Fibrochondrogenesis: lethal, autosomal recessive chondrodysplasia with distinctive cartilage histopathology.

Fibrochondrogenesis is a rare, neonatally lethal rhizomelic chondrodysplasia distinguished from other forms of lethal dwarfism by broad long-bone metaphyses, pear-shaped vertebral bodies, and by microscopic changes of cartilage with unique interwoven fibrous septa and fibroblastic dysplasia of chondrocytes. We report the second and third well-documented cases of this apparently autosomal recessive disorder and discuss the differential diagnosis.