We report a case of an aneurysmal bone cyst (ABC) originating in a rib. A 34-year-old woman was admitted to our medical department for evaluation of left rib pain and an abnormal shadow in the left 7th rib observed on chest radiography. Computed tomography (CT) revealed an osteolytic lesion involving the left 7th rib. Positron emission tomography/CT showed slight fluorodeoxyglucose uptake in the lesion. We performed 7th rib resection with a 4 cm margin from the tumor, including the intercostal muscles in the 6th and 7th interspaces. Histopathological examination of the resected specimen showed multiple blood-filled spaces and fibrous trabeculae, which confirmed the diagnosis of an ABC. The patient\'s postoperative course was uneventful. Although rare, clinicians should consider ABCs in the differential diagnosis of rib tumors.

METHODS: A 16-year-old boy presented with a recurrent distal femur aneurysmal bone cyst accompanied by a combined sagittal knee deformity (20° of femoral antecurvatum and 26.8° of tibial recurvatum) and limb shortening. After preoperative planning, the treatment involved new intralesional curettage, phenolization, and bone allograft filling. Additional procedures included distal extension femoral osteotomy with plate fixation, and proximal tibial osteotomy with, gradually corrected through a hexapod frame. At 2-year follow-up, lower limbs exhibited normoalignment and equal length.
CONCLUSIONS: Complex knee deformities may occur with tumoral lesions around the knee but can be effectively addressed through double osteotomy and application of a hexapod frame.

BACKGROUND: Aneurysmal bone cyst (ABC) is an uncommon, benign, vascular multicystic bony lesion that most frequently develops in the first two decades of life. The metaphysis of long bones, pelvic, and vertebral column are the most common locations. The precise underlying pathophysiology of ABCs formation remains unclear; however, it is believed that reactive processes subsequent to trauma or vascular disturbance may play an important role. Involvement of the skull base rarely occurs with a prevalence of up to 5% of intracranial ABCs.
METHODS: An 18-year-old adolescent female with a history of progressive blurred vision since three months ago presented to our office. The brain and orbital MRI demonstrated no abnormal findings. After three months of glucocorticoid treatment with the diagnosis of multiple sclerosis, the visual impairment of the left eye deteriorated abruptly. The patient underwent an MRI and the imaging study demonstrated a well-defined 30 × 22 × 20-mm lesion at the anterior clinoid process with an extension to the optic canal and ethmoid sinus. The patient underwent pterional craniotomy, and the tumor was resected. The histopathological examination was suggestive of ABC.
CONCLUSIONS: ABC and other conditions should be considered in young-age people with an early unilateral decline in vision and imaging studies should be obtained in early stages and during follow-ups.

OBJECTIVE: We report a case of fibrous dysplasia (FD) with aneurysmal bone cyst (ABC)-like change in a child with orbital involvement, review the related cases, and discuss clinical features, therapy, and prognosis of this disease.
METHODS: A 10-year-old girl had right proptosis (degree of exophthalmos: OD 16 mm, OS 13 mm) and limited vision (visual acuity: OD 1.0, OS 0.8) without trauma. Preoperative CT showed a 5.0*4.3 cm right-sided crania-orbital communicating tumor. MRI indicated a well-defined multicystic mass with scattered fluid levels and soap bubble-like alterations. The child underwent total tumor resection and orbital parietal titanium mesh reconstruction. At 20 months of follow-up, the child has recovered from ocular problems, and the tumor has not recurred.
CONCLUSIONS: FD combined with ABC rarely occurs in orbit and generally begins with ocular symptoms. The etiology is uncertain. Early diagnosis and surgery are essential. Complete resection is suggested whenever possible because residual lesions may recur.

BACKGROUND: Intraosseous hemangioma is a rare benign vascular tumor of the bone that can affect any body part; however, the most common site is the vertebra, followed by calvarial bones.
METHODS: We present a case of intraosseous hemangioma in a 23-year-old male who presented a feeling of fullness in the throat for 3 months. The hyoid bone level had a hard mass of about 5 cm. Fine needle aspiration showed 5 mL dark bloody aspirates. Magnetic resonance image showed a 5.3 cm mixed signal intensity lesion in the hyoid body.
METHODS: Histopathologic examination showed intraosseous hemangioma with aneurysmal bone cyst (ABC)-like changes in the hyoid bone.
METHODS: The mass was completely removed without significant problems.
RESULTS: Complete mass excision and symptomatic improvements were achieved, and no subsequent relapses were observed.
CONCLUSIONS: The authors experienced a case of intraosseous hemangioma with ABC-like changes. There has been no case report of intraosseous hemangioma in the hyoid bone. This case showed a spectral pattern of the ABC-like changes developing from the underlying bone tumor as a secondary change. ABC-like changes in bone tumors can mislead the diagnosis. Careful examination of the tumor is essential for the correct diagnosis of ABC or ABC-like changes.

BACKGROUND: Aneurysmal bone cyst (ABC) is a rare primary or secondary tumor that usually occurs in young women aged between 10 and 20 years, mostly in the long tubular bone and spine. However, there are no definite standards for its clinical treatment. To our knowledge, this is the first report of a young female patient with distal radius ABC who was successfully treated with tumor resection and autogenous fibular head transplantation.
METHODS: A 28-year-old married Chinese young woman presented to our hospital with swelling and pain in her right wrist for 2 years and aggravation of wrist movement restriction for 1 week.
METHODS: Pathological biopsy confirmed ABC.
METHODS: We performed a pathological examination of the tumor on the right wrist and preliminarily confirmed the diagnosis of ABC. The right wrist joint was reconstructed by total surgical resection of the ABC tumor in the right wrist joint and autogenous fibular head transplantation.
RESULTS: During follow-up within 7 years, good right wrist function was confirmed. The tumor did not recur, the swelling of the right wrist disappeared, the joint pain and limitation of movement significantly improved, and the function of the right wrist was not impaired in daily activities. Radiography showed that the fracture had healed.
CONCLUSIONS: Our results suggest that autofibular head transplantation is an effective treatment for reconstruction of wrist function in adult patients with ABC of the distal radius.

BACKGROUND: A soft tissue aneurysmal bone cyst is an extremely rare tumor. The objective of the article is to present the clinical, radiological, and histopathological features of a very unusual neoplasm of soft tissues.
METHODS: A 13-year-old male patient presented a painful, mobile, and rapidly growing mass on the posteromedial aspect of his left knee. Imaging studies revealed a mass that arose from the medial surface of the distal sartorius muscle, with extension to the subcutaneous fat tissue. It was a well-circumscribed solid tumor with a peripheral rim calcification on plain film, computerized tomography, and ultrasound (zonal phenomenon). On magnetic resonance imaging, a heterogenous mass on T1-weighted images (WI) and T2-WI was seen, with a peripheral hypointense rim in both sequences. An outstanding edema on T2-WI extending to the soft tissue and muscles of the medial compartment of the knee was detected. The mass was resected, and the \"tumoral mimickers\" histopathological and molecular (next-generation sequencing) diagnoses confirmed a soft tissue aneurysmal bone cyst. A follow-up showed that the patient was free of disease 12 months after surgery.
CONCLUSIONS: Soft tissue aneurysmal bone cyst is a rare tumor. Appropriate clinical and radiological correlation should be performed to differentiate it from other tumor mimickers.

Fibrous dysplasia (FD) is a rare skeletal disorder characterized by abnormal fibro-osseous connective tissue replacing normal bone. Despite its benign behavior, craniofacial FD can cause morphological disfigurement, headache, and even blindness as a result of the produced mass effect. Surgical resection is recommended when the patient shows apparent clinical symptoms or aggravating facial asymmetry. Postoperative complications have been reported, such as hematoma, surgical site infection, abscess formation, resorption of the bone graft used for reconstruction, and recurrence. An aneurysmal bone cyst (ABC) is a rare benign bony lesion that can occur secondary to preexisting bone tumor. Secondary ABCs in craniofacial FD are extremely rare in the literature, accounting for less than 30, all of which are either case reports or series. We report an extremely rare case of symptomatic secondary ABC arising from craniofacial FD that had been misdiagnosed with abscess formation or recurrence and was surgically removed. Notably, 17 years elapsed between the primary surgery and the complication of secondary ABC. The patient underwent total removal of secondary ABC. After surgery, symptoms were relieved, with no recurrence observed during a 6-month follow-up.

BACKGROUND: Aneurysmal bone cyst is composed of variable -sized cystic blood-filled spaces separated by connective tissue septae. First-line surgical resection of spinal aneurysmal bone cyst in a child with limited total blood volume can lead to massive intraoperative bleeding, thus limiting extent of resection. Our Centre\'s has good experience of using absolute alcohol as an effective immediate devascularizing agent during vertebral hemangioma surgery in children.
METHODS: We report the first case of pediatric lumbar primary aneurysmal bone cyst in which completely blood-less piecemeal total resection of the lesion was performed after intraoperative absolute alcohol intralesional sclerotherapy.
RESULTS: Completely blood-less piecemeal total resection of the lumbar aneurysmal bone cyst was performed after intraoperative absolute alcohol intralesional sclerotherapy.
CONCLUSIONS: Intraoperative absolute alcohol intralesional sclerotherapy is a very effective devascularizing adjunct for complete piecemeal resection of spinal aneurysmal bone cyst in children with limited blood volume.

To describe clinical and imaging features and surgical treatment of equine mandibular aneurysmal bone cysts (ABCs) with β-tricalcium phosphate (TCP).
3 horses (cases 1, 2, and 3) and 1 pony (case 4) with histologically confirmed ABC.
All cases had mandibular swelling with intact adjacent skin. Cases 1 to 3 had a body condition score of 3/5 and case 4 had 2/5 and showed quidding during mastication and, at oral examination, large interdental spaces and loose elements adjacent to the swelling. Radiography or CT was performed in all cases. In cases 1, 3, and 4, an expansile septate cystic space-occupying lesion with mass effect on the adjacent cortices and teeth was seen without compact bone destruction. Case 2 showed a heterogeneous osteolytic mass with multifocal cortical lysis and interruption. Case 4 had severe dental abnormalities of deciduous and precursors of permanent teeth. ABCs were surgically treated and filled with only TCP (case 3) or in combination with autologous bone marrow (cases 1, 2, and 4).
Cases 1 through 3 showed an uneventful reduction in ABC size with increased opacity/attenuation. In case 4, a surgical site infection occurred. After removal of TCP remnants, the ABC healed satisfactorily, but remaining dental abnormalities necessitated dietary adjustments to maintain an acceptable body condition score.
Treatment of ABCs with TCP had a favorable outcome and good long-term prognosis. In young specimens, the expansile effect on the development and eruption of neighboring teeth can influence and determine final functionality of the diseased dental quadrant.