Deck 20: Bones, Joints, and Soft Tissue Tumors

Question 1

Osteoid osteoma is a small benign bone tumor associated with pain that is disproportionate to the size of the lesion. This pain is caused by an excess of which of the following substances?

A) Interleukin (IL)-1 and IL-6
B) Leukotrienes
C) Prostaglandin E₂
D) Complement C₃
E) Bradykinin

Answer 1

Prostaglandin E₂

Question 2

Loss of heterozygosity, structural rearrangements, or point mutations of the retinoblastoma tumor suppressor gene (RB) are found in 60%-70% of all sporadic bone tumors. Which of the following is the best classification for this tumor?

A) Osteosarcoma
B) Osteoblastoma
C) Osteoid osteoma
D) Chondrosarcoma
E) Ewing sarcoma

Answer 2

Osteosarcoma

Question 3

The autosomal dominant bone disorder caused by a mutation of fibroblast growth factor receptor 3 (FGFR3) is characterized by short stature, rhizomelic shortening of limbs, frontal bossing of the skull, and midface abnormalities. Which of the following disorders is described by these characteristics?

A) Achondrogenesis
B) Achondroplasia
C) Multiple epiphyseal dysplasia
D) Synpolydactyly
E) Holt-Oram syndrome

Answer 3

Achondroplasia

Question 4

Compression fractures of vertebral bodies seen in elderly women are causally related to reduced recruitment of osteoclasts. This process is associated with an increased concentration of which chemical mediators in the bone?

A) Prostaglandins
B) Leukotrienes
C) Cytokines such as interleukin (IL)-1 and IL-6
D) Oncogenes such as c-MYC and K-RAS
E) Fibroblast growth factors

Question 5

Trinucleotide CTG repeat expansion plays a role in the pathogenesis of which of the following muscle diseases?

A) Duchenne muscular dystrophy
B) Becker muscular dystrophy
C) Autosomal dominant limb girdle muscular dystrophy
D) Autosomal recessive limb girdle muscular dystrophy
E) Myotonic dystrophy

Question 6

A 20-year-old man is being treated for a soft tissue tumor of the lower extremity. The tumor is composed of malignant spindle-shaped cells and epithelial cells that form gland-like structures. Which of the following is the most likely diagnosis?

A) Leiomyosarcoma
B) Malignant fibrous histiocytoma
C) Primitive neuroectodermal tumor
D) Synovial sarcoma
E) Rhabdomyosarcoma

Question 7

The primitive neuroectodermal tumor (PNET) of soft tissues has the same histologic features and the same chromosomal translocation as which of the following bone tumors?

A) Osteosarcoma
B) Chondrosarcoma
C) Ewing sarcoma
D) Malignant fibrous histiocytoma
E) Giant cell tumor of bones

Question 8

Which of the following muscle diseases is classified as an ion channel myopathy (channelopathy)?

A) Dysferlin deficiency
B) Becker muscular dystrophy
C) Malignant hyperpyrexia
D) Central core disease
E) Myotubular myopathy