U2-Robbins -C26: Bones, Joints & Soft Tussue Tumors Flashcards
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 followup
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?
□ (A) Desmoid tumor
□ (B) Recurrent Hodgkin lymphoma
□ (C) Rhabdomyosarcoma
□ (D) Leiomyosarcoma
□ (E) Malignant fibrous histiocytoma
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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?
□ (A) Damage to the articular cartilage by chemotherapeutic agents
□ (B) Infiltration of the synovium by leukemic cells
□ (C) Synovial proliferation from cytokine secretion by leukemic cells
□ (D) Excessive production of uric acid from dying leukemic cells
□ (E) Hemorrhages into the joint as a result of deranged platelet function
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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?
□ (A) Form collagen
□ (B) Resorb bone
□ (C) Synthesize osteoid
□ (D) Elaborate cytokines
□ (E) Divide
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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?
□ (A) Osteochondroma
□ (B) Vitamin D deficiency
□ (C) Degenerative osteoarthritis
□ (D) Hyperparathyroidism
□ (E) Paget disease of bone
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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?
□ (A) Positive Borrelia burgdorferi serologic test
□ (B) Positive acid-fast stain of joint tissue
□ (C) Serum positive for rheumatoid factor
□ (D) Hyperuricemia
□ (E) Calcium pyrophosphate crystals in a joint aspirate
g
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?
□ (A) Ankylosing spondylitis
□ (B) Osteoid osteoma
□ (C) Fibrous dysplasia
□ (D) Osteosarcoma
□ (E) Enchondroma
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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?
□ (A) Vimentin
□ (B) Neuron-specific enolase
□ (C) Cytokeratin
□ (D) Factor VIII
□ (E) CD3
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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?
□ (A) Malignant fibrous histiocytoma
□ (B) Organizing abscess
□ (C) Nodular fasciitis
□ (D) Superficial fibromatosis
□ (E) Lipoma
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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?
□ (A) Borrelia burgdorferi
□ (B) Treponema pallidum
□ (C) Neisseria gonorrhoeae
□ (D) Staphylococcus aureus
□ (E) Haemophilus influenzae
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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?
□ (A) Decreased osteoprotegrin production
□ (B) Decreased sensitivity of osteoblasts to dihydroxycholecalciferol
□ (C) Decreased secretion of interleukin-1, interleukin-6, and tumor necrosis factor-α by monocytes
□ (D) Increased sensitivity of bone to the effects of parathyroid hormone
□ (E) Mutation in the fibroblast growth factor receptor 3 gene
□ (F) Synthesis of chemically abnormal osteoid
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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?
□ (A) Nodular fasciitis
□ (B) Liposarcoma
□ (C) Osteosarcoma
□ (D) Rhabdomyosarcoma
□ (E) Hemangioma
□ (F) Chondrosarcoma
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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?
□ (A) Leiomyosarcoma
□ (B) Synovial sarcoma
□ (C) Desmoid tumor
□ (D) Mesothelioma
□ (E) Osteoblastoma
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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?
□ (A) Chronic osteomyelitis
□ (B) Vitamin D deficiency
□ (C) Postmenopausal bone loss
□ (D) Parathyroid adenoma
□ (E) Monoclonal gammopathy
□ (F) Chronic renal failure
□ (G) Malabsorption
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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?
□ (A) Paget disease of bone
□ (B) Osteoarthritis
□ (C) Gout
□ (D) Multiple myeloma
□ (E) Rheumatoid arthritis
N
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?
□ (A) Rheumatoid factor
□ (B) Chlamydia trachomatis
□ (C) Epstein-Barr virus
□ (D) HLA-B27
□ (E) Borrelia burgdorferi
N
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?
□ (A) Osteolysis with osteosclerosis
□ (B) Bone mass with bony destruction
□ (C) Cortical nidus with surrounding sclerosis
□ (D) Involucrum and sequestrum
□ (E) Soft-tissue hemorrhage and swelling
N
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?
□ (A) Osteoblasts
□ (B) Chondroblasts
□ (C) Osteoclasts
□ (D) Primitive neuroectodermal cells
□ (E) Plasma cells
N
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?
□ (A) Activation of neutrophils by phagocytosis of urate crystals
□ (B) Inflammation of synovium caused by infection with Borrelia burgdorferi
□ (C) Inflammation of the synovium caused by tumor necrosis factor
□ (D) Synthesis of antibodies against HLA-B27 antigen
□ (E) Granulomatous response to long-standing Treponema pallidum infection
N
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?
□ (A) Brown tumor of bone
□ (B) Enchondroma
□ (C) Ewing sarcoma
□ (D) Fibrous dysplasia
□ (E) Giant-cell tumor
□ (F) Osteoblastoma
□ (G) Osteochondroma
□ (H) Osteosarcoma
N
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?
□ (A) Activation of neutrophils by phagocytosis of urate crystals
□ (B) Chronic inflammation caused by Borrelia burgdorferi infection
□ (C) Release of TNF causing acute joint inflammation
□ (D) Deposition of serum cholesterol into the synovium
□ (E) Granulomatous inflammation caused by Mycobacterium tuberculosis infection
□ (F) Reduced metabolism of homogentisic acid
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A 48-year-old man has had increasing pain in the left knee for the past 4 years, but the pain has become worse in the
past week. On physical examination, the left knee is slightly swollen and warm to the touch. The cell count of a joint
aspirate shows increased neutrophils. The figure shows a smear preparation of the fluid. The patient experiences reduced
knee joint mobility over the next 5 years. He also develops congestive heart failure, diabetes mellitus, and hepatic
cirrhosis. Which of the following laboratory findings is most characteristic of this disease process?
□ (A) Serum ANA titer 1 : 1024
□ (B) Positive serologic test result for Borrelia burgdorferi
□ (C) Serum calcium level 14.5 mg/dL
□ (D) Positive urine culture for Chlamydia trachomatis
□ (E) Serum ferritin level 7245 ng/mL
□ (F) Hemoglobin S concentration 96% on hemoglobin electrophoresis
□ (G) Serum parathyroid hormone level 72 pg/mL
□ (H) Serum rheumatoid factor titer 1 : 512
□ (I) Positive serologic test result for syphilis
□ (J) Serum urea nitrogen level 110 mg/dL
□ (K) Serum uric acid level 15.8 mg/dL
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