Cloverleaf skull syndrome. An autopsy case and review of literature.

An autopsy case of cloverleaf skull deformity associated with hydrocephalus, systemic skeletal malformation including facial dysostosis, fused elbow, syndactyly of the toes, odd digits and striking anomaly of tracheal cartilage is presented. Extra-skeletal abnormalities included covered anus, dermal sinus and the absence of corpus callosum and the septum pellucidum. Several basal skull deformity appeared to be a primary morphologic alteration associated with premature closure of the specific sutures, which terminally resulted in life-threatening hydrocephalus. Histological investigation showed the abnormalities of endochondral ossification in the cartilage at the epi- and meta-physis of the fused elbows. In addition, electron microscopical study revealed unusual fat droplet-containing chondrocytes even in the resting and multiplicative phase. Association of the tracheal anomaly with this syndrome was disclosed in this case. Generalized bone and cartilage abnormalities not only in the skeletal system but also in the internal organs strongly suggest that this disorder involves generalized osteocartilagenous system. The present case makes a total of 14 cases of the cloverleaf skull syndrome reported in the Japanese literatures to date. Major clinical and pathologic findings of these cases were summerized.