270 Chapter 17 for instance, dermatopathologist in diagnosing melanocytic lesions387, among breast pathologists388 and in diagnosing thyroid lesions389. Patients whose diagnosis of invasive adenocarcinoma is a false positive and whose tumor size is less than 3cm won’t be administered adjuvant treatment. On the other hand, patients with larger AIS lesions that are mistakenly diagnosed as invasive adenocarcinoma could be subjected to unnecessary adjuvant therapy, and therefore to overtreatment. The IASLC Pathology Committee suggests in their paper on defining invasive patterns317, that “in case of doubt whether an area should be designated as invasive or noninvasive, most of the group decided in favor of upgrading”. In contrast, our study and the study of Boland and colleagues 2016 suggest that downgrading can in this situation reliably be performed. Visca et al commented in an editorial on the upgrading statement in the recent manuscript of the pathology panel of IASLC390, that ‘upgrading’ is not in line with the TNM’s usual approach, which suggests in doubtful cases to downstage lesions instead of upstaging them”182. It’s probable that AIS is frequently misdiagnosed as invasive adenocarcinoma in routine clinical practice, which is supported by an upsurge in invasive adenocarcinomas detected at lower stages. According to Ganti et al.’s analysis of the US Cancer Statistics database, the incidence of stage I NSCLC rose from 10.8 to 13.2 per 100,000 between 2010 and 2017391. In other organs where an in-situ category has been recognized a relative survival of 100% is reported in the Netherlands392. In the USA the tendency of overdiagnosis in early stage cancer exists, as the relative survival exceeds 100% (greater longevity compared to an equivalent group from the general population)393. This favors the premise that these early-stage cancers, which presumably lack metastatic potential and have limited lethal consequences, are generally detected incidentally or via screening in individuals who are otherwise healthier or health-conscious than their counterparts in the general population394. For lung adenocarcinoma in-situ these data are not available and probably hidden in the early-stage invasive carcinomas395. This is due to the pattern-recognition approach as opposed to the morphology approach in the revised classification. Histological detail All the studies before 1971 about histology (also called microanatomy) of the pulmonary parenchyma have been summarized by a group of Japanese scientists396. Interestingly, the knowledge development of the secondary pulmonary lobule was obtained in lungs of coalminers, where the pigmented macrophages were aligned in the lobular septa and because of the high number of macrophages, this was macroscopically visible, similar to smoker’s lungs. The ventilation function of the lung (flow of outside air in and out of the alveolus) has an escape mechanism for focal differences in air pressure. To this end, at the alveolar level the pores of Kohn allow air passage between alveoli. A relatively recent schematic drawing of the lobular architecture shows that the edge of the secondary lobule is a continuous line. In one of the pulmonary adenocarcinomas
RkJQdWJsaXNoZXIy MTk4NDMw