A case of odontogenic keratocyst in the buccal space: characterization by multimodality imaging including computed tomography, diffusion-weighted magnetic resonance imaging, and ultrasonography.

Odontogenic keratocyst (OKC) is a relatively common non-inflammatory jaw lesion. OKC is known to occur most often in the mandibular angle and mandibular ramus, but rarely outside the bone. In this report, we describe characteristic multimodality imaging of OKC in the buccal space, especially diffusion-weighted MR imaging (DWI) with apparent diffusion coefficient (ADC) mapping, extra-oral and intra-oral ultrasonography. On clinical examination, an approximately 20 mm in diameter mass with elastic hardness was found the left side of the buccal area. Contrast-enhanced CT showed areas of internal non-contrast lesions in the left buccal space. On T1-weighted image, the mass showed multilocular high signal intensity, and homogeneous internal. T2-weighted images revealed high signal at the marginal part and slightly median signal in the internal part. STIR images revealed a heterogeneous high signal in the interior. Furthermore, DWI and ADC map showed high signal and moderate-to-low signal intensity, respectively. ADC value of the lesion was 1.55 × 10-3 mm2 s-1. On extra-oral ultrasonography, the tumor showed clear boundary, hypoechoic, homogeneous internal architecture and vascular signals, and heterogeneous hard of the lesion. On intra-oral ultrasonography also showed clear boundary, hypoechoic, homogeneous internal architecture, heterogeneous hard of the tumor, and back echo enhance. The histopathologic diagnosis based on a full excisional specimen was odontogenic keratocyst. This case suggests that multimodality imaging, especially MR imaging with ADC and DWI, and extra and intra-oral ultrasonography with color Doppler imaging and elastography, could be effective for evaluating buccal lesions.

A case of radicular cyst on deciduous tooth in a 7-year-old child.

Radicular cysts are the most common cystic lesions in the oral cavity, and have a rare occurrence in the primary dentition. We report a case of radicular cyst of mandible in child by multimodal imaging including panoramic radiography, CT, and MR imaging. A 7-year-old girl presented with swelling and without pain, and hypoesthesia on the right side of the mandible. On clinical examination, an expansive lesion with undulation was found to the buccal cortex of the right side of the mandible. Panoramic radiograph showed a unilocular radiolucency with well-defined margin, displaced tooth, and root resorption in the right mandible. Regarding CT imaging, axial soft tissue algorithm CT and bone tissue algorithm CT showed a low-attenuation internal structure and expansion of the buccal cortex of the right side of the mandible. Three-dimensional-CT showed expansion of the buccal cortex of the right side of the mandible. Multiplanar reformation imaging showed displaced tooth, root resorption, and expansion of the buccal cortex of the right side of the mandible. On T1-weighted image, the expansive lesion showed low signal intensity, and T2-weighted and STIR images revealed high signal intensity. A partial biopsy of the mandibular region was performed. Histopathological diagnosis was radicular cyst caused by apical periodontitis with abscess. This case suggests that multimodal imaging, especially CT and MR imaging, could be effective for evaluating mandibular lesions in child.

Characteristic multimodal imaging of palatal follicular lymphoma: a case report on effectiveness of CT, diffusion-weighted MR imaging and intraoral ultrasonography.

Oral lymphomas are relatively uncommon. Follicular lymphoma is the second most common subtype of non-Hodgkin lymphoma. We report characteristic multimodal imaging of palatal follicular lymphoma, especially CT, diffusion-weighted MR imaging (DWI) and intraoral ultrasonography. A 67-year-old woman presented with swelling on the right side of the palate within 2 months. On clinical examination, an approximately 35 × 20 mm mass lesion with elastic soft was found to overlay the right side of the palate. Contrast-enhanced CT image showed a mass with homogeneous enhancement on the right side of the palate, and bone tissue algorithm CT showed focal erosion of the right posterior maxilla. Regarding MR imaging, on T1-weighted image, the mass showed low signal intensity and homogeneous enhancement, and T2-weighted and STIR images revealed intermediate and high signal intensity, respectively. Furthermore, DWI and apparent diffusion coefficient (ADC) map showed high and low signal intensity, respectively. ADC value of the mass was 0.60 × 10-3 mm2s-1. On intraoral ultrasonography, the mass showed clear boundary, hypoechoic echogenicity, homogeneous internal architecture, vascular signals using color Doppler imaging and heterogeneous hard using strain elastography. A partial biopsy of the palatal region was performed. Histopathological diagnosis was follicular lymphoma. This case suggests that multimodal imaging, especially CT, DWI with ADC map and intraoral ultrasonography with color Doppler imaging and strain elastography, could be effective for evaluating palatal lesions.

Medication-related osteonecrosis of the jaw in a patient with multiple myeloma: an unusual case with tumor in the surgical specimen.

Multiple myeloma is characterized by a neoplastic proliferation of plasma cells primarily in the bone marrow. Neoplastic plasma cells stimulated osteoclasts, and destroy bone tissue, causing bone pain, pathological fractures, paralysis due to spinal cord compression, and hypercalcemia. Bisphosphonates are used as supportive therapy in the management of multiple myeloma. Medication-related osteonecrosis of the jaw (MRONJ) is a well-known complication of treatment with bisphosphonates, denosumab, and other drugs, such as anti-angiogenic agents and novel anti-cancer drugs. We report MRONJ in a patient with multiple myeloma, especially an unusual case with tumor in the surgical specimen. A 73-year-old woman presented with pain on the left side of the mandible within 3 months. On clinical examination, an exposed bone without purulent drainage presented on the left side of the mandible. Before 2 years, she received chemotherapy of zoledronate for multiple myeloma at another hospital. Panoramic imaging showed radiopacities of bone in the left side of the mandibular molar area. Multidetector computed tomography (MDCT) with axial, multiplanar reformation (MPR) and three-dimensional (3D) images showed the sequestrum without periosteal reaction. She was diagnosed as MRONJ, and underwent surgery. Finally, the surgical specimen was diagnosed as multiple myeloma in the sequestrum. This case suggests that the evaluation of the surgical specimen of MRONJ could be essential for detection of primary tumor.

Central giant cell lesion of the mandible in a 2-year old girl.

Central giant cell lesions are rare, benign, osteolytic, pseudocystic, solitary, localized lesions that are common in the skeletal structure, but less so in the maxillofacial region. Furthermore, to perform panoramic radiography and cone-beam computed tomography, it is necessary to prepare patients properly and to position their heads carefully. However, this can be difficult in pediatric patients, who may be anxious. In this report, we describe the case of a central giant cell lesion of the mandible in a 2-year-old girl that was evaluated with multidetector computed tomography.