Primary Bone Tumors of the Skull: Spectrum of 125 Cases, with Review of Literature

Using dermal filler to camouflage forehead osteoma: A case report

Objective

To review the technique and outcomes of using dermal filler to camouflage forehead osteoma, providing a minimally invasive alternative to surgical excision.

Background

Forehead osteoma, commonly known as a forehead bump or bone spur, can be a cosmetic concern. Surgical excision, while effective, carries risks of scarring and postoperative complications. An innovative approach using dermal filler offers a potential solution.

Methods

A hyaluronic acid‐based filler is injected into the deep subcutaneous plane over the bony prominence using a cannula. The fanning technique ensures even distribution of the filler. The procedure's safety, patient selection, and communication between the injector and patient are emphasized to achieve optimal results.

Results

The technique provides immediate aesthetic improvement with results that can last up to 12 months, depending on the filler used. While generally safe, potential complications include infections, swelling, asymmetry, and lumpiness. Proper technique, patient selection, and good communication between the injector and patient are critical to achieving optimal outcomes.

Conclusion

Using dermal filler to camouflage forehead osteoma is a minimally invasive alternative to surgical excision, offering immediate and long‐lasting results with minimal downtime and fewer risks. Further studies are needed to refine the technique and optimize outcomes.

Differential diagnosis of an osseous cranial tumor from Hellenistic Muğla, Turkey

OBJECTIVE

This project evaluates a cranial lesion from a Hellenistic-era individual excavated by the Muğla Archaeological Museum in Gülağzı, Turkey.

MATERIALS

An osseous tumor measuring 3.02 × 3.54 × 2.98 cm originating from the occipital bone of a probable young adult male.

METHODS

The tumor was examined using gross morphological inspection, plain radiography (x-ray), and computed tomography (CT) imaging to identify potential differential diagnoses for the osseous cranial tumor.

RESULTS

The lesion in question displays features highly consistent with both osteoid osteoma and osteoblastoma. The tumor had a non-sclerotic, sharply demarcated border, a radiolucent nidus measuring less than 2 centimeters in diameter, and homogeneous sclerotic bone surrounding the nidus.

CONCLUSIONS

Differential diagnosis determined the osseous tumor to be a benign neoplasm, and in this case the features of the tumor are highly consistent with a diagnosis of either osteoblastoma or osteoid osteoma.

SIGNIFICANCE

The identification of novel neoplastic cases in paleopathology represents an important contribution to ongoing discussions regarding the temporality and regional variability of neoplastic conditions in the past. Additionally, a rigorous diagnostic study augmented by x-ray, CT scans, and 3D modeling provides data that can be utilized in future paleopathological studies.

LIMITATIONS

Diagnostic interpretation would be aided by histological examination of the tumor, which was impossible in this case. Histological examination would provide a definitive diagnosis.

SUGGESTIONS FOR FURTHER RESEARCH

Given the high incidence of benign tumors in the clinical literature but a paucity of reports in the paleopathological record, further research is indicated to better understand the implications of benign neoplasms in antiquity.

MRI-Based Radiomics Differentiates Skull Base Chordoma and Chondrosarcoma: A Preliminary Study

Simple Summary

In this study, we created a novel MRI-based machine learning model to differentiate skull base chordoma and chondrosarcoma with multiparametric signatures. While these tumors share common radiographic characteristics, clinical behavior is distinct. Therefore, distinguishing these tumors before initial surgical intervention would be useful, potentially impacting the surgical strategy. Although there are some limitations, such as the risk of overfitting and the lack of an extramural cohort for truly independent final validation, our machine learning model distinguishing chordoma from chondrosarcoma yielded superior diagnostic accuracy to that achieved by 20 board-certified neurosurgeons.

Abstract

Chordoma and chondrosarcoma share common radiographic characteristics yet are distinct clinically. A radiomic machine learning model differentiating these tumors preoperatively would help plan surgery. MR images were acquired from 57 consecutive patients with chordoma (N = 32) or chondrosarcoma (N = 25) treated at the University of Tokyo Hospital between September 2012 and February 2020. Preoperative T1-weighted images with gadolinium enhancement (GdT1) and T2-weighted images were analyzed. Datasets from the first 47 cases were used for model creation, and those from the subsequent 10 cases were used for validation. Feature extraction was performed semi-automatically, and 2438 features were obtained per image sequence. Machine learning models with logistic regression and a support vector machine were created. The model with the highest accuracy incorporated seven features extracted from GdT1 in the logistic regression. The average area under the curve was 0.93 ± 0.06, and accuracy was 0.90 (9/10) in the validation dataset. The same validation dataset was assessed by 20 board-certified neurosurgeons. Diagnostic accuracy ranged from 0.50 to 0.80 (median 0.60, 95% confidence interval 0.60 ± 0.06%), which was inferior to that of the machine learning model (p = 0.03), although there are some limitations, such as the risk of overfitting and the lack of an extramural cohort for truly independent final validation. In summary, we created a novel MRI-based machine learning model to differentiate skull base chordoma and chondrosarcoma from multiparametric signatures.

[Artificial ulcer with perforating bone defect on the scalp due to repeated - scratching attacks in dementia syndrome]

HISTORY

 We report on a 72-year-old demented patient with a palm-sized skin defect on the scalp, who has been manipulating her head several times a day with her fingers but also with sharp objects for many months.

CLINICAL FINDINGS

 A 4 × 6 cm circular, cleanly granulated ulcer was visible on the high parietal surface. On general examination, the patient was little affected: no fever, no signs of inflammation around the ulcer, no evidence of meningitis.

EXAMINATIONS

 There was no histological evidence of the presence of a malignant or benign tumor. A CT of the skull showed a bony defect measuring 2.6 × 3.3 cm without involvement of the dura. The whole body CT without pathological findings.

THERAPY AND COURSE

 First, a protective helmet was made for the patient. Subsequently, a titanium plate was surgically inserted as a bone substitute and the defect was closed by means of transpositionoplasty. In the two-year follow-up, no tumor disease was detected.

CONCLUSION

 Due to the lack of evidence of tumorigenesis in a follow-up period of two years, we evaluate the lesion as an artificial ulcer with perforating bone defect caused by repeated scratching attacks in the context of dementia syndrome.

Deep Learning for Classification of Bone Lesions on Routine MRI

Background

Radiologists have difficulty distinguishing benign from malignant bone lesions because these lesions may have similar imaging appearances. The purpose of this study was to develop a deep learning algorithm that can differentiate benign and malignant bone lesions using routine magnetic resonance imaging (MRI) and patient demographics.

Methods

1,060 histologically confirmed bone lesions with T1- and T2-weighted pre-operative MRI were retrospectively identified and included, with lesions from 4 institutions used for model development and internal validation, and data from a fifth institution used for external validation. Image-based models were generated using the EfficientNet-B0 architecture and a logistic regression model was trained using patient age, sex, and lesion location. A voting ensemble was created as the final model. The performance of the model was compared to classification performance by radiology experts.

Findings

The cohort had a mean age of 30±23 years and was 58.3% male, with 582 benign lesions and 478 malignant. Compared to a contrived expert committee result, the ensemble deep learning model achieved (ensemble vs. experts): similar accuracy (0·76 vs. 0·73, p=0·7), sensitivity (0·79 vs. 0·81, p=1·0) and specificity (0·75 vs. 0·66, p=0·48), with a ROC AUC of 0·82. On external testing, the model achieved ROC AUC of 0·79.

Interpretation

Deep learning can be used to distinguish benign and malignant bone lesions on par with experts. These findings could aid in the development of computer-aided diagnostic tools to reduce unnecessary referrals to specialized centers from community clinics and limit unnecessary biopsies.

Funding

This work was funded by a Radiological Society of North America Research Medical Student Grant (#RMS2013) and supported by the Amazon Web Services Diagnostic Development Initiative.

Differential Diagnosis of Calvarial Tumors: A Series of 8 Cases

Introduction To present and discuss the clinical presentations, investigations, and treatment options for skull bone tumors.

Materials and Methods This study was conducted from January 2019 to December 2019 at the Department of Neurosurgery. During this period, eight patients presented with skull bone tumor in the outpatient department. All patients were thoroughly investigated. Surgery was conducted on six patients and two patients had disseminated carcinoma; hence, surgery was not done. Patients were regularly followed-up after the surgery.

Results In our study, out of eight cases, five were females and three were males. We had two cases of fibrous dysplasia, two cases of osteomas, and one case each of brown tumor, metastases from lung carcinoma, metastases from follicular carcinoma of thyroid, and Ewing sarcoma/primitive neuroectodermal tumor (PNET). Excision of tumor was performed where indicated and adjuvant chemo- and radiotherapy was suggested wherever required.

Conclusion Bony tumors of the skull are uncommon diseases for the neurosurgeons. These tumors require a careful diagnosis with suitable radiological examinations and proper clinical correlation for proper management.

Aggressive growing of the infantile cavernous hemangioma of the calvaria: a case report and review of literature

INTRODUCTION

Primary intraosseous cavernous hemangiomas of the skull are very rare in the pediatric age group and usually slow-growing tumors.

CASE REPORT

We present a case of 5-month-old girl with a left occipital cavernous hemangioma that is rapidly growing. The subcutaneous occipital tiny mass was first noted at birth, and the lesion became rapidly enlarged in size and became soft for 3 months. The left occipital subcutaneous lesion was 4.0 × 4.0 × 2.0 cm (AP × LR × HT) in size. There was no history of trauma or bone tumor in her family. She underwent resection of the lesion, and a pathologic diagnosis of calvarial cavernous hemangioma was made. No recurrence was seen 1 year after surgery.

CONCLUSION

The rapid growth of the infant cavernous hemangioma might be related to not only bleeding and/or congestion of the lesion but the immature thin skull of the infant.

Patient-Specific Three-Dimensional Printing Guide for Single-Stage Skull Bone Tumor Surgery: Novel Software Workflow with Manufacturing of Prefabricated Jigs for Bone Resection and Reconstruction

OBJECTIVE

To describe a novel system workflow to design and manufacture patient-specific three-dimensional (3D) printing jigs for single-stage skull bone tumor excision and reconstruction and to present surgical outcomes of 14 patients.

METHODS

A specific computer-aided design/computer-aided manufacturing software and hardware system was set up, including a virtual surgical planning subsystem and a 3D printing-associated manufacturing subsystem. Computed tomography data of the patient's skull were used for 3D rendering of the skull and tumor. The output of patient-specific designing included a 3D printing guide for tumor resection and a 3D printing model of the bone defect after tumor excision. A polymethyl methacrylate implant was fabricated preoperatively and used for repair.

RESULTS

The specific 3D printing guide was used to design intraoperative jigs and implants for 14 patients (age range, 1-72 years) with skull bone tumors. In all cases, the cutting jig allowed precise excision of tumor and bone, and implants were exact fits for the defects created. All operative results were successful, without intraoperative or postoperative complications. Postoperative computed tomography scans were obtained for analysis. Postoperative 3D measurement of the skull symmetry index (cranial vault asymmetry index) showed significant improvement of head contour after surgery.

CONCLUSIONS

The computer-aided design/computer-aided manufacturing system described allows definitive preoperative planning and fabrication for treatment of skull bone tumors. Apparent benefits of the method include more accurate determination of surgical margins and better oncological outcomes.

Bony lesions of cranium and spine: A study of 123 cases

CONTEXT

Bony lesions involving the cranium and spine have a wide range of etiologies, ranging from congenital, traumatic, inflammatory, to neoplastic.

AIM

The aim was to analyze the histological spectrum of various bony lesions of cranium and spine received as biopsies from the neurosurgery department in our hospital.

MATERIALS AND METHODS

There were 123 cases of bony lesions of cranium and spine diagnosed over a period of 5 years during 2015-2019 in the neuropathology laboratory. These cases were studied retrospectively.

RESULTS

Out of the total 123 cases of bony lesions analyzed, 75 affected the cranium and 48 affected the spine. Overall, neoplastic lesions (83) were more frequent than the nonneoplastic lesions (40). In the cranium, neoplastic lesions (66/75) outnumbered the nonneoplastic ones (9/75), whereas in the spine, nonneoplastic lesions (31/48) were more common. Chordoma (40/83) was the most common neoplasm, whereas tuberculous osteomyelitis (30/40) was the most common nonneoplastic lesion encountered. Majority of the patients were adult males aged between 21 and 50 years. Rare lesions such as spinal osteochondroma, poorly differentiated neoplasm metastatic to the cervical spine from a primary salivary gland neoplasm, spinal metastasis of a glioblastoma, and intraosseous meningioma of cranium were recorded.

CONCLUSIONS

The study provides epidemiological information regarding the incidence and nature of bone lesions of the spine and cranium.

Printing a patient-specific instrument guide for skull osteoma management

BACKGROUND

To surgically remove osteoma and to keep an optimal cosmetic profile would be very challenging. To solve the difficulty, we utilized the three-dimensional (3D) printing technologies in generating a patient-specific instrument guide (PSIG) for the safe removal of a skull bone tumor.

METHODS

The preoperational brain computed tomography (CT) provided the digital imaging with thin slices, and then images were reconstructed into a 3D skull model. Based on the model, we designed a PSIG to make landmarks on the osteoma to avoid excessive removal of the skull bone. During the operation, the surgeons could remove the osteoma piece by piece by using the landmark as a reference point.

RESULTS

The PSIG was successfully applied to remove an osteoma that measured 60 × 48 × 40 mm over the left frontoparietal skull of a female patient. The 3D CT reconstruction taken both before and 4 months after surgery showed a significant change in the appearance of the osteoma.

CONCLUSION

The PSIG was able to guide the surgeon in the safe removal of the skull osteoma, as well as in maintaining the cosmetic skull profile.

Custom-Made Porous Hydroxyapatite Cranioplasty in Patients with Tumor Versus Traumatic Brain Injury: A Single-Center Case Series

BACKGROUND

Cranioplasty is a common neurosurgical procedure with the goal of restoring skull integrity. Custom-made porous hydroxyapatite prostheses have long been used for cranial reconstruction in patients with traumatic brain injury. We present a large consecutive series of 2 groups of patients undergoing cranioplasty with hydroxyapatite custom bone and compare the adverse events (AEs) between the 2 groups.

METHODS

We examined a series of consecutive patients who underwent cranioplasty using custom-made porous hydroxyapatite implants following tumor resection and traumatic brain injury at a single center between March 2003 and May 2018. The implants were designed and produced according to the surgeon's specifications and based on the patient's computed tomography scan data obtained through a standardized protocol. AEs were recorded.

RESULTS

Information on 38 patients with tumor and 39 patients with traumatic brain injury was collected and analyzed. A significant difference in the timing of surgery was found between the 2 groups; single-stage surgery was performed in 84% of patients in the tumor versus 8% of those in the traumatic brain injury group (P < 0.0001). The rate of AEs was not significantly different between the 2 groups (P = 0.4309) and was not related to the timing of surgery.

CONCLUSIONS

Custom-made hydroxyapatite cranioplasty is a solution for cranial reconstruction in patients with cranial tumors. The low incidence of AEs in a consecutive series of patients with either trauma or tumors demonstrates that these prostheses represent a safe solution independent of the characteristics of cases.

What's that big thing on your head? Diagnosis of a large frontoparietal lesion on an Eastern Zhou skull from Henan, China

We carried out a differential diagnosis of a large frontoparietal lesion on a human skull from a Late Bronze Age archaeological site located on the Central Plain of China, dating to between 771 and 476 BC. The head of this individual was covered in cinnabar, a mercury-based pigment that later was used for medicinal purposes in China. The lesion was well-circumscribed and involved the outer and inner tables of the skull, slight diploë thickening, and coarsening of bone trabeculae with expansion of intertrabecular spaces. We show that the observed changes are most consistent with cavernous hemangioma of the skull, a benign vascular malformation that preferentially affects older adults. Hemangiomas are often neglected in the paleopathological literature because of their benign nature - they tend to be asymptomatic and do not affect quality of life to a significant degree. Nevertheless, they produce characteristic lesions that can be confused with several other conditions with unrelated etiologies, including congenital hemoglabinopathies, traumas, malignant or benign neoplasms, and Paget's disease. We outline the diagnostic criteria that distinguish cavernous hemangioma from other conditions affecting the skull.

Three-Dimensional Craniofacial Bone Reconstruction With SmartBone on Demand

This is a report of a 34-year-old male lacking of bone development in the frontal and orbital part of the skull due to a surgical removal of a right orbital-front osteoma at the age of 5. The integrity of the craniofacial district was important for the young patient also for social acceptance and self-esteem.Based on computed tomography patient images, a skull model was reconstructed, both digitally and on 3-dimensional real model, to best design the needed bone graft. Defect wide extension and surface curvature called for the use of the puzzle technique, where the whole graft is composed by several elements, mechanically slotting into each other. The realization was made possible thanks to the use of a composite xenohybrid bone substitute specifically developed for reconstructive surgery (SmartBone, by Industrie Biomediche Insubri SA). SmartBone technology allowed the realization of custom-made grafts which perfectly joined each other and fitted the bone defect thanks to mechanical strength, also at low thicknesses and wide extensions.The postoperative course was uneventful and computed tomography scans showed new bone formation and complete calvaria continuity already 10 months after surgery, with no signs of inflammation over the entire follow-up.This case study represents a proof of concept that SmartBone on Demand custom-made bone grafts, together with puzzle technique, are effective, easy to handle and provide final excellent functional and aesthetic results.

Mastoid osteoma in a prehispanic cranium (1390 A.D.) from Northern Chile

OBJECTIVE

Osteomas are slow-growing benign tumors that can affect the skull, most frequently the parietal and frontal. Temporal bone osteomas are more common in the external acoustic meatus and exceptional in the mastoid region. The rarity of mastoid osteomas is confirmed by the fact that very few cases have been reported in the clinical and paleopathological literature. The aim of this paper is to report a new paleopathological case of mastoid tumor in a Pre-Hispanic adult cranium.

MATERIALS

The skull derives from the Chunchuri (today Dupont-1 site) Pre-Hispanic site in Northern Chile (1390 A.D).

METHODS

Macroscopical examination and high-resolution tomography were used to assess the cranium.

RESULTS

The CT scan revealed a well demarcated lesion suggestive of a mastoid osteoma.

CONCLUSIONS

This case adds new evidence regarding the antiquity of primary neoplasms in ancient populations and reinforces the importance of high resolution imaging in paleopathological research.

SIGNIFICANCE

Due to the antiquity of the remains this is probably the oldest reported case of mastoid osteoma.

LIMITATIONS

The patrimonial nature of the remains did not allow histopathological studies.

SUGGESTIONS FOR FURTHER RESEARCH

Further intensive review of archeological skeletal collections is needed to better understand the epidemiology of neoplastic lesions in past populations.