Department of Diagnostic and Clinical Medicine and of Public Health, Institute of Pathology, University of Modena and Reggio Emilia, Modena (MO), Italy.
Provincial Health Care Services, Institute of Pathology, Santa Maria del Carmine Hospital, Rovereto, TN, Italy.
Neoplasma. 2018 Sep 19;65(5):651-655. doi: 10.4149/neo_2018_170701N452. Epub 2018 Sep 4.
In comparison with the 7th Edition, the 8th Edition of the American Joint Committee on Cancer (AJCC) staging system no longer considers the mitotic count in the a or b T1 categorization for melanoma, but it adopts a sub-stratification based on the Breslow's depth. Today, the death burden of thin melanoma is still severe, despite of attempts for early screening. We believe that a bio-histological implementation may explain this evidence. It is generally accepted that melanoma progression includes two subsequent phases: the radial growth phases (RGP) and the vertical growth phase (VGP). If left untreated, RGP is able to move towards VGP. In this second phase, melanoma grows as a malignant, mitotically active, tumor with invasive and metastatic capacities. By our experience, thin melanoma includes three bio-histological subtypes: the non-tumorigenic micro-invasive RGP without significant regression, the micro-invasive RGP with regression of uncertain tumorigenic potential at diagnosis, due to the extensive presence (> 75%) of regression which could contain a VGP clone, and the micro-invasive tumorigenic VGP. Therefore, we are prone to support that the prognosis of thin melanoma is correlated with the type of growth phase inside it.
与第 7 版相比，第 8 版美国癌症联合委员会（AJCC）分期系统不再将有丝分裂计数考虑在 a 或 b T1 分类的黑色素瘤中，但它采用了基于 Breslow 深度的亚分层。尽管进行了早期筛查，但目前薄型黑色素瘤的死亡负担仍然很严重。我们认为生物组织学的实施可能可以解释这一证据。人们普遍认为黑色素瘤的进展包括两个后续阶段：径向生长阶段（RGP）和垂直生长阶段（VGP）。如果不进行治疗，RGP 能够向 VGP 发展。在第二阶段，黑色素瘤作为一种具有侵袭性和转移性能力的恶性、有丝分裂活跃的肿瘤生长。根据我们的经验，薄型黑色素瘤包括三种生物组织学亚型：非肿瘤性微侵袭性 RGP，没有明显的退行性变；诊断时退行性变不确定的肿瘤发生潜能的微侵袭性 RGP，由于退行性变广泛存在（>75%），退行性变中可能包含 VGP 克隆；以及微侵袭性肿瘤性 VGP。因此，我们倾向于认为薄型黑色素瘤的预后与其内部的生长阶段类型有关。
