Hidero Ohki

Anaplastic large cell lymphoma in gingiva: case report and literature review

We report an unusual case of gingival anaplastic large-cell lymphoma (ALCL) that occurred in a 76-year-old Japanese woman who showed marked gingival swelling in both the maxilla and mandible. Although the patient received caries and periodontal therapy at the outpatient clinic of our dental hospital, the gingival swelling remained and she was referred to the oral surgery department, where a biopsy of the gingiva was performed. The specimens showed proliferation of large atypical and amphophilic epithelioid cells beneath the covering epithelium. Immunohistochemical analysis of the proliferating cells revealed positivity for CD30 and T-cell markers, such as CD45RB, as well as CD45RO antibodies, and they were weakly positive for the granzyme B antibody. In contrast, the tumor cells were negative for all B-cell markers as well as for CD3, CD56, S-100 protein, epithelial membrane antigen, and p80(NPM/ALK) antibodies. Based on the clinical and histopathologic features, the lesion was diagnosed as an ALCL in both the upper and the lower gingiva. This is an extremely rare case, in which a specific subtype of T-cell lymphoma appeared in the oral cavity.

Unusual radiographic appearance of ossifying fibroma in the left mandibular angle

Ossifying fibroma is usually a unilocular lesion with a well-defined, thinly corticated margin radiographically, although various patterns have been noted. The patient was a 27-year-old woman with a painless radiolucent lesion demonstrated on panoramic radiography to involve the root-apex area of the left lower second and third molars. Radiographically, the lesion had some features of a benign tumour, such as an odontogenic myxoma. However, the deep invaginations towards the interalveolar septa suggested a simple bone cyst, whereas the irregular margin and lack of expansion or mandibular canal displacement were consistent with a malignant lesion. A hard tissue component was confirmed only by soft-tissue mode CT. Although this lesion was histopathologically diagnosed as ossifying fibroma, the conflicting imaging findings were challenging and very intriguing.

Fibroblast VEGF-receptor 1 expression as molecular target in periodontitis.

AIM Degradation of extracellular matrices is an integral part in periodontitis. For antagonizing this pathophysiological mechanism, we aimed at identifying gene expression profiles in disease progression contributing periodontitis-associated fibroblasts (PAFs) versus normal gingival fibroblasts to determine their molecular repertoire, and exploit it for therapeutic intervention. MATERIALS AND METHODS Applying an exploratory analysis using a small number of microarrays in combination with a three dimensional (3D) in vitro culture model that incorporates some aspects of periodontitis, PAFs were initially characterized by gene-expression analyses, followed by targeted gene down-regulation and pharmacological intervention in vitro. Further, immunohistochemistry was applied for phosphorylation analyses in tissue specimens. RESULTS PAFs were characterized by 42 genes being commonly up-regulated >1.5-fold, and by five genes that were concordantly down-regulated (<0.7-fold). Expression of vascular endothelial growth factor (VEGF)-receptor 1 (Flt-1) was highly enhanced, and was thus further explored in in vitro culture models of periodontal fibroblasts without accounting for the microbiome. Phosphorylation of the VEGF-receptor 1 was enhanced in PAFs. Receptor inhibition by a specific VEGF-receptor inhibitor or intrinsic down-regulation by RNAi of the VEGF-receptor kinase in 3D gel cultures resulted in significant reduction in collagen degradation associated with increased tissue inhibitor of metalloproteinase expression, suggesting that Flt-1 may contribute to periodontitis. CONCLUSION Based on the finding that VEGF-receptor kinase inhibition impaired collagen degradation pathways, Flt-1 may represent a candidate for therapeutic approaches in periodontitis.

Mandibular metastases from follicular carcinoma of the thyroid gland: a case report

A case of metastatic thyroid carcinoma near the left mandibular ramus with a cyst-like appearance on rotational panoramic radiographs is reported. A 55-year-old woman complained of a continuous sense of incongruity for 3–4 years since extraction of the left mandibular third molar. The lesion, with apparent gingival swelling around the left second molar, was painless and was cyst-like in appearance on plain radiographs. On the basis of the radiological findings, a benign odontogenic tumor was suspected, but computed tomography (CT) showed destruction of the lingual cortical bone with soft tissue invasion to the masticator space. The final histopathological diagnosis was metastatic follicular carcinoma of the thyroid gland. When investigating cyst-like radiolucent lesions with thick sclerotic margins and irregular areas on plain radiographs, we recommend using CT to evaluate the effect of the lesion on cortical bone.

Malignant lymphoma arising from postoperative benign lymphoepithelial lesion. Report of a case and review of literature.

患者は42歳女性。約3年前から両側耳下腺部が腫張し, その増大と口腔乾燥感の増強のため1993年7月当科を受診した。顔貌はび漫性に両側耳下腺部が腫脹し, 触診で, 左側では比較的境界明瞭な鶏卵大の弾力性やや硬の腫瘤1個, 右側では胡桃大の同様の腫瘤2個を触知した。各種臨床検査および画像所見でも腫瘤に対する診断を確定しえず, 耳下腺腫瘍の可能性も考慮して確定診断を得る目的で左側耳下腺浅葉切除術を施行した。2か月後右側耳下腺浅葉切除術を施行した。病理組織学的診断はいずれもBenign lymphoepithelial lesion (LEL) であった。術後約1年を経過し, 左側の耳下腺部に大豆大の腫瘤が出現し漸次増大傾向を示したため, 1995年2月生検を行いdiffuse medium sized cell lymphomaと診断された。その後駿河台日大病院内科へ転科し, CHOP療法を5クール, MEK-2療法4クールの化学療法を受け1997年まで経過観察中である。本症例は, Pan B cellマーカーであるCD20陽性で, TcellマーカーであるCD3は陰性を示したところから, 耳下腺のリンパ上皮性疾患を基盤として発生したMALT lymphomaと診断した。