple alloantibodies. CONCLUSION: This case for the first time presents the co-existence of two diseases, of increased prevalence in those of African descent, but to date not described in the literature to occur concurrently

A Hidden Population of Massive Stars with Circumstellar Shells Discovered with the Spitzer Space Telescope

We have discovered a large number of circular and elliptical shells at 24 microns around luminous central sources with the MIPS instrument on-board the Spitzer Space Telescope. Our archival follow-up effort has revealed 90% of these circumstellar shells to be previously unknown. The majority of the shells is only visible at 24 microns, but many of the central stars are detected at multiple wavelengths from the mid- to the near-IR regime. The general lack of optical counterparts, however, indicates that these sources represent a population of highly obscured objects. We obtained optical and near-IR spectroscopic observations of the central stars and find most of these objects to be massive stars. In particular, we identify a large population of sources that we argue represents a narrow evolutionary phase, closely related or identical to the LBV stage of massive stellar evolution.Comment: 23 pages, 9 figures, accepted for publication in A

European Bone Marrow Working Group trial on reproducibility of World Health Organization criteria to discriminate essential thrombocythemia from prefibrotic primary myelofibrosis

BACKGROUND: The World Health Organization classification of myeloproliferative neoplasms discriminates between essential thrombocythemia and the prefibrotic phase of primary myelofibrosis. This discrimination is clinically relevant because essential thrombocythemia is associated with a favorable prognosis whereas patients with primary myelofibrosis have a higher risk of progression to myelofibrosis or blast crisis. DESIGN AND METHODS: To assess the reproducibility of the classification, six hematopathologists from five European countries re-classified 102 non-fibrotic bone marrow trephines, obtained because of sustained thrombocytosis. RESULTS: Consensus on histological classification defined as at least four identical diagnoses occurred for 63% of the samples. Inter-observer agreement showed low to moderate kappa values (0.28 to 0.57, average 0.41). The percentage of unclassifiable myeloproliferative neoplasms rose from 2% to 23% when minor criteria for primary myelofibrosis were taken into account. In contrast, the frequency of primary myelofibrosis dropped from 23% to 7%, indicating that the majority of patients with a histological diagnosis of primary myelofibrosis did not fulfill the complete criteria for this disease. Thus, over 50% of cases in this series either could not be reproducibly classified or fell into the category of unclassifiable myeloproliferative neoplasms. CONCLUSIONS: World Health Organization criteria for discrimination of essential thrombocythemia from prefibrotic primary myelofibrosis are poorly to only moderately reproducible and lead to a higher proportion of non-classifiable myeloproliferative neoplasms than histology alone