Miettinen M, Fetsch J F
Department of Soft Tissue Pathology, Armed Forces Institute of Pathology, 6825 16th Street NW, Bldg. 54, Rm. G090, Washington, DC 20306-6000, USA.
Histopathology. 2006 Jan;48(1):97-105. doi: 10.1111/j.1365-2559.2005.02292.x.
Smooth muscle tumours (SMTs) have been traditionally divided into benign leiomyomas (LM) and malignant leiomyosarcomas (LMS) based on cytological atypia, mitotic activity and other criteria. In most instances, this dichotomous approach works, but in some instances the biological potential cannot be determined with certainty. This is often because some, but not all criteria for malignancy have been met or because the tumours are occurring in unusual settings for which there are sparse substantive data. Tumours falling into the latter categories are often designated as 'smooth muscle tumours of uncertain malignant potential'. For most non-hormonally influenced SMTs, the presence of significant atypia plus mitotic activity equates with a diagnosis of LMS. However, not all tumours classified as LMSs have a similar prognosis, as a number of other factors, including tumour size, depth, grade and resectability, affect outcome. For example, cutaneous SMTs, regardless of mitotic activity and atypia, have potential largely limited to local recurrence, whereas subcutaneous and deep LMSs have a definite metastatic potential. Angioleiomyoma is the most common SMT of peripheral soft tissues, but deep peripheral LMs are distinctly rare and should be approached with caution. Hormonally influenced oestrogen- and progesterone receptor-positive uterine and extrauterine SMTs in women have unique criteria, including the allowance of higher mitotic activity for the benign LM designation. SMTs of female genital tract can be assessed with criteria similar to uterine tumours. Because of the rarity of these tumours, experience is more limited, and more caution is needed to assess the potential of tumours with mitotic activity and atypia. This review summarizes the current knowledge, guidelines, prognostic data and controversies for the classification of SMTs of soft tissue and most visceral sites.
传统上，平滑肌肿瘤（SMTs）根据细胞学异型性、有丝分裂活性及其他标准分为良性平滑肌瘤（LM）和恶性平滑肌肉瘤（LMS）。在大多数情况下，这种二分法是有效的，但在某些情况下，其生物学潜能无法明确确定。这通常是因为满足了部分而非全部恶性标准，或者肿瘤发生在缺乏实质性数据的特殊情况下。属于后一类的肿瘤通常被指定为“恶性潜能不确定的平滑肌肿瘤”。对于大多数非激素影响的SMTs，显著异型性加上有丝分裂活性等同于LMS的诊断。然而，并非所有被归类为LMS的肿瘤都有相似的预后，因为许多其他因素，包括肿瘤大小、深度、分级和可切除性，都会影响预后。例如，皮肤SMTs，无论有丝分裂活性和异型性如何，其潜能主要局限于局部复发，而皮下和深部LMSs则有明确的转移潜能。血管平滑肌瘤是周围软组织中最常见的SMT，但深部周围LM明显罕见，应谨慎处理。女性受激素影响的雌激素和孕激素受体阳性的子宫和子宫外SMTs有独特的标准，包括对于良性LM的指定允许更高的有丝分裂活性。女性生殖道的SMTs可以用与子宫肿瘤相似的标准进行评估。由于这些肿瘤罕见，经验更为有限，在评估有丝分裂活性和异型性的肿瘤潜能时需要更加谨慎。本综述总结了软组织和大多数内脏部位SMTs分类的当前知识、指南、预后数据及争议。
