UNASSIGNED: Giant cell tumors of bone (GCTB) are infrequent tumors that usually impact the epiphyses of long bones and uncommonly manifest in the ribs. Herein, we report a case of asymptomatic GCTB directly invading the lung tissue.
METHODS: A 36-year-old man was referred to our emergency department with only left chest pain. Computed tomography revealed a large heterogeneous solid cystic mass in the left lung apex and amorphous calcification and distraction in the posterior part of the left fourth rib. Histological examination also exhibited that the GCTB originated from the rib. The patient underwent an en-bloc resection with no recurrence in his one-year follow-up.
UNASSIGNED: GCTB is characterized by osteoclast-like multinucleated giant cells and can exhibit aggressive local behavior. GCTB in the rib is rare, mainly found in the posterior arc. Radiographic features include lytic lesions with bone remodeling, often seen eccentrically in long bone epiphyses. Aggressive tumors may show cortical destruction and soft tissue extension. Surgery is often recommended for GCTB management, aiming for complete resection with sufficient surgical margins.
CONCLUSIONS: The absence of well-defined diagnostic criteria hinders the accurate diagnosis of GCTB, making a comprehensive assessment through radiological and histological examinations crucial. Upon physical examination, GCTB should be considered in the differential diagnosis for mediastinal lesions, regardless of their size. Furthermore, surgical removal can be taken into account as the primary treatment strategy for tumors that originate from the posterior arc of the ribs, such as GCTB.

Bone tumors of the upper limb are a common cause of bone pain and pathological fractures in both old and young populations. Surgical reconstruction and limb salvage have become valid options for these patients despite this kind of surgery being challenging due to the need for wide bone resection and the involvement of surrounding soft tissues. Computer-assisted technology helps the surgeon in pre-operative planning and in designing customized implants. The aim of this study was to investigate the surgical outcomes and complications of custom-made prostheses in oncologic reconstruction of the upper limb and if they are reliable options for patients suffering from aggressive tumors. An electronic search on PubMed, Google Scholar, and Web of Knowledge was conducted to identify all available articles on the use of custom-made prostheses in oncological resections of the upper limb. Twenty-one studies were included in the review, comprising a total of 145 patients with a mean age of 33.68 years. The bone involved was the humerus in 93 patients, and the radius was involved in 36 patients. There were only six cases involving proximal ulna, three cases involving the scapula, and seven cases involving the elbow as well as soft tissues around it. The most frequent primary tumor was the giant cell tumor, with 36 cases, followed by osteosarcoma with 25 cases, Ewing Sarcoma with 17 cases, and Chondrosarcoma with 7 total cases. Forty patients were affected by bone metastases (such as renal cell cancer, breast cancer, melanoma, and rectal cancer) or hematologic diseases involving bone (lymphoma, myeloma, or non-Hodgkin disease). Custom-made prostheses are a viable option for patients who suffer from malignant tumors in their upper limbs. They are a reliable aid for surgeons in cases of extensive resections.

BACKGROUND: Papillary intralymphatic angioendothelioma (PILA) is an exceptionally rare metastasizing soft tissue tumor. It tends to arise in the subcutaneous tissues of distal extremities in children. Only four intraosseous PILA cases have been reported until now in English language literature.
METHODS: We present a case of PILA arising in the distal femoral epiphysis of a 50-year-old female patient. It started as a relentless pain in her left knee. A plain radiography revealed a radiolucent area in the left internal femoral condyle. Computerized tomography revealed a 1-cm lytic lesion with a sclerotic rim. Magnetic resonance images showed a significant bone marrow edema signal focused on a 1-cm subchondral lesion suggestive of an intraarticular osteoid osteoma. Histologically, the tumor contained vascular channels covered by a single endothelial layer with intraluminal papillary endothelial structures lined with hobnail cells. Immunohistochemically, the cells were positive for ERG, CD31, and D2-40. The tumor underwent cryoablation and 6 months later, after local recurrence or tumor persistence, a wide tumor resection was referred. After 7 years of follow-up, the patient displayed neither local recurrence nor distant metastases.
CONCLUSIONS: Primary intraosseous PILAs are exceedingly rare tumors that should be considered in the differential diagnosis of vascular bone tumors.

Megaprostheses are well-known, reliable, and effective reconstruction prostheses used in oncologic surgery for limb salvage in patients affected by primary or metastatic bone tumors. Rehabilitation plays a major role after MUTARS replacement, with the aim of improving function after surgery and maintaining the highest possible quality of life. Only a few studies have been published about the use of megaprostheses for the upper limb. The aim of this narrative review is to describe the results of functional and rehabilitative outcomes of patients affected by bone primary or metastatic bone cancer of the upper limb and surgically treated with MUTARS prostheses. A comprehensive search was conducted on PubMed and Scopus using the following MESH terms: \"Mutars\", \"Megaprosthesis\", \"bone\", \"tumors\", \"metastasis\", \"upper limb\", \"rehabilitation\", \"outcome\", \"quality of life\", and 10 studies were included. The most frequent oncological pathology was found to be metastases of the proximal humerus treated with modular endoprosthesis or modular reverse implants. Outcome measures used were ROM, MSTS, ASES, DASH, Constant-Murley score, Enneking score, VAS, MEP, TESS, and WOSI. Reconstruction of the proximal humerus with the MUTARS system seemed to be a valid treatment option after bone tumor resection. Rehabilitation after MUTARS surgery is very relevant, but currently, functional and rehabilitative outcomes are inadequately represented in the literature. Hence, further studies are needed to define standardized rehabilitation protocols after oncological orthopedic surgery that can be applied routinely in clinical practice.

Osteosarcoma (OS) is the most common type of primary bone malignancy. Common genetic variants including single nucleotide polymorphisms (SNPs) have been associated with osteosarcoma risk, however, the results of published studies are inconsistent. The aim of this study was to systematically review genetic association studies to identify SNPs associated with osteosarcoma risk and the effect of race on these associations. We searched the Medline, Embase, Scopus from inception to the end of 2019. Seventy-five articles were eligible for inclusion. These studies investigated the association of 190 SNPs across 79 genes with osteosarcoma, 18 SNPs were associated with the risk of osteosarcoma in the main analysis or in subgroup analysis. Subgroup analysis displayed conflicting effects between Asians and Caucasians. Our review comprehensively summarized the results of published studies investigating the association of genetic variants with osteosarcoma susceptibility, however, their potential value should be confirmed in larger cohorts in different ethnicities.

Patient specific instrumentation (PSI) and intraoperative surgical navigation (SN) can significantly help in achieving wide oncological margins while sparing bone stock in bone tumour resections. This is a systematic review aimed to compare the two techniques on oncological and functional results, preoperative time for surgical planning, surgical intraoperative time, intraoperative technical complications and learning curve. The protocol was registered in PROSPERO database (CRD42023422065). 1613 papers were identified and 81 matched criteria for PRISMA inclusion and eligibility. PSI and SN showed similar results in margins (0-19% positive margins rate), bone cut accuracy (0.3-4 mm of error from the planned), local recurrence and functional reconstruction scores (MSTS 81-97%) for both long bones and pelvis, achieving better results compared to free hand resections. A planned bone margin from tumour of at least 5 mm was safe for bone resections, but soft tissue margin couldn\'t be planned when the tumour invaded soft tissues. Moreover, long osteotomies, homogenous bone topology and restricted working spaces reduced accuracy of both techniques, but SN can provide a second check. In urgent cases, SN is more indicated to avoid PSI planning and production time (2-4 weeks), while PSI has the advantage of less intraoperative using time (1-5 min vs 15-65 min). Finally, they deemed similar technical intraoperative complications rate and demanding learning curve. Overall, both techniques present advantages and drawbacks. They must be considered for the optimal choice based on the specific case. In the future, robotic-assisted resections and augmented reality might solve the downsides of PSI and SN becoming the main actors of bone tumour surgery.

BACKGROUND: Small cell osteosarcoma is an extremely rare histopathological variant of conventional osteosarcoma. Due to nonspecific symptoms, most osteosarcomas of the jaws are misdiagnosed as periapical abscesses and mistreated by teeth extraction and drainage.
METHODS: We report, to our knowledge, the seventh case of small cell osteosarcoma in gnathic sites affecting the mandible of an old female with history of a large painful swelling related to the right mandibular molar area for 2 months. Cone-beam computed tomography scan showed an osteolytic lesion related to the lower molar area with involvement of the inferior alveolar nerve. An incisional biopsy was taken, and after histopathological examination and immunohistochemical staining, a diagnosis of small cell osteosarcoma was reached. Hemi-mandibulectomy was performed by a maxillofacial surgeon. No clinical evidence for recurrence was noted until manuscript writing.
CONCLUSIONS: Accurate diagnosis is very important, and general practitioners should be aware of this entity considering that small cell osteosarcoma has a poor prognosis when compared to conventional osteosarcoma.

Background and Objectives: Melorheostosis, also referred to in the literature as Leri\'s disease, is an unusual mesenchymal dysplasia with the clinical appearance of benign sclerosing bone dysplasia; it frequently occurs in late adolescence. Any bone in the skeletal system can be affected by this disease, though the long bones of the lower extremities are the most common, at any age. Melorheostosis has a chronic evolution, and symptoms are usually absent in the early stages. The etiopathogenesis is still unknown, however, numerous theories have been proposed that could explain the appearance of this lesion formation. An association with other benign or malignant bone lesions is also possible, and associations with osteosarcoma, malignant fibrous histiocytoma, or Buschke-Ollendorff syndrome have also been reported. There have also been reported cases of the malignant transformation of a pre-existing melorheostosis lesion into malignant fibrous histiocytoma or osteosarcoma. The diagnosis of melorheostosis can be made only based on radiological images, but, due to its polymorphism, additional imaging investigations are often necessary and sometimes only a biopsy can establish a definite diagnosis. Because there are currently no guidelines for treatment based on scientific evidence, due to the low number of cases diagnosed worldwide, our objective was to highlight the early recognition and specific surgical treatments for better prognosis and outcomes. Materials and Methods: We conducted a review of the literature consisting of original papers, case reports, and case series and presented the clinical and paraclinical characteristics of melorheostosis. We aimed to synthesize the treatment methods available in the literature as well as determine possible future directions related to the treatment of melorheostosis. Furthermore, we presented the results of a case of femoral melorheostosis admitted to the orthopedics department of the University Emergency Hospital of Bucharest in a 46-year-old female patient with severe pain in the left thigh and limitation of joint mobility. Following the clinical examination, the patient complained of pain in the middle third of the left thigh in the antero-medial compartment; the pain appeared spontaneously and was aggravated during physical activity. The pain started about two years prior, but the patient experienced complete pain relief after the administration of non-steroidal anti-inflammatory drugs. In the last six months, the patient presented an increase in pain intensity without significant improvement following the administration of non-steroidal anti-inflammatory drugs. The patient\'s symptoms were mainly determined by the increase in the volume of the tumor and the mass effect on the adjacent tissues, especially on the vessels and the femoral nerve. The CT examination and bone scintigraphy showed a unique lesion in the middle third of the left femur and no oncological changes in the thoracic, abdominal, and pelvic regions; however, at the level of the femoral shaft, there was a localized cortical and pericortical bone lesion formation that surrounded approximately 180 degrees of the femoral shaft (anterior, medial, and lateral). It had a predominantly sclerotic structure but was associated with lytic areas with thickening of the bone cortex and areas of periosteal reaction. The next therapeutic gesture was to perform an incisional biopsy using a lateral approach at the level of the thigh. The histopathological result supported the diagnosis of melorheostosis. Additionally, immunohistochemical tests completed the data obtained after the microscopic examination through the classic histopathological technique The patient was discharged and included in a full medical recovery program for eight weeks in a specialized medical center, during which she also received analgesic treatment in maximum doses, but without improvement regarding her symptoms. Taking into account the chronic evolution of the pain, the complete lack of response to conservative treatment after eight weeks, and the lack of treatment guidelines in the case of melorheostosis, a surgical approach needed to be considered. The surgical option in this case, considering the circumferential location of the lesion at the level of the femoral diaphysis, was a radical resection. The surgical approach consisted of segmental resection to healthy bone tissue and reconstruction of the remaining defect with a modular tumoral prosthesis. At the 45-day postoperative control, the patient no longer complained of pain in the operated-on limb and was mobile with full support without gait difficulties. The follow-up period was one year, and the patient presented complete pain relief and a very good functional outcome. Results: In the case of asymptomatic patients, conservative treatment seems to be a good option with optimal results. However, for benign tumors, it remains unclear whether radical surgery is a viable option. Conclusions: Melorheostosis remains an incompletely understood disease, given the limited number of cases worldwide, and thus, there is a lack of clinical guidelines regarding specialized treatment.

With an annual incidence of less than 1%, Ewing sarcoma mainly occurs in children and young adults. It is not a frequent tumor but is the second most common bone malignancy in children. It has a 5-year survival rate of 65-75%; however, it has a poor prognosis when it relapses in patients. A genomic profile of this tumor can potentially help identify poor prognosis patients earlier and guide their treatment. A systematic review of the articles concerning genetic biomarkers in Ewing sarcoma was conducted using the Google Scholar, Cochrane, and PubMed database. There were 71 articles discovered. Numerous diagnostic, prognostic, and predictive biomarkers were found. However, more research is necessary to confirm the role of some of the mentioned biomarkers. .

BACKGROUND: Chondroblastoma (CB) is a rare, benign cartilage-producing tumor, typically affecting the epiphysis of long bones in skeletally immature individuals. There have been only limited case reports describing the cytomorphologic features of this tumor, and thus the cytopathologic diagnostic criteria are controversial. Herein, we report the cytologic findings of 10 CB cases, discuss the diagnostic criteria and critical differential diagnosis, along with a comprehensive review of the literature.
METHODS: We performed a retrospective search of our cytopathology and surgical pathology databases for cases diagnosed as CB that had corresponding cytology specimens from four large medical institutions. All available cytopathology specimens were retrieved and reviewed. Clinicopathologic and radiologic data were recorded.
RESULTS: Ten cases were retrieved from 8 patients aged 15-42 years (mean, 24 years), five of whom were males. Eight cases represented primary tumors while 2 cases were recurrences. Three cases occurred in the femur, two cases occurred in the humerus, while 1 case occurred in each of the glenoid, talus, and proximal phalanx of the 3rd toe. The cytologic diagnosis of CB was achieved in 7 cases. The neoplastic mononuclear cells were present in all cases and their cytologic features were similar. These cells displayed round to oval eccentric nuclei, evenly distributed chromatin, and inconspicuous nucleoli; few of which had nuclear indentations. Multinucleated giant cells were present in 9 cases (90%). Fragments of chondromyxoid matrix were present in 4 cases on cytologic preparations (40%). Cell blocks were available in 8 cases. Mononuclear and multinucleated giant cells were present in all adequate cell blocks and their cytologic features were identical to those seen in the smears. The chondroid matrix was present in only three of the adequate cell blocks (43%).
CONCLUSIONS: We concluded that with the appropriate clinical and radiologic setting, the diagnosis of CB can be achieved on cytology if characteristic chondroblasts are present. The presence of chondromyxoid matrix is a helpful clue but is not necessary for the diagnosis. As in surgical pathology, cytologic evaluation of bone tumors should be interpreted in conjunction with clinical and radiologic findings.