4.5 of 42 Ratings
A 12-year-old girl with a several-year history of multiple bony protuberances presents to your clinic for evaluation. On examination, she has palpable masses about the bilateral knees, wrists, and shoulders. Radiographs are shown in Figures A and B. Which of the following is true with respect to this patient's underlying disorder?
Progressive thinning of cartilaginous cap is concerning for malignant transformation
Patients with the EXT2 mutation have a more severe presentation than those with EXT1 mutation
Overall rate of malignant transformation is around 25%
Analysis of her physis would reveal a decrease amount of heparan sulfate
Distal lesions are more likely to undergo malignant transformation than proximal lesions
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Mutations in the tumor suppressor genes EXT1 and EXT2 gene leads to a condition characterized by which of the following images.
Which of the following radiographs (Figures A-E) is consistent with a disorder that is inherited in an autosomal-dominant inheritance pattern?
A 15-year-old boy presents with a painful mass over his great toe. It has been slowly growing over the past year. Clinical photograph and radiograph are shown in Figures A and B. What is the most appropriate treatment?
Observation and shoe wear modification
Osteotomy through the base of the tumor and local wound care
Radiotherapy and surgical excision
An 18-year-old male presents with the radiographs shown in Figures A and B. Genetic work-up reveals a defect in the EXT-1 gene. What is his underlying diagnosis, and which mesenchymal tumor is he most at risk of developing?
Multiple hereditary exostosis, chondrosarcoma
Multiple enchondromatosis, hemangioma
Multiple hereditary exostosis, enchondroma
Multiple enchondromatosis, chondroblastoma
Multiple hereditary exostosis, osteosarcoma
Which of the following radiographs represent typical findings seen with a mutation of the EXT1, EXT2, or EXT3 genes?
A 15-year-old male presents with 7 months of pain at the region of the hallux lesion shown in Figure A and B. His primary care physician initially diagnosed the lesion as a wart and it was unsuccesfully treated with a topical salicylic acid preparation. A radiograph is shown in Figure C. What is the next step in management?
Neoadjuvant chemotherapy followed by surgical excision with subsequent adjuvant chemotherapy
600-800 cgy irradiation
Observation with serial radiographs every 6 months
Nail removal and surgical excision of the lesion
A defect of which of the following genes is associated with an increased risk of chondrosarcoma and is inherited in an autosomal dominant manner?
A 19-year-old male has a heritable condition represented by the radiograph in Figure A. He visits a geneticist and genetic screening reveals he has a EXT 1 gene mutation. Counseling for the patient would include telling the patient that he is more likely to have all of the following compared to a patient carrying the EXT 2 gene mutation EXCEPT:
More limb malalignment
Lower functional knee and elbow range of motion
Lower rate of sarcomatous transformation
Higher rate of pelvic and flatbone involvement
A 22-year-old female with hereditary osteochondromas has difficulty supinating and pronating her forearm. Radiographs are shown in Figure A. Which of the following procedures would most effectively improve forearm rotation in this patient?
Combined radius and ulna corrective osteotomy
Radial shaft osteotomy
Radial head resection
Ulnar osteotomy and lengthening
Which of the following is NOT associated with the condition shown in figure A?
subluxation of the radiocapitellar joint
valgus defomity of the knee
ulnar deviation of the wrist
absence of the thumb
All of the following statements regarding hereditary multiple exostosis (HME) are correct EXCEPT?
It is inherited in an autosomal dominant fashion
Mutations in HME affect the prehypertrophic chondrocytes of the growth plate
It is caused by mutations in either EXT1, EXT2, or EXT3 genes
Radiographically, the exostoses are in direct connection to the medullary cavity
Radiographically, the exostoses grow towards the physis
All of the following are true of multiple hereditary exostoses (MHE) EXCEPT?
Autosomal dominant inheritance
Caused by mutation(s) in the EXT1/EXT2/EXT3 genes
Exostoses grow towards the joint in MHE but away from the joint in solitary osteochondromas
The most common joint affected is the knee
The rate of transformation to chondrosarcoma is less than 10% in MHE
A 23-year-old male reports a firm, immobile mass behind his tibia that creates pain when he walks long distances or uses stairs. He reports no night pain or constitutional symptoms. His WBC, LDH, and Alkaline phosphatase are normal. Radiographs are shown in Figures A and B. A T1 MRI is shown in Figure C. What is the next most appropriate step in management?
Neoadjuvant chemotherapy followed by surgical resection followed by adjuvant chemotherapy
Radical margin resection with allograft-prosthetic reconstruction
External beam irradiation
Curettage with adjuvant liquid nitrogen application