Gelatinous transformation of the bone marrow.

A study of so-called gelatinous transformation of the bone marrow in 14 patients is presented. The condition is characterized by the presence of extracellular "gelatinous" material, fat atrophy, and associated focal marrow hypoplasia and is often mistaken as representing edema, necrosis, or amyloid. Histochemical studies indicate that the extracellular substance is hyaluronic acid. Though the lesion is usually associated with severe weight loss and cachexia, it appears that factors other than malnutrition must play a significant role in the pathogenesis of gelatinous transformation. Anemia, frequently seen in these patients, does not appear to be a consequence of gelatinous transformation.