Rosh Internal Medicine Boost Practice Exam

What is the likely cause of high serum alkaline phosphatase and radiographs showing lytic lesions in a patient?

1. Chronic soft tissue degeneration

2. Hypervascular bone

3. Bone cancer

4. Fracture healing

The correct answer is: Hypervascular bone

The presence of high serum alkaline phosphatase coupled with radiographs showing lytic lesions is indicative of increased bone turnover and suggests a process involving abnormal bone metabolism, often associated with conditions that lead to increased osteoblastic activity. In this context, hypervascular bone can result in increased osteoclastic activity, leading to lytic lesions observable on radiographs and elevated alkaline phosphatase due to heightened bone remodeling. Hypervascularity in the bone typically indicates conditions such as metastatic disease, Paget's disease, or other neoplastic processes, which can lead to significant changes in bone architecture characterized by both lytic and sclerotic lesions. The elevated alkaline phosphatase level reflects the increased osteoblastic activity often triggered by such pathological processes. This is consistent with a high turnover state of bone, consistent with the presence of lytic lesions and the biochemical markers detected in the patient. Therefore, the scenario presented matches with hypervascular bone as a unifying cause of the symptoms observed.