Leiomyomatous hamartoma mainly occurs in the liver, spleen, kidney and lung. It is rarely found in the oral region.

　We report a case of leiomyomatous hamartoma arising in the hard palate of a 6-month-old female infant. Six months after her birth, her parents consulted the obstetrician about a tumor of the hard plate and were referred to our department. Although it had been recognized since her birth, she could suck milk without any problems. The results of medical examination revealed that there was no problem in general condition. The tumor was an elastic soft, and cord-like mass that measured about 15 × 3 mm and was localized in the incisive papilla. The primary clinical diagnosis was a benign tumor of the hard palate. An excisional biopsy was carried out in the outpatient clinic by using local anesthesia. Immunohistochemical analysis showed positive reactions for α-smooth muscle actin (α- SMA) and HHF35, which showed the growth of smooth muscle. A histological diagnosis of leiomyomatous hamartoma was established. Postoperative observation has revealed no recurrence as of 13 years after the operation.

Although eye complications after neck dissection (ND) are rare, such complications may lead to blindness and therefore have a serious impact on the patient’s quality of life. We report a case of anterior ischemic optic neuropathy (AION) that developed after metachronous bilateral RND. The patient was a 55-year-old woman who underwent right RND for cervical lymph node metastases from squamous cell carcinoma of the tongue. Eight months after the first RND on the right side, left cervical lymph node metastases developed, and left RND was consequently performed. On the third day after the second RND, AION developed, and on the ninth day, she lost her vision. Ischemic optic neuropathy after ND is a serious complication to recognize.

Paranasal sinuses and the mandible are the most common sites of metastasis from renal cell carcinoma in the oral and maxillofacial region. Renal cell carcinoma with maxillary gingival metastasis is rare. We report a case of renal cell carcinoma diagnosed after discovery of a maxillary gingival swelling. The patient was a 77-year-old man who presented to our department with swelling of the left maxillary gingiva. An exophytic mass measuring 41 × 31 mm was found in the maxillary gingiva between the left central incisor and the left first premolar. Based on the results of a biopsy and imaging examinations, metastasis of a renal cell carcinoma to the maxillary gingiva was diagnosed. Because an abdominal aortic aneurysm was detected on the computed tomographic scan, coil embolization and stent-graft insertion were performed. Meanwhile, the intraoral tumor rapidly increased in size. A left nephrectomy and maxillary partial resection were performed with the patient under general anesthesia. Renal cell carcinoma with metastasis has a poor prognosis; however, long-term survival of 7 years since the initial surgery was obtained. The patient has metastasis to the left ilium, but recurrence of the primary lesion and the intraoral metastasis has not occurred.

We report a case of sialadenoma papilliferum arising in the left retromolar region. An 81-year-old woman visited our hospital with a chief complaint of an oral mass in the left retromolar region, which was found to be elastic, soft, and papillary on palpation and measured 12 × 7 mm. The tumor was removed with the patient under general anesthesia, and the excised specimen was histologically diagnosed as sialadenoma papilliferum. Laboratory test results showed that squamous cells were immunoreactive for AE1/AE3, EMA, CEA, p40, p63, and Ki-67. Luminal cells within the ductal structures positively stained for CK7, EMA, and S-100, whereas no staining for CEA or α- SMA was noted. Basal cells within the ductal structures were immunoreactive for CK5/6, 7, CAM5.2, p40, and p63, while the reactivity of myoepithelial cells was not specific. The postoperative course of the patient was uneventful, and no recurrence was detected on a follow-up examination performed 2 years 9 months after surgery.

We report a case of metastasizing ameloblastoma arising in the mandible that was treated surgically along with multiple lung metastases. The patient was an 11-year-old girl who presented with paresthesia in the region of the right mandible. She had a history of epilepsy and cataplectic scoliosis. A biopsy was performed under local anesthesia, and the pathological diagnosis was ameloblastoma. Given her young age, to preserve the mandible, we enucleated the tumor under general anesthesia; we repeated the surgery 4 times because of local recurrence.

　Computed tomography performed 3 years 9 months after the biopsy depicted multiple metastases in both lungs and local recurrence in the mandible. Resection of the middle lobe (S4, S5) and S6 of the right lung, partial resection of S6 and S8 of the left lung, and resection of the mandibular tumor and immediate reconstruction with a titanium plate were performed. On the basis of the pathological similarity of the mandible and lung tumors, we diagnosed metastatic ameloblastoma of the mandible. Five years after surgical treatment, there was no evidence of tumor recurrence.

Ameloblastic carcinoma is a rare type of odontogenic tumor. We report a case of peripheral ameloblastic carcinoma occurring in the maxilla. A 73-year-old man was referred to our hospital because of a mass of the right maxillary gingiva. Biopsy yielded a diagnosis of ameloblastic carcinoma, and partial resection of the maxilla was performed. Invasion into the bone was not observed in the excised specimen, and peripheral ameloblastic carcinoma was diagnosed. About one and a half years after the operation, there were no symptoms of recurrence. However, there are cases in which local relapse occurs several years later, and long-term observation is necessary.

We report a suspected case of intestinal Behçet’s disease diagnosed from a refractory oral ulcer. A 78-year-old man was referred to our department because of intractable ulceration of the oral cavity.

　The ulcer was located in the mucosa of the left upper lip and measured 38 × 26 mm. No eye symptoms, skin manifestations, or vulvar ulcers were noted, and incisional biopsy revealed no malignancy. The ulcer finally contracted following 2 months of topical steroid administration; however, a month later, a new ulcer appeared on the right buccal mucosa.

　We referred the patient to the department of gastrointestinal medicine to investigate the association between the intractable ulceration of the oral cavity and gastrointestinal disease. The patient underwent lower gastrointestinal tract endoscopy, which revealed multiple punched-out ulcers in the ileocecal region and large intestine. Accordingly, Crohn’s disease was ruled out; however, intestinal tuberculosis was not ruled out completely. Because the inflammation was mainly composed of neutrophils with no sign of infection on pathological examination, intestinal Behçet’s disease was suspected. Systemic administration of steroids was initiated; the ulcers in the oral cavity and ileocecum disappeared after 3 months. Long-term follow-up is necessary for ulcer recurrence.

Diffuse sclerosing osteomyelitis of the mandible (DSO) is a non-bacterial osteomyelitis that has been considered one of the symptoms of chronic recurrent multifocal osteomyelitis or synovitis, acne, pustulosis, hyperostosis and osteitis syndrome, which are autoinflammatory diseases. DSO is clinically difficult to diagnose, and no clear consensus has been established regarding its management. We herein present a pediatric case of DSO successfully treated by anti-TNF-α therapy.

　A 13-year-old Japanese child was referred to our clinic because of swelling of the right mandibular gingiva. Antibiotics were administered as an initial treatment, but were ineffective. We used hyperbaric oxygen therapy and performed mandibular corticotomy; however, these treatments were also ineffective. Incisional biopsy of the mandible region was performed, revealing DSO. Treatment with a corticosteroid was begun, and clinical symptoms dramatically decreased. However, we could not decrease the corticosteroid dose owing to the recurrence of inflammatory symptoms. Bisphosphonate or disease-modifying antirheumatic drug treatment was also effective but was stopped owing to adverse reactions. Then, the patient was treated with anti-TNF-α antibody. After administration, remarkable improvement of inflammatory findings was confirmed. In addition, no major side effect or complication was encountered, and a complete response has been achieved for 2 years. This case provides a basis for the future appropriate management of DSO using anti-TNF-α antibody in pediatric patients.

The authors report a case of localized amyloidosis arising in the mandible. The patient was a 65-year-old woman who presented at our department with a chief complaint of swelling of the mandibular gingiva. We recognized an elastic hard tumor on the buccal side from the right mandibular second premolar region to the right mandibular canine tooth region, which measured 23 × 12 mm. A diagnosis of amyloidosis was made based on the biopsy results. Further testing done in our Hematology Department did not reveal systemic amyloidosis or multiple myeloma. Excision was done with the patient under general anesthesia, and the histopathologic diagnosis was amyloidosis. Currently, six months after the surgery, the patient is doing well, and there has been no recurrence.

Fracture of the mandibular coronoid process is rare and account for only 1% of all mandibular fractures. The aim of this study was to assess the characteristics of patients with coronoid process fractures. Five cases of fractures of the mandible coronoid process were retrospectively studied from among 193 maxillofacial fractures occurring from 2009 to 2014. Five patients (3 males, 2 females) with 5 coronoid process fractures were admitted. The median age was 59 years. The fractures were mainly the result of stumbles. All patients had concomitant zygomatic fractures. Two patients with trismus were treated by concurrent open reduction and internal fixation of the coronoid processes and zygomatic fractures. The coronoid process was treated conservatively in 3 patients without trismus. Follow-up results showed significant improvement in mouth opening and pain in all patients.

Streptococcal toxic shock-like syndrome (streptococcal TSS) develops suddenly and causes disseminated intravascular coagulation, necrotizing fasciitis, septic shock, and multiple organ failure. The mortality rate of streptococcal TSS is higher than 40%. We report a case of streptococcal TSS that developed from a self-bite to the right buccal mucosa. A 70-year-old man was admitted to our hospital with severe swelling of the buccal region caused by self-biting the right buccal mucosa. On the next day, septic shock developed, followed by multiple organ failure. Streptococcus pyogenes was detected on a blood examination after a 5-day culture, and streptococcal TSS was diagnosed. The patient underwent debridement of the right buccal mucosa, was given antibiotics, and received glucose-insulin therapy and hypertensive chemotherapy in the intensive care unit for 10 days. He achieved complete recovery on day 46 of admission. He returned to his work, and streptococcal TSS has not recurred.

Epithelial myoepithelial carcinoma (EMC) is a relatively rare, low-grade malignant tumor of the salivary gland. We report our experience with the guided nerve regeneration of the lingual nerve using a nerve guide tube (Polyglycolic acid collagen tube: PGA-C tube) after resection of an EMC that developed in the submandibular gland. The patient was a 48-year-old woman who noticed swelling in the left mandibular region. She was given a diagnosis of a tumor of the left submandibular gland on computed tomography and magnetic resonance imaging, and we performed an excisional biopsy of the region including the left submandibular gland. Pathologically, EMC was diagnosed. Accordingly, we performed extended tumor resection, including partial resection of the lingual nerve. Lingual nerve regeneration was performed on the lingual nerve deficit measuring approximately 30 mm using a PGA-C tube. The patient began to recover the tactile perception approximately 3 months postoperatively and the ability to distinguish between sweet and salty tastes approximately 1 year postoperatively. At 2 years postoperatively, she is able to distinguish sour tastes and there has been no local recurrence. Induced nerve regeneration is effective for reconstructing sensory nerves resected during surgery for malignant tumors.

We report a case of myeloid sarcoma that occurred in the gingiva and buccal region and progressed to acute myeloid leukemia. An 82-year-old man was referred to our hospital because to undergo examination of right cheek and submandibular swelling. At presentation, swelling of the gingiva of the right lower molar and a tumor measuring 20 mm in diameter were noted in the right cheek region. We performed an incisional biopsy of the mass in the right buccal region, and the histopathological diagnosis was myeloid sarcoma. Therefore, we referred the patient to the department of hematology in our hospital. Considering the patient’s age, we performed observation without immediate therapeutic intervention. Blast cells appeared in peripheral blood after 6 months, which indicated the development of acute myeloid leukemia. Although we started remission induction therapy with a CAG regimen (cytarabine, aclarubicin, granulocyte colony-stimulating factor), complete remission was not achieved. Leukocytes and blast cells increased in peripheral blood, and the patient died 9 months after starting primary treatment.