The prognosis for patients with oral squamous cell carcinoma with extranodal extension (ENE) of cervical lymph nodes is poor. Postoperative high-dose cisplatin plus radiation is recommended for patients with ENE, although some reports suggest that postoperative therapy does not necessarily improve survival. The diagnostic criteria for ENE have not been established, and it is necessary to clarify the criteria when discussing treatment and prognosis. In this study, we investigated the efficacy of postoperative treatment by dividing ENE into two types: ENE-mi, which is an invasion of 2 mm or less outside the capsule, and ENE-ma, which is an invasion of more than 2 mm. Of 476 patients who underwent surgery for oral squamous cell carcinoma, 92 patients who underwent neck dissection as the initial treatment and had histologically-confirmed metastasis were included in the study. Of these, 39 had ENE (10 ENE-mi, and 29 ENE-ma). ENE (+) cases had significantly worse prognoses than ENE (-) cases. Furthermore, among ENE cases, ENE-ma cases had significantly worse prognoses than ENE-mi cases. In ENE (+) cases overall, postoperative treatment did not improve survival, but in ENE-ma cases, postoperative treatment significantly improved survival. Although this was a pilot study of a small number of patients, the results suggest that postoperative treatment may improve the survival rate of ENE-ma patients.

The AJCC/UICC TNM staging system was revised to the 8th edition. In this study, we analyzed the prognosis and risk of occult nodal metastasis in patients with tongue cancer to validate the usefulness of the 8th edition TNM classification. Ninety-two patients with tongue cancer diagnosed as T1-T2N0M0 according to the 7th edition of the TNM classification were evaluated for clinicopathological findings, overall survival, diseasespecific survival, and occult lymph node metastasis. The 5-year overall and disease-specific survival rates for all patients were 79.4% and 91.0% respectively. When reclassified based on the 8th edition T classification, 13 T1 patients were reclassified to T2 and 6 T2 patients were reclassified to T3. Multivariate analysis revealed that differentiation, local recurrence, and occult cervical lymph node metastasis were factors associated with overall survival. Of these, occult cervical lymph node metastasis was significantly associated with depth of invasion and tumor budding in a multivariate analysis. The 8th edition T classification considering the degree of depth was considered useful. These results suggest that the poor prognostic factors for early-stage tongue cancer are primary recurrence and occult neck metastasis, and that the 8th T classification reflecting the degree of depth is useful for predicting occult neck metastasis.

We report a case of inverted ductal papilloma (IDP) and mucous cyst on the lower lip. A 39-year-old man was referred to our department in August 2017 for a persistent mass on the lower lip after biting it by mistake in June. The mass was temporarily reduced at the hospital, but it began to re-swell in March 2019. We noted a hemisphere-shaped soft-elastic mass with a diameter of 10 mm in the middle of the lower lip mucosa. The mass showed a low signal on T1-enhanced contrast magnetic resonance imaging, and a mildly high signal on T2-enhanced imaging. Ultrasound revealed that the mass was internally anechoic. A clinical diagnosis of soft-tissue cyst was made, and removal of the mass was performed. The cysts were filled with a milky fluid and were adherent to the surrounding tissue. Histopathologically the ductal epithelium had proliferated, inverting into the papillary. We observed granulation tissue surrounded by a mucous cyst. A histopathological diagnosis of IDP and mucous cyst was made. No recurrence was noted one year after surgical removal of the mass.

Cement-osseous dysplasia is a disease of localized fibrotic connective tissue proliferation accompanying cementum or bone-like hard tissue at the tooth apex, while simple bone cyst is a specific disease featuring a bone cavity without epithelial lining. Here, we report a case of cement-osseous dysplasia associated with multiple simple bone cysts resembling bone cavities. A 60-year-old woman was referred to our hospital due to a complaint of recurring pain and swelling at her right mandibular molars over several years. Her dentist had found abnormalities in X-ray imaging. X-ray images showed a crescent shaped radio-opacity at the apex of the mandibular right first and second premolars, and also radiolucent areas in the right second molar mandible body, and the mandibular left second premolar and maxillary left canine apexes. Enucleation of the cement-osseous dysplasia and cystectomy were planned under a clinical diagnosis of cement-osseous dysplasia and residual and radicular cysts. However, the cystic lesions were revealed to be hollow, with no lining epithelium and only slight granulation-like tissue on the bone wall, except for hard tissue at the right mandibular premolars. The histopathological diagnosis was cement-osseous dysplasia. There has been no recurrence in the seven years since surgery and the patient has been doing well.

Stevens-Johnson syndrome (SJS) is a severe drug eruption that presents with fever, along with erythema, blisters, and erosion on the skin, oral cavity, eye conjunctiva and vulvar mucosa. Here we report a case of SJS without skin lesions in an 81-year-old man who underwent a tooth extraction at our department due to periodontitis. He developed a fever and swelling of the eyelids and lips during the night and visited our department because the symptoms had worsened. Upon examination, hyperemia of the bulbar conjunctiva and erosion in the oral cavity were observed, but no skin lesions were found. SJS was suspected by the dermatologist, and steroid therapy was started during hospitalization. Histopathological findings from a biopsy of the lip mucosa revealed necrotic changes in the epidermis, leading to a definitive diagnosis of SJS without skin lesions. A drug-induced lymphocyte stimulation test (DLST) was positive for acetaminophen, identifying the causative drug. When oral mucosal erosion with fever and eye symptoms such as and bulbar conjunctivitis is observed after the prescription of antibacterial drugs and antipyretic analgesics, drug-induced SJS should be suspected, even in the absence of skin symptoms, and a specialist should be consulted early. Furthermore, a biopsy analysis of the oral mucosa should be performed.

We report a case of Virchow (node) metastasis of cervical cancer concurrently with mandibular gingival cancer. A 58-year-old woman was referred to our department complaining of inflammation and pain in her right mandibular gingiva. A histopathological diagnosis of mandibular gingival squamous cell carcinoma (SCC) was obtained by biopsy. FDG-PET/CT showed significant accumulation in the cervix and left supraclavicular lymph node, suggesting the possibility of cervical malignancy. No cervical malignancy was found by a gynecological examination, so we performed marginal mandibulectomy and resected the lymph node. Histopathological examination of the lymph node revealed metastasis of the SCC. Postoperative gynecological examination also found no cervical cancer. However, we couldn’t exclude the possibility of distant metastasis of cervical cancer, so we performed postoperative chemotherapy with docetaxel, cisplatin and 5 -fluorouracil based on the gynecologist’s recommendation. The cervical cancer was confirmed six months after the chemotherapy. As immunohistochemical analysis revealed positive staining for p16 in the cervical cancer and metastatic lymph node but not in the oral cancer, we diagnosed the metastasis as Virchow metastasis of cervical cancer. The patient subsequently underwent chemoradiotherapy for the treatment of cervical cancer. As of eight years and nine months from the first visit, there has been no recurrence of oral or cervical cancer.

Tenosynovial giant cell tumor (TSGCT) is a benign tumor that mainly affects the joints of the fingers and knees, and is considered to be extremely rare in the temporomandibular joint. In this report, we describe a case of localized TSGCT in the temporomandibular joint. The patient, a 48-year-old male, had been suffering from pain in the right temporomandibular joint and right ear for several years, and had been treated by a general practitioner based on a diagnosis of temporomandibular joint arthrosis. CT images showed a soft tissue shadow in the posterior portion of the right mandibular head, but there was no evidence of destruction of the surrounding tissue or mandibular head resorption. MR images showed a nodular lesion between the right-side mandibular head and external auditory canal with low-signal area on T1-weighted and T2-weighted images. Two years after the first admission, the patient underwent enucleation of the tumor, and a diagnosis of TSGCT was obtained by histopathological examination. Two years have passed since the surgery.

　The aperture has remained at 40 mm, with no evidence of recurrence.

Schwannoma is a benign tumor developing from the Schwann’s sheath of peripheral nerves, constituted of Schwann cells and collagen fibrous matrix. The frequency of occurrence in the oral region is high in the tongue, while rare in the masseter muscle. Here, we report a case of schwannoma in the left masseter muscle. The patient was a 64-year-old man with indolent swelling of the left cheek, measuring 50×45 mm. Magnetic resonance imaging showed a 44 mm tumor with a clear margin. T1-weighted imaging showed a homogeneous signal similar to muscle, while T2-weighted imaging showed an internal non-homogeneous, low signal at the center. The tumor was removed from outside the mouth under general anesthesia. Motor nerve paralysis of the lower lip appeared after surgery but disappeared in two months. The tumor was covered with a capsule, and there was no adhesion with the surrounding tissue. Neural tissue was not found near the tumor. The histopathological diagnosis was schwannoma. Recurrence has not been observed in the 5 years and 11 months after surgery.

Venous malformation may occur in any tissue or organ, including the muscle. Although common in the masseter muscle, which is located in the head and neck region, intramuscular venous malformation rarely develops in the digastric muscle. We report a case of intramuscular venous malformation in the digastric muscle of a 13-year-old male patient who was referred to our hospital after complaining of a mass under the mentum. Upon investigation, a painless soft-elastic mass, 15 mm in diameter, was noted under the right mentum. Ultrasonography revealed an internal echo-heterogeneous mass in the oral side of the anterior belly of the right digastric muscle, with blood flow observed within the same lesion. Magnetic resonance imaging revealed a heterogeneous tumor-like-lesion in the right digastric muscle in T2-weighted short-tau inversion recovery images. Salivary gland disease was initially suspected; however, venous malformation was subsequently considered based on the imaging findings. We performed a surgical resection with a safety margin. Histopathological examination revealed a cluster of thin-walled vessels of irregular sizes within the skeletal muscle layer. Immunohistochemically, vascular endothelial cells did not show neoplastic growth.Based on our findings, the lesion was diagnosed as an intramuscular venous malformation in the digastric muscle. There was no recurrence during the 21-month follow-up term.

We report a case of childhood Sjögren’s syndrome (CSS) in a 13-year-old girl, diagnosed due to bilateral plunging ranula. Sjögren’s syndrome (SS) is an autoimmune disease in which various autoantibodies appear, mainly in sialadenitis and dacryoadenitis. Plunging ranula is a salivary gland disease often encountered in daily clinical work. It is considered to be one of the clinical symptoms of SS, but this is not widely known. MRI scans showed fluid retention in the bottom of the mouth on both sides, suggesting bilateral plunging ranula. Laboratory examination showed positivity for anti-Ro/SS-A antibody, anti-La/SS-B antibody, immunoglobulin G (IgG), rheumatoid factor (RF) and antinuclear antibody, indicating CSS. Fenestration of the plunging ranula and a lip biopsy were performed, and histopathological examination of the minor salivary gland revealed chronic inflammation; hence, a diagnosis of CSS was made. Examination in the rheumatology department showed no extraglandular symptoms, and the treatment policy was to conduct follow up. A favorable outcome was achieved, with no evidence of recurrence two years postoperatively.