Role of collagen and immunostaining for TGF-ß in the clinical and microscopic findings of pyogenic granuloma and peripheral ossifying fibroma.

BACKGROUND: Collagen is a component of Pyogenic Granuloma (PG) and Peripheral Ossifying Fibroma (POF) and performs different functions in these lesions. The objective of this study is to evaluate the role of collagen and immunostaining for Transforming Growth Factor beta (TGF-ß) in the clinical and microscopic findings of PG and POF. MATERIAL AND METHODS: PG (n=20) and POF (n=20) were selected for clinical evaluation (sex, age, localization, size and evolution time) and microscopic analysis (picrosirius red staining for collagen analysis and immunohistochemistry for TGF-ß) performed in the superficial and deep areas of the two lesions. ANOVA/Bonferroni and t-test, Pearson correlation and χ2 were used to compare the sites and parameters analyzed (p<0.05, GraphPad Prism 5.0). RESULTS: The depth of PG presented the highest amount of collagen (p<0.001), and its surface showed the lowest amount of type 1 collagen (yellow-red strong birefringence). Type 1 collagen gradually increased in depth of PG, surface and depth of POF (p<0.001). The number of TGF-ß+ cells was lower on the surface of PG compared with the depth of PG and the two areas of POF (p<0.001). Sex and localization did not affect these parameters, but the profile of collagen and immunostaining for TGF-ß suffered from modifications by the time of evolution and the size of the lesion. CONCLUSIONS: Although PG and POF are reactive gingival lesions, the expression of TGF-ß and its role in collagen showed different biological behaviors in these lesions, suggesting different biological origins for its components.

Is immunohistochemistry more sensitive than hematoxylin-eosin staining for identifying perineural or lymphovascular invasion in oral squamous cell carcinoma? A systematic review and meta-analysis.

BACKGROUND: This study aimed to analyze whether immunohistochemistry (IHC) is more sensitive than hematoxylin-eosin (H&E) staining for identifying perineural invasion (PNI) or lymphovascular invasion (LVI) in oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: In this systematic review and meta-analysis (Prospective Register of Systematic Reviews - CRD 42021256515), data were obtained from six databases (PubMed, Scopus, LILACS, Web of Science, EBSCO, LIVIVO, Embase) and the grey literature. Cross-sectional observational studies of the diagnostic sensitivity of IHC for PNI and LVI were included. Studies were selected in two phases: first collection and reference retrieval. The Quality Assessment of Diagnostic Accuracy Studies-2 tool assessed study quality, while the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach assessed evidence quality. The meta-analysis (random effects model) was performed using MedCalc 18.2.1 software (MedCalc®) (p<0.05). RESULTS: Four studies (560 patients with 295 biopsies) were analyzed. The combined sensitivity was 76% (95% confidence interval [CI], 44.30-97.19%) and specificity was 42% (95% CI, 23.40-62.02%). The positive predictive value (PPV) and negative predictive value (NPV) were 61% (95% CI, 49.78-71.53%) and 70% (95% CI, 37.63-94.43%). The overall accuracy was 58% (95% CI, 45.17-70.65%). The risk of bias was low, and GRADE analysis showed a very low certainty of evidence. CONCLUSIONS: Our data suggest that IHC staining to highlight PNI/LVI may be useful in cases in which H&E analysis results in a negative decrease in the prevalence of false-negative cases and underestimated treatment.