Lee Y T
Cancer Treat Rev. 1983 Jun;10(2):91-101. doi: 10.1016/0305-7372(83)90007-5.
Clinically, epithelial cancers (squamous cell carcinoma and adenocarcinomas) metastasize primarily by the lymphatic route, while mesenchymal sarcomas more frequently enter the blood stream directly. Nevertheless metastatic involvement of regional nodes has been seen in 13% of patients with soft tissue sarcomas and in 7% of bone sarcomas at initial presentation (29). About one-third of the leiomyosarcomas of the gastro-intestinal tract developed metastasis and about 90% of the metastasis were intra-abdominal (45). Liver is the most common site of metastasis, followed by peritoneal seeding and local recurrence or extension. Regional nodal metastasis also has been noted both initially and subsequently. The most important criterion of diagnosing leiomyosarcoma appears to be the presence of mitosis. Leiomyosarcoma with 1 mitosis per 2 high power fields or epithelioid leiomyosarcoma with 1 mitosis per 5 fields behaved aggressively. Additional criteria useful for diagnosing and for determining prognosis of malignancy include the presence of necrosis, cellular atypia, and the gross size of the tumor. In general, almost all tumors larger than 5 cm in diameter should be viewed with suspicion. For patients with gastric leiomyosarcomas, a proportion, sometimes as high as 14%, had perigastric lymph node involvement at diagnosis (9), and about 7% of those who relapsed had regional nodal metastasis (Table 2). For patients with leiomyosarcoma of the small intestine, about 5% of the patients had nodal metastasis initially, and 9% subsequently (Table 4). Regional lymphatic metastasis also has been reported in leiomyosarcoma of the colorectum. It is believed that wide resection of normal tissues (at least 10 cm margin on either side of tumor) and adjacent mesentery (with routine omentectomy for gastric lesions) not only may discover a higher frequency of occult metastasis in the regional lymph node, but will also decrease the chance of loco-regional relapse and the occurrence of sarcomatosis. As a result of this review and a previous one (30), the surgeon ought to consider when faced with a smooth muscle tumor of the gastro-intestinal tract a wide segmental resection including the adjacent mesentery and omentum, because (a) the precise histologic nature of the lesion (benign vs. malignant) is hard to define even by permanent sections; (b) the possibility of involvement of draining nodes exists and (c) little or no increase in morbidity is anticipated between a wide, as against a limited wedge or segmental resection of gastrointestinal tract. The last point does not need elaboration, except for the very unusual lesions of the duodenum, distal stomach or lower rectum. When adherence to this principle would require a pancreaticoduodenectomy, near total gastrectomy or abdominoperineal resection, it may be wise to establish a definitive histologic diagnosis of the primary lesion first, and to use a more conservative procedure initially.
临床上，上皮性癌（鳞状细胞癌和腺癌）主要通过淋巴途径转移，而间叶性肉瘤则更常直接进入血流。然而，在软组织肉瘤患者初诊时，13%出现区域淋巴结转移，骨肉瘤患者为7%（29）。胃肠道平滑肌肉瘤约三分之一发生转移，其中约90%为腹腔内转移（45）。肝脏是最常见的转移部位，其次是腹膜种植以及局部复发或扩散。初诊时及后续也均发现有区域淋巴结转移。诊断平滑肌肉瘤最重要的标准似乎是有丝分裂的存在。每2个高倍视野有1个有丝分裂的平滑肌肉瘤或每5个视野有1个有丝分裂的上皮样平滑肌肉瘤具有侵袭性。有助于诊断和判断恶性肿瘤预后的其他标准包括坏死、细胞异型性以及肿瘤的大体大小。一般来说，几乎所有直径大于5cm的肿瘤都应怀疑有问题。对于胃平滑肌肉瘤患者，诊断时一定比例（有时高达14%）的患者有胃周淋巴结受累（9），复发患者中约7%有区域淋巴结转移（表2）。对于小肠平滑肌肉瘤患者，约5%的患者初诊时有淋巴结转移，后续为9%（表4）。结直肠平滑肌肉瘤也有区域淋巴转移的报道。据信，广泛切除正常组织（肿瘤两侧至少10cm切缘）和相邻系膜（胃病变常规行大网膜切除术）不仅可能发现区域淋巴结中隐匿转移的频率更高，还会降低局部区域复发和肉瘤病发生的几率。基于本次综述及之前的一次综述（30），外科医生面对胃肠道平滑肌瘤时应考虑行包括相邻系膜和大网膜的广泛节段性切除，因为（a）即使通过永久切片也很难明确病变的精确组织学性质（良性与恶性）；（b）存在引流淋巴结受累的可能性；（c）预计广泛切除与胃肠道有限的楔形或节段性切除相比，发病率几乎没有增加或不增加。除十二指肠、胃远端或直肠下段的极特殊病变外，最后一点无需赘述。当遵循这一原则需要行胰十二指肠切除术、近全胃切除术或腹会阴联合切除术时，明智的做法可能是先对原发病变建立明确的组织学诊断，并先采用更保守的手术。
