Parosteal Lipoma Overlying an Osteochondroma of the Hyoid Bone: A Case Report and Literature Review

Parosteal lipomas and osteochondromas of the head and neck are uncommon benign tumors, constituting a small fraction of lipoma and bone tumor cases. We present a unique case of a 66-year-old male with a parosteal lipoma overlying an osteochondroma in the anterior midline neck, causing dysphagia. Surgical excision confirmed the diagnosis, and a literature review revealed similar cases predominantly adjacent to the mandible or calvaria. This case emphasizes the need to have parosteal lipoma and osteochondroma on the differential diagnosis for patients presenting with a firm mass of the central neck, especially with a history of trauma. Laryngoscope, 134:2844-2847, 2024.

Endoscopically-assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device

Background: Osteochondromas of the mandibular condyle show facial asymmetry and malocclusion. Because condylar osteochondromas are generally resected in a preauricular approach with risks of facial nerve injury and visible scar, the authors report endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device.Case presentation: A 38-year-old woman presented with malocclusion and facial asymmetry caused by deviation of the chin to the left. Computed tomography showed a hyperdense, well-circumscribed mass arising from the medial aspect of the right mandibular condyle with resorption of the skull base. The patient underwent an endoscopically-assisted intraoral condylectomy with a piezoelectric surgical device. The postoperative course was uneventful without trismus, malocclusion, or facial asymmetry, and there was no recurrence 4 years after surgery.Conclusion:Endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device is a minimally invasive and safe surgery.

Osteochondrolipoma of the foot treated by surgical excision: a case report and literature review

BACKGROUND

Osteochondromas, classified as a new benign subtype of lipomas and characterised by chondroid and osseous differentiation, are rare lesions that have been infrequently reported in previous literature. The maxillofacial region was reported as the most frequent localization, with infrequent occurrence in the lower limb. This paper represents the first documented case report of osteochondrolipoma in the foot.

CASE PRESENTATION

A 51-year-old male patient presented with a chief complaint of right foot pain at the plantar aspect, accompanied by the observation of swelling between the first and the second metatarsal shafts. His complaint of pain and swelling started 10 and 4 years prior, respectively. Since their onset, both symptoms have progressed in nature. Imaging revealved a large mass exhibiting a nonhomogenous composition of fibrous tissue and bony structures. Surgical intervention through total excision was indicated.

CONCLUSION

Osteochodrolipoma is a benign lesion that can affect the foot leading to decreased functionality of the foot due to the pain and swelling. Surgical excision is the recommended approach for this lesion, providing both symptomatic relief and confirmation of the diagnosis through histopathological examination.

Effect of Solitary Osteochondroma on Alignment and Length in the Lower Extremities

BACKGROUND

There is a lack of information about the effects of untreated solitary osteochondroma (SO) on longitudinal growth of the lower extremities in children and adolescents. This study aimed to assess the coronal alignment and length of the lower extremity in patients with SO around the knee and to identify the factors related to the development of deformities.

METHODS

We retrospectively reviewed 111 patients diagnosed with SO around the knee. The patients were classified into 2 groups depending on the location of the SO: 51 in the distal femur and 60 in the proximal tibia. Characteristics of the lesions, such as type, location, size, and distance from the joint line, were determined. Radiographic analysis of the lower limbs included mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, whole-leg length, femoral length, and tibial length.

RESULTS

The mean age at the time of diagnosis was 12.3±3.4 years. No statistically significant differences were found between the affected and contralateral sides for mechanical lateral distal femoral angle and mechanical medial proximal tibial angle in either the distal femur or the proximal tibia groups. In patients with femoral lesions, the femoral and whole-leg lengths were significantly shorter on the affected side than on the unaffected side ( P <0.001 and 0.002, respectively), and the mean differences were 2.1±3.6 and 2.1±4.4 mm, respectively. Univariate logistic regression analysis did not reveal any factors associated with limb length discrepancy (LLD). In patients with tibial lesions, no statistically significant differences were found in LLD.

CONCLUSIONS

SOs around the knee did not cause clinically significant deformity of the lower extremity. However, in contrast to proximal tibia lesions, SO in the distal femur was associated with the shortening of the affected limb. Consideration should be given to the development of LLD in skeletally immature children with SO in the distal femur.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Application of 3D-Printed Model in the Cervical Spine Osteochondroma Surgery: A Case Report

A 73-year-old woman having a throat lump sensation and dysphagia for the past several months presented at our otorhinolaryngology outpatient clinic. A physical examination disclosed a protruding subepithelial mass over the right tonsil fossa. The mass was not tender and had no mucosal lesions or signs of active infection. Therefore, we arranged face and neck computed tomography scans, which reported a solitary osseous lesion over the anterior-right aspect of the C1-2 joint. Considering the rarity and unfamiliar anatomy of this disease, we built a 3D-printed model to assist with the surgical rehearsal of the procedure as well as with a preoperation discussion with the patient and her family. We arranged a combined Otolaryngology-Neurosurgery department approach after discussion with the neurosurgeon and successfully removed the lesion without sacrificing the overlying longus capitis muscle. The pathology examination revealed no evidence of malignancy. The final diagnosis was cervical spine solitary osteochondroma. The patient had a complete recovery of both oral cavity and normal swallowing function. No tumor recurred during the 3-year follow-up. On the basis of this case, in-house 3D-printing technology can offer a rapid, reliable model for an interdisciplinary team to use to enhance personalized presurgical planning, thus providing better patient engagement during hospitalization.

Subungual Osteochondroma of the Great Toe: A Case Report

Bony outgrowths of the distal phalanx of the great toe have been described in the literature but rarely. These subungual bony outgrowths can be caused by subungual exostosis or subungual osteochondromas. Both of these abnormalities are bony outgrowths with differences in the cartilage cap wherein the exostoses have fibrocartilage, and osteochondromas have hyaline cartilage. The subungual exostosis and osteochondroma that are protruding present symptoms of pain, redness, and deformed nail bed, whereas the nonprotruding osteochondromas have only a lump as the presenting symptom. In both conditions, excision of the lesion and curettage of the base helps prevent a recurrence. Curettage at the end of the excision of the bony outgrowth is required to avoid recurrence. After excision, the specimen should be sent for histopathologic examination to differentiate between the exostosis and osteochondromas, which are underreported in subungual locations, and to rule out malignant transformation. We present a 13-year-old girl with an isolated subungual nonprotruding exostosis of the great toe that was treated by excisional biopsy. The histopathologic examination confirmed it as osteochondroma, which is underreported.

Medullary Compression by a Cervical Osteochondroma in a Patient with Multiple Hereditary Exostoses: A Case Report

CASE

A 19-year-old man with Multiple Hereditary Exostoses presented with cervical pain without neurological symptoms and/or signs. Magnetic resonance revealed a large C2 osteochondroma, occupying a part of the medullary canal. He was submitted to an en bloc resection with hemilaminectomy without fusion. At the 1-year follow-up, he presented resolution of pain and no neurological symptoms or signs, without cervical instability or radiological signs of disease recurrence.

CONCLUSION

Cervical osteochondroma is usually asymptomatic. Neurological compression and differentiation to chondrosarcoma are the main concerns. Surgical excision allows the local cure of the disease and is usually performed without fusion.

Is total-body MRI useful as a screening tool to rule out malignant progression in patients with multiple osteochondromas? Results in a single-center cohort of 319 adult patients

PURPOSE

To evaluate the results of total-body (TB) MRI used as a screening tool for assessment or exclusion of malignant transformation in patients with hereditary multiple osteochondromas (HMO).

PATIENTS AND METHODS

In a single-institute cohort of MO patients, 366 TB-MRI examinations, including T1-weighted and STIR images, were performed for screening and follow-up purposes to rule out the malignant transformation, and retrospectively analyzed. In each patient, the presence and location of osteochondromas in the axial and appendicular bones were recorded. Forty-seven patients underwent a second TB surveillance in this period. STIR sequences were used to identify sites of increased signal intensity that could represent suspicious thickened cartilage caps or indeterminate reactive changes related to osteochondromas.

RESULTS

In 82% of patients, one or more OC locations were determined in one or more flat bones. In 366 exams, nine OC (2,5 %) with suspicious imaging features were identified. These proved to be peripheral chondrosarcomas after targeted MRI and resection were performed. All nine malignant lesions were in flat bones (pelvis 5, ribs 3, scapula 1). Three of these patients were 19 years of age. In 12 patients who had peripheral or intraosseous low-grade chondrosarcoma in their history, before their first TB-MRI, no new lesions were identified. Twenty-three additional TB-MRI exams, demonstrating focal high T2 signal intensity, also gave rise to performing additional targeted MRI. One OC of the distal femur was excised and appeared benign. No suspicious cartilage caps were depicted on the remaining 22 targeted MRI exams but instead increased T2 signal was clarified by reactive changes (frictional bursitis, soft tissue edema) in close relation with benign osteochondromas. No malignant lesions were found in 47 patients who had a second TB surveillance (mean interval between exams 3.2 years, range 2-5 years).

CONCLUSION

TB-MRI can identify malignant transformation of osteochondromas in HMO patients. All peripheral chondrosarcomas occurred in flat bones (ribs, scapula, pelvis) in our study. TB-MRI might assist in triage between higher risk patients with a high burden of OC, including the location of OC in main flat bones vs lower risk patients without OC of the flat bones.

Unique skin findings in a case of the A3 pulley trigger finger due to an osteochondroma

Trigger finger is usually caused by stenosing tenosynovitis and hypertrophy of the retinacular sheath, and the most common site of tendon triggering is the A1 pulley. Although the A3 pulley trigger finger has been described in a few cases caused by hypertrophy of the retinacular sheath and ganglion, associated skin findings have not been reported to date. Herein, we report a rare case of the A3 pulley trigger finger due to osteochondroma with unique skin findings in a 50-year-old woman. In this case, we observed a V-shaped skin depression on the palmar side of the proximal interphalangeal joint of the right middle finger during finger locking. Additionally, we observed bilateral linear skin depressions on the sides of the proximal phalange. These findings might be caused by the traction force on the A3 pulley, connected to the skin via the Grayson and Cleland ligaments, which are fibrous tissues that connect the skin and tendon sheath.

Tibial nerve compression due to osteochondroma of the fibular head: A case report

RATIONALE

Osteochondroma is one of the most common primary benign bone tumors. In most cases, this disease is asymptomatic. However, it may become symptomatic owing to nerve and vascular compression when it affects the knee joint. Isolated tibial nerve palsy caused by proximal fibular osteochondroma is rare.

PATIENTS CONCERNS

A 60-year-old male, was treated for degenerative arthritis of the right knee, referred to the right great toe flexion limitation that occurred 3 weeks prior.

DIAGNOSES

Magnetic resonance imaging revealed compression of the tibial nerve and surrounding muscles due to an osseous lesion in the fibular head. A nerve conduction test confirmed tibial neuropathy in the right lower leg.

INTERVENTIONS

Exploratory surgery was performed to decompress the tibial nerve and remove the bony lesion histopathologically diagnosed as an osteochondroma.

OUTCOMES

Fifty-five months postoperatively, toe flexion recovered to normal. No recurrence of osteochondroma was observed.

LESSONS

As in our case, if a bony lesion is diagnosed on radiographs with neurological symptoms, early decompression surgery is necessary. Moreover, since it can be misdiagnosed as a simple bony spur, magnetic resonance imaging and tissue biopsy are also indicated.

Pediatric Peroneal Nerve Palsy Secondary to Fibular Osteochondroma

Peripheral nerve injuries due to mass effect from bony lesions can occur when the nerve exists in an anatomically constrained location, such as the common peroneal nerve at the fibular head which passes into the tight fascia of the lateral leg compartment. We report a case of a pediatric patient who developed a common peroneal nerve palsy secondary to an osteochondroma of the fibular head and describe the clinical evaluation, radiographic findings, and surgical approach. Rapid diagnosis and nerve decompression after the onset of symptoms restored full motor function at the 8-month postoperative mark.

Calcaneus as a Rare Location of Solitary Osteochondromas: Two Case Reports

Osteochondromas are the most common benign bone tumors, with an incidence of 36% to 41% among benign bone tumors. They can be caused by genetics, trauma, and growth defects. The incidence of all osteochondromas in the hands and feet is approximately 10%, and they are extremely rare in the calcaneus. They generally arise from the metaphysis and metaphyseal-diaphyseal region of the long bones. Osteochondromas, which are generally painless, are noted with signs of inflammation in the bursa, vascular and nerve compression, pain caused by joint deterioration, swelling in the subcutaneous tissue, or gait disturbance. The incidence of malignant transformation of solitary osteochondromas is 1%. We present two cases, an 11-year-old male patient and a 32-year-old male patient, diagnosed with osteochondroma in the calcaneus.

Solitary osteochondroma of the rib: An unusual chest wall tumor in the pediatric age group

Pediatric chest wall tumors are unusual and can arise from bone structures or from adjacent soft tissues. Osteochondroma is a benign cartilaginous tumor arising from the metaphysis of bone; however, it is more common in extremity rather than in membranous bone. Although benign, osteochondroma of the rib may lead to fatal complications such as pneumothorax, hemothorax, fractures, and pleural or pericardial effusion. Therefore, some form of surgical management becomes necessary to treat these lesions. We present a case of 7-year-old female child with solitary osteochondroma of the rib. The tumor was surgically excised and the child is asymptomatic on follow-up.

Bizarre parosteal osteochondromatous proliferation (Nora's lesion) of the hand: management of a rare clinical entity

Bizarre parosteal osteochondromatous proliferation, or Nora's lesion, is a rare benign tumour of the bone, most commonly described in the hands and feet. We present the case of a female patient in her 20s attending the hand clinic with a sudden onset, atraumatic swelling on the proximal phalanx of her right ring finger. The patient retains good hand function and remains asymptomatic 3 months after surgical excision. Our case highlights the importance of being aware of this diagnosis and differentiating it from other malignant, as well as benign tumours of the hand.

Benign Brain and Spinal Tumors Originating from Bone or Cartilage

Benign osseocartilaginous tumors of the spine are overall uncommon, representing between 1 and 13% of all primary bone tumors and less than 10% of all spinal tumors. Tumors in this category include osteoblastic lesions such as the related osteoid osteoma and osteoblastoma, and cartilage-forming lesions including osteochondroma, chondroma, and chondroblastoma. Aneurysmal bone cysts, giant cell tumors of bone, and eosinophilic granulomas also comprise benign tumors of the spine arising from bone. There is significant heterogeneity in the epidemiology, molecular biology, imaging features, and optimal treatment of these lesions. For example, osteoid osteoma is characterized by high expression of the cyclooxygenase enzymes, making it amenable to treatment with anti-inflammatory drugs initially, whereas other lesions such as osteoblastoma may require intralesional curettage or en bloc resection sooner. Generally, en bloc resection is preferred when possible to minimize risk of recurrence. Further, some tumors may arise in the setting of syndromic conditions, such as multiple chondromas arising in Ollier disease or Maffucci syndrome, or as part of genetic disorders, such as osteochondromas in the context of hereditary multiple exostosis. These lesions may present with local pain, cause neurological compromise or be discovered incidentally on routine imaging. The Enneking classification and Weinstein-Boriani-Biagini system are routinely used to classify lesions and assist in surgical planning. More novel techniques such as radiofrequency ablation and laser photocoagulation have been applied for the treatment of osteoid osteoma and may have utility in the treatment of other lesion types. A multidisciplinary approach is critical in the management of benign lesions of the spine, and both chemotherapeutic and surgical approaches are routinely used.

Thin Cartilage Cap May Be Related to the Spontaneous Regression in Pediatric Patients with Osteochondroma

BACKGROUND

The spontaneous regression of osteochondromas is rare, and only a few cases have been reported. Furthermore, the precise mechanism underlying spontaneous regression is unknown. This study aimed to examine the radiological findings of osteochondromas that had spontaneous regression and to identify potential indicators of this uncommon phenomenon in skeletally immature patients with osteochondromas.

METHODS

We included 28 patients (15 males and 13 females) who met the eligibility criteria between 2002 and 2019. The mean age at initial diagnosis was 9.7 years old (2-16 years). The mean follow-up period was 6.4 years (3-16 years).

RESULTS

Of the 28 patients, 10 (35.7%) had osteochondroma resolution. The osteochondroma resolved in one patient and regressed in nine. Tumor shrinkage is related to the thickness of the cartilage cap. The thickness of the cartilage cap did not correlate with age.

CONCLUSIONS

Tumor shrinkage is associated with a thinner cartilage cap on magnetic resonance imaging. The thickness of the cartilage cap may be an important predictor of spontaneous regression in pediatric patients with osteochondroma.

Extraosseous osteochondroma of superficial fascia layer of the heel: A case report and review of literature

RATIONALE

Osteochondroma is a common benign bone tumor consisting of cartilage-covered bone confluent with the medullary canal of the epiphysis. Extraosseous osteochondroma shares the same appearance and histologic features as a typical osteochondroma but does not have any attachment to surrounding bone structures. Because of its low incidence, extraosseous osteochondroma is uncommon in clinical workups and thus prone to misdiagnosis. The diagnosis of extraosseous osteochondroma should be considered when there is a well-defined bony mass in the soft tissue with no direct continuity with the adjacent bone or joint. Here, we present a case of an imaging diagnosis of "calcified bursitis in the subcutaneous superficial fascial layer" and a postoperative pathological diagnosis of "extraosseous osteochondroma."

PATIENT CONCERNS

The patient was a 61-year-old man who had a right plantar heel mass for 2 years and recently visited the hospital because of discomfort in shoes.

DIAGNOSES

The patient was diagnosed with pathological examination.

INTERVENTIONS

After completing the relevant preoperative examination and preoperative preparation and excluding contraindications to surgery, surgery was performed under nerve block anesthesia.

OUTCOMES

We performed surgical resection, and the patient did not have obvious discomfort when discharged from the hospital. Auxiliary examination showed no abnormalities.

LESSONS

For foot tumors, we need to consider the possibility of extraosseous osteochondroma. After completing the auxiliary examination, we should determine the relationship between the tumor and its surrounding tissues and blood supply before surgery to avoid causing major trauma.

Misdiagnosis of Extraskeletal Osteochondroma in the Foot: A Report of 3 Cases

CASES

Two women presented with newly growing callosities beneath the first and second metatarsal heads, initially believed to reflect gastrocnemius tightness and plantar plate pathology. In another man, swelling at the posterolateral aspect of the heel was mistaken for a Haglund deformity. Subsequent imaging of each patient led to delayed diagnosis of extraskeletal osteochondroma (ESO). Surgical excision resolved symptoms in all 3 with no recurrence over 12 months later.

CONCLUSIONS

Whenever bony prominences newly develop in soft tissues of the foot, ESO should be suspected and appropriate imaging obtained. We describe physical features to help differentiate ESO from other common causes of foot overload.

Rapidly Growing Solitary Osteochondroma in the Adult Finger A Case Report

Osteochondromas are common benign bone tumors that are most commonly found in children and adolescents. They are usually slow-growing and located at the metaphysis of the long bones. When present in adults in atypical locations or with concerning features, such as thickened cartilage cap and rapid growth, osteochondromas warrant imaging to assess the risk of malignant transformation into chondrosar- coma and may require surgical excision. Here, we describe the unusual case of an adult male with a rapidly growing osteochondroma of the proximal phalanx that subsequently underwent surgical excision.

Osteochondroma : the local effects and the management

Osteochondroma is a common benign bone tumour, presenting as a single or multiple lesions, pedunculated or sessile type, mainly in 1st-2nd decades and mostly in males. The presented case series, studied the local effect of (osteochondroma) at the end of long bones with best line of treatment (RQ). Eighteen patients with osteochondromas, with an age range of 9- 45 years, mean age 19.6 ± 11.147 years, were seen from October 2016 to November 2018. There were 8 cases with painful lesion due to (mechanical interaction) or (pressure on near by neurovascular bundle), or from (inflamed bursa). Four cases were asymptomatic, 3 cases had Growth disturbances of the fellow bone, 3 cases presented with neurological symptoms and one case had vascular complications. Osteochondromas may present with different types of local effects on its surrounding tissues. Surgical excision is the best line of treatment.

Femoral Injury Over the Site of Spontaneous Regression of an Osteochondroma in a Teenage Athlete

ABSTRACT

The spontaneous regression of an osteochondroma is extremely rare. We report a case of medial femoral condyle impaction fracture over the site of spontaneous regression of a pedunculated osteochondroma discovered on advanced imaging after an acute injury in a 16-year-old male American football athlete. Although spontaneous regression of an osteochondroma has been described, the case presented reveals questions regarding resultant architectural changes to the bone after resorption, leaving it prone to injury. This is the first case that describes increased injury risk potential at the site of osteochondral regression.

Giant ulcerative benign osteochondroma of shoulder

Osteochondromas in hereditary multiple exostosis have increased risk of malignant transformation as compared with solitary osteochondromas. We present a case of a 54-year-old man who presented to us with complaints of swollen mass of the left shoulder with an ulcerative lesion. Radiograph showed a sessile growth from the proximal humerus and scapula. MRI revealed a sessile osteochondroma measuring about 11×10.1×8.0 cm. The malignant nature of the disease was anticipated due to increased cap thickness and non-healing ulcer, however, biopsy showed a benign lesion without any sarcomatous change. The patient was successfully treated with extra-periosteal excision and was recurrence-free at 24 months follow-up. This case illustrates an extra-articular giant osteochondroma of the proximal humerus, with possible signs of a malignant lesion but diagnosed benign on biopsy. We conclude that a biopsy should always preclude definitive management as this can change the overall mortality and morbidity of the patient.

Non-subungual presentation of osteochondroma in toes-A case report with review of literature

A 23-year-old male presented with long-standing swelling in the middle of the third toe right side with difficulty in wearing footwear. Clinical examination revealed it as bony hard fixed swelling moving with interphalangeal joint movements. Clinical diagnosis of benign bony swelling was made and radiological investigation demonstrated features suggestive of osteochondroma. En-mass excision of the lesion was done, with histo-pathological confirmation of osteochondroma. Although the subungual presentation of osteochondroma or exostosis in toes is quite common, the astounding non-subungual presentation should also be kept in mind as a plausible differential diagnosis of benign bony swelling in toes.

Arthroscopic Resection of Distal Clavicular Osteochondroma: A Case Report

CASE

A 23-year-old boy presented with a 3-month history of right shoulder pain. Radiographs and computed tomography showed an exostosis on the inferior aspect of the distal clavicle. It was osteotomized and removed by arthroscopy. The histological examination confirmed the diagnosis of osteochondroma. The patient was found asymptomatic with full range of motion in the last clinical control at 1 year of follow-up.

CONCLUSION

This case report shows an arthroscopic resection of distal clavicular osteochondroma achieving complete resection of the tumor with an excellent clinical outcome. The technique offers a direct view of the inferior aspect of the clavicle and preserves the acromioclavicular joint.

Rare Osteochondroma of the Posterior Talar Process: A Case Report

Osteochondromas are benign bone tumors that arise from divergent cartilage formation, most commonly in childhood versus adulthood. We report the case of a healthy 42-year-old woman who presented with an unusual solitary posterolateral ankle mass with associated pain and ankle impingement with 6-week follow-up. The patient was successfully treated with open surgical excision, with bone sent for pathologic diagnosis of benign osteochondroma. The patient returned to normal baseline function with no pain at 6-week follow-up. An open posterior ankle incision approach was performed to remove suspicious enlarged bony growth from the posterior talar process to be sent for pathologic evaluation. Pathologic evaluation reported benign osteochondroma of the posterior talar process, and the patient subsequently had routine healing of the postoperative incision site and return to full function without pain or disability at 6-week follow-up. This case study adds to the current understanding, incidence, occurrence, and treatment of rare osteochondromas occurring in the posterior talar process.

Popliteal artery entrapment syndrome secondary to a femoral osteochondroma

BACKGROUND

Osteochondromas (or exostoses) are the most common benign tumors of the bone. Vascular complications of these tumors are rare but have been increasingly reported in recent literature.

AIM

Throughout an unusual case report of popliteal artery entrapment syndrome secondary to a femoral osteochondroma, we highlight the necessity of thorough clinical and radiological examinations as well as meticulous and prompt surgical resection.

CASE REPORT

A 27-year-old male patient, who had been diagnosed with multiple osteochondromas and had never been operated on, presented with a one-year history of exercise-induced left calf pain, paresthesias of the left leg and pallor in cold weather. After radiographic and Computed Tomography angiographic evaluation, we diagnosed distal femur osteochondroma associated with an arterial compression of the left popliteal artery. A surgical treatment of all lesions was performed. No operative complications occurred. The pain was relieved. Good postoperative results have been noticed.

CONCLUSION

Popliteal aretery entrapment syndrome may be caused by solitary or multiple osteochondromas around the knee. Therefore, prophylactic resection of exostoses in the surrounding area of a vessel should be performed. Moreover, the orthopedic surgeon should consider and prevent vascular complications during surgical resection of knee osteochondromas.

Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion) in the Medial Sesamoid of the First Toe

Bizarre parosteal osteochondromatous proliferation, or Nora's lesion, is a unique bony lesion that generally originates from the small bones of the hands and feet in young adults. We report a case of a bizarre parosteal osteochondromatous proliferation originating from the medial sesamoid of the first toe that was managed surgically by en bloc excision. At 5-year follow-up, there was no evidence of recurrence.

Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion) of Mandible With Recurrence: Case Report and Review of Literature

Bizarre parosteal osteochondromatous proliferation (BPOP) is a rare benign lesion exhibiting radiographic and histologic features that can be mistaken for malignancy. Most cases have been reported in the small tubular bones of the hands and feet, but involvement of the skull and jaws is extremely rare. Here, we present a case of BPOP involving the mandible in a 23-year-old male that, after initial excision, recurred within 18 months. To the best of our knowledge, this is only the third published case of BPOP arising in the mandible.

The natural history of multiple osteochondromas in a large Italian cohort of pediatric patients

IMPORTANCE

Multiple osteochondromas is a rare hereditary skeletal disorder, characterized by bony protrusions arising from growth plates on long bones during skeletal development. The disorder frequently leads to diminished stature, deformities and functional limitations. Understanding of the natural history of multiple osteochondromas and its evolution in children and adolescents is limited.

OBJECTIVE

To provide valuable information on the natural history of multiple osteochondromas, to inform recommendations for treatment and prevent impairments caused by osteochondromas.

DESIGN

This retrospective cohort study in children with multiple osteochondromas includes longitudinal data collected from first to last follow-up visit for patient demographics, and over 36 months for disease evolution.

SETTING

Data were collected from the Registry of Multiple Osteochondromas, which includes data from circa 1200 patients with multiple osteochondromas treated from 2003 to 2017 at IRCCS Istituto Ortopedico Rizzoli in Bologna.

PARTICIPANTS

Patients ≤18 years with multiple osteochondromas, who provided written informed consent and had data for ≥1 12-month follow-up visit.

MAIN OUTCOME(S) AND MEASUREMENT(S)

Demographics, clinical features, incidence of surgeries, and disease evolution (progression or regression) were assessed. Results were summarized using descriptive statistics, annual rates of new clinical features and surgeries, and Kaplan-Meier estimates. Patient height was evaluated following Italian growth charts.

RESULTS

158 patients were included in these analyses. Throughout follow-up, 80.4% of patients developed new osteochondromas, 57.6% developed new deformities, 23.4% developed new functional limitation(s). New osteochondroma(s) were developed by 28.5% patients by Month 12, 39.9% at Month 24, 50% at Month 36. Most new osteochondromas were detected in the younger population; patients aged 0-4 years underwent a significantly higher number of lesions within 12, 24 and 36 months of follow-up. The overall incidence of patients with ≥1 new deformity within 12 months was 17.7%, with incidences decreasing with increasing age (p = .023). In addition, the analyses on height highlight that 13 years is a cut off age for slow growth of the stature (p < .0005). At last follow-up visit, 46.2% of patients had disease progression, while regression (spontaneous and surgical) occurred in 7.6% (p = .007).

CONCLUSIONS AND RELEVANCE

This natural history study reports the main set of clinically relevant data for patients with multiple osteochondromas during skeletal development, providing insight for patient management and development of therapeutic interventions.

Symptomatic Scapular Osteochondromas: Case report

Osteochondroma is a developmental lesion rather than a true neoplasm. Osteochondromas are composed of cortical and medullary bone with an overlying hyaline cartilage cap and must demonstrate continuity with the underlying parent bone cortex and medullary canal. Osteochondromas may be solitary or multiple. We report  the case of a patient carrying the here ditary form and who has presented a thoracic deformity and a progressive dyspnea for 5 months. Imaging was related to a bulky osteochondroma of the scapula responsible for thoracic deformity. Benign character was confirmed on the histology data and the resection was performed posteriorly with muscular preservation.

Osteochondroma of ventral scapula associated with chest pain due to rib cage compression: A case report

RATIONALE

The scapula is relatively rare site for osteochondroma. Scapula osteochondroma is usually asymptomatic, however it may present with features such as pseudowinging, snapping scapula, bursa formation, chronic pain, and cosmetic deformities. To our best knowledge, this is the first report in the English literature about osteochondroma of ventral scapula associated with chest pain due to rib cage compression.

PATIENT CONCERNS

A 14-year-old boy was transferred to the orthopedic clinic from thoracic surgery department with a complaint of intermittent, dull, and diffuse aching pain around left chest wall and back from the past 2 months. The patient was previously diagnosed with multiple osteochondromas on another side; proximal tibia and distal femur.

DIAGNOSIS

A radiopaque mass like lesion was observed on the scapula in the posteroanterior view of the chest, and compression of chest wall was also seen. In chest computed tomography (CT), pedunculated outgrowing bony mass was noted in the anterior aspect of the left scapular wing, which showed the continuity of bony cortex and medulla. This bony mass showed the mass effect on the left chest wall, causing left thoracic cavity deformity by making it narrower than the right INTERVENTIONS:: Surgery was performed under general anesthesia. After the surgery, the arm was immobilized by putting it in an abductor pillow brace for 3 weeks, and during that period pendulum exercise was permitted.

OUTCOMES

The patient's symptoms resolved in the immediate postoperative period. At 1 year's follow-up, the patient was symptom free and there was no evidence of recurrence of the tumor.

LESSONS

We recommend that in case of patients who have a history of osteochondroma and complaint of chest pain, surgeons should become suspicious of the presence of osteochondroma of the ventral scapula. In this situation, we recommend chest radiography, pulmonary function test, and chest CT for early detection and treatment.

Osteosarcoma in the coracoid process that mimicked an osteochondroma: A case report

RATIONALE

Osteosarcomas are the most common primary malignant bone tumors in children and young adults; these tumors often affect the metaphyses of long bones such as the proximal humerus, proximal tibia, and distal femur. In contrast, osteosarcoma of the coracoid process is extremely rare.

PATIENT CONCERNS

Herein, we describe a case of osteosarcoma affecting the coracoid process in a 40-year-old woman. The patient presented with shoulder pain, weakness, and an inability to raise her left arm. She had no previous record of shoulder injury and no significant family history.

DIAGNOSES

Her C-reactive protein levels were normal, whereas her erythrocyte sedimentation rate and alkaline phosphatase levels were elevated. Imaging studies led to the initial diagnosis of osteochondroma.

INTERVENTION

The patient underwent surgical resection. However, the postoperative pathological results revealed an osteosarcoma. The patient transferred to another hospital for subsequent treatment, and her outcome is unknown.

LESSONS

A misdiagnosis or inadequate and/or delayed treatment for a coracoid process osteosarcoma could have grave consequences. Computed tomography and magnetic resonance imaging are essential for a diagnosis, and a biopsy can effectively confirm the diagnosis. Our findings suggest that considering only a single factor, or using incomplete information, can lead to an arbitrary diagnosis.

Popliteal Artery Pseudoaneurysm Caused by Osteochondroma

A 16-year-old boy developed pulsating pain and dysesthesia in his right knee. Computed tomography showed a large aneurysm in the right upper popliteal artery and a spiked bone tumor arising from the right distal femoral shaft. Pseudoaneurysm due to osteochondroma was suspected, and the patient underwent emergency surgery. A 2-mm pinhole was detected in the arterial wall behind the tumor. After resection of the tumor, the damaged arterial wall was removed, and the defect was repaired using a saphenous vein patch. We suggest that patch repair is preferable to direct closure or end-to-end anastomosis to prevent recurrent pseudoaneurysm at a later time, even if the defect is small.

Unsuspected osteochondroma-like outgrowths in the cranial base of Hereditary Multiple Exostoses patients and modeling and treatment with a BMP antagonist in mice

Hereditary Multiple Exostoses (HME) is a rare pediatric disorder caused by loss-of-function mutations in the genes encoding the heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. HME is characterized by formation of cartilaginous outgrowths-called osteochondromas- next to the growth plates of many axial and appendicular skeletal elements. Surprisingly, it is not known whether such tumors also form in endochondral elements of the craniofacial skeleton. Here, we carried out a retrospective analysis of cervical spine MRI and CT scans from 50 consecutive HME patients that included cranial skeletal images. Interestingly, nearly half of the patients displayed moderate defects or osteochondroma-like outgrowths in the cranial base and specifically in the clivus. In good correlation, osteochondromas developed in the cranial base of mutant Ext1f/f;Col2-CreER or Ext1f/f;Aggrecan-CreER mouse models of HME along the synchondrosis growth plates. Osteochondroma formation was preceded by phenotypic alteration of cells at the chondro-perichondrial boundary and was accompanied by ectopic expression of major cartilage matrix genes -collagen 2 and collagen X- within the growing ectopic masses. Because chondrogenesis requires bone morphogenetic protein (BMP) signaling, we asked whether osteochondroma formation could be blocked by a BMP signaling antagonist. Systemic administration with LDN-193189 effectively inhibited osteochondroma growth in conditional Ext1-mutant mice. In vitro studies with mouse embryo chondrogenic cells clarified the mechanisms of LDN-193189 action that turned out to include decreases in canonical BMP signaling pSMAD1/5/8 effectors but interestingly, concurrent increases in such anti-chondrogenic mechanisms as pERK1/2 and Chordin, Fgf9 and Fgf18 expression. Our study is the first to reveal that the cranial base can be affected in patients with HME and that osteochondroma formation is amenable to therapeutic drug intervention.

Peroneus Quartus Muscle

The peroneus quartus (PQ) muscle is a rare but sometimes missed potential etiology of ankle pain and tendon subluxation. We report the case of a 16-year-old boy who presented with lateral right ankle pain and subluxation of peroneal tendons. He had a history of non-Hodgkin lymphoma and palpable distal fibular osteochondroma. Seven months after excision of the exostosis and repair of the peroneal tendon retinaculum, the pain recurred. Imaging showed a split peroneus brevis (PB) tendon. During surgery, a PQ muscle was found and excised, and the PB tendon was repaired. One year after surgery, the patient's symptoms were resolved.

Pediatric Trigger Finger due to Osteochondroma: A Report of Two Cases

Background: The trigger finger is characterized by the painful blocking of finger flexor tendons of the hand, while crossing the A1 pulley. It is a rare disease in children and, when present, is usually located in the thumb, and does not have any defined cause. Methods: We report 2 pediatric trigger finger cases affecting the long digits of the hand that were caused by an osteochondroma located at the proximal phalanx. Both children held the diagnosis of juvenile multiple osteochondromatosis. They had presented at the initial visit with a painful finger blocking. Surgical approach was decided with wide regional exposure, as compared with the trigger finger traditional surgical techniques, with the opening of the A1 pulley and the initial portion of the A2 pulley, along with bone tumor resection. Results: Patients evolved uneventfully, and recovered the affected finger motion. Conclusion: It is important to highlight that pediatric trigger finger is a distinct ailment from the adult trigger finger, and also in children is important to differentiate whenever the disease either affects the thumb or the long fingers. A secondary cause shall be sought whenever the long fingers are affected by a trigger finger.

Solitary osteochondroma arising in lumbar spinous process: Case report

Solitary osteochondromas rarely occur in the axial skeleton. Those tumors mostly arise on the posterior elements of the cervical column causing various symptoms especially when developing within the spinal canal. Exophytic lumbar variety is uncommon presenting with palpable mass or spinal deformity. We report a 20-year-old man presenting with a solid painless mass at the lower lumbar region. Radiological examinations revealed an exophytic lesion arising in the third lumbar spinous process appearing to be a solitary osteochondroma. The lesion was treated by en-bloc resection; histopathological examination confirmed the diagnosis of osteochondroma with no evidence of recurrence at the end of 2-year follow up.