Paget's Disease of Bone

This patient aged 70 years male with history of CABG and bone pains exhibits cotton wool appearance, widened diploae, coarse trabecular pattern of the left femur, not so classical picture frame of L2 vertebral body, nonhomogenous presentation of left sacral ala. Diagnosis- Pagets disease of the bone

Case Submitted by-Dr UV Krishna Murthy and Dr MGK Murthy.

About Pagets disease- 3 to 4 % of the general population above the age of 40 years is expected to harbour the disease. Highest incidence is in the 7 and the 8 decades with male preponderance.  There is genetic predisposition to the disease with other theories of etiology being viral ( paramyxoma virus ) / Autoimmune / Vascular / Connective tissue disease / Metabolic ( parathormone abnormality ) / truly neoplastic. The basic defect is excessive and abnormal remodeling of the bone. Clinically varies from being asymptomatic to bone pains, fractures, anemia, expansion of the bones particularly with reference to craniofacial ( in India, manifesting as frequent changing of the spectacles frames ).

Radiological Findings

Skeletal survey continues to be the number one diagnostic parameter.  Skull 25-65%, spine 30-75%, pelvis 30-75%, proximal long bones 25-30% involvement.

  Depends on the stage of presentation

a)      Lytic ( Incipient – Active ) – Gross Destructive, Expansile, radio lucency of the region with advanced wedging of osteolysis demonstrating chronic sharp margin without sclerosis ( Blade of grass sign )

b)      Mixed ( Active ) - Coarse thickening of the trabecular and the cortical pattern with enlarging of the bone, with areas of new bone formation, with possible incremental fractures and cotton wool appearance of the skull.

c)      Blastic ( late inactive ) – Predominantly new bone formation.

    Nuclear Scintigraphy – Shows hyperactivity in all the phases. CT is more demonstrative of the plain radiographic findings.   MR is good for differentiating and excluding sarcomatous transformation ( 1% of the cases ) – Is reflected as focal bone destruction through the cortex, with the breach and invading the neighboring the soft tissues