111.A 55-year-old woman presents with pain in her right hip and thigh. The
pain started approximately 6 months ago and is a deep ache that worsens
when she stands or walks. Your examination reveals increased warmth over
the right thigh. The only laboratory abnormalities are alkaline phosphatase
656 IU/L (normal 23–110 IU/L), elevated 24-hour urine hydroxyproline, and
osteocalcin 13 ng/mL (normal 6 ng/mL). X-ray of hips and pelvis shows oste-
olytic lesions and regions with excessive osteoblastic activity. Bone scan shows
significant uptake in the right proximal femur. Which of the following would
you include in your differential diagnosis?
a. Paget’s disease
b. Multiple myeloma
c. Osteomalacia
d. Osteoporosis
e. Hypoparathyroidism
112.A 66-year-old man with no previous significant illness presents with
back pain. The patient had felt well except for an increase in fatigue over the
past few months. He suddenly felt severe low back pain while raising his garage
door. Physical examination reveals a well-developed white male in acute pain.
His pulse is 88 beats per minute and blood pressure is 150/90 mm Hg. The
conjunctivae are pale. There is marked tenderness to percussion over the lum-
bar spine. The following laboratory data are obtained: hemoglobin 11.0 g/dL
(normal 13–16 g/dL), serum calcium 12.3 mg/dL (normal 8.5–11 mg/dL),
abnormal serum protein electrophoresis with a monoclonal IgG spike, urine
positive for Bence-Jones protein, and abnormal bone marrow smear. X-rays
reveal lytic lesions of the skull and pelvis and a compression fracture of lum-
bar vertebrae. A potential underlying mechanism for the symptoms observed
in this case is which of the following?
a. Increased IL-1, IL-6, and TNF-αby plasma cells
b. Increased release of histamine from mast cells
c. Decreased RANK expression on osteoclasts
d. Decreased RANK-L levels
e. Decreased production of M-CSF
Specialized Connective Tissues: Bone and Cartilage 199