A case of retinoblastoma metastasizing to the mandible and review of literature.

OBJECTIVES: The aim of this case report and review was to determine the characteristics of retinoblastoma. METHODS: One case report was introduced along with previous reports on retinoblastoma metastasizing to the mandible. RESULTS: Sixteen cases from 14 reports were included in this study. Including the present case, 11 of 16 patients died within 8 months. DISCUSSION: Retinoblastoma rarely metastasizes to the mandible. However, metastasis to other organs should be considered, and specialists should be consulted if retinoblastoma metastasis to the mandible is observed. Moreover, it is necessary to follow up patients after multidisciplinary therapy is completed, because subsequent complications of the teeth and jawbones associated with therapy could occur.

Keratocystic odontogenic tumor arising at the mandibular ramus with an impacted tooth: a case report and mimic lesions.

OBJECTIVES: To consider the biologic behaviors of keratocystic odontogenic tumors (KCOTs) and ameloblastomas and dentigerous cysts. METHODS: A 63-year-old Japanese man presented with swelling and discomfort in the left cheek during jaw movement. Examination revealed a multilocular lesion within the mandible extending from the left second premolar to the left mandibular ramus and coronoid process; the lesion contained a deviated impacted tooth. The tumor had expanded beyond the bone and was invading the masseter and medial pterygoid muscles. Marginal mandibulectomy with a free iliac bone graft was performed. RESULTS: No recurrence was observed during a 7-year follow-up. DISCUSSION: The histopathological diagnosis of the lesion showed it was a KCOT. These tumors usually grow within the bone, causing bone expansion. However, this tumor had expanded beyond the bone and invaded surrounding muscles. Thus, KCOTs can, in rare cases, manifest themselves as described here. Evaluating preoperative images and histopathological findings is important to determine the optimal treatment strategy.

Rapid growing myofibroma of the gingiva: report of a case and review of the literature.

PURPOSE: Myofibroma is a rare benign tumor of myofibroblasts that rarely exhibits rapid enlargement and is misinterpreted as a malignant lesion. The aim of this study was to investigate its growth potential and to evaluate the usefulness of preoperative immunohistochemical study for an accurate diagnosis. MATERIALS AND METHODS: A case of rapidly growing myofibroma of the lower gingiva was analyzed using 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography fused with computed tomography (PET/CT) and immunohistochemical study of Ki-67 and p53. The English-language literature from 1981 to 2012 also was reviewed. RESULTS: An 18F-FDG PET/CT image displayed a high accumulation (maximum standardized uptake value, 14.1) in the lesion. A biopsy specimen showed mitotic activity of spindle-shaped cells, but atypia was not present. The MIB-1 labeling index was 10%, and the p53 test result was negative. The preoperative diagnosis of benign tumor of smooth muscle origin was made from the histopathologic and immunohistochemical features. In a review of 94 cases, tumors involved the mandible (33%), gingiva (23%), tongue (15%), cheek or buccal mucosa (12%), palate (8%), lip (4%), and other areas (5%). Nine cases (9.6%) were described as rapidly enlarging, and 8 cases (8.5%) were suspected of malignancy at initial diagnosis. The preoperative biopsy with immunohistochemical study established an accurate diagnosis in 83% of myofibromas, and no recurrences were reported in these patients. CONCLUSIONS: Careful diagnosis is necessary because these lesions sometimes present clinical and radiologic features that resemble those of malignant tumors. Preoperative immunohistochemical analysis should be performed to avoid misdiagnosis or unnecessary aggressive therapy.

Oral liposarcoma in elderly: Case report and literature analysis.

RATIONALE: Oral liposarcoma is an extremely rare lesion that is often clinically misdiagnosed as a benign lesion because of its asymptomatic and indolent clinical course. we report a case of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) of buccal mucosa, provisionally diagnosed as lipoma. PATIENT CONCERNS: A 97-year-old female was referred to dentistry and oral surgery department with an asymptomatic mass on the right buccal mucosa which had been present for an unknown period of time. DIAGNOSIS: Magnetic resonance imaging demonstrated a well-circumscribed lesion at the right buccal mucosa, and a lipoma was suspected. INTERVENTIONS: Surgical removal was performed, and a diagnosis of ALT/WDL was made. She and her family refused additional treatment due to her age. OUTCOMES: At the 10 months follow-up, the patient remained free of disease. LESSONS: The indolent clinical course and small size of oral liposarcoma can lead to provisional clinical diagnosis of benign lesion.

Comparison of diagnostic accuracy between [18F]FDG PET/MRI and contrast-enhanced MRI in T staging for oral tongue cancer.

OBJECTIVE: Integrated PET/MRI with [18F]FDG is advantageous in that it enables simultaneous PET and MR imaging with higher soft-tissue contrast, multiplanar image acquisition, and functional imaging capability without using fat suppression and gadolinium-based contrast agents (GBCAs). The aims of this study were to demonstrate the feasibility of [18F]FDG PET/MRI for assessing the extent of the primary tumor (T) in oral tongue cancer (OTC) based on the 8th edition of American Joint Committee on Cancer (AJCC) cancer staging system, and to compare the diagnostic accuracy between [18F]FDG PET/MRI and contrast-enhanced MRI (ceMRI). METHODS: 18 patients with biopsy-proven operable OTC underwent preoperative regional [18F]FDG PET/MRI and ceMRI within 2 weeks. For [18F]FDG PET/MRI, rainbow-colored PET images were overlaid on the corresponding MR images. Tumor size and the depth of invasion (DOI) were visually measured on [18F]FDG PET/MRI and ceMRI. The size, DOI, and clinical T stage were evaluated using the final surgical pathology as the reference. RESULTS: Of the 18 OTCs, one was not detected by ceMRI due to metal artifacts from an artificial denture, and another due to superficial type (pathological DOI = 0 mm). Tumor sizes measured by ceMRI and [18F]FDG PET/MRI had significant positive correlations with the pathological size (r = 0.80 and r = 0.90, respectively), and DOIs measured by ceMRI and [18F]FDG PET/MRI had significant positive correlations with the pathological DOI (r = 0.74 and r = 0.64, respectively). The means ± SD of size (mm) were 20.4 ± 9.1, 22.9 ± 10.9, and 26.2 ± 10.0, and those of DOI (mm) were 7.1 ± 2.5, 6.9 ± 2.2, and 5.8 ± 3.2 for ceMRI, [18F]FDG PET/MRI, and pathology, respectively. A significant difference was observed in tumor size between ceMRI and pathology (p < 0.05), whereas no significant differences were observed between any other sizes, DOIs, or T stages. The accuracy for T status was 72% (13/18 including 2 undetectable cases) for ceMRI and 89% (16/18) for [18F]FDG PET/MRI. CONCLUSIONS: Although shallow DOIs are often overestimated, regional [18F]FDG PET/MRI without fat suppression and gadolinium enhancement is comparable to and may be substituted for ceMRI in preoperative T staging for OTC patients, reducing metal artifacts and avoiding the adverse effects of GBCAs.

Ossifying fibroma in the mandibular angle mimicking metastatic clear cell renal cell carcinoma: A case report.

RATIONALE: Ossifying fibroma is benign fibro-osseous neoplasm. The authors report a case of ossifying fibroma in the mandibular angle suspected as metastasis of clear cell renal cell carcinoma. PATIENT CONCERNS: A 74-year-old man presented to the primary hospital complaining of frequent urination. A tumor in the left kidney was detected via an abdominal computed tomography scan. The patient then visited the Department of Urology at our hospital. DIAGNOSES: According to whole-body imaging examinations, the patient was suspected of having renal cancer with mandibular metastasis. Also, a cystic lesion of the maxilla was revealed. INTERVENTIONS: Left nephrectomy was performed by urologists, and the patient was diagnosed with clear cell renal cell carcinoma of the left kidney. Approximately 1 month later, resection with a safety margin of the mandibular lesion and removal of the maxillary lesion were performed by oral and maxillofacial surgeons. OUTCOMES: The patient was diagnosed with ossifying fibroma of the mandible and an odontogenic keratocyst of the maxilla via a histopathological examination. Eighteen months have passed since the operation without clinical and imaging findings associated with recurrence. LESSONS: Ossifying fibroma in the mandibular angle of elderly patients is extremely rare. Surgeons should consider the possibility of metastasis when osteolytic lesions of the jaw are found in patients with cancer.

Osseous choristoma of the tongue: A case report with dermoscopic study.

Osseous choristomas are rare benign lesions characterized by ectopic bone formation in the soft tissue of the head and neck region. Dermoscopy visualizes the morphological characteristics that are not observable by the naked eye, and may be used for the evaluation of calcification under the skin. The present study reports a case of an osseous choristoma arising in the tongue, and reveals the dermoscopic features of osseous choristoma from a surgical specimen. A 7-year-old boy was referred to the Department of Dentistry and Oral Surgery, with an asymptomatic pedunculated mass in the tongue. The lesion was removed completely with the adjacent normal tissue under general anesthesia. Dermoscopy of the surgical specimen revealed the hypovascular and homogeneous pattern of the lesion with round extruded whitish material. Based on dermoscopic findings, the presence of calcified hard tissue in the submucosa was verified by the dermatologist. Radiographic examination of the surgical specimen revealed the lesion contained a radiopaque trabeculated mass. Histologically, the lesion contained an osseous tissue, and the pathological diagnosis of osseous choristoma was made following consideration of the ectopic bony tissues that were localized away from the maxillo-mandibular bone. The postoperative course was uneventful with no signs of recurrence during the 36 months following surgery. To the best of the author's knowledge, this is the first report of evaluation of osseous choristoma using dermoscopy. The observation indicates the usefulness of dermoscopy for the diagnosis of oral ossified lesion in oral soft tissue.

Mandibular metastasis as the first clinical indication of occult lung adenocarcinoma with multiple metastases: A case report.

RATIONALE: Although metastases to the oral and maxillofacial region (OMR) are rare, the lung is the most common primary site metastasizing to the OMR. PATIENT CONCERNS: An 83-year-old woman presented with reports of trismus, occlusal discomfort, swelling, and spontaneous pain in the right buccal region. Despite the absence of abnormal chest imaging findings, immunohistochemical analysis of biopsy specimens of the mandible and the thyroid indicated that the patient had multiple metastases from a lung poorly differentiated adenocarcinoma. DIAGNOSES: Metastases to the OMR and the thyroid from an undiscovered lung adenocarcinoma. INTERVENTIONS: Gefitinib was started as first-line chemotherapy, and zoledronic acid was administered for bone metastases. OUTCOMES: Follow-up imaging examinations showed ossification and deformation of the right mandibular ramus and the condylar process. Although 2 years have passed since the first visit to our hospital, lung lesions have not been confirmed by imaging examinations. LESSONS: Clinicians should consider the possibility that symptoms in the OMR may be the first clinical sign of an undiscovered distant primary tumor, and the primary tumors may not be detected by imaging examinations even when metastases to the OMR are revealed.

Denosumab-related osteonecrosis of the jaw in a patient with bone metastases of prostate cancer: A case report and literature review.

Denosumab, a human monoclonal antibody directed against the receptor activator of nuclear factor-κß ligand (RANKL), is used for the treatment of patients with metastatic cancer of the bone or osteoporosis. Recent reports have demonstrated that denosumab can induce osteonecrosis of the jaw (ONJ), but reported cases of this are uncommon. The present study reports the case of an 86-year-old male with prostate cancer patient exhibiting bone metastases who developed ONJ whilst receiving denosumab. To elucidate the influence of denosumab on the development of ONJ, the present study also reviewed the literature, including clinical trials and case reports. In the clinical trials, the prevalence of denosumab-related ONJ was higher in patients with cancer compared with those with osteoporosis. The high risk of ONJ in patients with cancer was thought to be associated with the differing dose and frequency of denosumab administration. The prevalence of ONJ was not significantly different between patients receiving denosumab and bisphoshonate (BP). In the reported cases, denosumab-related ONJ had a similar clinical presentation to BP-related ONJ. There was also a tendency for denosumab-related ONJ to develop in the mandible of elderly patients. Previous invasive dental treatment was a commonly shared characteristic of patients with denosumab-related ONJ. A complex medical history was also suspected to affect the prevalence. No clear association between the dose or duration of denosumab treatment and the development of ONJ was observed. Although conservative treatments are given for denosumab-related ONJ, non-improving cases were managed surgically with primarily positive results. Because denosumab may offer superior results compared with BP for the treatment of metastatic cancer of the bone or osteoporosis, the use of denosumab is expected to increase in the near future. Clinicians should also be aware of the risk factors for denosumab-related ONJ, in order to aid in its diagnosis. In addition, patients treated with denosumab should receive prophylactic treatment to maintain their oral health prior to, during and after denosumab treatment.