A 60-year-old man comes to the office due to a 4-month history of increasing midthoracic back pain, which is aggravated by coughing. The patient has also had right thigh pain but no numbness or weakness in the legs and no bowel or bladder incontinence. He has no other medical conditions. Vital signs are within normal limits. On examination, there is tenderness over the eighth and ninth thoracic vertebrae. Neurologic examination is normal. The prostate is normal in size and has no palpable nodules. Imaging studies reveal enlarged vertebral bodies with cortical thickening. Serum testing for which of the following would most likely help establish a diagnosis in this patient?

Question

A 60-year-old man comes to the office due to a 4-month history of increasing midthoracic back pain, which is aggravated by coughing.  The patient has also had right thigh pain but no numbness or weakness in the legs and no bowel or bladder incontinence.  He has no other medical conditions.  Vital signs are within normal limits.  On examination, there is tenderness over the eighth and ninth thoracic vertebrae.  Neurologic examination is normal.  The prostate is normal in size and has no palpable nodules.  Imaging studies reveal enlarged vertebral bodies with cortical thickening.  Serum testing for which of the following would most likely help establish a diagnosis in this patient?

Quizplus · Accepted Answer

11ec160b_3a62_d681_9249_1d20001cc076_MD0001_00 This older patient with multifocal bone pain has enlarged vertebral bodies with cortical thickening on imaging, which is consistent with Paget disease of bone (PD). PD is characterized by excessive and disordered bone formation. It commonly affects the skull, long bones of the extremities, and vertebral column. In addition to pain and deformity, vertebral involvement can lead to spinal stenosis, nerve compression, and compression fracture. The increased formation of new bone in PD is associated with an elevated serum alkaline phosphatase level, but because the changes occur slowly, serum calcium and phosphorus levels are often normal. Radiographs typically reveal lytic or mixed lytic-sclerotic lesions, thickening of cortical and trabecular bone, and bony deformities. In the vertebrae, bony enlargement and cortical thickening may create an appearance resembling a picture frame. (Choice A) The level of 25-hydroxyvitamin D reflects total body vitamin D stores and is useful in the diagnosis of osteomalacia. In addition to bone pain, osteomalacia causes muscle weakness and difficulty walking. X-ray reveals diffuse demineralization, often with insufficiency fractures, rather than cortical thickening. (Choice C) The erythrocyte sedimentation rate reflects circulating levels of inflammatory proteins and is elevated in many inflammatory and malignant conditions. It is classically elevated in polymyalgia rheumatica; this condition causes pain in the shoulders, hips, and proximal extremities, but x-rays are normal. It can also be strikingly elevated in multiple myeloma, which can cause osteolytic lesions resembling early pagetic lesions but does not cause cortical thickening. (Choice D) Hyperparathyroidism can present with bone pain, typically in association with hypercalcemic manifestations (eg, constipation, renal stones). X-ray of the vertebral column reveals cortical thinning, not thickening. (Choice E) Prostate-specific antigen is used in the diagnosis of prostate cancer. Bone metastasis in prostate cancer appears on x-ray as focal sclerotic lesions, and most patients have palpable nodules on prostate examination. Educational objective: Paget disease of bone is characterized by excessive and disordered bone formation. It commonly affects the skull, long bones, and vertebral column. The increased formation of new bone is associated with an elevated serum alkaline phosphatase level. Radiographs shows lytic or mixed lytic-sclerotic lesions, thickening of cortical and trabecular bone, and bony deformities.

A 60-Year-Old Man Comes to the Office Due to a 4-Month