Fluorescence visualization detection of field alterations in tumor margins of oral cancer patients.

PURPOSE: Genetically altered cells could become widespread across the epithelium of patients with oral cancer, often in clinically and histologically normal tissue, and contribute to recurrent disease. Molecular approaches have begun to yield information on cancer/risk fields; tissue optics could further extend our understanding of alteration to phenotype as a result of molecular change. EXPERIMENTAL DESIGN: We used a simple hand-held device in the operating room to directly visualize subclinical field changes around oral cancers, documenting alteration to fluorescence. A total of 122 oral mucosa biopsies were obtained from 20 surgical specimens with each biopsy being assessed for location, fluorescence visualization (FV) status, histology, and loss of heterozygosity (LOH; 10 markers on three regions: 3p14, 9p21, and 17p13). RESULTS: All tumors showed FV loss (FVL). For 19 of the 20 tumors, the loss extended in at least one direction beyond the clinically visible tumor, with the extension varying from 4 to 25 mm. Thirty-two of 36 FVL biopsies showed histologic change (including 7 squamous cell carcinoma/carcinomas in situ, 10 severe dysplasias, and 15 mild/moderate dysplasias) compared with 1 of the 66 FV retained (FVR) biopsies. Molecular analysis on margins with low-grade or no dysplasia showed a significant association of LOH in FVL biopsies, with LOH at 3p and/or 9p (previously associated with local tumor recurrence) present in 12 of 19 FVL biopsies compared with 3 of 13 FVR biopsies (P=0.04). CONCLUSIONS: These data have, for the first time, shown that direct FV can identify subclinical high-risk fields with cancerous and precancerous changes in the operating room setting.

Intramandibular inflammatory myofibroblastic tumor--a true neoplasm or reactive lesion?

OBJECTIVE: Inflammatory myofibroblastic tumor (IMT) is an uncommon lesion reported to arise in various organs and by convention believed to be a nonneoplastic reactive inflammatory condition. Because of its radiographic and histologic similarities to malignancy, IMT can pose a considerable diagnostic dilemma. The purpose of this study is to report the first intramandibular IMT and to discuss the possible nature of this lesion. STUDY DESIGN: Detailed documentation of clinical, radiographic, and histologic features; literature review. RESULTS: This lesion showed distinct radiographic, histologic, and immunohistochemical features. The lesion recurred 14 months after initial removal with almost identical histology. CONCLUSION: This is the first documented case of an intramandibular IMT. Due to the rarity of these lesions, their clinical sequelae and prognosis are undetermined. As a result of specific immunohistochemical phenotyping and clinical behavior of this lesion, we favored a diagnosis of inflammatory myofibroblastic tumor. Wide excision with a long-term clinical follow-up is required.

Toluidine blue staining identifies high-risk primary oral premalignant lesions with poor outcome.

There is a pressing need for the development of visual aids that will facilitate the detection of oral premalignant lesions (OPLs) with a high-risk of progression. Preliminary data suggest that toluidine blue stain may be preferentially retained by OPLs with high-risk molecular clones. In this study, we monitored OPLs from 100 patients without any history of oral cancer for an average of 44 months in order to evaluate the association of toluidine blue status with clinicopathologic risk factors, molecular patterns (microsatellite analysis on seven chromosome arms: 3p, 9p, 4q, 8p, 11q, 13q, and 17p) and outcome. Toluidine blue-positive staining correlated with clinicopathologic risk factors and high-risk molecular risk patterns. Significantly, a >6-fold elevation in cancer risk was observed for toluidine blue-positive lesions, with positive retention of the dye present in 12 of the 15 lesions that later progressed to cancer (P = 0.0008). This association of toluidine blue status with risk factors and outcome was evident even when the analysis was restricted to OPLs with low-grade or no dysplasia. Our results suggest the potential use of toluidine blue in identifying high-risk OPLs.

3p14 and 9p21 loss is a simple tool for predicting second oral malignancy at previously treated oral cancer sites.

Treatment induces reactive changes that often resemble low-grade dysplasia at former oral cancer sites, complicating histopathological assessment. We tested a set of microsatellite markers shown previously to be predictive of progression for oral premalignant lesions for the ability to predict development of second oral malignancy (SOM). Sixty-eight oral leukoplakia at former cancer sites (with known outcome, 36 progressed to SOM) were evaluated for loss of heterozygosity at 19 loci on seven chromosome arms. 3p and/or 9p loss in these posttreatment leukoplakia was associated with a 26.3-fold increase in risk of developing SOM compared with those that retained both of these arms (P < 0.001), with 60% of cases with loss of heterozygosity developing SOM in 2 years. In contrast, histological diagnosis (moderate or severe dysplasia versus hyperplasia or mild dysplasia) had only a 1.7-fold increase in risk (P = 0.11). The identification of 3p and 9p loss in posttreatment lesions could serve as a simple and direct test for stratifying risk of SOM development.