A 72-year-old female presents with progressive bilateral hip and pelvic soreness as well as back pain and headaches. X-rays of the pelvis and biopsy specimen are shown in Figure 8–35A and B.
Figure 8–35 A–B
What is his most likely diagnosis?
- Osteosarcoma of the pelvis
- Osteopetrosis
- Paget disease
- Osteomyelitis
Discussion
The correct answer is (C). Paget disease is a remodeling disease characterized initially by osteoclast-mediated bone resorption and then disordered bone formation. On plain radiographs, coarsened trabeculae and cortical thickening are seen; there may be loss of distinction between the cortices and the medullary cavity and gross enlargement of the bone. Histologic appearance of this condition after
bone biopsy reveals profound osteoclastic bone resorption with abnormal bone formation in a mosaic pattern. Prominent cement lines are seen. There is woven bone and irregular sections of thickened trabeculae.
What abnormal laboratory finding would you expect to find?
- Increased thyroid-stimulating hormone
- Increased alkaline phosphatase level
- Decreased thyroid-stimulating hormone
- Decreased alkaline phosphatase level
Discussion
The correct answer is (B). Increased alkaline phosphatase is a signal of increased bone turnover. These markers are also seen in the urine: N-telopeptide, hydroxyproline, and deoxypyridinoline. Calcium level is usually normal in Paget disease.
Objectives: Did you learn...?
To recognize the clinical features of Paget disease? To recognize the histologic features of Paget disease?
