BACKGROUND: Menkes disease (MD) is a rare, inherited, multisystemic copper metabolism disorder. Classical Menkes disease is characterized by low serum copper and ceruloplasmin concentrations, leading to multiple abnormalities in the whole-body, especially in connective tissue and central nervous system. However, serum copper and ceruloplasmin levels are not reliable diagnostic biomarkers due to the low concentrations in healthy newborns either. The featured imaging manifestations play an important role in diagnosing Menkes disease. To our knowledge, there are few reports on the systemic imaging manifestations of Menkes disease.
METHODS: A 4-month-old male patient presented with recurrent seizures. He had cognitive, intellectual, growth, gross motor, precision movement, and language developmental lags. The patient\'s hemoglobin and serum ceruloplasmin level were low. On MRI, increased intracranial vascular tortuosity, cerebral and cerebellar atrophy, white matter changes, and basal ganglia abnormalities were observed. Plain radiograph revealed wormian bones, rib flaring, metaphyseal spurring, and periosteal reactions in the long bones of the limbs. A pathogenic variant in ATP7A gene was identified in the patient, so he was confirmed the diagnosis of Menkes disease. His symptoms did not improve despite symptomatic and supportive treatment during his hospitalization. Unfortunately, the infant died 3 months after leaving hospital.
CONCLUSIONS: A comprehensive and intuitive understanding of the disease\'s imaging manifestations can help clinicians to identify the disease and avoid delays in care.

Osteochondromas arising from the interosseous border of the distal tibia are rare, but cases have been reported previously in the literature. In long-standing cases, they can cause a \"mass effect\" resulting in the deformation of the bones around the ankle joint, mechanical restriction of joint movement, and even degenerative joint disease. Hence, they need to be resected if patients present with such impending complications. Several surgical techniques have been described previously for tumor resection including the anterior approach and the trans-fibular approach, the latter of which required a fibular osteotomy with or without fibular reconstruction. The surgical technique described here utilizes the posterolateral approach to the ankle joint for tumor excision, thus avoiding the need for any osteotomy or fibular reconstruction and reducing the risk of injury to major neurovascular structures. It also reduces the need for long-term immobilization and promotes a faster return to activity.

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular tumor, which can pose a diagnostic dilemma. It affects women more than men and is mainly found in the liver, lung, and bone. To date, there are no known predisposing factors. Limited data are available on the management of EHE at metastatic stages. The only optimal treatments to prevent metastatic dissemination are surgical resection and amputation in addition to radiotherapy at early stages. The oncologist in this rare entity plays an important role in the guided and standardized management of this disease, especially for advanced stages. In this article, we report the case of a 74-year-old patient admitted with swelling on the outer aspect of the right calf associated with pain and total functional impairment of the limb. The diagnosis favored a high-risk vascular tumor resembling EHE, confirmed by bone (tibia) and soft tissue biopsy. The patient underwent staging investigations, revealing diffuse metastases to the liver, bones, and lungs. The objective of this article is to advocate for oncological intervention in this entity, particularly in the advanced stages of the disease. Despite its rarity, the advancement of clinical trials and therapeutic recommendations remains crucial for optimal treatment.

BACKGROUND: Adolescents with juvenile idiopathic arthritis (JIA) tend to engage in less physical activity than their typically developing peers. Physical activity is essential for bone development and reduced physical activity may detrimentally effect bone health. Thus, we examined differences in total body bone mineral content (BMC) and areal bone mineral density (aBMD) between adolescents with JIA and adolescent controls without JIA. We also examined associations between moderate-to-vigorous physical activity (MVPA), lean mass, and bone outcomes.
METHODS: Participants included 21 adolescents with JIA (14 females, 7 males) and 21 sex- and age-matched controls aged 10-20 years. Assessments included: height; weight; triple-single-leg-hop distance (TSLH); MVPA by accelerometry; and total body BMC, aBMD, and lean mass measured using dual X-ray absorptiometry. Height-adjusted z-scores were calculated for BMC and aBMD and used for all analyses. Multiple linear mixed effects models examined group differences in BMC and aBMD, adjusting for sex, maturity, MVPA, TSLH, and lean mass. Participants clusters, based on sex and age (within 18 months), were considered random effects.
RESULTS: Adolescents with JIA had lower total body aBMD z-scores [β (95% CI); -0.58 (-1.10 to -0.07), p = 0.03] and BMC z-scores [-0.47 (-0.91 to -0.03), p = 0.04] compared with controls. Mean daily MVPA was 22.0 min/day lower in adolescents with JIA than controls; however, MVPA was not associated with aBMD [-0.01 (-0.01 to 0.01), p = 0.32] or BMC [0.00 (-0.01 to 0.00), p = 0.39]. Lean mass was positively associated with aBMD [0.05 (0.01 to 0.09) g/cm2, p = 0.03] and BMC [0.06 (0.03 to 0.10) g, p < 0.001].
CONCLUSIONS: Adolescents with JIA had lower total body aBMD and BMC compared with sex- and age-matched controls without JIA. Group differences in bone outcomes were not associated with the lower MVPA participation of adolescents with JIA. Despite this, physical activity should still be encouraged as it promotes physical well-being.

Two main problems examining the mechanism of cancer progression in the tissues using the computational models are lack of enough knowledge on the effective factors for such events in vivo environments and lack of specific parameters in the available computational models to simulate such complicated reactions.
In this study, it was tried to simulate the progression of cancerous lesions in the bone tissues by an independent parameter from the anatomical and physiological characteristics of the tissues, so to degrade the orthotropic mechanical properties of the bone tissues, a virtual temperature was determined to be used by a well-known framework for simulation of damages in the composite materials. First, the reliability of the FE model to simulate hyperelastic response in the intervertebral discs (IVDs) and progressive failure in the bony components were verified by simulation of some In-Vitro tests, available in the literature. Then, the progression of the osteolytic damage was simulated in a clinical case with multiple myeloma in the lumbar vertebrae.
The FE model could simulate stress-shielding and diffusion of lesion in the posterior elements of the damaged vertebra which led to spinal stenosis. The load carrying shares associated with the anterior half and the posterior half of the examined vertebral body and the posterior elements were estimated equal to 41 %, 47 % and 12 %, respectively for the intact condition, that changed to 14 %, 16 % and 70 %, when lesion occupied one third of the vertebral body.
Correlation of the FE results with the deformation shapes, observed in the MRIs for the clinical case study, indicated appropriateness of the procedure, proposed for simulation of the progressive osteolytic damage in the vertebral segments. The future studies may follow simulation of tumor growth for various metastatic tissues using the method, established here.

BACKGROUND: Coronavirus disease 19 (COVID-19) is a viral infection mediated by coronavirus-2 that causes severe acute respiratory syndrome (SARS-CoV-2). The disease may affect biochemical parameters and electrolytes. C-terminal cross-linking telopeptide (CTX-I) is released during mature bone resorption and is a biomarker for predicting bone resorption.
OBJECTIVE: As the pandemic progressed, understanding the effects of COVID-19 disease remained critical. Inflammatory responses triggered by the virus can result in a bone metabolism regulation imbalance. As such, this study aimed to analyze serum levels of CTX-I, calcium (CA), phosphorus (P), magnesium (Mg), C-reactive protein (CRP), and alkaline phosphatase (ALP) in COVID-19 patients to investigate the relationship between bone resorption and the disease.
METHODS: The study included 56 individuals with COVID-19 (divided into mild, moderate and severe subgroups depending on disease severity) and 25 healthy adults as a control group. Serum CTX-I concentrations were measured with enzyme-linked immunosorbent assay (ELISA). In addition, CRP, Ca, Mg, P, and ALP levels were measured using an automated clinical chemistry analyzer.
RESULTS: Serum CTX-I levels were significantly higher in COVID-19 patients than in the control group (p < 0.05). Furthermore, a positive weak relationship was detected between CRP and CTX-I (r = 0.303, p < 0.05).
CONCLUSIONS: Increased serum CTX-I levels in the patient group caused COVID-19-driven bone degradation, though serum CTX-I levels did not differ according to disease severity.

A 23-year-old female patient presented with radicular back pain, perineal numbness, and urinary retention. The patient was diagnosed with cauda equina syndrome and magnetic resonance imaging (MRI) of the spine revealed an enhancing osseous lumbar lesion causing severe central stenosis. A core needle biopsy of the lumbar spine showed microscopic features compatible with a small round blue cell tumor. CD99 and FLI1 were positive in the tumor cells. Next-generation sequencing demonstrated a EWSR1::FLI1 fusion. Given these findings, the spine lesion was diagnosed as Ewing sarcoma. The patient underwent surgical decompression of L2. On further workup, an MRI revealed an ill-defined enhancing mass of the right distal femur. This area was biopsied, demonstrating a fibro-osseous lesion with osteoblast proliferation containing nuclear atypia, low mitotic activity, and SATB2 positivity, diagnosed as low-grade central osteosarcoma (LGCOS). The patient underwent resection, which showed a classic LGCOS by histomorphology. Although fluorescence in-situ hybridization study for MDM2 gene amplification was negative, the overall findings are most consistent with LGCOS. These neoplasms are considered to be synchronous due to the presentation of each entity within 6 months. Considering the aggregate yearly incidence of Ewing sarcoma (approximately 1 case per 750 000 per year) and LGCOS (approximately 1 case per 10 million per year), the aggregate yearly probability of developing both of these genetically unrelated tumors in a single individual is 1 per 7.5 trillion per year, and it is likely such an event has never happened in the past.

Epithelioid angiosarcoma is a rare variant of angiosarcoma characterized by an epithelioid morphology that mimics carcinoma. Therefore, multicentric epithelioid angiosarcoma is easily misdiagnosed as bone metastasis from carcinoma and has an aggressive clinical course. Here, we present a rare case of a 61-year-old male with multicentric epithelioid angiosarcoma of the bone. Plain radiography, CT, and MRI revealed multiple osteolytic lesions in both femurs; some lesions showed soft tissue extension with cortical bone destruction. Interestingly, PET-CT revealed that the lesions were only distributed along the bones of the lower extremities, including the pelvic bones, femurs, and tibiae. Despite histological analysis initially suggesting metastatic carcinoma, after additional immunohistological staining, including that for vascular markers (CD31 and ERG), the final diagnosis was epithelioid angiosarcoma. A better understanding of the clinicoradiological features of this disease may help eliminate diagnostic confusion and provide better management.
상피상 혈관육종은 혈관에 생기는 육종 중 드문 변이이다. 이 종양은 대개 연부조직에서 발생하고, 뼈에서 발생하는 경우는 특히 드물다. 다발성으로 발생한 경우 이 종양은 이차성 골전이와 혼동될 수 있으며, 매우 치명적인 임상 진행을 보일 수 있다. 우리는 61세의 남성에서 다발성으로 발생한 상피상 혈관육종의 증례를 보고하고자 한다. 이 종양은 혈관성 파종으로 인해 발생한 것으로 추정된다. 엑스선 단순 촬영, CT 및 MRI에서 양쪽 하지 장골에 여러 개의 골융해성 병변이 관찰되었다. 이 중 일부는 골피질을 파괴하면서 연조직성 병변도 동반되었다. 초기 영상의학적 검사 결과로는 전이성 암종이 의심되어, PET-CT를 촬영하였다. 흥미롭게도, PET-CT에서는 이러한 병변들이 양쪽 하지 뼈의 반골, 장골, 경골을 따라 분포하고 있어, 혈관을 따라 파종할 가능성이 있는 혈관육종의 가능성도 확인되었다. 병리학적 소견에서 또한 처음에는 전이성 암종의 가능성을 고려하여 추가적인 면역 화학 염색 검사를 시행하였다. 그러나, 혈관성 표지자인 CD31, ERG 등의 검사 결과 강한 양성 소견을 보여 최종적으로 이 병변은 상피상 혈관육종으로 진단되었다. 이번 증례를 통해 뼈에 일차성으로 발생한 상피상 혈관육종에 대한 임상적, 영상의학적 특징을 정리하여, 진단적 혼동을 줄이고 더 나은 치료 방법을 제공하는데 도움이 될 것이다.

Primary leiomyosarcoma of the bone is rare. Histologically, it resembles leiomyosarcoma of soft tissue. Given the rarity of this entity, its diagnosis should be made only after clinical studies and workup have excluded metastasis from other sites. Herein, we describe an additional case of primary bone leiomyosarcoma. We report a 32-year-old female patient, who presented with right knee pain and was found to have a right distal femur mass by imaging studies. Biopsy showed a neoplasm composed of fascicles of spindle cells, arranged in different patterns, with significant pleomorphism. The tumor cells were positive for smooth muscle actin, focally positive for desmin and H-caldesmon. No other masses in the body were detected by imaging studies. The diagnosis of leiomyosarcoma of the bone was rendered. Given the broad diagnostic differential of primary bone leiomyosarcoma, it is important to be aware of this rare bone tumor phenotype and of its histomorphologic and immunohistochemical features for an accurate diagnosis.

As bones age in most mammals, they typically become more fragile. This state of bone fragility is often associated with more homogenous collagen fiber orientations (CFO). Unlike most mammals, bats maintain mechanically competent bone throughout their lifespans, but little is known of positional and age-related changes in CFO within wing bones. This study tests the hypothesis that age-related changes in CFO in big brown bats (Eptesicus fuscus) differ from those of the standard mammalian model for skeletal aging, the C57BL/6 laboratory mouse. We used data from quantitative polarized light microscopy (qPLM) to compare CFO across the lifespan of long-lived big brown bats and age matched C57BL/6 mice. Eptesicus and C57BL/6 mice displayed idiosyncratic patterns of CFO. Consistent age-related changes were only apparent in the outer cortical bone of Eptesicus, where bone tissue is more longitudinally arranged and more anisotropic in older individuals. Both taxa displayed a ring of more transversely oriented bone tissue surrounding the medullary cavity. In Eptesicus, this tissue represents a greater proportion of the overall cross-section, and is more clearly helically aligned (arranged at 45° to the bone long axis) than similar bone tissue in mice. Bat wing bones displayed a proximodistal gradient in CFO anisotropy and longitudinal orientation in both outer and inner cortical bone compartments. This study lays a methodological foundation for the quantitative evaluation of bone tissue architecture in volant and non-volant mammals that may be expanded in the future.