CASE 1465 Published on 28.02.2002

Pyknodysostosis: radiographic findings


Musculoskeletal system

Case Type

Clinical Cases


P. Polat, M. Kantarci, F. Alper, MB Koruyucu


1 years, male

Clinical History
The plain radiography findings of pyknodysostosis were described in a 1-year-old male patient.
Imaging Findings
The patient presented with short stature and frontal bossing.

The patient was examined by conventional radiography. Lateral plain radiography of the skull showed prominent sclerosis at the skull base. Frontal bossing was seen. The mandible was hypoplastic (Fig. 1). Plain radiography of the extremities and columna vertebralis revealed diffuse osteosclerosis and bone expansion at the metaphyseal regions of the tubular bones (Fig. 2a). There were horizontal and transverse radiolucent lines in the metaphyses of long bones. Anteroposterior radiography of the columna vertebralis, ribs, clavicles and pelvis showed the vertebrae to be markedly increased in density. The pelvic bones were also sclerotic and showed bone within bone appearances (Fig. 2b).

Pyknodysostosis is a rare autosomal dominant sclerosing bone disorder. It is characterised by short stature, brachycephaly, short and stubby fingers, open cranial sutures and fontanelle, and diffuse osteosclerosis, where multiple fractures of long bones and osteomyelitis of the jaw are frequent complications (1).

Radiographic findings include generalised osteosclerosis (2). Metaphyseal modelling is only mildly abnormal, and the medullary cavities may be narrowed. The bones of the hands and feet are short, with osteolysis of the distal phalanges. In the skull, a marked delay in closure of the sutures is evident. Wormian bones are common. A thick and sclerotic skull base is also seen. The vertebral bodies are sclerotic, and errors in vertebral segmentation may be present. Osteopetrosis and dysosteosclerosis should be taken into consideration in differential diagnosis.

Differential Diagnosis List
Final Diagnosis
Case information
DOI: 10.1594/EURORAD/CASE.1465
ISSN: 1563-4086