Primary osseous leiomyosarcoma of humerus misinterpreted as aneurysmal bone cyst: A case report and literature review.

RATIONALE: Primary leiomyosarcoma of the bone (LMSB) is a rare aggressive sarcoma with limited treatment options. Histopathologic and immunohistochemical features are similar to their more common uterine and soft tissue counterparts. However, its broader spectrum of histopathologic features and rarity make diagnostic challenges. PATIENT CONCERNS: We present a case of LMSB in a 20-year-old female who presented with left shoulder aching pain for 3 months. An osteolytic intramedullary lesion was found in the left proximal humeral epi-metaphysis. DIAGNOSES: Initial open biopsy showed a giant cell tumor of bone with aneurysmal bone cyst (ABC)-like changes. However, an open biopsy followed by extended curettage showed LMSB with ABC-like changes. INTERVENTIONS: Wide excision of the lesion and bipolar hemiarthroplasty followed by concomitant chemoradiation therapy was conducted. The mass was completely removed without significant problems. OUTCOMES: Complete mass excision and symptomatic improvements were achieved, and no subsequent relapses were observed. LESSONS: The authors encountered a rare case of LMSB. Most occurrences are in the lower extremity and trunk, respectively. ABC-like changes in bone tumors can lead to misdiagnosis. In this case, the ABC-like changes developed from the underlying LMSB as a secondary alteration. A careful examination of the underlying bone tumor is crucial to avoid misdiagnosing it as ABC or exhibiting ABC-like changes. Moreover, there has been no case report of LMSB with secondary ABC-like changes in bone.

Giant Cell Lesions of the Jaws: A Work on Current Concepts and Making Through a Working Classification.

INTRODUCTION: Giant cell-rich lesions are a diverse group of lesions that usually occur in bone and contain varying numbers of reactive osteoclastic-type multinucleate giant cells. These lesions present a challenge in pathologic diagnosis, often requiring a combination of clinical, radiographic, and histopathological assessments. The present retrospective observational study aims to provide a concise diagnostic criterion by combining all these parameters, which will aid in effective diagnosis and targeted treatment planning in the future. MATERIAL AND METHOD: Previously diagnosed cases of these lesions were taken from the archives and categorized as Central Giant Cell Granuloma (CGCG), CGCG with secondary Aneurysmal Bone Cyst (ABC), primary ABC, and Brown's Tumour. Their demographic characteristics along with clinical, radiological, and histological data were retrieved and compiled into the table. The data was then analyzed and classified into aggressive and non-aggressive CGCG according to the criteria set in the study. RESULT: 10 reported cases were of isolated CGCG, 5 were CGCG with secondary ABC, 5 of Brown's tumor and 3 were that of conventional ABC. Out of these, the lesions showing extensive size along with an increased number of giant cells were categorized under aggressive CGCG, whereas those with less aggressive characteristics were categorized under non-aggressive CGCG. The aggressive category comprised 5 cases of isolated CGCG, 2 cases of CGCG with secondary ABC, 3 cases of primary ABC, and 5 of brown tumor, whilst the rest of the cases were categorized under non-aggressive CGCG. CONCLUSION: Since all these share overlapping features, thereby this type of concise categorization is the dire need so that the lesions can have a precise diagnosis with treatment and follow-up intervals for aggressive lesions.

Nanopore DNA Sequencing Detected Chromothripsis-Induced PAFAH1B1::USP6 Rearrangement in Periosteal Solid Aneurysmal Bone Cyst Initially Diagnosed as Osteosarcoma.

An aneurysmal bone cyst (ABC) is a benign bone neoplasm that typically occurs during the first and second decades of life. ABC usually presents as a rapidly growing intramedullary expansile mass with multiple blood-filled cysts in the metaphysis of the long tubular bones. Here, we report a case of a periosteal solid ABC that was initially diagnosed as a high-grade surface osteosarcoma. A 10-year-old male was referred to our hospital for swelling and tenderness of the left upper arm. Radiography revealed periosteal mass without fluid-fluid levels. On performing open biopsy, the tumor showed hypercellular proliferation of uniform spindle to epithelioid cells with brisk mitotic activity (up to 12/2 mm2) and lace-like osteoid formation, which was diagnosed as a high-grade surface osteosarcoma. After one course of chemotherapy using adriamycin and cisplatin, peripheral sclerosis was conspicuous, which led to pathological review and revision of diagnosis as "possibly osteoblastoma." The patient was disease-free for 4 years after marginal resection and curettage. Retrospective nanopore DNA sequencing unexpectedly detected a PAFAH1B1::USP6 rearrangement. The fusion gene was further validated using reverse transcription-polymerase chain reaction and the diagnosis was revised to ABC. Chromothripsis involving chromosome 17 has also been identified. Methylation analysis classified the present tumor as an ABC or non-ossifying fibroma using t-distributed stochastic neighbor embedding and unsupervised hierarchical clustering. This case report highlights the utility of nanopore DNA sequencing for soft tissue and bone tumor diagnosis.

Analysis of Diagnosis and Treatment Strategies for Primary Juvenile Psammomatoid Ossifying Fibroma Complicated With Primary Aneurysmal Bone Cyst.

BACKGROUND: Juvenile Psammomatoid Ossifying Fibroma (JPOF) is a type of noncancerous bone tumor that usually affects adolescents in the craniomaxillofacial area. Clinical manifestations are usually symptoms caused by the tumor's invasive compression of surrounding tissues. Aneurysmal Bone Cyst (ABC) is also a benign bone tumor, and it typically occurs in long bones and the spine. Only 2% to 3% of cases occur in the head and neck. Due to the rarity of this combination of clinical cases, clinicians face difficulties in comprehensively understanding this complex lesion. Therefore, a comprehensive review of the clinical manifestations and characteristic imaging findings is necessary for surgeons. CASE PRESENTATIONS: On April 6, 2019, a 13-year-old boy presented with left maxillofacial bulge and pain for 1 month. Magnetic resonance imaging of the paranasal sinuses showed an irregular hive-like mass signal in the left maxillary sinus, and cystic changes with fluid levels were seen in the lesion. After the initial diagnosis of JPOF with primary ABC, we decided to perform a facial mid-facial resection of maxillary sinus tumor to remove the tumor tissue. Finally, after 3 recurrences and 4 operations, there was no tumor recurrence for 20 months after the last operation, and the patient was still under continuous follow-up. CONCLUSIONS: This case provided a reference for the diagnosis and treatment of JPOF combined with ABC. In particular, a new understanding of the association between the two diseases and the management of recurrence were proposed, which had the potential to improve clinical understanding of this complicated condition.

[Pediatric neurosurgical treatment of aneurysmal bone cyst at the level of thoracic spine]. / Aneurysmás csontcysta gyermek-idegsebészeti megoldása a háti gerinc magasságában.

Aneurysmal bone cysts are benign but locally aggressive bone tumours, most often affecting children and young adults. In this case report, we present the clinical  picture of a 15-year-old boy with progressive, chronic back pain. An MRI of thoracic spine  confirmed a T2 cystic spinal tumour. After considering potential options surgical removal was our choice and gross total removal was achieved with T1-3 short-segment fixation. Aneurysmal bone cysts are often rapidly expanding lesions with vascular  transformation. In order to avoid irreversible damage, in addition to early diagnosis, it is necessary to carefully consider the therapeutic options, perform surgical removal and stabilization as necessary. In case of the presented patient, extensive surgical removal and short-segmentation were performed. At 18 months of follow-up, he had no complaints and was asymptomatic. Follow-up imaging studies showed no residual or recurrent tumour to date.

Maxillary Aneurysmal Bone Cyst in a Young Dog-A Case Report.

This case report describes an aneurysmal bone cyst in the maxilla of a young dog. It describes the clinical presentation, diagnostics, management, and successful outcome of this highly unusual case. Bone cysts are described as benign, cavitated lesions within bone that are lined by reactive tissues. There is no epithelial lining in the lesions. Bone cysts usually contain hemorrhage or serosanguinous fluid. They usually appear in the long bones, and present as a swelling with or without pain.

Large skull osteoblastoma presented as aneurysmal bone cyst (ABC).

Aneurysmal bone cysts (ABCs) are rare benign vascular bony lesions mostly encountered in young patients. These cysts can occur as primary lesions or, less frequently, secondary to other pathologies such as osteoblastomas. Skull ABCs are rare and can extend intracranially, presenting with hydrocephalus and bleeding. Here we illustrate the case of a 9-year-old male who presented with headache, nausea, and vomiting, without neurological deficit. Radiological investigations showed a soap-bubble lesion with mass effect over the right cerebellum. The patient underwent right sub-occipital craniotomy with marginal wide resection of the cystic lesion. The patient had excellent outcomes. The histopathological report was consistent with osteoblastoma with an aneurysmal bone cyst.

Aneurysmal bone cyst: Is selective arterial embolization effective as curettage and bone grafting?

INTRODUCTION: Aneurysmal bone cyst (ABC) is a lytic benign bone lesion representing about 1% of all primary bone tumors. Method to treat ABC's have developed over time. The standard of care cure for ABC has been curettage with or without bone grafting of the defect but is burdened by recurrence rates of approximately 25%-31%. Based on the assumption that ABCs usually supplied by one or more pathological feeding arteries, selective arterial embolization has been described as an adjuvant preoperative procedure to reduce intra-operative hemorrhage, and as primary treatment for lesions in difficult surgical access. In the current study, we therefore asked whether (1) a single or a repeat selective arterial embolization (SAE) for treating ABCs would produce comparable healing rates compared with curettage and bone grafting; (2) evaluated the relationship of recurrence in relation to the site of the cyst, the age, and gender of the patients; and (3) the two techniques differ in term of long-term complication. MATERIAL AND METHODS: We retrospectively reviewed 265 patients who underwent curettage and bone grafting or SAE performed at our institute from 1994 to 2018. The diagnosis of ABC was always established with percutaneous CT-guided biopsy or open biopsy. Patients were followed clinically with plain radiographs or CT scan at 3, 6, 9, and 12 months then annually in the absence of symptoms. Treatment success was determined evaluating pre- and postprocedural imaging according to Chang classification. RESULTS: Two hundred and nineteen were treated with curettage and bone grafting (curettage group), and 46 with SAE Group. Of the 219 patients treated with Curettage and bone grafting (curettage group), 165 out of 219 (75.3%) experienced bone healing, while local recurrence was observed in 54 cases (24.7%) after 12 months on average (range: 3-120 months) from surgery. After the first SAE, bone ossification was seen in 27 (58.7%), without needing any further treatment. Eleven recurred patients were treated with SAE (four patients need two while seven need three SAE to heal), and eight patients with curettage and bone grafting. Thirty-eight out of 46 (82%) patients experienced bone ossification regardless the number of SAE. The overall rate of local recurrence for all patients was 26.7%. SAE group presented a lower complication rate (6%) where two patients experienced skin necrosis, and one limb-length discrepancies (2% of all cohort). DISCUSSION: The use of SAE is an attractive option to treat ABC as it combines on one hand a lower complication rate than curettage and bone grafting, on the other it can be carried out in case of nonresectable ABCs, significantly reducing the size of viable ABC lesions, fostering bone remodeling and mineralization, and most importantly, significantly improving the patient's quality of life.

Does the preoperative neutrophil-to-lymphocyte ratio have a prognostic value in aneurysmal bone cysts?

OBJECTIVES: The aim of this study was to evaluate the prognostic value of neutrophil-to-lymphocyte ratio (NLR), lymphocyte-tomonocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) in aneurysmal bone cysts (ABCs). PATIENTS AND METHODS: Between February 2001 and August 2019, a total of 86 patients (44 males, 42 females; mean age: 21.5±15.2 years; range, 2 to 73 years) with a histologically confirmed diagnosis of ABCs who did not receive cancer treatment previously and had a minimum follow-up period of 24 months were retrospectively analyzed. Data including age, sex, side, tumor location, pre-treatment complete blood count analysis results, preferred surgical method, follow-up period, presence of recurrence, and date of recurrence were recorded. Preoperative NLR, LMR and PLR values were calculated in all patients. RESULTS: The mean follow-up was 56.7±13.5 (range, 24 to 179) months. Forty-one (47.7%) ABCs were located in the lower extremities, 36 (41.8%) in the upper extremities, and nine (10.4%) in the pelvic girdle. A statistically significant difference was detected in the NLR values according to recurrence status (p=0.023). The PLR and LMR values were not significant for area under the curve, while NLR values were significant for recurrence. The cut-off value was determined as 2.054. Those with an NLR of ≥2.054 were found to have a 4.561-fold higher risk of recurrence than those with an NLR of <2.054 (odds ratio [OR]=4.561). CONCLUSION: Our study results suggest that NLR, which is the pre-treatment inflammatory index, is a prognostic factor in patients with ABCs. Although NLR alone is not decisive in patients with elevated NLR, it can be used to evaluate the clinical prognosis and recommend an appropriate treatment strategy.

Secondary aneurysmal bone cyst of the frontal bone with fibrous dysplasia showing rapid expansion: a case report.

A 19-year-old woman presented with swelling of the left forehead without pain. She did not have any relevant past or family history. Computed tomography showed destruction of the outer cortex of the frontal bone. A solitary mass lesion with a fluid collection was detected with magnetic resonance imaging. Because the swelling of the left forehead had enlarged rapidly with osteolytic changes, surgical removal of the lesion was performed. The lesion appeared to be enveloped in a fibrous capsule. The soft lesion was removed from the frontal bone. The outer frontal bone was absent, although the inner frontal bone was preserved. Then, the frontal bone was resected with margins from the edge of the erosion. The dura mater under the lesion was intact. A cranioplasty was performed using titanium mesh. On histological examination, the trabecular bones revealed irregular shapes and arrangements, indicating fibrous dysplasia. There was a continuous high-cell-concentration pathological lesion outside the fibrous dysplasia. There were numerous cells, such as mononuclear cells, osteoclast-like multinucleated giant cells, foam cells, and red blood cells. The osteoclast-like multinucleated giant cells and other cells did not show significant nuclear atypia. Immunostaining with H3.3G34W was negative, and the ubiquitin-specific peptidase 6/Tre-2 gene showed no rearrangements. The histopathological diagnosis was secondary aneurysmal bone cyst with fibrous dysplasia. Additional postsurgical therapy was not performed. There has been no evidence of recurrence of the lesion for two years.

Aneurysmal Bone Cyst of the Orbit With USP6 Gene Rearrangement.

PURPOSE: Aneurysmal bone cyst (ABC) of the orbit is a very rare tumor, occurring mostly in the pediatric population, and can result in sight threatening complications and disfigurement. This review discusses previously reported cases with a focus on evolving treatment options and molecular genetics. METHODS: We report the youngest case of an orbital ABC with a confirmed gene fusion: a 17-month-old girl, with confirmed FGFR-UPS6 (Fibroblast Growth Factor Receptor 1-ubiquitin specific peptidase 6/tre-2). A literature search for relevant publications on the topic was performed via Medline and PubMed, with the appropriate data extracted. RESULTS: Thirty-two cases of orbital aneurysmal bone cyst were identified in the literature. Presentations are varied and can include pain, proptosis, decreased vision, and extraocular motility disturbance. Typical imaging and histopathology findings are discussed, in particular the usefulness of identifying USP6 gene arrangements. Treatment modalities are reviewed including surgery, embolization, and receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors. Recurrences can occur, usually within 2 years. CONCLUSIONS: Orbital ABC is a neoplasm that presents unique diagnostic and treatment challenges. Gene rearrangements can confirm primary ABC and rule out other underlying pathology. Disfigurement and sight threatening complications can occur due to both the disease process and with treatment. Outcomes may be improved with the use of systemic therapy.

Aneurysmal bone cyst of the temporal bone presenting with reversible vestibular impairment.

BACKGROUND: Aneurysmal bone cysts are expansile benign lesions associated with compressive destruction and obscure pathogenesis. The most common sites of temporal bone involvement are the petrous apex, squamous portions and mastoid. CASE REPORT: This paper reports a right temporal aneurysmal bone cyst in a 51-year-old man who presented clinically with facial palsy, and hearing loss and impaired vestibular function. Magnetic resonance imaging and computed tomography findings were consistent with a diagnosis of aneurysmal bone cyst. Inter-operative findings showed that the lesion had caused compressive damage to the internal auditory canal. Following surgical excision, the patient experienced vertigo, indicating recovery of vestibular function. Follow-up imaging revealed complete resection without clinical recurrence. CONCLUSION: To our knowledge, this is the first report of aneurysmal bone cyst invasion of the inner auditory canal. Our clinical experience indicates that vestibular nerve damage recovery is relatively uncommon. This case report will hopefully inform future studies.

The treatment of aneurysmal bone cysts.

PURPOSE OF REVIEW: Aneurysmal bone cysts are rare, locally aggressive bone tumors. Optimal treatment of ABCs is still matter of debate as therapies including sclerotherapy, selective arterial embolization and systemic treatment with denosumab are increasingly utilized, in addition to or instead of traditional curettage. The purpose of this review is to discuss current concepts and difficulties in diagnosing and treating primary ABCs, based on latest available literature. RECENT FINDINGS: In diagnostics, multiple new fusion partners of USP-6 have been described on next-generation sequencing specifically for primary ABCs. In a recent systematic review, failure rates of percutaneous injections and surgery were comparable. In a literature review, the use of denosumab seemed effective but resulted in multiple cases of severe hypercalcemia in children. SUMMARY: Accurately diagnosing primary ABC is crucial for treatment decisions. Curettage remains a valid treatment option, especially with adjuvant burring, autogenous bone grafting and phenolization. Percutaneous sclerotherapy represents a solid alternative to surgery, with polidocanol showing good results in larger studies. Systematic therapy with denosumab exhibits favorable results but should be reserved in the pediatric population for unresectable lesions, as it may result in severe hypercalcemia in children. When selecting a treatment option, localization, stability and safety should be considered.

Unusual presentation of aneurysmal bone cyst with scoliosis: a case report.

BACKGROUND: Aneurysmal bone cysts are benign bone tumors that not uncommonly involves the spine. However, this involvement can cause scoliosis, albeit rarely. This report focuses on the importance of proper management for complete tumor resection to prevent recurrence and spinal deformity. CASE PRESENTATION: A 12-year-old Middle Eastern boy, with a history of T11 aneurysmal bone cyst resection and bone grafting carried out at another hospital, presented with spine deformity of 4 months' duration. The deformity was not associated with pain or neurological deficit. A whole-spine magnetic resonance imaging with contrast confirmed the recurrence of the aneurysmal bone cyst. Posterior spinal instrumentation with corpectomy of T11 was then performed, and confirmed with histopathology the recurrence of aneurysmal bone cyst. Two years post-corpectomy, deformity correction was done from T5-L4. CONCLUSION: Management of aneurysmal bone cysts requires meticulous planning and full excision to prevent recurrence, especially in the growing spine. If neglected, it can cause major spinal deformities and cord compression, which places a medical burden on the patient and family. To avoid such complications, treating aneurysmal bone cysts along with scoliosis correction can prevent deformity progression.

Aneurysmal bone cyst of the proximal femur concomitant with Graves' disease and Moyamoya disease: report of a rare case.

Aneurysmal bone cyst is a type of benign bone pathology with expansile and osteolytic features whose etiology remains unclear. Graves' disease is an autoimmune disease characterized by diffuse goiter and hyperthyroidism. Moyamoya disease is a progressive cerebral vasculopathy. It has been reported that Graves' disease and Moyamoya disease share a similar etiology involving cytokines and autoimmune and genetic factors. There are no previous reports regarding the relationship between aneurysmal bone cyst and Graves' disease. Here, we present the rare case of a 25-year-old woman with suspected aneurysmal bone cyst of the left proximal femur and a definite preoperative diagnosis of Graves' disease, in whom lesion resection combined with left total hip replacement was indicated. Biopsy confirmed the diagnosis of aneurysmal bone cyst. Three days postoperatively, the patient developed acute ischemic cerebral infarction owing to Moyamoya disease, which was subsequently confirmed. This case elucidates the potential interaction among aneurysmal bone cysts, Graves' disease, and Moyamoya disease and provides lessons regarding appropriate perioperative preparation for patients with Graves' disease who require surgery to avoid potential severe complications.

A sizeable aneurysmal bone cyst of the mandibular ramus on 15-year-old patient. Intraoral approach.

Aneurysmal bone cysts (ABCs) are benign, non-neoplastic bone lesions, which contain blood and demonstrate a destructive pattern. They rarely occur in the head and neck region, with the mandible being the most common site of craniofacial origin. They develop in the second decade of life and their etiology is obscure. ABCs can sometimes demonstrate distinct radiological features and imaging is also necessary for preoperative planning. Surgery is the mainstay of treatment. The ABC should be excised in toto and usually osteotomies and primary reconstruction are necessary. We present a case of sizeable ABC of the mandibular ramus that was excised intraorally, without the need of combined approaches or reconstruction.

[Giant cell-containing tumors of bone and differential diagnoses]. / Riesenzell-haltige Tumoren des Knochens und Differenzialdiagnosen.

Osteoclastic giant cells represent a common cellular component of lesions arising in bone. Highlighting this morphological finding, the current WHO classification of bone tumors defines a diagnostic group comprising aneurysmal bone cyst, giant cell tumor of bone and non-ossifying fibroma, which may display morphologic similarities while being distinct with regard to molecular and biological features. Starting with these tumors - putting a focus on lesions arising in bone - this article gives a survey of other (chondrogenic and osteogenic) tumors that frequently contain osteoclastic giant cells, which may, particularly in small biopsies, enter differential diagnosis. Overlapping features with selected giant cell-containing soft tissue tumors, which may be of differential diagnostic relevance in daily routine, are discussed.

Aneurysmal bone cyst and osteoblastoma after neoadjuvant denosumab: histologic spectrum and potential diagnostic pitfalls.

The use of denosumab to treat giant cell tumors of bone (GCT) and other giant cell-containing bone tumors has become more common. While the clinicopathologic features of denosumab-treated giant cell tumors of bone have been well-illustrated, descriptions of other denosumab-treated bone tumors are very limited. Surgical pathology files of two institutions and consultation files from two authors were searched for denosumab-treated aneurysmal bone cysts and denosumab-treated osteoblastomas. Clinicopathologic features were reviewed and analyzed. We identified four patients with denosumab-treated bone tumors other than GCT from our surgical pathology and consultation files, including two aneurysmal bone cysts and two osteoblastomas. All were treated with denosumab for 0.5-7.0 (median 4.5) months. Radiologically, denosumab-treated tumors showed decreased size with increased ossification and mineralization on CT and heterogeneous intermediate to hypointense signal on MRI. Histologically, denosumab-treated aneurysmal bone cyst contained thin, elongated, curvilinear, and anastomosing strands of bone with empty lacunae, while denosumab-treated osteoblastoma showed circumscribed nodules of woven bone lined by small osteoblasts. Denosumab-treated aneurysmal bone cyst and osteoblastoma showed treatment-related morphologic changes that can mimic other bone neoplasms. Their recognition requires correlation with the clinical history of denosumab use and radiologic findings.

Osteoblastoma of the Temporal Bone in a Child.

This report describes osteoblastoma of the temporal bone found on a well-child visit. The relevant clinical, radiographic, and histologic features are described. The tumor was completely resected via a transtemporal approach. The differential diagnosis for these tumors include osteoma, giant cell tumor, histiocytosis, aneurysmal bone cyst and sarcoma. Histologic findings are critical for determining the proper diagnosis.