Congenital solitary osseous choristoma of the left lateral canthus: a case report.

BACKGROUND: An ocular osseous choristoma is a growth of mature, compact bone in the ocular or periocular soft tissue, and it is the rarest form of ocular choristoma, accounting for only 1.7% of all epibulbar choristomas. CASE PRESENTATION: Herein we present the case of a 20-month-old girl who was referred to the oculoplasty clinic with a progressively growing mass in the left lateral canthus. It had been present since birth without ocular involvement. Upon examination the mass was firm with a smooth surface, measured 9 × 6 × 3 mm, and exhibited no episcleral attachment or ocular involvement. An excisional biopsy was performed, and the histopathological findings were consistent with osseous choristoma of the left lateral canthus. CONCLUSIONS: This report highlights the importance of considering osseous choristoma in the differential diagnosis of eyelid lesions, particularly those that have been present since birth. It also emphasizes the need for further studies investigating associations between osseous choristomas and ocular canthi.

Fully Endoscopic Resection of Frontal Osteomas.

BACKGROUND: Osteomas are the most common primary bone tumors of the calvaria, with an incidence of less than 0.5%. In skull vault osteomas, the exostotic form that grows from the outer table is more common than the enostotic ones which arise from the inner table and grow intracranially. Osteomas of the forehead are very noticeable and disfiguring; patients usually seek medical advice for cosmetic reasons. Forehead osteomas were traditionally excised via either a direct incision over the lesion using the naturally occurring creases or a conventional bicoronal flap. More recently, endoscopic approaches for excision of forehead osteomas were introduced. The results were very encouraging and the technique was adopted by many groups worldwide yet with many technical variations. In this chapter we elaborate on the surgical technique and nuances of the fully endoscopic resection of frontal osteomas. METHODS: From a prospective database of endoscopic procedures maintained by the senior author, clinical data, imaging studies, operative charts, and videos of cases of forehead osteomas were retrieved and analyzed. The pertinent literature was also reviewed. RESULTS: The surgical technique of the fully endoscopic resection of frontal osteomas was formulated. CONCLUSION: The endoscopic technique has many advantages over the conventional procedures. In our hands, the technique has proven to be less time-consuming, efficient, and minimally invasive with excellent cosmetic results.

Osteoid osteoma appearing after bony fracture in a girl with osteogenesis imperfecta.

Osteoid osteoma (OO) is a common, benign bone tumor. However, there are no case reports of OO associated with osteogenesis imperfecta (OI), or pathological fractures in OO. A 3-year-old girl with OI sustained a complete right tibial diaphyseal fracture. Bony fusion was completed after 4 months of conservative therapy; nevertheless, 18 months later spontaneous pain appeared at the fracture site, without any cause. Plain radiographs showed a newly apparent, rounded area of translucency 1 cm in diameter, just overlapping the previous fracture. Images obtained using three-dimensional time-resolved contrast-enhanced magnetic resonance angiography showed strong central enhancement in the early phase, with an apparent nidus, suggesting the diagnosis of OO. Nineteen months after the first fracture, while skipping, the patient refractured her tibial diaphysis at the site of the previous fracture. This is a very rare case of OO, apparently co-existing with OI and leading to a bony fracture. In our case, the combination of bone fragility in OI and a recent fracture at the site of the OO may have caused the re-fracture.

Ribbing disease of the femur: a rare entity.

Ribbing disease is a rare benign bone dysplasia characterized by progressive cortical thickening of the diaphyses of long bones in adult patients. The literature provides limited insight into its natural radiological progression and anatomical distribution. Single-bone involvement is particularly uncommon, with prior cases exclusively affecting the tibia. This case report outlines the unique presentation of Ribbing disease in a 20-year-old male, localized to the left femur. The patient's history revealed intermittent left thigh pain persisting for more than 2 years, with no identifiable triggers or relief factors. Early radiographic imaging revealed no significant abnormalities, but subsequent imaging, conducted 1 year after the initial presentation, revealed focal fusiform widening and cortical thickening of the mid-diaphysis of the left femur. MRI further revealed circumferential cortical thickening with bone marrow edema, corroborated by CT, which revealed cortical thickening with near-complete obliteration of the intramedullary cavity. The patient was managed with nonsteroidal anti-inflammatory drugs and activity modifications. Misinterpretation of the radiographic findings of the osteoid osteoma led the patient to undergo radiofrequency ablation. This case highlights the challenges in diagnosing Ribbing disease and emphasizes the importance of considering it in the differential diagnosis of chronic limb pain. Continued reporting of cases contributes to enhancing our understanding and management of this rare skeletal dysplasia.

Update on musculoskeletal applications of magnetic resonance-guided focused ultrasound.

Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive, incisionless, radiation-free technology used to ablate tissue deep within the body. This technique has gained increased popularity following FDA approval for treatment of pain related to bone metastases and limited approval for treatment of osteoid osteoma. MRgFUS delivers superior visualization of soft tissue targets in unlimited imaging planes and precision in targeting and delivery of thermal dose which is all provided during real-time monitoring using MR thermometry. This paper provides an overview of the common musculoskeletal applications of MRgFUS along with updates on clinical outcomes and discussion of future applications.

Growth rate, impact of smoking and management of incidentally found paranasal sinus osteomas.

OBJECTIVE: To build upon existing literature regarding growth rate of asymptomatic, incidentally found paranasal sinus (PNS) osteomas, evaluate potential factors associated with growth rate and present an argument for how to follow up. METHODS: At our institution, EPIC SlicerDicer was used to screen imaging studies using keyword 'osteoma' and included patients with at least 2 imaging studies 6 months apart that both demonstrated a PNS osteoma(s). Imaging studies with the largest time interval were selected. Non-PNS osteomas were excluded. RESULTS: 47 patients that fit this criterion with a median duration of interval imaging of 35.9 months. Growth rate was measured to be 0.39 mm/year in the cephalocaudal direction and 0.45 mm/year in the mediolateral direction, together averaging 0.42 mm/year. Increases in growth rate additionally did not appear to impact the likelihood of developing conditions including nasal polyposis or chronic sinusitis and symptoms such as sinus pressure, headache, postnasal drip, or congestion. Those with interval scans >36 months were found to have a slower growth rate than those with closer interval scans. Furthermore, former smokers and current smokers had significantly greater growth rates than nonsmokers. CONCLUSION: Given their slow growth rate, we conclude that select lesions likely do not require follow-up. If there is concern that growth could cause an obstructive complication, such as blocking the frontal outflow tract, we argue a single scan at one year is appropriate. If there is additional growth on this scan, surveillance scans up to 3 years could be performed to assess stability. Lastly, while there was a significant growth rate for smokers compared to non-smokers, the slow growth rate is unlikely to influence management.

Questioning the value of stalk drilling after external auditory canal osteoma excision: case series, literature review, and meta-analysis.

OBJECTIVES: To question the value of drilling the site of the stalk ("insertion site" or "stalk" drilling) of a pedunculated external auditory canal osteoma (EACO) in reducing recurrence. DATA SOURCES: A retrospective medical chart review of all patients treated for EACO in one tertiary medical center, a systematic literature review using Medline via "PubMed", "Embase", and "Google scholar" search, and a meta-analysis of the proportion for recurrence of EACO with and without drilling. RESULTS: The local cohort included 19 patients and the EACO origin was the anterior EAC wall in 42% and the superior EAC wall in 26%. The most common presenting symptoms were aural fullness and impacted cerumen (53% each), followed by conductive hearing loss (42%). All patients underwent post-excision canaloplasty, and one sustained EACO recurrence. Six studies suitable for analysis were identified (63 EACOs). Hearing loss, aural fullness, otalgia, and cerumen impaction were the most common clinical presentations. The most common EACO insertion site was the anterior EAC wall (37.5%), followed by the superior EAC and posterior walls (25% each). The inferior EAC wall was least affected (12.5%). There was no significant difference in recurrence between EACOs whose stalk insertions were drilled (proportion 0.09, 95% confidence interval [CI] 0.01-0.22) to the ones whose insertion was not drilled (proportion 0.05, 95% CI 0.00-0.17). The overall recurrence proportion was 0.07 (95% confidence interval 0.02-0.15). CONCLUSION: EACO insertion site drilling does not reduce recurrence and should be avoided in the absence of a definite pedicle projecting to the EAC lumen.

A comprehensive MRI analysis of osteoid osteomas in patients with diverse radiological features across various regions.

BACKGROUND: Magnetic resonance imaging (MRI), which does not involve ionizing radiation, is the preferred imaging modality for diagnosing osteoid osteoma (OO), an ailment more common in children and young adults. PURPOSE: This study aims to perform a literature review and delineate the MRI findings of OO lesions in patients exhibiting varying radiological features across different regions. MATERIALS AND METHODS: A retrospective study included 63 patients diagnosed with OO through MRI, assessed independently by two blinded radiologists using both standard and dynamic contrast-enhanced MRI techniques. After excluding 7 patients with prior biopsy, surgery, or RFA, the study included 56 patients with 57 lesions. RESULTS: Of 57 lesions evaluated, 50 were in long, and 7 in flat bones. One patient presented with two separate nidi within the intertrochanteric region. Most of the lesions, 49 (86%), were extra-articular, while 8 (14%) were intra-articular. The nidus was intracortical in 45 (78.9%) patients, intramedullary in 5 (8.8%), subperiosteal in 5 (8.8%), and endosteal in 2 (3.5%). Average nidus diameter was 7.02 ± 2.64 mm (3-12.6 mm). Central nidal calcification was present in 68.4% (n = 39) cases. Contrast enhancement was intense at 90.5%, moderate at 9.5%. Reactive sclerosis around the nidus was severe (50.9%), moderate (22.8%), and mild (26.3%). Bone marrow edema was severe (70.2%), moderate (14.0%), and mild (15.8%). Soft tissue edema was identified in 77.2% of all lesions. CONCLUSION: To minimize delays in diagnosis and treatment, radiologists should become acquainted with the typical OO MRI findings and the atypical MRI findings that might be mistaken for other conditions.

Miliary osteoma cutis in a climbing mantella frog (Mantella laevigata).

A climbing mantella frog (Mantella laevigata) was presented with nodular thickened skin. Histological examination revealed dermal nodules composed of differentiated bone consistent with miliary osteoma cutis, a non-neoplastic condition where bone is abnormally deposited within the skin. This is the first report of idiopathic osteoma cutis in an amphibian.

Rare Germline Variants in the Adenomatous Polyposis Coli Gene Associated with Dental and Osseous Anomalies.

APC is a tumor suppressor gene that exerts its effect through the regulation of the Wnt signaling pathway. Loss of function mutations of the gene are associated with familial adenomatous polyposis (FAP). Early diagnosis in FAP patients is essential to prevent the development of colorectal cancer. Extraintestinal manifestations often precede the formation of the polyposis; therefore, these manifestations may serve as a clinical indicator for the condition. The aim of this study was to assess genotype-phenotype associations between the location of APC mutations and various extraintestinal features, mainly focusing on osseous and dental anomalies. Analyses of our cases and the mutations available in the literature with these manifestations revealed that mutations in the N-terminal region (amino acids 1-~1000) of the protein are more frequently associated with only osseous anomalies, whereas dental manifestations are more prevalent in mutations in the middle region (amino acids 1000-~2100). In addition, supernumerary teeth were found to be the most common dental feature. Since dental abnormalities often precede intestinal polyposis, dentists have a crucial role in the early identification of patients at risk.

Large Peripheral Osteomas and Dental Implants: A Case Report.

Peripheral osteoma of the jaw is a rare, benign, slow-growing lesion, which usually appears as a unilateral, pedunculated, radiopaque mass protruding from the periphery and is generally solitary. Multiple osteomas without any syndromic involvement are rare. In the present case, a 75-year-old male patient underwent implant placement in the edentulous posterior ridges of the maxilla and mandible. Over 7 years, multiple masses gradually proliferated in the buccal bone of the implant in three different sextants of the posterior region, reaching a size of 2.0 cm. Clinically and radiologically, these lesions were presumed to be peripheral osteomas and were surgically removed because the large mass made self-performed oral hygiene and maintenance of peri-implant health difficult. The histopathological evaluation confirmed that peripheral osteomas were both compact and cancellous. The patient did not exhibit any other clinical manifestations of Gardner syndrome. Whether dental implant placement and loading are involved in the occurrence of peripheral osteomas is unclear, but they might have affected the consistent growth of the mass as a reactive mechanism. After resection, the functional abilities of chewing and self-cleansing significantly improved. No recurrence of peripheral osteoma was observed after 1 year of follow-up, and peri-implant health was well maintained. Within the limitations of the present case report, multiple peripheral osteomas can occur adjacent to dental implants without any syndromic issues, and a large mass of PO can harm peri-implant health which requires surgical removal. It is speculated that dental implants may be associated with the slow and consistent growth of PO.

Osteoid osteomas of the hip: a well-recognized entity with a proclivity for misdiagnosis.

OBJECTIVES: The diagnosis of osteoid osteomas (OO) about the hip can be challenging as presenting symptoms can mimic other, more common, periarticular pathologies. Our aims were to identify the most common misdiagnoses and treatments, mean delay in diagnosis, characteristic imaging features and provide tips for avoiding diagnostic imaging pitfalls for patients with OO of the hip. METHODS: We identified 33 patients (34 tumors) with OO about the hip who were referred for radiofrequency ablation between 1998 and 2020. Imaging studies reviewed included radiographs (n = 29), CT (n = 34), and MRI (n = 26). RESULTS: The most common initial diagnoses were femoral neck stress fracture (n = 8), femoroacetabular impingement (FAI) (n = 7), and malignant tumor or infection (n = 4). The mean time from symptom onset to diagnosis of OO was 15 months (range, 0.4-84). The mean time from initial incorrect diagnosis to OO diagnosis was 9 months (range, 0-46). CONCLUSIONS: The diagnosis of OO of the hip is challenging, with up to 70% of cases initially misdiagnosed as a femoral neck stress fracture, FAI, bone tumor, or other joint pathology in our series. Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings are critical for making an accurate diagnosis. KEY POINTS: • The diagnosis of osteoid osteoma of the hip can be challenging, as demonstrated by long delays in time to initial diagnosis and high rates of misdiagnoses which can lead to inappropriate interventions. • Familiarity with the spectrum of imaging features of OO, especially on MRI, is imperative given the increase in the utilization of this modality for the evaluation of young patients with hip pain and FAI. • Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings, including bone marrow edema and the utility of CT, are critical for making a timely and accurate diagnosis.

The role of choriocapillaris vessel density in the pathogenesis of macular neovascularization associated with choroidal osteoma.

PURPOSE: To detect the vessel density of choriocapillaris (CC) vascular network in eyes affected by choroidal osteoma and in eyes complicated by macular neovascularization (MNV), using optical coherence tomography angiography (OCTA). METHODS: In this retrospective study, twenty-eight eyes of 28 patients were divided into three groups: group 1 including patients with calcified choroidal osteoma, group 2 including patients with decalcified choroidal osteoma, and group 3 including patients with decalcified choroidal osteoma complicated by MNV. OCTA analyzed the vessel density of CC in these lesions localized in the peripapillary region. RESULTS: We enrolled 12 eyes with calcified choroidal osteoma, 11 eyes with decalcified choroidal osteoma, and 5 eyes with decalcified choroidal osteoma complicated by MNV. The eyes with decalcified choroidal osteoma and MNV revealed a statistically significant reduction in vessel density of the CC respect to the other groups (p < 0.001). Moreover, the vessel density of CC in decalcified choroidal osteoma was significantly reduced compared to calcified choroidal osteoma (p < 0.001). CONCLUSIONS: OCTA allowed a quantitative evaluation of choriocapillaris vessel density in choroidal osteoma, in order to detect the changes of this vascular network, which could lead to the development of MNV. Therefore, OCTA could be a new diagnostic tool in the clinical management of the choroidal osteoma. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05342324.

Subdural osteoma in an adolescent patient with epilepsy: an unusual case report and literature review.

OBJECTIVE: Subdural osteoma (SO) is a rarely reported benign tumor, and there is no report of SO manifested with epileptic seizures. We aim to further the understanding of SO-related epilepsy. METHODS: Here, we report a meaningful case of epilepsy secondary to SO. A systematic review of the literature about SO using the electronic database PubMed and Web of science up to December 2022 was conducted. RESULTS: A 15-year-old girl presented with epileptic seizures for 8 years. Magnetic resonance imaging revealed an irregular lesion with heterogeneous signal in the right frontal convexity. Right frontal craniotomy was performed to remove the lesion. The pathological diagnosis was SO. Histological analysis revealed that the mechanosensitive ion channels Piezo 1/2 were upregulated in the brain tissue compressed by the osteoma, compared with the levels in the osteoma-free region. Seizure freedom was obtained during the 6-month follow-up after the surgery. We identified 24 cases of SO in 23 articles. With our case, a total of 25 cases with 32 SOs was included. Of 25 cases, 24 are adults, and 1 is a child. Seizure has been reported only in our case. Frontal osteoma was found in 76% of the patients. Symptoms were cured in 56% of the patients after surgery. CONCLUSION: Surgery is a safe and effective approach to the treatment of symptomatic osteoma. Mechanical compression on cerebral cortex may be a predisposing factor of the epileptogenesis caused by the SO.

Radiofrequency ablation is as safe and effective as surgical excision for spinal osteoid osteoma: a systematic review and meta-analysis.

BACKGROUND: Osteoid osteoma (OO) is a primary benign tumor that affects mainly young patients. Ten percent of all OO are located in the vertebral column. Treatment of spinal OO is challenging and there is no consensus in the literature on the best operative approach. PURPOSE: The aim of this systematic review and meta-analysis was to determine safety and efficacy of radiofrequency ablation (RFA) versus surgical excision for the treatment of spinal OO. METHODS: A literature search was performed on PubMed, Web of Science, and Embase from inception up to 22 March 2022. Studies addressing surgical excision or RFA for the treatment of spinal OO were included. The main outcomes evaluated were pain before and after intervention, the treatments success rate, defined as complete pain relief with no recurrence until the last follow-up, and the number and type of complications. RESULTS: Thirty-one studies (749 patients) were included. For patients who underwent surgical excision, 19 studies reported a mean treatment success rate of 85.6%, while in the RFA treatment group, 18 studies reported a mean success rate of 88.6%. At last follow-up, the pooled mean difference in pain scores from baseline on a 0-10 scale was 5.8 points in the surgical excision group and 6.7 points in the RFA group. Recurrences were observed in 5.6% of the patients who underwent surgical excision and in 6.7% of the patients treated with RFA. The complication rate was 7.8% in the surgical excision group and 4.4% in the RFA group. CONCLUSIONS: This meta-analysis found high global success rates for both surgical and RFA treatments. Both treatments were efficient in pain relief and presented a low rate of recurrences. The complication rate was low for both treatments. Compared to surgical excision, RFA is a less invasive procedure which proved to be a safe and as effective option for the treatment of spinal OO.

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.

Use of intraoperative bone scintigraphy for resection of spinal osteoid osteoma.

BACKGROUND: The location and proximity to the spinal cord in spinal osteoid osteoma can increase the likelihood of an incomplete resection. Intraoperative bone scintigraphy (IOBS) can be used to verify location and complete surgical resection. OBJECTIVE: To review our experience using IOBS for resection of intraspinal osteoid osteoma. METHODS: IRB approved, retrospective review of IOBS-guided resection over 10 years. Patients underwent injection of 200 uCi/kg (1-20 mCi) 99mTc-MDP 3-4 h prior surgery. Portable single-headed gamma camera equipped with a pinhole collimator (3- or 4-mm aperture) was used. Images were obtained pre-operatively, at the start of the procedure, and intraoperatively. Operative notes were reviewed. Evaluation of recurrence and clinical follow-up was performed. RESULTS: Twenty IOBS-guided resections were performed in 18 patients (median age 13.5 years, 6-22 years, 12 males). Size ranged 5-16 mm, with 38.9% (7/18) cervical, 22.2% (4/18) thoracic, 22.2% (4/18) lumbar, and 16.7% (3/18) sacral. In all cases, IOBS was able to localize the lesion. After suspected total excision, IOBS altered the surgical plan in 75% of cases (15/20), showing residual activity prompting further resection. Median length of follow-up was 6 months (range 1-156 months) with 90% (18/20) showing complete resection without recurrence. Two patients had osteoid osteoma recurrence at 7 and 10 months following the original resection, requiring re-intervention. CONCLUSIONS: IOBS is a useful tool for real-time localization and assessment of spinal osteoid osteoma resection. In all cases, IOBS was able to localize the lesion and changed surgical planning in 75% of cases. Ninety percent of patients achieved complete resection and remain recurrence free.

Musculoskeletal oncology and thermal ablation: the current and emerging role of interventional radiology.

The role of interventional radiology (IR) is expanding. With new techniques being developed and tested, this radiology subspecialty is taking a step forward in different clinical scenarios, especially in oncology. Musculoskeletal tumoral diseases would definitely benefit from a low-invasive approach that could reduce mortality and morbidity in particular. Thermal ablation through IR has already become important in the palliation and consolidation of bone metastases, oligometastatic disease, local recurrences, and treating specific benign tumors, with a more tailored approach, considering the characteristics of every patient. As image-guided ablation techniques lower their invasiveness and increase their efficacy while the collateral effects and complications decrease, they become more relevant and need to be considered in patient care pathways and clinical management, to improve outcomes. We present a literature review of the different percutaneous and non-invasive image-guided thermal ablation methods that are currently available and that could in the future become relevant to manage musculoskeletal oncologic diseases.

Navicular Bone Fracture after Radiofrequency Ablation in a Patient with Osteoid Osteoma.

Osteoid osteoma (OO) is a benign bone tumor that presents with nocturnal pain. Computed tomography (CT)- guided radiofrequency ablation (RFA) has been widely performed for OO, and major adverse events post-RFA are rare. We report a case of OO in the left navicular bone of a 15-year-old male. He underwent RFA for OO, and the pain improved temporarily. At the 1-month follow-up, the patient complained of left foot pain, and a CT examination revealed a fracture of the ablated navicular bone. Fractures are rare but must be taken into account after bone RFA.

A delayed diagnostic case with complaints of severe lower back pain and sciatic nerve symptoms caused by osteoid osteoma of the sacrum: A case report.

BACKGROUND: Osteoid sacral osteomas are rare. Patients present with severe lower back pain and, rarely, sciatic nerve symptoms. CASE PRESENTATION: Herein, we report a patient with delayed diagnosis with complaints of severe lower back pain and sciatic nerve symptoms compressed by a sacral osteoid osteoma. En bloc tumor resection was performed using computed tomography (CT)-based navigation. Complete resolution of symptoms was achieved immediately after surgery. CONCLUSION: Even if a patient with an osteoid osteoma has sciatic symptoms, spinal surgeons should recognize a subgroup of patients with unexpected spinal or pelvic tumors compressing the nerve root.