Tadaaki Sasaki

Expression of metastasis suppressor gene (KAI1/CD82) in oral squamous cell carcinoma and its clinico-pathological significance

In this study, we investigated the expression of the KAI1/CD82 gene in oral squamous cell carcinoma (oral SCC). We studied 43 oral SCC patients. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed to evaluate expression of this gene, and results were compared to the clinico-pathological findings. Twenty-five specimens (58.1%) were KAI1/CD82-positive, and 18 (41.9%) were negative. There were statistically significant relationships between gene expression and both histological malignancy (P=0.0205) and mode of invasion (P=0.0315). But there were no correlations of expression with tumor status, regional lymph node metastasis, pathological lymph node metastasis or histological differentiation. No significant relationship was observed between patient survival and expression of KAI1/CD82 by tumors. The results of this study suggest that the KAI1/CD82 gene may not be a useful predictor of prognosis, although decreased gene expression may be associated with increased invasive ability of oral SCC.

Volume-corrected mitotic index as a prognostic factor in oral squamous cell carcinomas

In order to predict the prognosis of patients with oral squamous cell carcinomas, volume-corrected mitotic index (M/V index), as well as histopathological and clinical indices were estimated in 50 oral squamous cell carcinoma tumors. Histological malignancy (P = 0.0005), mode of invasion (P = 0.0168) and M/V index (P = 0.0093) showed a significant correlation with survival according to univariate survival analysis. According to multivariate survival analysis (Coxs regression model), the M/V index was the best predictor of the techniques studied of patient prognosis. The M/V index also showed significant correlation with DNA ploidy. The present results suggest that the M/V index is an important prognostic factor for oral carcinoma. Furthermore, the M/V index and DNA ploidy appear to provide similar prognostic information.

Massive tumour arising from the hard palate after excision of a pleomorphic adenoma

A 60-year-old Japanese woman presented to the Department of Oral and Maxillofacial Surgery at Dokkyo University Hospital in 1982 with episodes of bleeding in the mouth. Clinical examination showed a 20 × 12 × 10 mm tumour in the right hard palate and no regional lymphadenopathy. It was excised under general anaesthesia and shown to be a pleomorphic adenoma. Follow-up was continued for six months but the patient was lost to follow-up until April 1994 when she presented to our hospital with a remarkable swelling of the face and repeated bleeding in the mouth. She was poorly nourished, her weight was 31 kg, and she could not walk by herself. She had a huge swelling of the right face roughly 170 × 200 × 140 mm in size, producing a severe form of hemifacial macrosomia with protrusion of the right buccal region and deviation of the nasal and lip regions to the left (Fig. 1). Conventional radiographs showed extensive resorption of the right maxillary bone and radio-opacities which indicated that the tumour was partially calcified. Magnetic resonance imaging (MRI) showed a tumour arising from the maxilla, almost entirely occupying the alveolar process and compressing the right maxillary sinus and the anterior aspect of the nasal cavity. The orbital floor seemed to be free of the lesion. The margins were relatively smooth and well-defined (Fig. 2). Incisional biopsy confirmed the diagnosis of carcinoma ex pleomorphic adenoma. In 1994 under general anaesthesia, through Webers and intraoral incisions, a flap was raised and the lesion was exposed. The mass extended to both maxillary bones, right maxillary sinus, right ethmoid sinus, right nasal fossa, right orbital floor, and right intratemporal fossa. There was no invasion in the right frontal sinus or cerebral region. The mass was almost surrounded by a capsule and was easily separated from the surrounding tissue. The tumour was completely Fig. 1 Photographs of the tumour: frontal view (left top), inferior view (right top), right lateral view (left bottom), and left lateral view (right bottom).

Diagnostic imaging of tongue cancer. Comparison with Histopathological Findings.

舌癌における腫瘍の診断にはMRIも多く用いられているが炎症等の非腫瘍性変化を伴うときは, 画像上の予想浸潤範囲が実際の腫瘍浸潤範囲と異なることも経験される。そこで, 今回術前MR画像診断における予想腫瘍局在範囲と実際の手術切除物の病理組織学的浸潤範囲との整合性, 組織分化度や浸潤部の間質反応の要因を含めて検討を行った。対象は1990年から2000年までの間に当科を受診し, 病理組織学的検査にて診断された舌扁平上皮癌でMRI撮影した45例とした。MR撮影装置はSHIMADZU社製, 超伝導1.5Tで, 撮影法はスピンエコー法, T1強調像, T2強調像, 造影MR画像を行った。画像評価として腫瘍の有無の判定のほか予想腫瘍浸潤範囲の計測を行った。切除物の病理組織学的浸潤範囲の計測, 組織分化度, 浸潤様式, 間質のリンパ球浸潤, 線維化の有無について評価を行った。T1強調像における感度は64.5%, 特異度70%, 精度65.5%, T2強調像の感度は89.9%, 特異度80%, 精度87.3%, 造影MR画像, 感度は75%, 特異度90%, 精度78.6%, となり, 感度は特にT2強調像で最も高く腫瘍の検出には有効であると考えられた。発育様式, 分化度, 浸潤様式, 間質におけるリンパ球浸潤, 線維化の有無について, MR診断の感度が高かったT2強調像での腫瘍境界性状について大きく明瞭型と不明瞭型の2群にわけその関連性をFisher検定にて求めた。その結果, 特に内向型の発育様式を示す腫瘍で不明瞭型を示す傾向がみられた。次に病理組織学的腫瘍深達度が20mm以下の群と20mmをこえる群の2群に分け, 3タイプのMR撮像条件における両者の相関係数を求めたところ腫瘍径20mm以下の群よりも20mmをこえる群において, 特にT2強調画の相関係数は0.91と高値で強い相関を示した。T2強調画は切除範囲の決定に参考になると考えられた。

Clinical studies of the squamous cell carcinoma of the lower gum.

1977年1月より1988年12月までの12年間に獨協医科大学口腔外科を受診した下顎歯肉扁平上皮癌一次症例23例について, 臨床病態所見ならびに治療成績について検討を行い, 以下の結果が得られた。1.性別では, 男性16例, 女性7例 (男女比2.29: 1) で, 初診時年齢は39歳から86歳までに分布し, 平均65.0歳であった。2.T分類ではT456.5%, T230.4%, T18.7%, T34.3%, N分類では, N152.2%, N030.4%, N2, N3各8.7%, M分類ではM18.7%であった。3.13例 (56.5%) に下顎骨の吸収がみられ, その様式はerosive type 4例, invasive type 9例で, 後者に吸収範囲が大きい傾向であった。4.下顎骨の吸収像と臨床進行度, 浸潤様式, 核DNAパターンとは, 一定の関係がみられた。5.治療法は, 放射線単独7例, 手術単独, 手術+放射線, 放射線+化学療法各4例, 手術+化学療法, 手術+放射線+化学療法各2例であった。6.治療成績は, 5年累積生存率43.4%で, 腫瘍の進展度, 治療法の相違が予後に影響を与えたと思われた。7.原発巣の核DNA量は, 臨床所見ならびに腫瘍浸潤様式とよく相対し, 下顎歯肉癌においても, 悪性度の指標や予後の推測に有用となり得ることが示唆された。