When more than one focus of stromal invasion is present in a superficially invasive cervical squamous cell carcinoma (SCC), determination of the tumoral lateral extent/horizontal extension, and hence tumor-nodes-metastases (TNM) staging, can be problematic. In recent years, a diagnostic approach to distinguish multifocal pT1a1 from pT1b cases has gained increased attention. These criteria call for classifying SCC as multifocal when invasive foci are separated by blocks of uninvolved cervical tissues, and/or are located on separated cervical lips in a tumor that is discontinuous, and/or are situated far apart (≥2 mm) from each other. In this study, we assess our experience with multifocal stage pT1a1 cervical SCC that was retrospectively classified as such using these criteria. Slides from the loop electrosurgical excision or conization specimens, comprising 212 pT1a1, 173 pT1a2, and 206 pT1b cases, were reviewed. Twenty-four (11%) of the 212 pT1a1 cases were classified as multifocal after review. The 24 multifocal pT1a1 cases were compared with the 188 unifocal pT1a1 cases regarding a variety of clinicopathologic parameters. Notably, these 2 groups showed no significant differences regarding all parameters that were evaluated, including patient age, recurrence rate, primary tumoral features in the primary excision specimen (rate of positive margins, median depth of stromal invasion, frequency of lymphovascular invasion), and frequency of residual disease in additional excisions. In summary, we demonstrate comparably favorable patient outcomes in both unifocal and multifocal cases of pT1a1 SCC of the cervix, and, accordingly, we conclusively affirm the validity of the aforementioned criteria for establishing multifocality.
Statistical physics models for aftershocks and induced seismicity