Albers-Schönberg disease (autosomal dominant osteopetrosis) typically presents with which of the following classic radiographic hallmarks, particularly visible in the axial skeleton or long bones?

Explanation:
Osteopetrosis is caused by defective osteoclast function, leading to failure of bone resorption and remodeling. This results in dense, sclerotic, but brittle bones. Radiographically, the failure of remodeling leaves older, smaller bone models encased within newer bone, creating a 'bone-in-bone' appearance (endobone). In the spine, the endplates become densely sclerotic, creating a 'sandwich vertebra' appearance. 'Rugger jersey' is seen in renal osteodystrophy; 'bamboo spine' in ankylosing spondylitis; and 'picture frame' in Paget's disease. Reference: Tachdjian's Pediatric Orthopaedics, 6th Edition.