Amyloidosis is a rare disease characterized by the deposition of an insoluble fibrillar protein in various organs and classified into two categories: systemic and localized. In the oral and maxillofacial region, the occurrence sites of localized amyloidosis are the buccal mucosa, sublingual gland, lip, palate and tongue. We report a case of localized nodular amyloidosis in the sublingual gland and submucosa of the mouth floor. A 72-year-old woman presented a nodular mass in the left side of the floor of her mouth and was referred to our hospital for further examination and treatment. Intraoral examination showed an elastic-hard, well-circumscribed mass, covered with normal epithelium, measuring approximately 32 × 15 mm in size. The pathological diagnosis via biopsy was amyloidosis (AL amyloidosis of the Aλ type). We diagnosed localized amyloidosis, as examination data did not support a diagnosis of systemic amyloidosis and multiple myeloma. The mass was removed surgically under general anesthesia. Seventeen months have since passed, with no sign of recurrence.

Sialolithiasis is a common disease of the salivary glands. The exact cause is unclear; however, cases caused by a foreign body are rare. Herein, we report a case of sialolithiasis in the submandibular duct formed around a hair in a patient with trichotillomania and trichophagia. A 51-year-old woman visited our hospital with an acute episode of pain and swelling in the left submandibular region after eating. Computed tomography revealed swelling of the left submandibular gland with no definite sialoliths. The clinical diagnosis was acute sialadenitis. Oral antibiotic administration (levofloxacin 500 mg/day) was promptly initiated. However, her symptoms worsened, and she returned to our hospital 10 hours later. A very small sialolith was observed through the oral mucosa near the opening of the Wharton’s duct. The sialolith was removed surgically and found to be accompanied by a hair upon gross examination. The surgical site healed after one week without any complications. There has been no recurrence in the three years and two months after the operation.

Dipeptidyl peptidase-4 (hereinafter referred to as DPP-4) inhibitors are used in diabetes therapy. They lower blood glucose by inhibiting DPP-4 and promoting insulin secretion. Here, we report a case of oral mucous membrane pemphigoid caused by the oral administration of a DPP-4 inhibitor. A 61-year-old female with gingival erosion and bleeding in the maxilla from the right first premolar to the left first premolar was referred to our department. On the first visit, redness, blisters, erosion, and the Nikolsky phenomenon were observed in the aforementioned region. A biopsy was performed for suspected pemphigoid. A histopathological

diagnosis of pemphigoid was obtained using HE staining and the fluorescent antibody method. The patient had diabetes and had been taking a combination drug containing vildagliptin (DPP-4 inhibitor) and metformin hydrochloride for two years and six months. We suspected that the pemphigoid was caused by the DPP-4 inhibitor. A request for a prescription modification was made to the internal medicine department, and the DPP-4 inhibitor was replaced with canagliflozin hydrate. The symptoms (redness, blisters, erosion, and the Nikolsky phenomenon) disappeared one month after suspension of the drug containing the DPP-4 inhibitor. Furthermore, relapse has not occurred in the 2 years since.

Sialolithiasis rarely originates in the minor salivary glands, and multiple sialoliths in the minor salivary glands is extremely rare. No report in the literature has described sialoliths with concomitant mucous cysts in the minor salivary glands. We report a rare case of multiple mucous cysts and sialoliths in the minor salivary glands. A 73-year-old man presented with an approximately two-year history of a small nodule that he noticed on the left buccal mucosa. He subsequently developed multiple small nodules on the bilateral buccal mucosa and was referred to our hospital for further evaluation. Examination showed multiple, elastic, hard well-defined nodules on the bilateral buccal mucosa. Magnetic resonance imaging revealed several hyperintense cysts on T2-weighted images. A biopsy of the largest nodule revealed sialolithiasis of the minor salivary gland with mucous cysts. All nodules were extirpated under general anesthesia; we extirpated six mucous cysts and many surrounding minor salivary glands. Based on the histopathological evaluation, we diagnosed the patient with sialolithiasis of the minor salivary glands. Three of the six mucous cysts contained sialoliths. The patient’s postoperative course was uneventful, and no recurrence had been observed after one year.

Psoriatic arthritis (PsA) is a common relapsing inflammatory skin disease associated with joint symptoms in patients with psoriasis. Temporomandibular joint (TMJ) disorders are found in 68.8% of affected patients, however most cases of PsA associated with TMJ ankylosis are not reported. We experienced a case of TMJ ankylosis suspected to be caused by PsA. The patient was a 45-year-old male who had developed erythema of the skin and was diagnosed with psoriasis vulgaris at approximately 27 years of age. He was referred to us due to limited range of mouth opening as well as pain in the bilateral TMJ. Panoramic radiography revealed narrowing of the bilateral TMJ space, while computed tomography imaging showed prominent destructive and sclerosing changes in the bilateral mandibular condyle and glenoid fossa. Blood test results indicated a mildly decreased ferritin level and were negative for rheumatoid factor. The patient initially refused surgery and was given mouth opening exercises, though he stopped going to follow-up examinations. A few years later, he returned to our department with the same complaints, and a gap arthroplasty with a temporalis myofascial flap was performed. At a follow-up examination two years later, his maximal mouth opening had been maintained at 34 mm.

Sialadenoma papilliferum-like intraductal papillary tumor is a benign salivary gland tumor that arises from the glandular tissue. A 52-year-old woman was referred to our hospital with a small painless mass on her tongue. Examination revealed a 6 × 6 mm, dome-shaped, non-tender, firm to hard fixed mass with a smooth surface on the left side of the posterior part of the lateral border of the tongue. The clinical diagnosis was a benign tumor of the tongue. Therefore, neither an initial biopsy nor imaging studies were performed prior to an excisional biopsy of the lesion under local anesthesia. The lesion was excised by making a curvilinear incision at the posterior border of the tumor, separating it by sharp dissection, and completely excising it, followed by primary closure. It was easy to separate the tumor from the surrounding tissues and the surgical specimen comprised a circular hard tumor. The histopathological diagnosis was sialadenoma papilliferum-like intraductal papillary tumor. There had been no recurrence as at 1.5 years after the excision.

Eltrombopag is the world’s first orally administrable hematopoietic factor preparation, and has been covered by insurance since 2011. We report a case of idiopathic thrombocytopenic purpura (ITP) in which eltrombopag was administered to control oral bleeding. The patient was an 81-year-old woman. Her medical history included gastric ulcer and post helicobacter pylori eradication therapy. In March 2018, she visited our department with the chief complaint of persistent bleeding from the left buccal mucosa. At the first visit, a hematoma and slight persistent bleeding were observed in the left buccal mucosa in the oral cavity. The patient visited our hospital’s hematology department because her blood test for suspected bleeding diathesis revealed a markedly low platelet count of 0.2 × 10⁴/μ L. As a result, ITP was diagnosed. Steroid therapy was started at our hospital, denture use was discontinued, and local hemostasis was continued. Oral administration of eltrombopag was started on the 2nd day of illness, and 10 units of concentrated platelets were administered on the 3rd day of illness. Complete hemostasis was achieved on the 5th day of illness. After that, the patient was discharged without rebleeding, since the platelet count had recovered to 3.2×10⁴/μ L on the 17th hospital day.

Immunostimulatory effects of immune checkpoint inhibitors and radiotherapy have attracted much attention in the treatment of malignant melanoma. We present a case in which multidisciplinary treatment including both of these produced a remarkable antitumor effect in an amelanotic malignant melanoma (AMM).

A 67-year-old woman visited the nearby general hospital with the chief complaint of a mass in the gingiva of the left maxilla. The mass was resected; however, since it was diagnosed as spindle cell carcinoma, she was referred to our hospital for additional treatment. A partial resection of the left maxilla was performed under general anesthesia, and histopathological examination revealed AMM. Additional resections were performed for positive excisional margins; however, four months later metastasis was found in the left upper internal deep cervical lymph node. Although a left radical neck dissection was performed, ten months later recurrence was observed in the left side mandibular branch medial and the left first sternocostal joint. Twelve courses of Nivolumab and four courses of Ipilimumab were administered, then following radiotherapy (32 Gy) the tumor disappeared. Three years and one month have passed since the end of treatment, and there has been no recurrence or distant metastasis.