Skeletal Disorders: Bone Cysts, Hypophosphatasia, and Osteoporosis Clarified

Bone cysts are benign, fluid‑filled cavities within bone (simple/unicameral or aneurysmal). Hypophosphatasia is a rare genetic disorder causing deficient alkaline phosphatase, impairing bone mineralization. Both are skeletal disorders.

Not Skeletal Disorders

• Osteomalacia: Metabolic bone disease (vitamin D deficiency) → soft bones.
• Hematopoiesis: Normal blood cell formation in marrow—not a disorder.
• Osteoporosis: A skeletal disease (low bone mass, microarchitectural deterioration), distinct from developmental disorders like cysts or hypophosphatasia.

Accurate classification guides appropriate workup and management.