MR imaging of symptomatic osteochondromas with pathological correlation

A Solitary, Large Calcaneal Osteochondroma Growing Extensively After Skeletal Maturity: A Case Report and Review of the Literature

Although osteochondromas are the most common benign tumors in the skeleton, calcaneal osteochondromas are very rare. New onset of pain or rapid growth of the tumor, especially after the closure of the epiphyseal growth plate, might reflect malignant transformation. However, enlargement of solitary osteochondromas reported as benign in a skeletally mature patient is present in the literature. We report the clinical and radiologic findings of a calcaneal osteochondroma with an extremely rare placement and painful rapid growth causing limited ambulation in a 27-year-old male. After surgical removal of the tumor, histologic examination demonstrated no evidence of malignancy, and there was no recurrence during the three-year follow-up.

Treatment Strategy of Fractured Osteochondroma in the Young Athlete's Knee

Purpose: The main purpose of this study was to compare the clinical outcome of surgery versus observation in young athletes with fractured osteochondromas in the knee. The secondary aim was to evaluate displacement versus non-displacement fractures with regards to functional recovery. Methods: A retrospective analysis was performed in young athletes with fractures of osteochondromas in the knee. In the surgery group, resection of the osteochondromas was performed due to pain persisting at 4 weeks after injury. In contrast, patients with pain diminishing within 4 weeks after injury were observed without surgery. Displacement was defined as a gap widening of ≥1 mm between fragments, or translation of >50% of the distal fragment in relation to the proximal fragment. The time to return to the original sport was compared between groups. Results: The study sample was composed of 21 patients with a mean age of 12 years (range 9-16 years). There were 14 patients in the surgery group and 7 patients in the observation group. There were 10 patients (71%) with displacement and 4 patients (29%) with non-displacement fractures in the surgery group. Surgery was required more frequently in displacement than in non-displacement fracture patients (p = 0.01). The mean time to return to the original sport was 2.1 ± 1.1 and 7.2 ± 4.1 weeks in the surgery and observation groups, respectively (p < 0.01). Conclusions: Surgical excision is preferable in a young athlete's knee presenting with displacement of fractured osteochondromas due to disabling symptoms and in order to allow them to return faster to original sports activities.

Osteochondromas: An Updated Review of Epidemiology, Pathogenesis, Clinical Presentation, Radiological Features and Treatment Options

Osteochondroma, the most common benign bone tumor, is a projection on the external surface of the bone, which can be sessile or pedunculated. 85% of osteochondromas present as solitary lesions, while 15% occur in the context of hereditary multiple exostoses (HME), a genetic disorder that is inherited in an autosomal dominant manner. Although often asymptomatic, symptoms may eventuate from compression of adjacent vessels or nerves, fractures, osseous deformities, bursa formation, or malignant transformation. Cartilage cap thickness >2 cm in adults or >3 cm in children as well as new onset of pain or growth, or rapid growth of the lesion, especially after the closure of the growth plate, might reflect cancerous transformation. Surgical resection is indicated for symptomatic lesions, complications, cosmetic reasons or malignant transformation. Excision of the tumor with free margin is the treatment of choice. Local recurrence is less than 2% if complete resection is achieved.

A Rare Case of Intra-articular Osteochondroma of the Femoral Neck: A Case Report

INTRODUCTION

The osteochondroma (OC) is considered a benign tumor with long bone preference. It presents usually at the metaphyseal part of the bone, with rare cases of intra-articular origins especially in the hip joint. The presentation of such rare cases varies according to its site and mass effect, which may compress the adjacent nerves, tendon, or vascular structures.The femoral neck OC carries a higher risk of femoral head vascular injury and necrosis, as well as sciatic nerve injury, which requires careful preoperative planning and intraoperative cautions. We report a rare case of intra-articular OC in the hip.

CASE REPORT

A 28-year-old male, presented to our hospital, with complaints of right-side gluteal pain, decrease hip joint extension, and feeling of a hard mass for 2 years. The radiographic evaluation showed an osseous mass related posterior and inferior to the right femur neck, with cortical and medullary continuation, and cartilaginous cap on the magnetic resonance image. The suspicious was OC, and planned for excision and histopathological evaluation. The excision was done through lateral hip approach, and it was intra-articular with marked stretching of the joint capsule. Complete excision was done, as close as possible to the femoral neck cortex using saw and osteotomes, followed by prophylactic fixation using two cannulated screws. The histopathology reports confirm the diagnoses, and the patient started on hip range of motion and abductor strengthening exercises. Over a 4-month follow-up period the patient showed significant improvement in his hip range of motion.

CONCLUSION

The intra articular OC of the hip is as rare presentation of the OC, which carries the risks of avascular necrosis as well as nerve compression. Clinical suspicion, proper planning, and histopathological evaluation are needed for better results.

Fractured osteochondroma presenting with popliteal pseudoaneurysm: Case report and review of literature

Osteochondroma, the most common tumor of bone, is usually asymptomatic. Vascular complications are an atypical presentation and include true or false aneurysm formation, deep venous thrombosis, and arterial insufficiency. A review of the English literature identified 130 cases of osteochondroma-related vascular complications. We describe the case of a 38-year-old man presenting with left calf pain and swelling who was diagnosed with the rare constellation of a popliteal pseudoaneurysm and incidental peroneal vein thrombosis secondary to a fractured femoral sessile osteochondroma. This was treated with resection of the osteochondroma, excision of the aneurysm, and primary end-to-end anastomosis of the artery.

Femoral osteochondroma responsible for ischiofemoral impingement, bursitis, and secondary lipoma arborescens mimicking malignant transformation

We present the case of a 53-year-old woman with a known history of hereditary multiple exostosis disease referred for further imaging work-up after ultrasound and computed tomography leading to the suspicion of malignant transformation of an osteochondroma (exostosis) located on the posteromedial aspect of the right proximal femur. Imaging examinations suggested an ischiofemoral impingement resulting in a secondary bursitis associated with the development of an internal lipoma arborescens. This rare association explained the complexity of the diagnosis. Magnetic resonance imaging (MRI) played a key role in correctly identifying this benign complication of the osteochondroma and in distinguishing those observations from a secondary exostotic chondrosarcoma. MRI findings were subsequently confirmed at surgery and pathological examination.

Osteoblastic Osteosarcoma Arising beneath an Osteochondroma in an 11-Year-Old Male with Multiple Hereditary Exostoses

Introduction

Multiple hereditary exostoses (MHE) is a rare autosomal dominant disorder characterized by the presence of multiple skeletal deformities. They are painless slow-growing lesions. Malignant transformation tends to occur later in adulthood and has only been seen in 1–5% of patients.

Objective

We describe the clinical, radiological, and pathological characteristics of a child with MHE who developed osteoblastic osteosarcoma beneath an osteochondroma.

Case Presentation

An 11-year-old male Rwandan presented to our hospital with a two-week history of a dull persistent pain in his left distal femur and loss of weight and appetite. There was no relief with pain killers. He was a known case of multiple hereditary exostoses diagnosed at age 3. He began experiencing mild symptoms 6 months prior to admission which worsened in the last two weeks prior to his admission. On examination, he had multiple palpable bony swellings bilaterally on the proximal humeri and distal femurs. X-rays showed multiple exostoses and MRI showed a lesion with heterogeneous signal intensities that suggested malignant transformation. At surgery, a necrotic lesion beneath the exostosis was excised and sent for histopathological analysis which confirmed osteochondroma with an osteoblastic osteosarcoma in the marrow cavity. Chemotherapy and limb-salvaging surgery were done and he has recovered well.

Conclusion

Osteosarcomas arising at sites of MHE have not been previously reported in Africa. These tumors rarely undergo malignant transformation.

Solitary Osteochondroma of the Ventral Scapula Associated with Large Bursa Formation and Pseudowinging of the Scapula: A Case Report and Literature Review

Osteochondroma (OC) is the most common benign bone tumor and may occur on any bone in which endochondral ossification develops. Although scapular OC accounts for less than 5% of the cases of solitary OC, OC is the most common lesion among the tumors and tumor-like lesions of the scapula. OC that develops near the medial scapular border easily causes friction with the ribcage; hence, almost half the number of cases of OC associated with marked bursa formation develops in the ventral scapula. We report a case of a 27-year-old female with a painful OC of the ventral scapular surface associated with large bursa formation and pseudowinging of the scapula. After l2 years of follow-up with magnetic resonance imaging, we confirm that the accompanied bursa left at surgery disappears.

Hereditary multiple exostoses as a novel cause of bilateral popliteal artery aneurysms in the elderly

Hereditary multiple exostoses (HME) is a genetic condition characterized by the development of multiple osteochondromas during childhood and adolescence. On rare occasions, these bony tumors can be associated with vascular injury, most commonly involving the popliteal artery. Such patients typically present with vascular complications in adolescence and young adulthood. We report an autopsy study of an elderly man who presented with bilateral popliteal artery pseudoaneurysms in the setting of HME at age 81. This is the oldest patient presenting with a vascular complication due to HME reported to date, as well as the only known case of bilateral popliteal pseudoaneurysms caused by HME. This is also the only autopsy study of this vascular complication so far reported. Our case illustrates that vascular complications from HME can occur even in the elderly, and may show bilateral involvement.

Retrocalcaneal Bursitis due to Rare Calcaneal Osteochondroma in Adult Male : Excision and Outcome

Introduction:

Osteochondroma is the most common benign tumour of the bone and is considered as developmental lesion of the bone. Common site of osteochondroma presentation is around the knee but calcaneal osteochondroma as such is a rare entity. Osteochondromas grow during childhood through adolescence, but usually the growth of osteochondroma ends when the epiphyseal plates close. In an adult, growth of an osteochondroma suggests the diagnosis of a malignant transformation. However, it can also present as pressure symptom in later phase of life. Here, we presented a case of retrocalcaneal bursitis in late phase of life of a male farmer due to late growth of osteochondroma.

Case Presentation:

We report a case of calcaneal osteochondroma which is an extremely rare site of occurrence with painful swelling of ankle causing limitation of walking in a 58-year-old male. Surgical excision of tumour followed by a histological confirmation reported negative for any malignant changes.

Conclusion:

There may be chances of osteochondroma being a reason for retrocalcaneal bursitis. It is possible of late detection of benign osteochondromas which show symptomatic growth and pressure effect in skeletally mature patients without malignant transformation.

Imaging of benign complications of exostoses of the shoulder, pelvic girdles and appendicular skeleton

Exostoses are the most common benign bone tumors, accounting for 10 to 15% of all bone tumors. They develop at the bone surface by enchondral ossification and stop growing when skeletal maturity has been reached. At first, exostoses are covered by a smooth cartilage cap that progressively ossifies with skeleton maturity. Then they may regress, partly or even completely. Osteochondromas may be solitary or multiple, with the latter associated with hereditary multiple exostoses (HME). Exostoses develop during childhood and become symptomatic during the third decade of life in the case of solitary exostoses, or earlier, in case of HME. They stop growing after puberty, when the epiphyseal plates close. Most exostoses remain asymptomatic. Local complications, usually benign, may occur, such as fractures or mechanical impingements upon nearby structures. In rare cases, sarcomatous degeneration occurs. Most of these complications have been described in case reports. This article describes the imaging features of benign complications of exostoses of the shoulder, pelvic girdles and appendicular.

Evaluation and management of ischiofemoral impingement: a pathophysiologic, radiologic, and therapeutic approach to a complex diagnosis

Ischiofemoral impingement syndrome (IFI) is an underrecognized form of atypical, extra-articular hip impingement defined by hip pain related to narrowing of the space between the ischial tuberosity and the femur. The etiology of IFI is multifactorial and potential sources of ischiofemoral engagement include anatomic variants of the proximal femur or pelvis, functional disorders as hip instability, pelvic/spinal instability, or abductor/adductor imbalance, ischial tuberosity enthesopathies, trauma/overuse or extreme hip motion, iatrogenic conditions, tumors and other pathologies. Magnetic resonance imaging (MRI) is the diagnostic procedure of choice for assessing IFI and may substantially influence patient management. The injection test of the ischiofemoral space (IFS) has both a diagnostic and therapeutic function. Endoscopic decompression of the IFS appears useful in improving function and diminishing hip pain in patients with IFI but conservative treatment is always the first step in the treatment algorithm. Because of the ever-increasing use of advanced MRI techniques, the frequent response to conservative treatment, and the excellent outcomes of new endoscopic treatment, radiologists must be aware of factors that predispose or cause IFI. In addition, focused treatment in these conditions is often more important than in secondary impingement. In this article, we briefly describe the anatomy of the IFS, review the clinical examination and symptoms, assess the diagnostic imaging criteria and pathophysiological mechanisms, and develop an understandable classification of IFI, with particular focus on its etiology, predisposing factors, and associated musculoskeletal abnormalities. We also assess the role of the radiologist in the diagnosis, treatment, and preoperative evaluation of both primary and secondary IFI.

A case report of osteochondroma with unusual clinical and imaging presentation

Osteochondroma or exostosis is a bony developmental anomaly, which arises from exophytic outgrowth on bone surfaces in a characteristic manner. Osteochondroma is asymptomatic and grows away from the nearby joint. This paper reports an unusual presentation of osteochondroma in which the patient was surprisingly completely symptomatic. The lesion grew toward the nearby joint and the radiographic findings were not compatible with surgical findings.

Spontaneous healing of an osteochondroma fracture

Osteochondroma is the most common benign tumor of bone, usually asymptomatic. Fracture of an osteochondroma is a rare complication and has been recognized as a cause of pain. Treatment of this fracture is controversial and some authors suggest fracture as an indication for surgical excision. We present a case of fractured osteochondroma that healed without complication.

Diagnosis of hyperostosis of the medial calcaneal tubercle similar to a heel spur

Calcaneal osteochondromas are rare conditions. To our knowledge, we present the first report of a calcaneal osteochondroma in an adolescent patient that was surprisingly similar to a heel spur, and, in addition, symptoms due to compression of the medial plantar nerve were present.

Intraarticular osteochondroma of shoulder: a case report

Osteochondroma is a cartilage-capped osseous protrusion that arises from the surface of a bone. Osteochondroma occurs mostly in the metaphysis of long tubular bones such as the femur, tibia, and humerus. Osteochondroma is rare in the diaphysis and in the epiphysis. There was only one case in which a patient had a limited range of motion in the shoulder joint due to an intraarticular osteochondroma of the proximal humerus. We present a rare case of intraarticular osteochondroma involving the proximal humerus with pathologic findings and imaging features on computed tomography and magnetic resonance imaging.

Bilateral ischiofemoral impingement in a patient with hereditary multiple exostoses

The skeletal anatomy of the hip provides two main locations for impingement: abnormal contact between the acetabulum and femur (femoroacetabular impingement) or between the ischium and femur (ischiofemoral impingement). We report a case of bilateral ischiofemoral impingement in a patient with hereditary multiple exostoses. The association of exostoses and femoral metaphyseal widening resulted in the narrowing of the ischiofemoral spaces. Pain was improved on the left side by resection of the ischial exostosis.

Fracture of an osteochondroma of the femoral neck caused by impingement against the ischium

This article describes 2 cases of osteochondroma emanating from the posterior aspect of the femoral neck with a fracture at the base of its stalk caused by impingement between the tumor and the ischium. A 44-year-old man and a 57-year-old man presented with left hip pain. Radiographs revealed a mass at the posterior aspect of the femoral neck. Computed tomography and magnetic resonance imaging revealed that the mass was fractured at the stalk. The relationship between the tumor and the ischium was examined with an image intensifier. The tumor impinged on the ischium with slight flexion and external rotation of the hip joint. In both patients, the tumor was excised, and the pathological report was osteochondroma. At follow-up, the patients had full hip joint range of motion, and lateral radiographs of the left hip joint showed complete resection of the tumor without recurrence. To the authors' knowledge, the current cases are the first reports of fracture of an osteochondroma with confirmed impingement using an image intensifier pre- and intraoperatively. Both patients had histories of restricted hip range of motion and a sudden onset of pain. After excision, the patients recovered to activities of daily living with no complications. An osteochondroma at the posterior aspect of the femoral neck can impinge on the ischium and fracture at its base with a sudden onset of pain. Awareness of this mechanism of impingement may lead to a better understanding of patient symptoms caused by osteochondroma of the femoral neck.

Large soft tissue osteochondroma of the heel: a case report and literature review

Soft tissue osteochondromas are the rare tumors of the foot. We present an unusual case of a 30-year-old woman who had a large osteochondroma originating from the soft tissue in the heel region. She made an uneventful recovery following excision. No recurrence was noted at 36 months follow-up. To the best of authors' knowledge, such presentation has not been reported before in the English language-based medical literature.

Giant solitary osteochondroma arising from the fifth metatarsal bone: a case report

Accounting for 20% to 50% of all benign forms, solitary osteochondroma is the most common bone tumor. The long bones of the lower extremity are most frequently affected, whereas the small bones of the hands, feet, pelvis, scapula, and spine are less common locations. Osteochondromas are benign osseous neoplasms with a distinct hyaline cartilage cap originating from the physis, and they cease to grow with skeletal maturity. Treatment of osteochondroma is usually conservative, unless symptoms, usually pain, are progressive or the lesion demonstrates rapid or new growth, or if enlargement after skeletal maturation is noted or malignant transformation is suspected. In this report, we describe the case of an adult with a giant, symptomatic osteochondroma localized to the fifth metatarsal. The lesion was treated with excision, and after more than 2 years of follow-up, no evidence of recurrence was noted. This case demonstrated that, despite the benign nature of the lesion, a large osteochondroma could localize to a metatarsal.

Sino-orbital osteoma: a clinicopathologic study of 45 surgically treated cases with emphasis on tumors with osteoblastoma-like features

CONTEXT

Osteomas are limited almost exclusively to craniofacial and jaw bones. Histologically, they can be divided into ivory, mature, or mixed types. Osteomas may have osteoblastoma-like areas and distinguishing it from true osteoblastoma can be challenging. Some believe osteomas with osteoblastoma-like features behave more aggressively.

OBJECTIVE

To perform a clinicopathologic comparison of sino-orbital osteomas both with and without osteoblastoma-like features.

DESIGN

We studied 45 surgically excised sino-orbital osteomas. Tumors were categorized as ivory, mature, or mixed type and presence of osteoblastoma-like areas and Paget-like bone were noted. Clinical features of those with and without osteoblastoma-like areas were compared.

RESULTS

Men outnumbered women (3:2); median age was 37 years. Frontal sinus was the most common location (62%) followed by ethmoid and maxillary sinuses. Twelve tumors (27%) involved the orbit, 2 primarily and 10 secondarily. All cases were symptomatic with headache, sinusitis, visual changes, pain, and proptosis being most common. Seventeen tumors (38%) had osteoblastoma-like areas. Extension into an adjacent sinus/anatomic compartment was more common in osteoblastoma-like tumors (47% versus 29%), including more frequent orbital involvement (41% versus 13%). Visual changes were more frequent in the osteoblastoma-like group. Distribution of histologic subtypes and Paget-like bone were similar between the 2 groups. Osteomas with osteoblastoma-like features were more often incompletely excised (25% versus 14%). However, clinical recurrence was less common (8% versus 27%).

CONCLUSIONS

Osteoblastoma-like features are common in sino-orbital osteomas, but it does not correlate with more adverse clinical features or worse outcome. Osteoblastoma-like areas appear to represent active remodeling within an osteoma rather than defining a distinct clinicopathologic entity. Distinguishing it from osteoblastoma may require careful histologic evaluation and radiographic correlation.

A calcaneal osteochondroma with recurrence in a skeletally mature patient: a case report

Introduction

Osteochondroma is the most common benign tumor of the skeleton. However, calcaneal osteochondroma is very rare. Osteochondromas grow during childhood through adolescence, but usually growing ends when the epiphyseal plates close. In an adult, growth of an osteochondroma suggests the diagnosis of malignant transformation to a chondrosarcoma. However, enlargement of an osteochondroma reported as benign after skeletal maturity is present in literature.

Case presentation

We report the clinical and radiologic findings of a calcaneal osteochondroma with an extremely rare placement and painfull, rapid reccurence following surgical excision in a skeletally mature female. The lesion showed growth the first-operation later and was re-operated. Histopathological examination did not show malignancy.

Conclusion

It should kept in mind that benign osteochondromas can show symptomatic growth in skeletally mature patients without malignant transformation.

A calcaneal osteochondroma with recurrence in a skeletally mature patient: a case report

INTRODUCTION

Osteochondroma is the most common benign tumor of the skeleton. However, calcaneal osteochondroma is very rare. Osteochondromas grow during childhood through adolescence, but usually growing ends when the epiphyseal plates close. In an adult, growth of an osteochondroma suggests the diagnosis of malignant transformation to a chondrosarcoma. However, enlargement of an osteochondroma reported as benign after skeletal maturity is present in literature.

CASE PRESENTATION

We report the clinical and radiologic findings of a calcaneal osteochondroma with an extremely rare placement and painfull, rapid reccurence following surgical excision in a skeletally mature female. The lesion showed growth the first-operation later and was re-operated. Histopathological examination did not show malignancy.

CONCLUSION

It should kept in mind that benign osteochondromas can show symptomatic growth in skeletally mature patients without malignant transformation.

Giant solitary osteochondroma of the inferior medial calcaneal tubercle: a case report and review of the literature

Small osteophytes are frequently encountered in the foot and ankle, and are not to be confused with true osteochondromas, which are relatively uncommon in this region. They most often affect long bones of the appendicular skeleton but may involve flat bones as well. Osteochondromas are benign osseous neoplasms with a distinct hyaline cartilage cap originating from the physis and cease growing with skeletal maturity. Osteochondroma are often treated conservatively unless they become symptomatic, painful, demonstrate rapid or new growth, enlarge after skeletal maturity, and/or exhibit signs of malignant transformation. In this report, we present a case of a giant (8 cm x 4.2 cm x 2.1 cm) osteochondroma in an adult occurring on the inferior medial tubercle of the calcaneus that underwent excision, with 3.5 years of follow-up without recurrence. To our knowledge this is the largest osteochondroma affecting the inferior medial tubercle of the calcaneus. This case demonstrates that large osteochondromas may occur in the foot, and also confirms that benign osteochondroma growth may occur in adulthood. A detailed review of osteochondroma occurrence in the foot is presented along with a review of the diagnostic work-up to evaluate for malignant transformation.

LEVEL OF CLINICAL EVIDENCE

4.

Contour irregularities of the distal femur caused by developmental, traumatic, and benign cortically-based neoplastic conditions: radiographic and MRI correlation

This review illustrates the radiographic and magnetic resonance imaging (MRI) appearances of a variety of entities that result in surface contour abnormalities of the distal femur. Such abnormalities may result from developmental variants expressed in the growing skeleton, from trauma, or from cortically-based tumours. As the number of MRI examinations of the knee performed annually to exclude internal derangement increases, the frequency with which these variants and pathological entities are encountered will likewise increase. In most cases, the location of the lesion, as well as its specific imaging characteristics, will allow an accurate diagnosis.

Fractures of osteochondroma during physical exercise

BACKGROUND

The mechanism responsible and the best form of treatment for fractures of osteochondromas remain unclear.

PURPOSE

We studied the incidence, cause, treatment, and outcome of fractures of osteochondroma over a 17-year period.

STUDY DESIGN

Retrospective cohort study.

METHODS

We retrospectively reviewed all cases of osteochondroma at one institution over 17 years (1985 to 2002) to identify cases of fractures. These patients were then contacted for follow-up.

RESULTS

Seven cases of fracture through the stalk of a pedunculated osteochondroma were identified. All fractures were sustained during physical exercise. One fracture was due to a direct blow, and the others to indirect muscle or tendon injury. Five patients were treated surgically with excision of the osteochondroma, and the other two received nonoperative treatment consisting of restriction of physical activity and observation. In all cases, patients were able to resume sporting activity within 4 to 8 weeks. The recovery period was shorter for patients who received surgical treatment.

CONCLUSIONS

Surgical excision of the fractured osteochondroma may be preferable for patients engaging in sport.

Athletes with lower limb ischaemia

The case of a young healthy sportsman and acute exacerbation of chronic infragenicular pain is presented. Further investigation revealed an obstruction of the tibiofibular trunk due to an osteochondroma, arising from the fibula, which was immediately resected. Osteochondroma is observed in 1-2% of the population and may present with vascular complications. In young patients and athletes, leg pain may be of vascular origin due to an entrapment or compression and should always be considered.

Hereditary multiple exostoses: from genetics to clinical syndrome and complications

OBJECTIVE

To give an overview of genetic, clinical and radiological aspects in two families over four generations with known hereditary multiple exostoses (HME).

METHODS AND MATERIAL

After linkage analysis in both families to localize the defective gene, mutation analysis was performed in these genes to identify the underlying mutation. In the 31 affected individuals, location, number and morphology and evolution of exostosis, evolution of remodeling defects at the metaphysis, and the extent of possible complications were evaluated on clinical and imaging (plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI)) data over a lifetime period.

RESULTS AND CONCLUSIONS

Both families demonstrate the gene defect in the same EXT-2 gene locus on chromosome 11p. Exostoses are preferentially located in the lower extremity (hip, knee and lower leg), humerus, and forearm. Any other bone may be involved, except for the calvaria of the skull and the mandible. Exostoses are rather sessile than pedunculated. Exostosis is rarely present at birth but develops gradually and may persist to grow slowly after closure of the growth plates. Preferential expression of the remodeling defect was seen in the hip, distal femur (trumpet-shaped metaphysis) and forearm (shortening of the ulna with secondary bowing of the radius and development of a pseudo-Madelung deformity). These radiological manifestations start at the age of 4-5 years and become more obvious as the enchondral bone formation progresses with age. Reported complications in these families consist of local entrapment phenomenons (vessel, tendon, nerve), frictional bursitis, and sarcomatous transformation. MRI was able to suggest these complications and is the imaging technique of choice in the evaluation of symptomatic exostoses.