Osteoid Osteoma of the Talus Mimicking Pigmented Villonodular Synovitis in a 15-Year-Old Male: A Case Report.

Osteoid osteoma is a benign tumor of the bone which tends to occur in diaphysis or metaphysis of the long bones. The lesion is generally intraosseous with vague clinical symptoms, hence given the name "great mimicker". When located subperiosteally and juxtaarticulary, atypical clinical presentation and radiological may lead to a delayed or missed diagnosis. Performing surgery with a misdiagnosis carries the risk of incomplete resection of the lesion and recurrence. We report the case of a 15-year-old male with a subperiosteal osteoid osteoma of the talus, who was misdiagnosed with pigmented villonodular synovitis and operated through anterior ankle arthrotomy. A nodular lesion 1 cm in diameter with hard rubber consistency was removed from the dorsal aspect of the talar neck. The pathological specimens were consistent with subperiosteal osteoid osteoma. The patient's symptoms resolved rapidly in the early postoperative period. The patient remained asymptomatic at the 20th-month follow-up and the control MRI revealed no signs of recurrence. Atypical radiological and clinical presentation of juxtaarticular subperiosteal osteoid osteomas cause misdiagnosis, delay in diagnosis, incomplete resection and recurrence. It is important to keep in mind "juxtaarticular subperiosteal osteoid osteoma" in the differential diagnosis of cases with suspected Pigmented Villonodular Synovitis.

Preoperative Endovascular Embolization of Orbital Solitary Fibrous Tumor With 500-700 Micron Tris-Acryl Gelatin Microspheres.

The reported experience with preoperative embolization of solid orbital tumors is scarce. Herein, we present a case of a large and hypervascular orbital solitary fibrous tumor (SFT) in which 500-700 µm tris-acryl gelatin microspheres (TAGM) were used for preoperative embolization. A 41-year-old man presented with severe proptosis, palpable mass, restrictive myopathy, exposure keratopathy, and compressive optic neuropathy in the right orbit. Magnetic resonance imaging showed a 65x35x35 mm, diffusely contrast-enhanced tumor in the superior orbit, extending to the apex, and multiple intratumoral vascular flow voids. A diagnosis of SFT was made by incisional biopsy. Endovascular tumor embolization was performed with 500-700 µm TAGM. Two days later, the tumor was entirely removed with minimal bleeding. No embolization- or surgery-related complications and tumor recurrence or metastasis developed during the 42-month postoperative follow-up.

STAT3, VEGF, and PSMA Expression Patterns in Malignant Peripheral Nerve Sheath Tumors, Malignant Melanomas, and Glioblastomas: Does Staining Percentage and Intensity Have an Effect on Survival?

Malignant peripheral nerve sheath tumors (MPNSTs), glioblastomas (GBMs), and malignant melanomas (MMs) are neural crest-originating aggressive tumors with a poor prognosis. Signal transducer and transcription activator 3 (STAT3) plays a role in many biological processes, including cell life and proliferation, the acute phase response, chronic inflammation, autoimmunity, metabolism, and cancer progression, It is also known to be a prooncogenic transcription factor. Vascular endothelial growth factor (VEGF) is one of the most potent proangiogenic stimuli ever identified. It mediates tumor neovascularization, and is associated with angiogenesis and lymphangiogenesis. The prostate-specific membrane antigen (PSMA) folate hydrolase I, despite its name, has been found in tissues other than the prostate. It is overexpressed in prostate cancer cells and several other cancers, and has the potential to be a target for radioligand therapy. We investigated the value of STAT3, VEGF and PSMA immunohistochemical expression patterns and their effects on survival in MPNSTs, GBMs, and MMs. Their expression patterns were evaluated in 25 MPNSTs, 27 GBMs, and 25 MM cases. All GBM cases stained positively for STAT3 and VEGF. In the other groups, the staining patterns were heterogeneous. None of the cases showed positive staining with PSMA. There was no statistically significant difference in survival between cases with differing VEGF and STAT3 staining patterns in the MPSNT and MM groups, but there was an increase in mortality as the VEGF score increased in the GBM group. The suppression of VEGF and STAT3 may be a promising avenue for treatment of MPNSTs, GBMs, and MMs, although further research is needed.

Effect of bone morphogenic protein-2 and desferoxamine on distraction osteogenesis.

BACKGROUND: Angiogenesis is crucial for formation of a stable regenerate during distraction osteogenesis (DO). This experimental study evaluates if bone morphogenic protein-2 (BMP-2) and desferrioxamine (DFO), two agents which are known to induce neoangiogenesis in vivo, would increase angiogenesis and osteogenesis, and improve mechanical properties of bone regenerate in DO model. METHODS: Twenty-four tibias of 24 New Zealand rabbits were osteotomized and fixed with semi-circular fixators. Three groups of 8 animals were formed. BMP-2 soaked scaffolds were used in the first group, whereas daily local DFO injections were made in the second group. Subjects in the control group did not receive any agents during the surgery or in the distraction period. The rabbits in all three groups underwent distraction at a rate of 0.6 mm/day for 15 days following the 7-day latent period. Animals were sacrificed on day 38, and the tibia were harvested for histological and mechanical examination of the regenerate. RESULTS: All 24 rabbits survived the surgical procedure, and there were no side effects against the BMP-2 and local DFO. Three-point bending tests revealed a higher force (361 ± 267 N.) required for fracture in Group 1 (p: 0.018). Similarly, the bending moment in Group 1 (5.4 ± 4.0 Nmm) was significantly higher than the other groups (p: 0.021). There was no significant difference between the groups in terms of deflection and stiffness (p Ëƒ 0.05). Histologically, there was no statistical difference between the groups in terms of endochondral, periosteal, and intramembranous ossification and VEGF activity (p Ëƒ 0.05). CONCLUSION: BMP-2 and DFO stimulate angiogenesis by increasing VEGF activity. Angiogenesis is one of the most important mechanisms for the initiation and maintenance of new bone formation. Stimulation of angiogenesis in unfavorable biomechanical conditions may not be sufficient for ideal bone formation.

Malignant transformation of monostotic fibrous dysplasia into angiosarcoma in the proximal tibia.

The majority of bone angiosarcomas are primary tumors while secondary angiosarcomas arise after radiation therapy or bone infarctus. This article presents a case of malignant transformation of monostotic fibrous dysplasia into angiosarcoma. An 80-year-old female presented with pain on right cruris. Radiological examination revealed a lesion with lytic areas and destruction of cortical bone on right tibia. Gross and histopathological examination showed two areas with an abrupt transition. The solid component was composed of curved, immature bony trabeculae in a fibroblastic stroma. The other component involved epitheloid cells forming slit-like vascular spaces. The diagnosis of angiosarcoma and fibrous dysplasia was given. Malignant transformation of fibrous dysplasia into angiosarcoma is extremely rare; as this is the sixth case in the existing literature. Prognosis of fibrous dysplasia is generally good and less than 1% of the patients develop a malignant tumor. Therefore, patients with fibrous dysplasia should be offered a life-long follow-up.

The Ki-67 proliferation index predicts recurrence-free survival in patients with dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue sarcoma that originates from the dermis or subcutaneous tissue in the skin. While its prognosis is generally favorable, disease recurrence is relatively frequent. Because morbidity after repeated surgery may be significant, an optimized prediction of recurrence-free survival (RFS) has the potential to improve current management strategies. The purpose of this study was to investigate the prognostic value of the Ki-67 proliferation index with respect to RFS in patients with DFSP. We retrospectively analyzed data from 45 patients with DFSP. We calculated the Ki-67 proliferation index as the percentage of immunostained nuclei among the total number of tumor cell nuclei regardless of the intensity of immunostaining. We constructed univariate and multivariate Cox proportional hazards regression models to identify predictors of RFS. Among the 45 patients included in the study, 8 developed local recurrences and 2 had lung metastases (median follow-up: 95.0 months; range: 5.2-412.4 months). The RFS rates at 60, 120, and 240 months of follow-up were 83.8%, 76.2%, and 65.3%, respectively. The median Ki-67 proliferation index was 14%. Notably, we identified the Ki-67 proliferation index as the only independent predictor for RFS in multivariate Cox proportional hazards regression analysis (hazard ratio = 1.106, 95% confidence interval = 1.019-1.200, p = 0.016). In summary, our results highlight the potential usefulness of the Ki-67 proliferation index for facilitating the identification of patients with DFSP at higher risk of developing disease recurrences.

Rituximab Therapy for Recalcitrant Idiopathic Sclerosing Orbital Inflammation.

Three patients (3 female patients; aged 7, 35, and 61 years) who had recalcitrant idiopathic sclerosing orbital inflammation were treated with rituximab. The disease was bilateral in 1 patient (4 orbits in total): diffuse in 2 and localized in 2 orbits. It caused optic neuropathy in 1 orbit of each patient. Conventional immunotherapy and tumor debulking surgery were unsuccessful in controlling the disease. After rituximab infusions (375 mg/m2/week for 4 weeks), all patients improved symptomatically. Radiologically, the local lesions resolved completely and diffuse lesions partially. Two patients with recurrent inflammation during follow up (78, 58, and 51 months) responded well to immediate, short-term steroid treatments. Short-term rituximab therapy can induce effective remissions in patients with refractory idiopathic sclerosing orbital inflammation. Early and local lesions may respond better to treatment than diffuse lesions. Nevertheless, inflammatory exacerbations can occur during late follow up.

A Case Report of Primary Breast Angiosarcoma: Clinical Presentation and Outcome After Adjuvant Radiotherapy.

Angiosarcomas of the breast are infrequent subtypes of sarcoma that are often diagnosed after radiation therapy for primary breast cancer. Primary angiosarcomas (PAS) are rare tumors that constitute 0.04% of all malignant breast tumors. We report a case of a 40-year-old woman with a lump in the right breast and diagnosed as angiosarcoma by pathological evaluation. She underwent simple mastectomy followed by adjuvant radiation. She is alive and disease-free for 66 months although tumor size was large and one surgical margin was tumor positive. Breast angiosarcoma is often in advanced stage at diagnosis and tends to recur locally. Although surgical methods constitute the primary treatment, we believe that a multidisciplinary treatment strategy should be used in high-risk patients with large primary tumors and tumor positive margins.

Efficacy of Single-Dose Radiotherapy in Preventing Posttraumatic Tendon Adhesion.

Background and Aim Posttraumatic peritendinous adhesion is the greatest obstacle to achieve normal tendon function following lacerations of extrinsic flexor tendons of the hand. In this study, we aimed to evaluate whether single-dose radiotherapy (RT) has the potential to modulate intrasynovial tendon adhesions. Materials and Methods A total of 80 tendons from the third to fourth flexor profundus of both hind paws of 20 adult New Zealand rabbits were used in this study. Rabbits in the RT group received 3 Gy of X-irradiation in a single fraction. Histopathological evaluation of longitudinal sections of tendons was made using the Tang grading system for peritendinous adhesions. Intratendinous quality of the healing tissue in the laceration zone was assessed using a modified Movin scale. Results Adhesion and inflammatory response were greater in the RT group (p˂0.001). Tendon healing in the radiation group was found to be more uniform and organized compared with the control group. However, this difference was not statistically significant. The nuclei of the tenocytes in the radiation group showed a closer resemblance to normal tendon tissue when compared with the control group (p=0.007). Conclusions Despite RT's certain advantages such as extracorporeal use, anti-inflammatory effect, and homogenous tissue penetration, 3-Gy X-irradiation resulted in increased peritendinous posttraumatic adhesion, possibly due to dose imbalance. Increased roundness in the tenocyte nuclei was present in the RT group. Studies with different dosing regimens and a higher number of subjects are necessary to establish an ideal dose suppressing the synovial response without compromising tendon healing.

BRAF mutation, TERT promoter mutation, and HER2 amplification in sporadic or neurofibromatosis-related neurofibromas and malignant peripheral nerve sheath tumors: do these molecules have a signature in malignant transformation?

Peripheral nerve sheath tumors may occur sporadically or related to neurofibromatosis (NF). Unless the mechanisms of tumorigenesis in NF related malignant peripheral nerve sheath tumors (MPNST) are better understood, it remained unclear in sporadic cases. We aimed to investigate the genetic route for malignancy in both individuals with NF-1 and sporadic ones to open a way for targeted therapies in the future. We investigated the role of HER2 with Dual ISH DNA Probe Cocktail test, BRAF mutation (exon 15) and TERT promoter mutation frequency with Sanger sequencing method in respectively 25 sporadic neurofibromas, 25 NF-1 related neurofibromas and 25 MPNST cases from two institutes. Categorical data were analyzed and summarized as frequency and percentage. Statistical analysis was done with SPSS v.22 statistical package, and the statistical significance level was considered as 0.05. We identified TERT promoter mutation only in one sporadic MPNST (4%) and no BRAF mutation in any case. HER2 amplification is found in 10/25 (40%) MPNST cases. No mutations or gene amplification detected in neurofibromas (p < 0.001). MPNSTs are sarcomas with poor prognosis and limited treatment options. TERT promoter mutations and HER2 amplification may play a putative role in therapeutic purposes.

Bronchial Carcinoid Tumors with Massive Osseous Metaplasia: A Case Report and Review of the Literature.

Bronchial carcinoid tumors are primary lung neoplasms thought to originate from neuroendocrine cells, i.e. Kulchitsky cells, in the bronchial mucosa, although the type of cellular origin has not been clearly understood. A 61-year-old male patient underwent surgery and microscopic examination of the specimen revealed an anastomosing trabecular bony structure among the nests of tumor cells with round nucleus, granular chromatin, and large eosinophilic cytoplasm. Our case has been deemed worthy of being presented as bronchial carcinoid tumor with exaggerated osseous metaplasia.

Lipomatous Tumors in Pediatric Patients: A Retrospective Analysis of 50 cases.

OBJECTIVE: Although lipomatous tumors are the most common type of mesenchymal tumors in adults, they account for less than 10% of all soft tissue lesions in pediatric patients. In this descriptive study, we aim to present our series of pediatric lipomatous tumors consisting of lipoma, neural fibrolipoma, lipoblastoma, atypical lipomatous tumor, myxoid liposarcoma and pleomorphic liposarcoma, and to evaluate the clinicopathological characteristics of these tumors in reference to the literature. MATERIAL AND METHOD: In this study, pediatric lipomatous tumor cases diagnosed between 2002 and 2018 were screened from pathological archives and retrospectively evaluated. RESULTS: A total of 50 cases were diagnosed with lipomatous tumor within the mentioned period. Of the total cases, 24 were female (48%) and 26 were male (52%), with age distribution ranging from 1 to 204 months. Histopathological examination revealed lipoma in 26 cases (52%), lipoblastoma in 19 (38%), atypical lipomatous tumor in 2 (4%), myxoid liposarcoma in 2 (4%), and pleomorphic liposarcoma in 1 case (2%). CONCLUSION: Although lipomatous tumors are the most common type of mesenchymal tumors; they rarely occur in children. Since there is a limited number of studies on pediatric lipomatous tumors in the literature, there is insufficient data on the prevalence and incidence of these tumors. These tumors may slowly enlarge to greater sizes, especially those localized in deep tissues, and may cause various clinical symptoms by compressing surrounding tissues. Local recurrences may occur, even after total excision, and require close monitoring.

Evaluation of incidence and histolopathological findings of soft tissue sarcomas in genitourinary tract: Uludag university experience

ABSTRACT Purpose: In this study we aimed to review urological soft tissue sarcomas of genitourinary tract that were diagnosed in our institution and their prognostic factors for survival. Materials and Methods: The clinical and pathological records of 31 patients who had diagnosis of soft tissue sarcomas primarily originating from the genitourinary tract between 2005-2011 were reviewed. Results: The most common site was kidney (17 cases, 54.8%), and most common diagnosis was leiomyosarcoma (11 cases, 35.4%). A total of 24 patients (77.4%) had surgical excision. The surgical margins were positive in 7 patients who presented with local recurrence after primary resection. Twelve patients developed metastatic disease. During follow-up (range 9-70 month), 26 of the 31 patients (88.9%) were alive. Significant survival differences were found according to histological type (p: 0.001), with lower survival rates for malignant fibrous histiocytoma. The tumor size, the presence of metastasis at the time of diagnosis and tumor localization were not statistically significant for overall survival. Conclusions: In our series, prostate sarcomas, paratesticular rhabdomyosarcoma and malignant fibrous histiocytoma had poor prognosis, especially in patients presenting with metastatic disease.

Evaluation of incidence and histolopathological findings of soft tissue sarcomas in genitourinary tract: Uludag university experience.

PURPOSE: In this study we aimed to review urological soft tissue sarcomas of genitourinary tract that were diagnosed in our institution and their prognostic factors for survival. MATERIALS AND METHODS: The clinical and pathological records of 31 patients who had diagnosis of soft tissue sarcomas primarily originating from the genitourinary tract between 2005-2011 were reviewed. RESULTS: The most common site was kidney (17 cases, 54.8%), and most common diagnosis was leiomyosarcoma (11 cases, 35.4%). A total of 24 patients (77.4%) had surgical excision. The surgical margins were positive in 7 patients who presented with local recurrence after primary resection. Twelve patients developed metastatic disease. During follow-up (range 9-70 month), 26 of the 31 patients (88.9%) were alive. Significant survival differences were found according to histological type (p: 0.001), with lower survival rates for malignant fibrous histiocytoma. The tumor size, the presence of metastasis at the time of diagnosis and tumor localization were not statistically significant for overall survival. CONCLUSIONS: In our series, prostate sarcomas, paratesticular rhabdomyosarcoma and malignant fibrous histiocytoma had poor prognosis, especially in patients presenting with metastatic disease.

Non-steroid anti-inflammatory drugs reduce the efficacy of autologous blood pleurodesis.

BACKGROUND: This study aims to perform autologous blood pleurodesis in an animal model and investigate the effects of paracetamol and diclofenac on autologous blood pleurodesis. METHODS: We divided 42 female Wistar albino rats (aged three months; average weight 275±25 g) into three major groups of 14. Each major group was further divided into two subgroups of seven rats to be sacrificed at seven days for early changes and 21 days for late changes. We performed autologous blood pleurodesis in all rats at a dose of 3 mL/kg. Group C (control group) was administered saline, group P was administered paracetamol, and group D was administered diclofenac for the postoperative five consecutive days as a single dose intraperitoneally. We sacrificed the rats at the designated dates and removed the thoracic cages en bloc. RESULTS: According to macroscopical and microscopical evaluation of the specimens, paracetamol led to a similar degree of adhesions with saline, whereas diclofenac significantly reduced the intensity of the desired adhesions between the two pleural sheets (p=0.05). CONCLUSION: Using anti-inflammatory analgesics following autologous blood pleurodesis may lead to unsuccessful outcome of the procedure.

Fibrous Dysplasia: Clinicopathologic Presentation of 36 Cases.

OBJECTIVE: Fibrous dysplasia is a slowly progressing bone lesion resulting from displacement of the normal medullary bone with abnormal fibroosseous tissue. The aim of this study was to assess the similarities and differences of our cases in relation to published reports. MATERIAL AND METHOD: In this study, the archives of the Uludag University Medical Faculty Department of Pathology were screened for fibrous dysplasia cases between 2004 and 2016. RESULTS: Within the mentioned period, there were 36 cases diagnosed as fibrous dysplasia. There were 21 male, and 15 female cases with an average age of 27.8±14.8 years (range 7-79 years). The most frequently affected sites were femur, costae, and craniofacial bones. There was one case localized to metacarpal bone, a very rare affection site. There were 4 polyostotic cases including 2 cases of McCune-Albright syndrome. Pelvic bone was affected in the polyostotic type, similar to published reports. Unlike former reports, however, long tubular bones were affected in male patients in our series. In our series, 32 cases had classical fibrous dysplasia, 3 cases had fibrocartilaginous, and one case had fibroosseous variants. Four cases localized to costae were accompanied by aneurysmal bone cyst. The presenting symptom was pathological fractures in a total of 4 cases, 3 localized to the femur, and 1 to the costa. Recurrence occurred in 5 cases treated with curettage. Two of the monostotic fibrous dysplasia cases developed malignant transformation into osteosarcoma. CONCLUSION: We conclude that our series of fibrous dysplasia cases have slight differences and mainly similar characteristics with the series reported earlier, when all features are taken into consideration.

Enhancer of zeste homologue 2 (EZH2) expression in synovial sarcomas as a promising indicator of prognosis.

Synovial sarcoma (SS) is a type of soft-tissue sarcoma, often linked to poor survival. Although overexpression of enhancer of zeste homologue 2 (EZH2) has been associated with poor prognosis in different tumors, a few studies investigated this link in SS. Here, we analyzed the relationship between EZH2 expression and prognostic factors in SS. We included 29 patients with SS. Immunostaining of EZH2 was performed with (D2C9) XPTM Rabbit mAb antibody, and the results were classified as low EZH2 expression (negative or weak expression) and high EZH2 expression category (moderate or strong expression). Analysis of survival in relation to prognostic factors was performed with Kaplan-Meier survival curves and Cox proportional hazard regression analysis. Our sample included 19/29 female and 10/29 male patients, with age range 16-63 years. The tumor diameter ranged from 2 to 15 cm. Necrosis was observed in 15/29 cases. Sixteen cases had >10 mitoses per 50 high-power fields (HPFs). Out of 29 cases, 14 showed low and 15 had high EZH2 expression. Statistically significant results were obtained for the association between the presence of metastasis and necrosis (p = 0.042), high EZH2 expression and distant metastasis (p = 0.018), high EZH2 expression and necrosis (p = 0.016), and high EZH2 expression and the tumor size >5 cm versus tumor size ≤5 cm (p = 0.014). Patients with all of the following: the tumor size ≤5 cm, low EZH2 expression, and without necrosis and distant metastasis had significantly longer survival time. Our results are consistent with previous studies, suggesting that EZH2 overexpression is an indicator of poor prognosis in SS.

Effects of hyperbaric oxygen therapy combined with platelet-rich plasma on diabetic wounds: an experimental rat model.

INTRODUCTION: Hyperbaric oxygen and platelet-rich plasma are used in the treatment of diabetic wounds. The aim of this study is to evaluate the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing diabetic wounds. MATERIAL AND METHODS: Thirty-six female Wistar albino rats were used in this study. Diabetes mellitus was induced chemically with an intraperitoneal injection of streptozotocin. The rats were divided into a control group, a hyperbaric oxygen group, a platelet-rich plasma group, and a combined therapy group. Platelet-rich plasma was applied just after the creation of the wound; hyperbaric oxygen treatment was carried out daily over 7 days. Wound healing was evaluated according to four parameters: ulcerations, epidermal thickness, density of dermal collagen fibers, and proliferation of dermal blood vessels. RESULTS: The number of active ulcers in the combined therapy group was fewer than in the control group (p = 0.039), and the wound area was greatest in controls (p < 0.001). The epidermal thickness in platelet-rich plasma and combined therapy groups was non-significantly greater than in the control group (p = 0.097 and p = 0.074, respectively). The amount of fibrous collagen in these two groups was greater than in the control group (p = 0.002). CONCLUSIONS: Combined hyperbaric oxygen and platelet-rich plasma therapy was found to be successful in diabetic wound healing. The combination therapy had no additive effect in terms of angiogenesis and the development of new collagen fibers.

Malignant glomus tumor with oncocytic features: an unusual presentation of dysphagia.

Glomus tumors in the gastrointestinal tract are unusual, as the previous series in the literature have been mainly limited to the stomach. Less than 10 cases of esophageal glomus tumors have been described in the literature. Oncocytic glomus tumors are a recently identified, rare variant of the glomus tumor. We report a 47-year-old female who presented with an approximately 3-month history of dysphagia and weight loss. Upper gastrointestinal endoscopy showed a black-purple, hypervascular, protruding lesion measuring approximately 65 mm at the 37th cm of the esophagus. The patient underwent an Ivor Lewis operation via open thoracotomy. The resected specimen had a protuberant, ulcerated mass measuring 80 × 35 mm in the posterior wall of the esophagus. Based on the histopathological, immunohistochemical and electron microscope findings, the final diagnosis was a malignant glomus tumor with oncocytic features. To our knowledge, this is the first report of a malignant glomus tumor with oncocytic features in an esophageal location.

The effect of HIF stabilizer on distraction osteogenesis.

OBJECTIVE: The aim of this study was to investigate the effect of an orally applicable hypoxia-inducible factor (HIF) stabilizer on distraction osteogenesis (DO) in a rat model. METHODS: The study included 24 Wistar albino rats undergoing osteotomy of the left tibia diaphysis. Rats were divided equally into experiment and control groups. Tibias were fixed using an external fixator. HIF stabilizer was administered to the experiment group. On the 5th postoperative day, distraction with increased rate (0.4 mm twice a day) was commenced and continued for 10 days. Histological and immunohistochemical evaluation was performed. RESULTS: Vascular endothelial growth factor levels of the experiment group were higher than those of the control group (p<0.05). The experiment group had slightly better intramembranous ossification quality than the control group on both Day 16 and 30. Endochondral ossification rates were better in the experiment group on Day 16. CONCLUSION: Vascular endothelial growth factor levels increased and stimulated angiogenesis in the presence of HIF pathway activation by oral administration of HIF stabilizer during DO. The biomechanical features of the distraction and angiogenesis should be coupled to achieve adequate bone homeostasis.