Pycnodysostosis with visceral manifestation and rickets.

Pycnodysostosis is a rare bone disease. Visceral manifestations associated with anemia and/or rickets have been reported in pycnodysostosis. Five children with typical findings of pycnodysostosis with hepatosplenomegaly, anemia with rickets, one with visceromegaly and anemia, and another with rickets alone are reported here. These findings strongly suggest that extramedullary erythropoiesis does occur in pycnodysostosis.