Subungual Osteochondroma of the Great Toe: A Case Report.

Bony outgrowths of the distal phalanx of the great toe have been described in the literature but rarely. These subungual bony outgrowths can be caused by subungual exostosis or subungual osteochondromas. Both of these abnormalities are bony outgrowths with differences in the cartilage cap wherein the exostoses have fibrocartilage, and osteochondromas have hyaline cartilage. The subungual exostosis and osteochondroma that are protruding present symptoms of pain, redness, and deformed nail bed, whereas the nonprotruding osteochondromas have only a lump as the presenting symptom. In both conditions, excision of the lesion and curettage of the base helps prevent a recurrence. Curettage at the end of the excision of the bony outgrowth is required to avoid recurrence. After excision, the specimen should be sent for histopathologic examination to differentiate between the exostosis and osteochondromas, which are underreported in subungual locations, and to rule out malignant transformation. We present a 13-year-old girl with an isolated subungual nonprotruding exostosis of the great toe that was treated by excisional biopsy. The histopathologic examination confirmed it as osteochondroma, which is underreported.

Osteochondrolipoma of the foot treated by surgical excision: a case report and literature review.

BACKGROUND: Osteochondromas, classified as a new benign subtype of lipomas and characterised by chondroid and osseous differentiation, are rare lesions that have been infrequently reported in previous literature. The maxillofacial region was reported as the most frequent localization, with infrequent occurrence in the lower limb. This paper represents the first documented case report of osteochondrolipoma in the foot. CASE PRESENTATION: A 51-year-old male patient presented with a chief complaint of right foot pain at the plantar aspect, accompanied by the observation of swelling between the first and the second metatarsal shafts. His complaint of pain and swelling started 10 and 4 years prior, respectively. Since their onset, both symptoms have progressed in nature. Imaging revealved a large mass exhibiting a nonhomogenous composition of fibrous tissue and bony structures. Surgical intervention through total excision was indicated. CONCLUSION: Osteochodrolipoma is a benign lesion that can affect the foot leading to decreased functionality of the foot due to the pain and swelling. Surgical excision is the recommended approach for this lesion, providing both symptomatic relief and confirmation of the diagnosis through histopathological examination.

Secondary peripheral chondrosarcoma in multiple osteochondromas: a retrospective single-institution case series.

BACKGROUND: Multiple osteochondromas is genetic disorder characterized by the formation of multiple benign cartilage-capped bone tumors, named osteochondromas, during skeletal development. The most feared complication is the secondary peripheral chondrosarcoma, a malignant cartilaginous neoplasm that arises from the chondroid cap of pre-existent osteochondromas. We conducted a retrospective cohort study on patients diagnosed and followed up from 1960 to 2019 to describe the clinical and pathological features of individuals affected by peripheral chondrosarcoma in multiple osteochondromas, to evaluate follow up information and individual outcome and to compare the results with literature. Data, including age, gender, site, histological grade, cartilage cap thickness, surgical treatments, surgical margins, genotype mutational status as well as treatment details were captured from the hospital electronic health records and from Registry of Multiple Osteochondromas. In addition, a complete histological review of all hematoxylin and eosin (H&E)-stained sections has been performed by expert pathologists. RESULTS: One hundred five of the screened cases were included in the present study. The age at diagnosis of SPC ranges from 13 to 63, with median age at diagnosis of 34 years. The site most frequently affected by malignant degeneration was the pelvis (46 patients, 44%) with higher incidence in male patients (32 males vs.14 females). The second one was lower limbs (including femur, fibula, or tibia), identified in 35 patients. Histological information - available for 103 patients - showed: 59 patients with grade 1; 40 patients had a grade 2 and 4 patients had a grade 3. The most common surgical treatment was the complete resection, followed by debulking, amputation and partial resection. Most of cases did not have recurrence of the disease. Outcome in disease-free survival highlights that a worse course of the disease was associated with histological grade 2 or 3, and partial resection surgery. In most of analyzed cases (94%) a pathogenic variant was identified. CONCLUSIONS: In conclusion, the present study gives an overview of the secondary peripheral chondrosarcomas, confirming that this disease represents an impacting complication for multiple osteochondromas patients and suggests that malignant transformation can occur also in younger patient, in a not irrelevant number of cases.

Robotic resection of a second rib osteochondroma.

A 43-year-old man presented with a several-month history of worsening left shoulder pain. On imaging, he was found to have an osseous mass arising from his left second rib and protruding into the soft tissues of his chest. The mass had radiographic characteristics consistent with those of an osteochondroma. He had point tenderness over the mass, and the area of point tenderness was consistent with his description of the location of his pain over the past several months. Based on his symptoms, he was taken to the operating room for robotic excision of this mass. He was placed in a right lateral decubitus position, and three robotic ports were inserted. The mass was identified based on landmarks and was dissected free. The bony attachment of the mass to the second rib was transected using a Kerrison rongeur. The mass was delivered into the chest and removed using an endobag. The patient was discharged the following day after removal of his Blake drain. His pain had completely resolved at the postoperative follow-up examination, and his final pathological report confirmed the benign diagnosis of osteochondroma.

Isolated Dysplasia Epiphysealis Hemimelica (Trevor Disease) of the Acetabulum: Literature Review.

Dysplasia epiphysealis hemimelica (DEH), also known as Trevor disease, is a rare pathologic proliferation of cartilage with unknown etiology creating cartilaginous osteochondroma exostoses intra-articularly or juxta-articularly. Herein, we reviewed the literature about acetabular osteochondroma in children and report a case of a 9-year-old boy who presented to the orthopaedic clinic with complaints of gait disturbance, right hip discomfort, and with increasing severity and frequency of hip subluxation episodes over the course of a year. Imaging studies revealed dysplasia of the right hip with subluxation secondary to acetabular lesion. The patient underwent surgical hip dislocation to facilitate surgical excision of the lesion and reduce hip, and pathology confirmed osteochondroma with chondromatosis. We report the early follow-up for this patient and discuss the value of surgical hip dislocation to manage intra-articular bone or cartilage lesions.

Solitary osteochondromas in paleo-oncology: A case report from 4th-century BCE Pontecagnano (southern Italy).

OBJECTIVE: This study presents a new case of solitary osteochondroma (SOC) identified on the proximal tibia of a 4th-century BCE individual from Pontecagnano (Salerno, Italy) with an aim to contribute to differential diagnosis of bone tumors in archeological contexts. MATERIALS: Paleopathological assessment of a male individual with an estimated age-at death of 45.9-62.9 years brought to light during the archaeological excavations in the funerary sector of 'Sica de Concillis' within the necropolis of Pontecagnano. METHODS: Macroscopic and radiographic analyses were performed for diagnostic purposes. RESULTS: The proximal portion of the right tibia exhibited a large exophytic bone formation extending from the anteromedial to the posteromedial portion of the diaphysis. The x-ray confirmed the lesion being characterized by regular trabecular bone tissue with cortico-medullary continuity. CONCLUSIONS: The lesion observed is diagnostic of sessile SOC, a neoplasm that must have had aesthetic and, possibly, neurovascular complications due to its large size. SIGNIFICANCE: By offering a detailed description of a case of tibial osteochondroma and discussing the possible complications the individual might have experienced during life, this study highlights the role and importance of benign bone tumors in paleo-oncology. LIMITATIONS: Histological analysis was not carried out in order to preserve the integrity of the affected tibia. SUGGESTIONS FOR FURTHER RESEARCH: More attention should be devoted to benign tumors in paleopathology as their occurrence and manifestations in the past will lead to a better understanding of their impacts on the quality of life of affected individuals and to greater knowledge of their natural history.

Sacroiliac joint involvement in osteochondromatosis: identifying its prevalence and characteristics from cross-sectional imaging

PURPOSE: Apart from a few case reports, sacroiliac joint (SIJ) involvement in osteochondromatosis has not been studied. We aimed to determine the prevalence and characteristics of such involvement using cross-sectional imaging. METHODS: In this retrospective study, three observers (one junior radiologist and two musculoskeletal radiologists) independently reviewed computed tomography (CT) or magnetic resonance imaging (MRI) of patients in our database who had osteochondromatosis (≥2 osteochondromas across the skeleton) for SIJ involvement. The final decision was reached by the consensus of the two musculoskeletal radiologists in a later joint session. RESULTS: Of the 36 patients with osteochondromatosis in our database, 22 (61%) had cross-sectional imaging covering SIJs (14 females, 8 males; age range 7-66 years; mean age 23 years; 13 MRI, 9 CT). Of these, 16 (73%) had intra-articular osteochondromas. For identifying SIJ osteochondromas on cross-sectional imaging, interobserver agreement was substantial [κ = 0.67; 95% confidence interval (CI): 0.34, 1.00] between the musculoskeletal radiologists and moderate (κ = 0.59; 95% CI: 0.23, 0.94) between the junior radiologist and the final consensus decision of the two musculoskeletal radiologists. In the cohort with cross-sectional imaging, the anatomical variations of the accessory SIJ (n = 6, 27%) and iliosacral complex (n = 2, 9%) were identified in six different patients with (n = 2) and without (n = 4) sacroiliac osteochondromas. CONCLUSION: Cross-sectional imaging shows frequent (73%) SIJ involvement in osteochondromatosis, which, although a rare disorder, nevertheless needs to be considered in the differential diagnosis of such SIJ anatomical variants as the accessory SIJ and iliosacral complex. Differentiating these variants from osteochondromas is challenging in patients with osteochondromatosis.

Regulatory role of human fibrocartilage stem cells in condyle osteochondroma.

OBJECTIVE: Osteochondroma is a common benign skeletal disorder for which different molecular and histological features of long bones have been reported. We investigated cell-of-origin and molecular mechanisms of a rare condylar osteochondroma (CO). METHODS: Human fibrocartilage stem cells (hFCSCs) isolated from CO and normal condyle tissue were used for RNA sequencing, real-time PCR, Western Blotting, immunohistology, flowcytometry, as well as for chondrogenic differentiation, proliferation, and apoptosis detection assays. RESULTS: HFCSCs were fewer in number with weaker proliferative capacity and higher apoptosis ratio in the CO group. During the chondrogenic inducing process, hFCSCs from CO were prone to form more mature and hypertrophic cartilage. The result of RNA sequencing of hFCSCs from CO and normal condyle revealed a correlation between the PI3K/AKT signalling pathway and CO. Activated PI3K/AKT signalling might lead to functional changes in hFCSCs by enhancing cell apoptosis in the developmental process of CO. Increased expression of BCL2-like protein 11 (BIM) in CO tissue also supports this conclusion. Furthermore, the activation of the PI3K/AKT pathway in TMJ of mice induced histological disorder and increased apoptosis in condylar cartilage. CONCLUSION: We conclude that the activation of PI3K/AKT signalling in hFCSCs of CO suggests a new hypothesis for the cell-of-origin of human CO and another possible target to treat it.

A possible case of "kissing" osteochondroma and multiple enchondromas in a medieval skeleton from the church of Sant' Agostino in Caravate (Northern Italy).

This work presents the neoplastic bone changes found in the lower limb of a medieval skeleton from the church of Sant' Agostino in Caravate (Northern Italy). After briefly assessing the individual's overall pathological picture, a differential diagnosis for the neoplastic changes is now proposed. These changes were analysed macroscopically and radiographically and subsequently evaluated considering the paleopathological and clinical literature available. The differential diagnosis allowed us to recognize a tibiofibular osteochondroma and some enchondromas in the medullary cavity of the tibia. The results presented here highlight the importance of radiological analyses in the recognition and study of bone neoplasms in the paleopathological field, further contributing to our knowledge of the presence of neoplasms in Medieval Northern Italy.

Characterization of primary fibular bone tumors and post-surgical clinical and functional outcomes.

OBJECTIVES: In this study, we present the characterization of tumors located in the fibula, which is a rare site for tumors, and the clinical and functional results of patients with fibular tumors that we operated in our clinic. PATIENTS AND METHODS: Between February 2008 and December 2018, a total of 104 patients (58 males, 46 females; mean age: 26±18 years; range, 3 to 78 years) who were operated for tumor located in the fibula were retrospectively analyzed. Demographic data, histopathological diagnosis, tumor localization, surgical method and postoperative complications, metastases, follow-up time, and functional results of the patients were recorded. The fibula was divided into three groups as proximal, diaphysis and distal one-third. RESULTS: The mean follow-up was 56±25.3 (range, 24 to 108) months. Eighty (76.9%), seven (6.7%) and 17 (16.3%) patients were located proximal, diaphysis and distal to the fibula, respectively. The number of patients with malignant tumors located in the fibula was 26 (25%), the tumor was benign in 54 (51.9%) patients and 24 (23%) tumors were borderline. The most common tumor localized to the fibula was osteochondroma with 28 (26.9%) patients. The most common malignant tumors located in the fibula were Ewing sarcoma and osteosarcoma in 11 patients each. The most common surgical method was curettage in 44 (42.3%) patients. Distant organ metastases were present in 18 (17.3%) patients. The Musculoskeletal Tumor Society score of 17 patients who underwent resection of the proximal fibula were 87%. CONCLUSION: Fibula is a rare location for tumors and fibula tumors tend to be located more proximal. Tumors located in the fibula have good functional outcomes after surgery.

Rapidly Growing Solitary Osteochondroma in the Adult Finger A Case Report.

Osteochondromas are common benign bone tumors that are most commonly found in children and adolescents. They are usually slow-growing and located at the metaphysis of the long bones. When present in adults in atypical locations or with concerning features, such as thickened cartilage cap and rapid growth, osteochondromas warrant imaging to assess the risk of malignant transformation into chondrosar- coma and may require surgical excision. Here, we describe the unusual case of an adult male with a rapidly growing osteochondroma of the proximal phalanx that subsequently underwent surgical excision.

Expression pattern and clinical significance of ß-catenin gene and protein in patients with primary malignant and benign bone tumors.

This study is aimed to unravel the status of local and circulating ß-catenin in different primary bone tumors and its relevance to tumor types, severity, and chemotherapy. The ß-catenin mRNA expression level and the expression of the protein (intensity level) were evaluated in tumor tissue and peripheral blood mononuclear cells of 150 patients with different types of primary bone tumors (78 malignant and 72 benign tumors) using Real-Time PCR and immunohistochemistry. The ß-catenin mRNA expression level and the expression of the protein were increased in bone tumors which was positively correlated with the tumor malignancy. Amongst osteosarcoma, Ewing's Sarcoma, chondrosarcoma, osteochondroma, Giant Cell Tumor, and exostosis tumors, the osteosarcoma, and Giant Cell Tumor groups showed the highest level of ß-catenin expression. The ß-catenin expression in malignant bone tumors was significantly correlated with tumor grade, size, metastasis, tumor recurrent, and the level of response to chemotherapy. A similar pattern of ß-catenin gene expression and its association with tumor characteristics was detected in the patient's peripheral blood cells. The simultaneous increase in the expression of the ß-catenin gene and protein in tumor tissue and in circulating blood cells and its relationship with tumor severity indicates the possible promoting role of ß-catenin in primary bone tumor pathogenesis.

Secondary peripheral chondrosarcoma arising in solitary osteochondroma: variables influencing prognosis and survival.

BACKGROUND: Secondary peripheral chondrosarcomas arising in solitary osteochondromas is an unusual complication, reported in small series. In this study, we aimed to present our experience with this rare variant of chondrosarcoma and compare results with already published data in order to determine prognostic factors for overall and disease-free survival. METHODS: The case study includes retrospective data from patients diagnosed at a single institution from 1943 to 2019. Clinical data were collected reviewing all available medical records from first to last follow-up visits. To exclude the presence of the Multiple Osteochondroma Hereditary Syndrome, few patients, with a suspect of a familial form of the disease, were evaluated for the presence of germline heterozygous variants in EXT1 and EXT2 genes. Results were summarized using descriptive statistics and statistical analysis were performed to reveal associations between variables. RESULTS: Two hundred and fourteen secondary peripheral chondrosarcomas that arose exclusively from solitary osteochondromas diagnosed in a multidisciplinary setting at the IRCCS Istituto Ortopedico Rizzoli were retrospectively identified, 66.4% males and 33.6% females with a median age at diagnosis of 38 years. The local recurrence rate was 17.3%, while the metastases one was 5.1%. Besides age, a high histologic grade is the only factor associated with worse 5-year and 10-year overall survival (log-rank p = 0.0005, HR = 3.74; 95% CI 1.69-8.26). Moreover, high histological grade (HR = 3.75; 95% CI = 1.69-8.34; p = 0.001) and surgical debulking (HR = 3.71; 95% CI = 1.57-8.79; p = 0.003) were associated with a significantly worse disease-free survival. CONCLUSIONS: Our study confirm the low-grade behavior of secondary peripheral chondrosarcomas and demonstrate that the best choice of treatment for those arising in solitary osteochondromas is the wide surgical excision, when possible. Location per se is not a factor that affects prognosis, while the accurate histological grade assessment is correlated with the tumor aggressiveness and a long term follow up is necessary for this rare variant of chondrosarcoma.

Osteochondroma formation is independent of heparanase expression as revealed in a mouse model of hereditary multiple exostoses.

Hereditary multiple exostoses (HME) is a rare, pediatric disorder characterized by osteochondromas that form along growth plates and provoke significant musculoskeletal problems. HME is caused by mutations in heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. Seemingly paradoxically, osteochondromas were found to contain excessive extracellular heparanase (Hpse) that could further reduce HS levels and exacerbate pathogenesis. To test Hpse roles, we asked whether its ablation would protect against osteochondroma formation in a conditional HME model consisting of mice bearing floxed Ext1 alleles in Agr-CreER background (Ext1f/f ;Agr-CreER mice). Mice were crossed with a new global Hpse-null (Hpse-/- ) mice to produce compound Hpse-/- ;Ext1f/f ;Agr-CreER mice. Tamoxifen injection of standard juvenile Ext1f/f ;Agr-CreER mice elicited stochastic Ext1 ablation in growth plate and perichondrium, followed by osteochondroma formation, as revealed by microcomputed tomography and histochemistry. When we examined companion conditional Ext1-deficient mice lacking Hpse also, we detected no major decreases in osteochondroma number, skeletal distribution, and overall structure by the analytical criteria above. The Ext1 mutants used here closely mimic human HME pathogenesis, but have not been previously tested for responsiveness to treatments. To exclude some innate therapeutic resistance in this stochastic model, tamoxifen-injected Ext1f/f ;Agr-CreER mice were administered daily doses of the retinoid Palovarotene, previously shown to prevent ectopic cartilage and bone formation in other mouse disease models. This treatment did inhibit osteochondroma formation compared with vehicle-treated mice. Our data indicate that heparanase is not a major factor in osteochondroma initiation and accumulation in mice. Possible roles of heparanase upregulation in disease severity in patients are discussed.

Chronic mandibular hypomobility related to a unilateral accessory condyle. A case report.

BACKGROUND: Chronic mandibular hypomobility is characterized by a long-standing limitation of the mouth opening related to multiple etiologies, including elongation of the coronoid apophysis. Unlike the most frequent pathologies that cause coronoid elongation, such as hyperplasia, osteoma (OM), and osteochondroma (OC), the accessory mandibular condyle (AMC) is a rare entity. Clinical Presentation: The AMC shows a configuration similar to a normal mandibular condyle with an articular surface covered by fibrocartilage that articulates with the temporal wall of the zygomatic bone, and histologically, does not show neoplastic growth. The patient was treated with a coronoidectomy, removing the coronoid apophysis as well as the AMC. CLINICAL RELEVANCE: This case report presents a case of an AMC to describe the clinical, imaging, surgical, and histological characteristics, establishing its differential diagnosis with hyperplasia, OM, and OC of the coronoid apophysis.

Benign cartilaginous tumors of the hand, a five-year retrospective study.

Benign and malignant cartilaginous bone tumors of the hand are rare findings, however representing a particular pathology due to the capacity to induce significant functional impairment. Even though a large proportion of tumors of the hand and wrist are benign, these may present destructive characteristics, deforming adjacent structures until compromising function. The most appropriate surgical approach for most benign tumors is intralesional lesion resection. Malignant tumors often require wide excision, up to segment amputation to obtain tumor control. A five-year retrospective study was performed on patients admitted in our Clinic with benign cartilaginous tumors of the hand, in which 15 patients were admitted within this period, 10 presenting with enchondroma, four presenting with osteochondroma, and lastly one with chondromatosis. After clinical and imaging evaluation, all the aforementioned tumors were surgically removed. Definitive diagnosis for all bone tumors, either benign or malignant, was established by tissue biopsy and histopathological examination, dictating therapeutic strategy.

Osteochondroma Pathogenesis: Mouse Models and Mechanistic Insights into Interactions with Retinoid Signaling.

Osteochondromas are cartilage-capped tumors that arise near growing physes and are the most common benign bone tumor in children. Osteochondromas can lead to skeletal deformity, pain, loss of motion, and neurovascular compression. Currently, surgery is the only available treatment for symptomatic osteochondromas. Osteochondroma mouse models have been developed to understand the pathology and the origin of osteochondromas and develop therapeutic drugs. Several cartilage regulatory pathways have been implicated in the development of osteochondromas, such as bone morphogenetic protein, hedgehog, and WNT/ß-catenin signaling. Retinoic acid receptor-γ is an important regulator of endochondral bone formation. Selective agonists for retinoic acid receptor-γ, such as palovarotene, have been investigated as drugs for inhibition of ectopic endochondral ossification, including osteochondromas. This review discusses the signaling pathways involved in osteochondroma pathogenesis and their possible interactions with the retinoid pathway.

Phalangeal Intra-Articular Osteochondroma Caused a Rare Clinodactyly Deformity in Children: Case Series and Literature Review.

Background: Various factors are discovered in the development of clinodactyly. The purpose of this retrospective study was to present a group of children with a rare clinodactyly deformity caused by phalangeal intra-articular osteochondroma and evaluate the efficacy of various treatment methods. Methods: All child patients that were treated for finger problems in our center between Jan 2017 and Dec 2020 were reviewed. A detailed analysis was made of the diagnosis and treatment methods in eight rare cases. X-rays and histopathology were applied. Results: A preliminary analysis of 405 patients in total was performed, and we included eight cases in our final analysis. This cohort consisted of 2 girls and 6 boys, with a mean age of 5.74 ± 3.22 years (range: 2y5m to 11y). Overall, four patients had their right hand affected and four patients had their left hand affected. One patient was diagnosed as having hereditary multiple osteochondroma (HMO) while the other seven patients were all grouped into solitary osteochondroma. Osteochondroma was proven in all of them by histopathology examination. Preoperative X-rays were used to allow identification and surgery planning in all cases. All osteochondromas were intra-articular and in the distal end of the phalanges, which is located opposite the epiphyseal growth area. All of the osteochondromas developed in half side of the phalanges. The angulation in the finger long axis was measured, and resulted in a mean angulation of 34.63 ± 24.93 degree (range: 10.16-88.91 degree). All of them received surgery, resulting in good appearance and fingers straightening. No recurrence was recorded. Conclusions: This retrospective analysis indicates that 10 degrees can be selected as the angulation level for diagnosis of clinodactyly deformities. What's more important, the abnormal mass proven by X-rays should be included as the classical direct sign for diagnosis. The first choice of treatment is surgery in symptomatic osteochondromas.