Hideki Komatsubara

Premalignant melanocytic dysplasia and malignant melanoma of the oral mucosa

Although malignant melanoma of the oral cavity frequently arises in pre-existing melanosis of the oral mucosa, little is known about oral melanoma precursor lesions. We reviewed three patients with premalignant melanocytic dysplasia and 14 with malignant melanoma of the oral mucosa. Thirteen of the 14 malignant melanoma cases had radial growth phases similar to those of acral lentiginous melanoma (ALM) of the skin. The prognosis of oral melanoma was not poor in contrast to that of cutaneous melanoma. Premalignant melanocytic dysplasia of the oral mucosa showed lentiginous or pagetoid proliferation of atypical melanocytes in the lower epithelium in the central part of the lesion, and lentiginous proliferation of dendritic melanocytes or simple hyperpigmentation in the basal cell layer in the peripheral part. These findings were similar to those of the radial growth phase of ALM of the oral mucosa.

Clinical evaluation of Lugol's iodine staining in the treatment of stage I–II squamous cell carcinoma of the tongue

Oral squamous cell carcinoma (OSCC) is often surrounded by epithelial dysplasia; leaving it unresected can result in local recurrence. Staining with Lugols iodine solution detects epithelial dysplasia in oral mucosa, but whether it decreases local recurrence after OSCC surgery is unknown. This study investigated local recurrence rates in patients with early tongue cancer who underwent surgery using Lugols staining. 93 patients with T1-2N0 tongue SCC underwent partial glossectomy using Lugols staining during surgery. Resection was performed at least 5mm from the margin of the unstained area. Patients were investigated retrospectively for local recurrence status. Postoperative histology revealed negative surgical margins for SCC or epithelial dysplasia in 81 patients, close margins for SCC in 5, positive margins for mild epithelial dysplasia in 6, and a positive margin for SCC in one. Those with a positive or a close margin for SCC underwent additional resection 2-4 weeks after surgery; one was proved histologically to have residual SCC. No patients developed local recurrence, but 2 died of neck metastasis and 2 of distant metastasis. The 5-year disease specific survival rate was 93.8%. Lugols staining during surgery can reduce local recurrence and improve survival in patients with early tongue SCC.

The observational study of delayed wound healing after tooth extraction in patients receiving oral bisphosphonate therapy.

INTRODUCTION In this study, we investigated whether such a discontinuation of oral bisphosphonate (BP) for 3 months might influence the incidence of BP-related osteonecrosis of the jaw (BRONJ) and wound healing after tooth extraction in patients receiving oral BP therapy. MATERIAL AND METHODS There were a total of 434 teeth in 201 patients (18 males and 183 females). The patients were divided into two groups depending on whether or not they underwent a 3-month discontinuation of BP therapy (BP- and BP+) before tooth extraction. In this observational study investigated delayed wound healing after tooth extraction in patients receiving oral BP therapy. RESULTS In all cases of the BP- group, there were no BRONJ although there was delayed wound healing in two cases. However, in one case of the BP+ group, oral BP was continued because it was deemed high risk to discontinue treatment by the patients physician. In this case, an intraoral fistula was still present with bone exposure at 120 weeks after extraction (BRONJ stage 1). CONCLUSION This study supports the idea of a drug holiday and encourages further clinical research on this topic of tooth extraction in patients receiving oral BP therapy.

Treatment and prognosis of malignant melanoma of the oral cavity: preoperative surgical procedure increases risk of distant metastasis

OBJECTIVE Many authors have reported that oral melanoma patients showed much worse prognosis than those with cutaneous melanoma. We investigated treatment method and prognosis of patients with oral malignant melanoma. STUDY DESIGN Twenty-one patients with oral melanoma treated at our hospital were investigated, with special reference to the influence of preoperative surgical procedures such as biopsy, incision, or tooth extraction on the prognosis. RESULTS All patients underwent surgery followed by immuno-chemotherapy with dimethyl triazeno imidazole carboxamide (DTIC), ninustine hydrochloride (ACNU), vincristine (VCR), and biologic response modifier OK-432. Local control was obtained in 20 of 21 patients. Lymph node metastasis appeared in 13 patients, but neck failure was not detected in any patients. Distant metastasis occurred in 9 patients in spite of loco-regional control. Five-year survival rate of 12 patients with no preoperative surgical procedure was 91.7%, while that of the 9 patients who had undergone surgical procedures before treatment was 25.9% (P < .05). CONCLUSIONS Oral melanoma patients can obtain a prognosis as good as that for cutaneous melanoma patients, when the above-mentioned therapy is used without any preoperative surgical procedures.

Evaluation of T-classifications of upper gingival and hard palate carcinomas—a proposition for new criterion of T4

Most carcinomas of upper gingiva and hard palate are classified as T4 stage on the basis of the UICC criteria, since they easily invade the underlying bone tissue. We classified 43 patients with squamous cell carcinoma of the upper gingiva in terms of three criteria: (1) the original T-classification by UICC, (2) the classification by the Japan Society for Head and Neck Cancer (JSHNC), and (3) a new classification in which the maxillary sinus or nasal floor is used as the defining borderline for T4 (MSF classification). Our study demonstrated that the new classification was superior with regard to distribution of patients by T stage, correlation with prognosis and choice of treatment method.

Establishment and characterization of a human adenoid cystic carcinoma line of the salivary gland which is serially transplantable and spontaneously metastasises to the lung in nude mice

Adenoid cystic carcinoma (ACC) is a rare malignant tumour of the head and neck occurring in the salivary glands. We established a human ACC line which is serially transplantable in nude mice and designated it as KOA-1. The KOA-1 tumour doubled in 9.3 days and retained the histological characteristics of a solid pattern of ACC even after 22 serial passages. The KOA-1 metastasised to the lung when transplanted subcutaneously into the back. This tumour line may serve as a useful model for exploration of the biological behaviour and treatment of human ACC.

p16 overexpression in malignant and premalignant lesions of the oral and esophageal mucosa following allogeneic hematopoietic stem cell transplantation

ObjectivesSecondary malignancy in the oral mucosa is recognized as one of the most serious complications in patients who received allogenic hematopoietic stem cell transplantation (HSCT). However, potential risk factors associated with carcinogenesis after HSCT that have been reported remain elusive. We experienced a rare case of secondary malignancies of the oral and esophageal mucosa and analyzed the expression of tumor suppressor gene product p16.Case reportA 35-year-old male had malignant lesions of the oral and esophageal mucosa two years after HSCT. Partial maxillectomy and endoscopic submucosal dissection were performed. Immunohistochemical analyses revealed that the tumor cells of malignant and premalignant lesions of the oral cavity and esophagus but not keratosis were positive for p16.ConclusionsPathological examinations with p16 immunohistochemistry may contribute to an early diagnosis of secondary malignancy after HSCT.