: We report a case of cytomegalovirus infection of the maxilla in a patient with malignant lymphoma. A 71-year-old woman who had received chemotherapy for malignant lymphoma for 12 years visited a local dentist because of pain in the right anterior maxilla, and apical periodontitis was diagnosed. Although she received root canal therapy and oral antimicrobial agents, her symptoms worsened, and she visited our hospital. She had a fever of 37.4℃ and swelling, redness, and spontaneous pain of the maxillary mucosa. Initial blood tests showed a leukocyte count of 2,100/mm 3 and a C-reactive protein level of 34.8 mg/dL, indicating an acute inflammatory response. She was admitted and received antimicrobial agents, granulocyte colony-stimulating factor, and γ-globulin. However, necrosis of the gingiva and alveolar bone of the right anterior maxilla progressed day by day. Although a biopsy was performed on the suspected recurrence of malignant lymphoma, no malignant cells were identified. As the patient’s condition improved, her symptoms subsided. However, since reinfection occurred later at the same site, curettage was performed. Histopathological examination of the curetted tissue established a diagnosis of cytomegalovirus infection. Subsequently, with the improvement of general condition, the oral symptoms also subsided.

Methotrexate (MTX) has been widely used to treat rheumatoid arthritis (RA). MTX-associated lymphoproliferative disorder (MTX-LPD) refers to lymphoid proliferation or lymphoma developing in an immunosuppressed patient who has received MTX. We report a case of MTX-LPD with gingival ulceration and jaw necrosis in a 70-year-old man who had received MTX for approximately 6 months to treat RA. The lesions were localized extranodally in the right side of the maxilla and both sides of the mandible. Biopsy specimens showed a lymphoplasmacytic infiltrate resembling diffuse large B-cell lymphoma. Immunohistochemically, Epstein-Barr virus was indentified. After withdrawal of MTX, the MTX-LPD spontaneously resolved within 4 weeks. Furthermore, some necrotic bone was naturally removed, and the exposed bone was covered by normal mucous membrane macroscopically. To date, there has been no evidence of disease recurrence.

TS-1は5FUのプロドラッグであるFTに，DPD阻害剤であるCDHPと胃腸毒性を軽減するOxoを配合した新しいフルオロウラシル系経口抗腫瘍剤でこれらの機能によって口腔癌にたいして安全且つ強力な抗腫瘍効果がある。TS-1は癌に対して放射線増感作用がある。われわれは術前TS-1と放射線同時併用療法をおこなった慢性腎不全によって人工透析を受けている患者における進行上顎歯肉癌の症例を報告する。患者は62歳男性で左側後方頬溝の周囲に40×25mm大の腫瘍が存在し,翼口蓋窩に浸潤していた（T4N1M0，Stage IVA）。CDHPが主に腎から排泄されるので腎機能が低下した患者にTS-1を投与すると，より高濃度の血中5FU濃度が維持され，毒性が増強する。本例ではTS-1投与時の5FU濃度の治療薬物血中濃度モニタリング（TDM）を行うことにより，透析を受けている慢性腎不全患者の上顎歯肉癌の治療にとって適したTS-1の投与量を推定し治療投与を行った。このプロトコールにおいて透析直後にTS-1を25mg×1回/日を隔日15回投与した。また放射線治療40Gyを併用した。骨髄抑制などの重篤な副作用なく安全に治療は行われ，PRの治療効果を得た。術前化学放射線同時併用療法が奏功したので根治的切除が可能であった。また切除標本の頭頸部癌取り扱い規約による組織学的効果判定はgrade IIであった。維持透析患者の上顎歯肉癌に対して血中薬物動態評価によるTS-1と放射線治療の併用は安全で有効な治療方法であった。

: External dental fistula originating from the maxilla mainly occurs at the alar base in the anterior tooth region and at the buccal region in the posterior tooth region. We describe a patient with a fistula at the nasal vestibule. The patient was a 50-year-old woman who had tenderness and swelling from the right nasal vestibule to the alar base. A dome-shaped nodular erythema of 3 mm in diameter was found at the nasal vestibule. The probe was guided toward the apex of the upper lateral incisor. A CT scan showed periapical trabecular bone loss at the upper lateral incisor, uniform radiolucency, and thinning of cortical bone on the labial aspect with partial loss of continuity. The lesion was adjacent to the nasal cavity floor. Surgery was performed for a diagnosis of radicular granuloma at the upper lateral incisor and external fistulation at the nasal vestibule. Below the piriform aperture, a white fibrous restiform structure 3 mm in diameter and 10 mm long extended from the apical lesion to the nasal vestibule. The suppurative inflammation at the apical lesion was blocked by the muscularis depressor septi and the muscularis nasalis but extended upward, resulting in a fistulation at the nasal vestibule.

We report the case of a salivary duct carcinoma thought to have arisen from a benign tumor of the submandibular gland. The patient was a 72-year-old man. He had a hard, elastic, painless mass measuring 30 ×20mm in the right submandibular region. CT and MRI revealed that the mass spread to the adjacent tissues with a rough margin and ipsilateral cervical lymph node metastases. He underwent excision of the right submandibular gland tumor combined with a radical neck dissection. On histological examination of the surgical specimens, malignant components were observed around hyalinized tissues, which were thought to be remnants of a benign tumor. On the basis of these histological findings, the tumor was diagnosed to be a salivary duct carcinoma, which was highly suspected to have undergone transformation from a benign tumor. The neck specimens had 17 histologically positive nodes, including 12 nodes showing extracapsular spread of tumor. He received postoperative chemoradiotherapy, but local failure with distant metastases developed, and the patient died 10 months after operation.

We report a rare case of brain abscess secondary to mandibular odontogenic infection. A 50-year-oldman developed an abscess of the infratemporal fossa, masticatory myositis, and temporal myositis caused bylower first molar marginal periodontitis. Incision and drainage were performed by an intraoral approach, andantibiotics were administered intravenously. On the 8th disease day, vomiting occurred, but responded to anantiemetic drug. On the 9th disease day, extraction of lower first molar and adrasion was performed, resulting inthe alleviation of local symptoms. However, a persistent headache occurred, CT and MRI scans revealed a brainabscess and subdural abscess in the temporal lobe, immediately above the skull internal base. The patient wasgiven a diagnosis of brain abscess caused by odontogenic infection. The abscess almost disappeared after conservativetherapy administered at the department of brain surgery, and no sequelae were noted. The abscess apparentlyexpanded directly and continuously from the skull base through the foramen ovale and foramen spinosum.This case emphasizes the need to diagnose brain abscess and subdural abscess as complications of odontogenicinfection.

We report a case of pleomorphic adenoma of the palate associated with squamous cell carcinoma of the superficial mucosa.The patient was a 50-year-old man. On presentation, a 17×20-mm, painless, elastic hard tumor with a clear border was seen on the right side of the palate, accompanied by an ulcer measuring 3-mm in diameter. To avoid effects on diagnosis, biopsy was done avoiding the ulcer with inflammatory reaction. A pleomorphic adenoma was diagnosed. The tumor was excised under the diagnosis of a benign tumor. The pathological diagnosis was a pleomorphic adenoma. However, squamous cell carcinoma was confirmed in the oral mucosal epithelium covering the tumor. These two tumors were not connected.

We report a case of pleomorphic adenoma in the retromolar region. The lesion was initiallydiagnosed as a malignant neoplasm on the basis of clinical features and biopsy findings.The patient was a 70-year-old man whose chief complaint was swelling of the left retromolar region.Examination at presentation revealed a tumor measuring 25×15mm accompanied by an ulcer.The lesion was identified as squamous cell carcinoma on examination of a biopsy specimen at another hospital. However, a biopsy done before surgery revealed mucoepidermoid carcinoma.With the patient under general anesthesia, the tumor was resected with the submaxillary lymph nodes.The final histopathological diagnosis was pleomorphic adenoma.The tumor apparently originated from the molar glands.