An animal model was used to evaluate the role of pin penetration into the hip joint as the cause of chondrolysis. The gross and microscopic studies, as well as the biochemical studies, showed changes indicating cartilage destruction. These changes were more severe when the pins remained in the joint. Immunologic studies showed some type of immunological interaction. The immunologic response may be initiated by release of cartilage byproducts. The initial insult of the slip may cause release of cartilage byproducts from the exposed growth plate within the joint, and is compounded by penetration of the pin in the hip joint.

Animals↗

PubMedDate not supplied

Deep juvenile xanthogranuloma: an unusual presentation.

Juvenile xanthogranuloma (JXG) is a disorder of histiocytes usually associated with cutaneous lesions. It may present a diagnostic dilemma in the absence of cutaneous lesions and when deeply located. Differentiation of JXG from other childhood histiocytosis syndromes, especially Langerhans' cell histiocytosis (LCH), is important. We describe an unusual case of deep JXG in a 27-month-old girl with multiple omental and peritoneal nodules presenting with ascites. Although a diagnosis of LCH was suspected clinically, the absence of Birbeck granules and S-100 protein and T6 antigen negativity, together with CD68 and factor XIIIa positivity, led us to a diagnosis of JXG. Physicians should be aware of the widening spectrum of manifestations of juvenile xanthogranuloma.

Abdomen↗