WBR0475

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Musculoskeletal/Rheumatology
Prompt	[[Prompt::A 74-year-old European man presents to the physician's office for bone pain and hearing loss. Following appropriate work-up, the physician explains to the patient that his condition is caused by bone remodeling due to a simultaneous increase in osteoclastic and osteoblastic activities. Which of the following is most likely associated with the patient's condition?]]
Answer A	AnswerA::Heart failure
Answer A Explanation	AnswerAExp::High-output heart failure is associated with Paget's disease of the bone due to increased rate of arteriovenous shunts.
Answer B	AnswerB::Hepatic failure
Answer B Explanation	AnswerBExp::Hepatic failure is not classically associated with Paget's disease of the bone.
Answer C	AnswerC::Renal failure
Answer C Explanation	AnswerCExp::Renal failure is not classically associated with Paget's disease of the bone.
Answer D	AnswerD::Rheumatoid arthritis
Answer D Explanation	AnswerDExp::Rheumatoid arthritis (RA) is not classically associated with Paget's disease of the bone.
Answer E	AnswerE::Osteopetrosis
Answer E Explanation	AnswerEExp::Osteopetrosis is not classically associated with Paget's disease of the bone.
Right Answer	RightAnswer::A
Explanation	[[Explanation::Paget's disease of the bone (osteitis deformans) is characterized by abnormal bone architecture due to increased bone cellular activity. It is caused by an increase in osteoclastic activity, which is presumed to be induced by an infectious process. Consequently, osteoblastic activity also increases. Nonetheless, a net increase in osteoclastic activity is still predominant, and a mosaic pattern of woven and lamellar bone with chalk-stick fractures is observed. Paget's disease of the bone preferentially affects the axial skeleton (pelvis, femus, lumbar spine, skull, and tibia). The disease usually affects patients older than 55 years of age of European descent. The diagnosis of Paget's disease of the bone is usually incidental, and the majority of patients are asymptomatic and require no pharmacologic therapy. The most common symptom is bone pain, which may be a result of a combination of diseases that affect the elderly, such as coexisting Paget's disease of the bone and osteoarthritis. Few patients complain of deafness, which is usually caused by involvement of the skull. Physical examination is usually unremarkable, but bone deformity may be visible. Typically, work-up of patients demonstrates elevated serum alkaline phosphatase. Paget's disease is associated with increased risk of arteriovenous shunts that cause high-output heart failure. Paget's disease is also associated with osteogenic sarcoma (osteosarcoma), a bone tumor that usually affects the metaphysis of long bones, obstructive hydrocephalus, and hypercalcemia due to prolonged immobilization. Treatment is generally reserved for symptomatic patients, where bisphosphonates are the optimal pharmacologic therapy for Paget's disease of the bone. Educational Objective: Paget's disease is caused by a simultaneous increase in osteoclastic and osteoblastic activities that result in bone remodeling and a mosaic bone pattern. Paget's disease of the bone is associated with increased risk of high output heart failure due to arteriovenous shunts. References: Ralston SH. Paget's disease of bone. N Engl J Med. 2013;368:644-50. First Aid 2014 page 420]]
Approved	Approved::Yes
Keyword	WBRKeyword::Paget's disease of bone, WBRKeyword::Paget, WBRKeyword::Paget's, WBRKeyword::Osteitis, WBRKeyword::Deformans, WBRKeyword::Osteitis deformans, WBRKeyword::Heart failure, WBRKeyword::High output heart failure, WBRKeyword::Arteriovenous, WBRKeyword::Shunt, WBRKeyword::Arteriovenous shunt, WBRKeyword::Osteogenic sarcoma, WBRKeyword::Osteosarcoma
Linked Question	Linked::
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