Chiho Hiraga

Background: Septic pulmonary embolism (SPE) is a rare complication of infection. Odontogenic sources are uncommon and easily overlooked, especially when typical symptoms are absent. Case Presentation: A 43‐year‐old man with poorly controlled diabetes presented with mandibular swelling and trismus without fever or respiratory symptoms. CT revealed a masticator space abscess and multiple peripheral cavitary pulmonary nodules consistent with SPE. Blood cultures were negative, but abscess culture identified Streptococcus constellatus and Parvimonas micra . Surgical drainage and intravenous antibiotics achieved full recovery. Conclusion: SPE can arise from odontogenic infection even without classic symptoms, requiring early imaging and multidisciplinary care.

Solitary plasmacytoma (SP) of the bone is a localized neoplasm of plasma cells that can involve the jaw. Epstein-Barr virus (EBV)-positive SP has been documented in immunocompetent individuals; however, its clinicopathological features and prognostic implications remain to be fully clarified. We report a case of EBV-positive SP of the maxilla in a 74-year-old partially edentulous man who presented with swelling in the left posterior maxilla. The lesion measured approximately 30 mm and was covered by intact mucosa. Histopathological examination and systemic evaluation confirmed EBV-positive SP localized to the maxilla. The patient initially received radiotherapy without effect. Subsequently, chemotherapy with ixazomib, lenalidomide, and dexamethasone was administered, resulting in a complete response. No local recurrence was observed after 2 years and 6 months of follow-up. This case highlights the potential for chemotherapy in managing radiotherapy-resistant EBV-positive SP. Further studies are warranted to better understand the pathogenesis and treatment strategies for this rare condition.

Background: Hyalinizing clear cell carcinoma (HCCC) is a rare, typically low‐grade malignant salivary gland tumor. We present a case of HCCC with multiple metastasis. Case Presentation: The patient was a 34‐year‐old woman with a tumor at the base of tongue. HCCC was diagnosed by FISH analysis for EWSR1‐ATF1 rearrangement after surgery. Systematic metastasis was identified at a three‐year follow‐up. Signs of Rouviere lymph metastasis and distant metastases (i.e., pleura, mediastinum, and gluteus maximus) were identified. The patient died because her condition deteriorated with multiple metastases. Conclusion: The potential for aggressive HCCC should be considered while offering treatment.

Background: Foreign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenic damage.Case Presentation: We describe a case of foreign body removal using a three‐dimensional reconstruction (3D) simulation application (ProPlan CMF™) involving a case of a 26‐year‐old male. The broken bur had been accidentally inserted when a lower wisdom tooth was extracted at a general dental office. The removal surgery was performed under preoperative simulation without complications (e.g., excessive bleeding and nerve paralysis).Conclusion: This case illustrates surgical techniques to safely remove foreign bodies in the mandible.

Background: Collision cancer consists of two histologically distinct and topographically independent tumors in the same lesion and is extremely rare in the oral mucosa.Case Presentation: We describe a case of oral collision cancer consisting of squamous cell and adenoid cystic carcinomas in the buccal mucosa of a 76‐year‐old man. Accurate diagnosis of resected specimens is histopathologically important in follow‐up as it can significantly affect treatment planning and prognosis.Conclusion: This case illustrates the importance of considering oral collision cancer comprising two cancerous components.