We examined the clinical characteristics of 18 cases of malignant lymphomas arising in the oral region which were diagnosed at our department during the 11 years from 2008 to 2018. The patients consisted of 10 males and 8 females whose mean age was 70.2 years. The primary site was the upper gingiva in 10 cases （55.6％）, and the initial symptoms were tumor mass and swelling in 15 cases （83.3％）. Only 7 cases （38.9％） were clinically diagnosed as malignant lymphoma at first visit, but the other 11 cases were difficult to diagnose correctly. The various clinical symptoms such as mass formation and ulcer made differential diagnosis difficult, and a definitive diagnosis could not be obtained by only a single biopsy. Therefore, we examined whether blood test results might be used as an indicator of the diagnosis or not. Our results showed that LDH in 8 of 17 cases （47.1％） and sIL-2R in 11 of 16 cases （68.8％） were high values. Furthermore, we examined whether lymphocyte-monocyte ratio （LMR） helped the diagnosis or not. Thirteen of 17 cases （76.5％） showed a low value of LMR. There was a significant difference in LMR compared to non-malignant lymphoma patients. LMR in the blood tests was also considered to be a useful marker for the diagnosis.

View full abstract

Spindle cell lipoma is a type of lipoma and is characterized by a mixture of fat spindle cells and increased fibrous tissue in adipose tissue. Reports of spindle cell lipoma in the oral region are rare in Japan. We herein report a case of spindle cell lipoma arising in the oral floor in a 69-year-old female. The patient was referred to our hospital with a chief complaint of swelling of the oral floor. T1- and T2-weighted MRI showed a high well-defined 30×25×27mm mass in the sublingual space. The tumor was excised under general anesthesia. The histopathological diagnosis was spindle cell lipoma. No evidence of local recurrence was observed during the three-year follow-up period.

View full abstract

We report a case of lower gingival squamous cell carcinoma of the right mandible, which completely responded to multidisciplinary therapy including nivolumab. The patient was an 86-year-old man. An elastic-hard mass （measuring 90×30mm） in the right mandible with pain and paresthesia of the lower lip were observed at the initial visit. The lesion was histopathologically diagnosed as squamous cell carcinoma by a biopsy, and he was treated with the combination therapy of cetuximab （Cmab） and paclitaxel （PTX） as chemotherapy. The size of the tumor was reduced by the chemotherapy, but we unwillingly applied Cmab therapy because the patient refused salvage surgery. Unfortunately, it was ineffective, and the second combination therapy of Cmab and PTX was unsuccessfully performed. Thereafter, palliative radiotherapy with 30Gy followed by nivolumab therapy was applied. However, interstitial changes in a part of the lung field were observed after performing nivolumab therapy three times, and we decided to discontinue the nivolumab therapy because of the high risk of developing interstitial pneumonia. Surprisingly, however, the mandibular tumor completely responded 4 months later. There has been no evidence of recurrence for 1 year and 8 months after showing complete response.

View full abstract

Epulis refers to a benign localized mass occurring on the gingiva, usually as a result of reactive or chronic inflammation. We report a case of giant epulis osteoplastica involving the right maxillary gingiva. A 42-year-old man was referred to our hospital with swelling of the right maxillary gingiva. He had first noticed the mass 4 months prior to visiting our hospital. The patient had received hemostatic treatment at a local dental clinic several times due to bleeding from the mass. Intraoral examination showed a pedunculated, elastic-hard, well-defined mass on the right maxilla. Computed tomography revealed a mass growing from the right maxillary gingiva, and a bone-like radiopaque image was found inside the lesion. Tumor excision was performed under general anesthesia. The specimen was 70×50×28mm in size, and histopathological examination confirmed epulis osteoplastica. The patient has shown no recurrence during 3 years and 3 months of postoperative follow-up.

View full abstract

Malignant melanoma is a malignant tumor derived from melanocytes, and typically occurs in the skin. Malignant mucosal melanoma rarely arises in the oral cavity, accounting for 0.5％ of all malignant melanomas. Amelanotic malignant melanoma lacking melanin pigment accounts for 2.0％ of malignant mucosal melanomas in the oral region. Here, we describe a patient who exhibited amelanotic malignant melanoma in the maxillary gingiva and palate.
A 64-year-old woman was referred to our department for examination and treatment of a nodular lesion in the right maxillary gingiva in February 2018. At the initial visit, a nodular lesion measuring 60×45mm was observed in the right maxillary gingiva. A biopsy was performed on the lesion, and histopathological evaluation yielded a diagnosis of amelanotic malignant melanoma. On preoperative analysis, the lesion was classified as cT4aN0M0, so we performed right maxillectomy. Postoperative histopathological analyses identified the tissue as an amelanotic malignant melanoma with venous and lymphatic invasion. Therefore, postoperative adjuvant therapy was planned. However, adjuvant therapy could not be performed in this case for economic reasons and because the patient did not consent to further treatment. Metastasis in the small intestine occurred 1 year postoperatively, and the patient died 6 months later.

View full abstract

We present a case of bilateral cervical lymph node metastases in tongue squamous cell carcinoma in which thyroid enlargement originating from chronic thyroiditis extended to the mediastinum. A 54-year-old woman with a mass on the margin of the right tongue was referred to our department. The medical history included mental retardation and chronic thyroiditis. The mass formation with induration and ulcer was located on the margin of the right tongue. Swollen lymph nodes were palpated on both submandibular regions. Several lymph node metastases were detected in the bilateral neck by CT, MRI, and US. The huge thyroid gland ranged from the oropharynx to the mediastinum, and the trachea was retracted to the left side. A clinical diagnosis of squamous cell carcinoma in the right tongue （T2N2cM0） was made, and partial tongue resection and bilateral neck dissection were performed. No postoperative tracheostomy was conducted due to the huge thyroid gland. The patient received postoperative strict respiratory management under sedation and postoperative chemoradiotherapy after extubation. Two years and 10 months after surgery, the patient had no recurrence or metastasis.

View full abstract

Programmed death 1 （PD-1） immune checkpoint inhibitors （ICIs） have demonstrated efficacy for recurrent and/or metastatic squamous cell carcinoma of the head and neck （R/M-SCCHN）. On the other hand, some patients are refractory to these inhibitors; although the efficacy of salvage chemotherapy after ICIs has been shown, there have been few reports on subsequent drug therapy options.
Herein, we present a case of recurrent oral cancer that showed significant efficacy in with multiple use of nivolumab and chemotherapy agents interchangeably. A 76-year-old female was previously treated with the EXTREME regimen （combined with cetuximab, 5-fluorouracil, and cisplatin） for recurrent oral cancer. Since the lesions clinically progressed, nivolumab was applied as second-line treatment. After nivolumab treatment, weekly Paclitaxel was administered as third-line salvage chemotherapy due to tumor progression. Then, nivolumab was administered multiple times with chemotherapy alternately, and a partial response was obtained. After 33 months from the first-line chemotherapy for recurrent oral cancer, the patient chose to receive palliative care owing to the development of a new lesion on the tongue. The patient died as a result of progressive disease one month later.

View full abstract