A young patient, 13 year old, was referred to our department to perform a vertebral column radiography requested from his orthopaedic in the assessment of scoliosis.
A young patient, 13 year old, was referred to our department to perform a vertebral column radiography requested from his orthopaedic in the assessment of scoliosis.
The radiographs showed as incidental findings pathognomonic signs of osteopetrosis type II (Fig.1.2.3). Careful analysis of the family history revealed that the cousin of the patient was diagnosed previously with the same disease.
Osteopetrosis (marble bone disease) is a descriptive term that refers to a group of rare, heritable disorders of the skeleton characterized by increased bone density on radiographs caused by impaired osteoclast maturation or function resulting in decreased bone resorption and modelling.
The same pathophysiological mechanism groups heterogeneous clinical and genetic types mainly distinguished in the severe infantile recessive and the more benign autosomal dominant types. The designation Albers Schonberg disease pertains to the autosomal delayed or benign form of osteopetrosis. The recessive type is also known as malignant osteopetrosis and presents in early childhood with fractures and the sequelae of pancytopaenia due to marrow space obliteration. Neurological complications are common, and are secondary to raised intracranial pressure due to calvarial expansion, and narrowing of the cranial foramina resulting in cranial nerve, spinal cord and vascular compression. Tooth eruption defects and severe dental caries are also common. This type of osteopetrosis is associated with a diminished life expectancy, with most untreated children dying in the first decade as a complication of bone marrow suppression. Patients with autosomal dominant form are phenotypically normal and usually asymptomatic, the diagnosis is often incidentally made on plain radiographs done for other reasons. Symptoms, when present may be directly related to the osteosclerosis such as cranial nerve affection caused by bony overgrowth around the foramina. Bone pain, increased fracture frequency are other well-known symptoms. Life span is normal and general health is unimpaired. There is a considerable number of clinical and radiographic variations in the autosomal dominant osteopetrosis, and two distinct radiologic types are generally distinguished. In type I, pronounced sclerosis of the skull and thickening of the cranial vault are evident, while the spine is almost normal. In type II, sclerotic vertebral end-plates alternate with the radiolucent regions of the disc spaces and the midportions of the vertebral bodies, producing a "sandwich” vertebra or “hamburger” vertebra appearance. This aspect of the spine is also defined "rugger jersey” spine. Another typical sign of osteopetrosis type II is represented by the so called endobones, found in the pelvis, especially within the ileum. This bone in bone appearance with several alternating bands of sclerosis and normal bone density suggests a cyclic course of defective bone formation, alternating with periods of normal bone formation. In type II the calvaria is almost unaffected. The classification of sclerosing bone dysplasias is made by a target site approach, so the radiologist plays a pivotal role in their recognition. Pycnodysostosis resembles osteopetrosis, both are dysplasias affecting endochondral ossification but dwarfism, short fingers with acro-osteolysis, mandible hypoplasia and lack of pneumatization of the paranasal sinuses characterize pycnodysostosis. Another dysplasia affecting endochondral and intramembranous ossification, dysosteosclerosis, resembles osteopetrosis but typically platyspondyly, hypoplasia of the pelvis and a radiolucent appearance of the widened metaphyseal portions of tubular bones are present. Infantile osteopetrosis warrants treatment because of the adverse outcome associated with the disease. Adult osteopetrosis requires no treatment by itself, though complications of the disease might require intervention.
Albers-Schonberg disease, autosomal dominant form type II.
The following characteristics can be observed in the anteroposterior and lateral X-ray images of the pelvis and spine:
In view of the incidental finding of bone sclerosis in a 13-year-old male patient undergoing evaluation for scoliosis, the following diagnoses or differential diagnoses could be considered:
Based on the patient’s age, clinical presentation (relatively asymptomatic, with incidental findings during scoliosis evaluation), and imaging characteristics (“sandwich vertebra” and “bone-in-bone” signs), the most likely diagnosis is:
Autosomal Dominant Osteopetrosis (Adult Type/Albers-Schönberg Disease, Type II).
If questions remain, further laboratory tests (hematologic parameters, calcium/phosphorus metabolism) or genetic testing can help confirm the subtype. In the absence of complications, no specific treatment is required, but regular follow-up is recommended.
For autosomal dominant osteopetrosis, no specific pharmacological or surgical intervention is generally required when the patient is asymptomatic. However, for cases presenting with nerve compression, pain, or fractures, symptom-based interventions may be warranted:
In the absence of pathological fractures or nerve compression, moderate exercise can help maintain muscle strength, joint mobility, and cardiorespiratory function. However, protective measures are crucial:
Disclaimer: This report is derived solely from the current imaging findings and documented medical history and is intended for reference purposes. It does not replace in-person consultations or professional clinical advice. If you have any questions or develop new symptoms, please consult a qualified physician and undergo further examination or treatment as needed.
Albers-Schonberg disease, autosomal dominant form type II.
