60 yrs old male with bony abnormality at upper tibia associated with sensorineural hearing loss. On laboratory examination serum alkaline phosphatase levels are (440mU/I) elevated and serum Ca ++ and PO4- are normal, Skeletal survey shows ivory vertebrae and cotton wool spots in x-ray skull.Diagnosis is –
**Core Concept**
Paget's disease of bone is a chronic focal skeletal disorder characterized by an abnormal breakdown and regrowth of bone tissue, leading to deformities and skeletal abnormalities.
**Why the Correct Answer is Right**
The patient's presentation of bony abnormality at the upper tibia, sensorineural hearing loss, elevated serum alkaline phosphatase levels, ivory vertebrae, and cotton wool spots on skull x-ray are classic findings in Paget's disease. The disease is associated with an imbalance between bone resorption and bone formation, leading to the characteristic features of bone deformities and increased serum alkaline phosphatase levels. The involvement of the skull and hearing loss are due to the abnormal bone growth and remodeling in the temporal bones.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not match the clinical presentation of Paget's disease. The patient's age, sex, and laboratory findings do not support a diagnosis of osteomalacia, which typically presents with hypocalcemia and increased alkaline phosphatase levels in the context of vitamin D deficiency or malabsorption.
* **Option B:** This option is incorrect as it does not account for the patient's sensorineural hearing loss and ivory vertebrae, which are characteristic features of Paget's disease. Osteopetrosis is a rare genetic disorder that typically presents with increased bone density and marrow failure, but it does not typically cause sensorineural hearing loss.
* **Option C:** This option is incorrect as it does not match the patient's laboratory findings and clinical presentation. Osteoporosis is a systemic skeletal disorder characterized by decreased bone density and increased risk of fractures, but it does not typically cause elevated serum alkaline phosphatase levels or sensorineural hearing loss.
**Clinical Pearl / High-Yield Fact**
Paget's disease of bone is a common cause of sensorineural hearing loss in adults, and it is often associated with other skeletal abnormalities such as bone deformities and increased serum alkaline phosphatase levels. A high index of suspicion is necessary for early diagnosis and treatment to prevent complications.
**Correct Answer:** D.