26 Bones, Joints, and Soft-Tissue Tumors
1 A 60-year-old woman comes to her physician because she has had lower back pain for 1 month. On physical examination, there are no remarkable findings except for pain on deep palpation of the abdomen. Findings from a routine urinalysis, CBC, and serum electrolyte panel all are unremarkable. Twenty years earlier, she was treated for Hodgkin lymphoma with abdominal irradiation and chemotherapy; there has been no evidence of recurrence during regular follow-up visits. MRI now shows a 10 × 15 cm ovoid mass of the left retroperitoneum. Which of the following is most likely to be found in the patient’s retroperitoneum?
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(E) 2 A 60-year-old man with a diagnosis of chronic myeloid leukemia is treated with intensive chemotherapy. He goes into remission, but develops pain in the left wrist. On physical examination, there is swelling and warmth on palpation of the wrist. Polarized light microscopy of fluid aspirated from the wrist joint shows needle-shaped crystals that display negative birefringence. Which of the following processes most likely played an important role in the pathogenesis of the patient’s wrist pain?
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(E) 3 A 42-year-old man on vacation is involved in a skiing accident in which he sustains a right tibial diaphyseal fracture. The fracture is set with open reduction and internal fixation for proper alignment. His vacation is not over, and 1 week later, he is in the ski lodge, sitting by the fire with drink in hand. There are now more osteoclasts in the region of the fracture. What is the most likely function of these osteoclasts?
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(E) 4 A 70-year-old man complains of right hip and thigh pain of several months’ duration. On physical examination, he has reduced range of motion in both hips, but there is no tenderness or swelling on palpation. Radiographs of the pelvis and right leg show sclerotic, thickened cortical bone with a narrowed joint space near the acetabulum. Laboratory studies show a serum alkaline phosphatase level of 173 U/L, calcium of 9.5 mg/dL, and phosphorus of 3.4 mg/dL. A bone biopsy is done; the figure shows the microscopic appearance of the specimen. What condition is most likely to produce these findings?
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(E) 5 A 35-year-old woman has experienced malaise, fatigue, and joint pain for the past 5 months. She has had progressive loss of joint motion, making it more difficult to walk and to use her hands. On physical examination, the joint involvement is symmetric, and most of the affected joints are in the hands and feet. The involved joints are swollen and warm to the touch. The right second and third digits have a “swan neck” deformity, and there is ulnar deviation of both hands. Reconstructive surgery is performed on her right hand. Microscopic views of the excised joint capsule tissue are shown in the figure. Which of the following laboratory findings is most likely to be reported in this patient?
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(E) 6 A 79-year-old man has had progressively worsening lower back, bilateral hip, and right shoulder pain for the past 6 years. He reports that he has had to buy larger hats. On physical examination, there is no joint swelling, erythema, warmth, or tenderness, but the range of motion is reduced. Radiographs of the affected joints show narrowing of joint spaces with adjacent bony sclerosis. A skull radiograph shows thickening of the skull bone. A bone biopsy specimen at the iliac crest shows a loss of normal trabeculae, with a mosaic pattern and increased numbers of osteoclasts and osteoblasts. Which of the following complications is the patient most likely to experience as a result of this condition?
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7 A 6-year-old boy complains of discomfort in the right upper neck that has worsened over the past 6 months. On physical examination, a 5-cm, firm mass is palpable in the right lateral neck. The mass is not painful or warm. The histologic appearance of this mass is shown in the figure. Which of the following immunohistochemical stains is most likely to be positive in the cells of this lesion?
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(E) 8 A 26-year-old man is struck in the left arm by a swinging steel beam at a construction site. On physical examination, a 4-cm area of the lateral upper left arm exhibits swelling and redness with pain on palpation. A radiograph of the left arm shows no fracture. Three weeks later, there now is a 2-cm, painful, well-circumscribed, subcutaneous mass at the site of the original injury. A radiograph shows a solid soft-tissue mass. Which of the following lesions is most likely to be present?
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(E) 9 Several days after an episode of urethritis, a 28-year-old man develops acute pain and swelling of the left knee. On physical examination, the knee is swollen and is warm and tender to the touch. No other joints seem to be affected. Laboratory examination of fluid aspirated from the left knee joint shows numerous neutrophils. A Gram stain of the fluid shows gram-negative intracellular diplococci. No crystals are seen. Which infectious agent is most likely responsible for this condition?
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(E) 10 A 75-year-old woman trips on the carpet in her home and falls to the floor. She immediately has marked pain in the right hip. On physical examination, there is shortening of the right leg and marked pain with any movement. A radiograph shows a right femoral neck fracture. The fracture is repaired. Six months later, a dual-energy x-ray absorptiometry (DEXA) scan of the patient’s left hip and lumbar vertebrae shows a bone mineral density 2 standard deviations below the young adult reference range. Which of the following processes contributes most to development of these findings?
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(F) 11 A 47-year-old man sees the physician because he has had dull, constant pain in the midsection of the right thigh for the past 4 months. On physical examination, there is pain on palpation of the anterior right thigh, which worsens slightly with movement. The right thigh appears to have a larger circumference than the left thigh. A radiograph of the right upper leg and pelvis shows no fracture, but there is an ill-defined soft-tissue mass anterior to the femur. MRI shows a 10 × 8 × 7 cm solid mass deep to the quadriceps, but it does not involve the femur. What is the most likely diagnosis?
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(F) 12 A 66-year-old man has experienced pain in the area around the left knee for the past 6 weeks. He can recall no trauma to the leg. On physical examination, no mass is palpable; there is no warmth or swelling, and there is no loss of range of motion. MRI shows a well-circumscribed, 4-cm mass superior and inferior to the patella. The mass is within soft tissue, without bony erosion. A biopsy of the mass is done; microscopically, the specimen shows a biphasic pattern of spindle cells and epithelial cells forming glands. Karyotypic analysis of tumor cells shows a t(X;18) translocation. What is the most likely diagnosis?
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(E) 13 A 63-year-old woman loses her balance and falls to the ground. She is unable to get up because of pain. On physical examination, there is marked tenderness to palpation and no range of motion because of pain in the right hip. A radiograph of the right leg shows a right femoral intertrochanteric fracture. Which of the following conditions is likely to be the most important factor contributing to the fracture?
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(G) 14 A 51-year-old man has experienced aching pain in the right knee, lower back, right distal fifth finger, and neck over the past 10 years. He notices that the joints feel stiff in the morning, but this passes quickly. The pain is worse toward the end of the day. On physical examination, there is no joint swelling, warmth, or deformity. Some joint crepitus is audible on moving the knee. Laboratory studies show normal levels of serum calcium, phosphorus, alkaline phosphatase, and uric acid. What is the most likely diagnosis?
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(E) 15 A 30-year-old man sees his physician because he has had cramping abdominal pain and bloody diarrhea for the past 4 days. On physical examination, there is diffuse tenderness on palpation of the abdomen. Bowel sounds are present. There are no masses and no organomegaly. A stool culture is positive for Shigella flexneri. The episode resolves spontaneously within 1 week after onset. Six weeks later, the patient sees his physician because of increasingly severe lower back pain. Physical examination now shows stiffness of the lumbar joints and tenderness affecting the sacroiliac joints. He is treated with ibuprofen. Several months later, the back pain recurs, and he complains of redness of the right eye and blurred vision. Serologic testing for which of the following is most likely to be positive in this patient?
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(E) 16 A 7-year-old boy sustained an open compound fracture of the right tibia and fibula in a fall from a barn loft to the floor below. On physical examination, the lower tibia and fibula can be seen protruding from the lower leg. The fracture is set by external manipulation, and the skin wound is sutured, but nothing more is done. One year later, he continues to have pain in the right leg, and a draining sinus tract has developed in the lateral lower right leg. A radiograph of the lower right leg is now most likely to show which of the following?
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(E) 17 A 45-year-old man has experienced pain in the area of the left hip and upper thigh for the past 7 months. On physical examination, there is tenderness on deep palpation of the left side of the groin. There is a reduction in range of motion at the left hip. There is no swelling or warmth to the touch. Pelvic and left leg radiographs show an upper femoral mass lesion arising in the metaphyseal region and eroding the surrounding bone cortex. The proximal femur is excised and on sectioning has the gross appearance shown in the figure. Which of the following cell types is most likely to be proliferating in this mass?
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(E) 18 An 18-year-old man sees the physician because he has had pain around the right knee for the past 3 months. There are no physical findings except for local pain over the area of the distal right femur. A radiograph of the right leg shows an ill-defined mass involving the metaphyseal area of the distal right femur, and there is elevation of the adjacent periosteum. A bone biopsy specimen shows large, hyperchromatic, pleomorphic spindle cells forming an osteoid matrix. What is the most likely diagnosis?
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(E) 19 A 38-year-old man who is otherwise healthy has experienced chronic leg pain for the past 4 months. On physical examination, there is local swelling with tenderness just below the right patella. A radiograph of the right lower leg shows a 4-cm cystic area in the right tibial diaphysis without erosion of the cortex or soft-tissue mass. A biopsy specimen shows increased numbers of osteoclasts in this lesion and fibroblast proliferation. Which of the following underlying conditions is most likely to account for these findings?
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(E) 20 A 9-year-old boy has had pain in the area of the right hip for the past 3 weeks. On physical examination, his temperature is 38.2°C. There is swelling with marked tenderness to palpation in the area of the right hip, pain, and reduced range of motion. Radiographs of the pelvis and legs show areas of osteolysis and cortical erosion involving the femoral metaphysis, with adjacent soft-tissue swelling extending from the subperiosteal region, and apparent abscess formation. Which organism is most likely to produce these findings?
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(E) 21 A 37-year-old woman has noticed increasing deformity and difficulty with movement involving her left hand over the past 6 months. On physical examination, there is a contracture involving the third digit of her left hand that prevents her from fully extending this finger. A firm, hard, cordlike, 1 × 3 cm area is palpable beneath the skin of the left palm. Microscopically, which of the following is most likely to be seen in greatest abundance composing this lesion?
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(E) 22 A 57-year-old woman has had increasing pain and deformities in her hands for the past 10 years. On physical examination, she has bilateral ulnar deviation and swan-neck deformities of several fingers. There is a subcutaneous nodule on the ulnar aspect of the right forearm. A biopsy specimen of the nodule has the microscopic appearance depicted in the figure. She improves with adalimumab therapy. Which of the following mechanisms plays the most important role in causing joint injury in her disease?
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(E) 23 A 12-year-old girl has complained of sudden onset of severe pain in her left knee that has awakened her from sleep on several occasions during the past 6 weeks. For each episode, her mother has given her acetylsalicylic acid (aspirin), and the pain has been relieved. On physical examination, there are no remarkable findings. A radiograph of the left knee shows a well-defined, 1-cm lucent area surrounded by a thin rim of bony sclerosis located in the proximal tibial cortex. The patient undergoes curettage of the lesion, and the pain does not recur. What is the most likely diagnosis of this lesion?
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(H) 24 A 23-year-old man has had pain in the area of the right knee for the past year. On physical examination, there is mild tenderness over a 2-cm focal area just below the patella laterally over the tibia. A radiograph of the right leg shows a 3-cm, broad-based excrescence projecting from the metaphyseal region of the upper tibia. The lesion is excised. The figure shows the gross appearance of the sectioned lesion. What is the most likely diagnosis?
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(H) 25 A 13-year-old, previously healthy boy has been complaining of pain in the right leg for the past month. There is no history of trauma or recent illness. On physical examination, there is warmth and tenderness to palpation of the right lower thigh anteriorly, and the circumference of the right thigh is slightly larger than that of the left. His temperature is 39°C. Laboratory studies show hemoglobin, 11.5 g/dL; hematocrit, 34.5%; MCV, 92 µm3; and WBC count, 15,200/mm3 with WBC differential count of 85% neutrophils, 10% lymphocytes, and 5% monocytes. A radiograph of the right leg shows a 6-cm expansile mass in the diaphyseal region of the right lower femur that extends into the soft tissue and is covered by layers of reactive bone. A biopsy of the mass is done, and microscopic examination of the specimen shows sheets of closely packed primitive cells with small, uniform nuclei and only scant cytoplasm. Karyotypic analysis of the tumor cells shows a t(11;22) translocation. What is the most likely diagnosis?
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(H) 26 For the past 4 months, a 51-year-old man has noticed episodes of intense local pain involving his left foot. Each episode follows a meal in which he consumes a bottle of wine (Merlot), and the pain may last hours to several days. Physical examination identifies the right metatarsophalangeal joint as the focus of this pain. There is tenderness and swelling, but minimal loss of joint mobility. A painless, 2-cm nodule with overlying ulcerated skin is present on the lateral aspect of the metatarsophalangeal joint. Beneath the eroded skin is a chalky white deposit of soft material surrounded by erythematous soft tissue. A firm, 1-cm subcutaneous nodule is present on the extensor surface of the left elbow. The nodule is excised and has the microscopic appearance shown in the figure. Which of the following mechanisms is most important in causing joint injury in his disease?
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(F) 27 An epidemiologic study of postmenopausal women is performed. The subjects undergo periodic examination by dual-energy x-ray absorptiometry (DEXA) scan performed on the hip and lumbar vertebrae to evaluate bone mineral density over the next 10 years. They respond to a survey regarding their past and present use of drugs, diet, activity levels, history of bone fractures, and medical conditions. A subset of the subjects is identified whose bone mineral density is closest to that of the young adult reference range and in whom no bone fractures have occurred. The survey data from this subset of women are analyzed. Which of the following strategies is most likely to be supported by the study data to provide the best overall long-term reduction in risk of fracture in postmenopausal women?
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(C) Stay updated, free articles. Join our Telegram channel
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