Differential diagnosis of perinatal hypophosphatasia: radiologic perspectives

Perinatal hypophosphatasia (HPP) is a rare, potentially life-threatening, inherited, systemic metabolic bone disease that can be difficult to recognize in utero and postnatally. Diagnosis is challenging because of the large number of skeletal dysplasias with overlapping clinical features. This review focuses on the role of fetal and neonatal imaging modalities in the differential diagnosis of perinatal HPP from other skeletal dysplasias (e.g., osteogenesis imperfecta, campomelic dysplasia, achondrogenesis subtypes, hypochondrogenesis, cleidocranial dysplasia). Perinatal HPP is associated with a broad spectrum of imaging findings that are characteristic of but do not occur in all cases of HPP and are not unique to HPP, such as shortening, bowing and angulation of the long bones, and slender, poorly ossified ribs and metaphyseal lucencies. Conversely, absent ossification of whole bones is characteristic of severe lethal HPP and is associated with very few other conditions. Certain features may help distinguish HPP from other skeletal dysplasias, such as sites of angulation of long bones, patterns of hypomineralization, and metaphyseal characteristics. In utero recognition of HPP allows for the assembly and preparation of a multidisciplinary care team before delivery and provides additional time to devise treatment strategies

Rare B-Cell Non-Hodgkin’s Lymphomas in Childhood and Adolescence

Non-Hodgkin’s lymphoma (NHL) results from malignant proliferation of lymphocytes and is generally restricted to lymphoid tissue such as lymph nodes, Peyer’s patches, and spleen. However, pediatric NHL can rarely and solely arise in other anatomical sites, such as the kidney, skin, lung, eye, bone, stomach, or cavities as an effusion. Adult-type lymphomas (chronic lymphocytic leukemia and multiple myeloma) have scarcely been reported in children. Understanding of these rare pediatric B-NHLs is mainly based on small pediatric case series or adult studies. Due to the limited number of cases the exact prevalence of the abovementioned NHL types cannot be easily estimated. Moreover, the index of suspicion is usually low because of the rarity, resulting sometimes in late diagnosis with a significant impact on prognosis. Since these NHL types are often more well-studied in adult population, adult-based therapeutic approaches are also applied in children. Prognosis in pediatric patients may be different from that of adults. So, more international collaborative efforts are needed in order to identify specific prognostic factors, including molecular and cytogenetic variables and define specific pediatric treatment protocols.</p