A rare case of progressive pseudorheumatoid dysplasia (PPD) in a 9-year-old girl is presented. Clinically, chronic painless swollen joints, accompanied by progressive motion restriction and progressive walking difficulties, were found. Radiologically, there was enlargement of the epimetaphyseal portions of the large joints, metacarpal heads, and phalanges, and generalized platyspondyly with irregular delineation of the endplates of the vertebral bodies. The radioclinical features at the peripheral joints were originally misdiagnosed as juvenile rheumatoid arthritis (JRA), and the structural spinal abnormalities were neglected and interpreted as Scheuermann's disease. However, the absence of active inflammatory parameters argues against JRA, whereas the low age of onset of the irregularities at the vertebral endplates is an argument against the diagnosis of Scheuermann's disease. The combination of the dysplastic abnormalities of the spine, with platyspondyly and Scheuermann-like lesions at an unusually low age of onset, and radiological features mimicking JRA of the peripheral joints, is the clue to the diagnosis of this rare autosomal-recessive disease. This case is the first to document the MRI features of PPD of the spine.

Two cases of pseudotumoral peliosis hepatis are presented with emphasis on MRI findings. One patient had four individual lesions, the other had two. Image characteristics in both were: heterogeneic signal intensity on T1-weighted images (T1WI) with areas of high-, intermediate, and low signal intensity; heterogeneic signal intensity on T2WI with presence of numerous intralesional "cystic" hyperintense areas with a hypointense border. Signal intensities on T1WI were iso- to hypointense in one case and mild central hyperintensities were demonstrated in the other case, probably due to intra-lesional hemorrhage or diffuse accumulation of fresh clotting within the sinusoids. One case demonstrated early enhancement of the peripheral borders in the arterial phase, and both demonstrated enhancement in the portovenous and late phases. One case was studied with Gd-BOPTA and iron oxides and demonstrated enhancement with both products, suggestive for the presence of hepatocytes and Kupffer cells. This is the first report of the use of hepato-specific contrast agents in this entity. Spontaneous regression of the lesions was demonstrated on a follow-up MR examination in one case.

We present a case of Langerhans' cell histiocytosis (LCH) of the liver and spleen in an adult. The imaging features are different from those in the few previously reported cases of individual organ involvement by LCH.