Sclerosing bone dysplasias: genetic, clinical and radiology update of hereditary and non-hereditary disorders

Abstract

There is a wide variety of hereditary and non-hereditary bone dysplasias, many with unique radiographic findings. Hereditary bony dysplasias include osteopoikilosis, osteopathia striata, osteopetrosis, progressive diaphyseal dysplasia, hereditary multiple diaphyseal sclerosis and pyknodysostosis. Non-hereditary dysplasias include melorheostosis, intramedullary osteosclerosis and overlap syndromes. Although many of these dysplasias are uncommon, radiologists should be familiar with their genetic, clinical and imaging findings to allow for differentiation from acquired causes of bony sclerosis. We present an overview of hereditary and non-hereditary bony dysplasias with focus on the pathogenesis, clinical and radiographic findings of each disorder.

Figure 1.

Osteopetrosis. (a) A 26-year-old male. Chest radiograph. Note the uniform sclerosis of the spine, ribs and long bones with undertubulation. (b) Radiograph of the left hand showing “bone-within-bone” appearance at the ends of the diaphysis of the digits (best seen within the second-finger proximal phalanx and metacarpal) (arrowheads). (c) Sagittal CT image of the lumbar spine showing “sandwich vertebrae” with increased sclerosis of the vertebral endplates. (d) Radiograph of the cervical spine with increased sclerosis of the cranial vault and cervical vertebra (arrows).

Figure 2.

Pyknodysostosis. (a) Unknown gender and age (from teaching file). Radiograph of the hand showing pointed finger tufts (arrowheads). (b) Lateral radiograph of the skull showing prominent sclerosis of the skull base (circle).

Figure 3.

Osteopoikilosis. A 14-year-old female. Pelvis radiograph showing multiple bilateral rounded lesions within the sacrum, iliac wings, pubic branches, acetabuli and femur (square).

Figure 4.

Osteopathia striata with cranial stenosis. A 10-year-old female. (a) Frontal radiograph of the lower legs showing longitudinal sclerotic striations in the metaphysis of both the femora and tibia. Note the aplasia of the proximal right fibula (arrow). (b) Axial CT image (in the bone window) of the skull. Note the thickened bone with ground-glass appearance of the spongiosa in the skull base. Note the sclerosis of the inner auditory canal (arrowhead), narrowing of the cranial neuroforaminae (arrow) and lack of pneumatization of the mastoids (curved arrow). (c) Three-dimensional CT reconstruction of the skull showing a well-demarcated cleft palate (arrow).

Figure 5.

Progressive diaphyseal dysplasia. A 50-year-old female. (a) Frontal radiograph of both elbows showing bilateral symmetric hyperostosis along the periostal and endosteal surfaces of the diaphysis of the long bones. (b) Frontal radiograph of the left hip showing sclerosis of the left iliac wing, ischium and diaphysis of the femur, with narrowing of the medullary canal and increase in the diaphyseal diameter (arrowhead). (c) CT scan of the skull base. Note the sclerosis of the skull base and around the temporomandibular joints (arrowhead). Note that maxillary sinus surgery has been performed.

Figure 6.

Multiple diaphyseal sclerosis (Ribbing disease). A 35-year-old female. Frontal radiograph of the lower legs showing bilateral asymmetrical endostal and periosteal sclerosis confined to the diaphysis of both tibia (arrowheads).

Figure 7.

Truswell–Hansen disease. (a) Lateral skull radiograph showing extensive cortical thickening (arrowheads). (b) Frontal radiograph of the hand showing marked syndactyly of the third and fourth fingers (arrowhead). (Courtesy of S Deepak Amalnath, MD, India).

Figure 8.

Melorheostosis. A 28-year-old female. (a) Radiograph of the right foot showing cortical and endomedullary hyperostosis of the diaphysis of the first metatarsal, first and second cuneiformes and navicular and talar bones (square). (b) Radiograph of the feet. This bilateral view shows unilateral (hemimelic) involvement.