Extragastrointestinal (Soft tissue) stromal tumors: An analysis of 48 cases with emphasis on histologic predictors of outcome
Extragastrointestinal (Soft tissue) stromal tumors: An analysis of 48 cases with emphasis on histologic predictors of outcome
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DOI：
10.1038/modpathol.3880099
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发表时间：
2000-05-01
期刊：
影响因子：
7.5
通讯作者：
Weiss, SW
中科院分区：
文献类型：
--
作者：
Reith, JD;Goldblum, JR;Weiss, SW
分析48例组织学上与胃肠道间质瘤相似但发生在腹部软组织的肿瘤的临床病理特征，以确定其与胃肠道肿瘤的总体相似性、生物学行为以及预测不良结局风险的参数。明确排除了典型平滑肌瘤和平滑肌肉瘤。肿瘤发生在32名女性和16名男性，年龄从31岁到82岁（平均58岁）。40例肿瘤起源于腹腔软组织，其余起源于腹膜后腔。它们的大小从2.1到32.0 cm不等，从纯圆形上皮样细胞组成的肿瘤到那些由短梭形细胞组成的肿瘤，其中一些病例显示混合模式。肿瘤表现出不同量的间质玻璃样变，粘液样变化和囊肿形成。肿瘤表达CD 117（c-kit受体）（100%）、CD 34（50%）、神经元特异性烯醇化酶（44%）、平滑肌肌动蛋白（26%）、结蛋白（4%）和S-100蛋白（4%）。根据以下几个参数评价肿瘤：大小（10 cm）、细胞结构（低或高）、有丝分裂（每50个高倍视野0 - 2个，每50个高倍视野>2个）、核分裂（1 - 3+）、细胞类型（上皮样、梭形或混合型）和坏死（不存在或存在）。这些参数，然后在单变量和多变量分析方面进行了评估不良或非不良的结果，前者定义为转移或死亡的肿瘤。获得了31例患者的随访信息（范围：4至84个月;中位数：24个月）。1例患者出现不良事件，因此从后续分析中排除。12例患者（39%）发生转移或死于肿瘤。在单变量分析中，细胞结构、有丝分裂活性（>2/50高倍视野）和坏死与不良结局风险的统计学显著增加相关。尽管样本量相对较小，但在多变量分析中，有丝分裂活性（相对风险，7.46; P = 0.09）和坏死（相对风险，3.75; P = 0.07）显示出独立预测值的趋势。组织学类型和结果之间无相关性。虽然只有39%的肿瘤表现为恶性，但这一数字可能是保守的估计，因为长期随访（>5年）仅适用于有限数量的患者。将患有胃肠道外间质瘤的患者分为具有0 - 1个不良组织学因素的患者和具有2 - 3个不良组织学因素的患者，可以将患者分为两组，这两组在短期内不良结局的风险明显不同（分别为0.02例事件和0.54例事件/人-年; P <0.001）。胃肠道外（软组织）间质瘤在组织学和免疫表型上与胃肠道间质瘤相似，但其侵袭性更类似于小肠间质瘤。
The clinicopathologic features of 48 tumors that were histologically similar to gastrointestinal stromal tumors but occurred in the soft tissues of the abdomen were analyzed to determine their overall similarity to their gastrointestinal counterpart, their biologic behavior, and the parameters that predict risk for adverse outcome. Classic leiomyomas and leiomyosarcomas were specifically excluded. The tumors occurred in 32 women and 16 men, who ranged in age from 31 to 82 years (mean, 58 years). Forty tumors arose from the soft tissue of the abdominal cavity, and the remainder arose from the retroperitoneum. They ranged in size from 2.1 to 32.0 cm and varied from tumors composed purely of rounded epithelioid cells to those composed of short fusiform cells set in a fine fibrillary collagenous background with some cases showing a mixed pattern. Tumors displayed variable amounts of stromal hyalinization, myxoid change, and cyst formation. The tumors expressed CD117 (c-kit receptor) (100%), CD34 (50%), neuron-specific enolase (44%), smooth muscle actin (26%), desmin (4%), and S-100 protein (4%). Tumors were evaluated with respect to several parameters: size (10 cm), cellularity (low or high), mitoses (0 to 2 per 50 high-power fields, >2 per 50 high-power fields), nuclear atypia (1 to 3+), cell type (epithelioid, spindled, or mixed), and necrosis (absent or present). These parameters were then evaluated in univariate and multivariate analysis with respect to adverse or nonadverse outcome, the former defined as metastasis or death from tumor. Follow-up information was obtained for 31 patients (range, 4 to 84 months; median, 24 months). One patient presented with an adverse event and, therefore, was excluded from subsequent analysis. Twelve patients (39%) developed metastases or died of tumor. In univariate analyses, cellularity, mitotic activity (>2 per 50 high-power fields), and necrosis were associated with statistically significant increases in the risk for adverse outcome. Despite the relatively small sample size, in a multivariable analysis mitotic activity (relative risk, 7.46; P = .09) and necrosis (relative risk, 3.75; P = .07) displayed trends toward independent predictive value. No association was noted between histologic pattern and outcome. Although only 39% of tumors behaved in a malignant fashion, this figure probably represents a conservative estimate because long-term follow-up (>5 years) was available for only a limited number of patients. Stratification of patients who have extragastrointestinal stromal tumor into those with 0 to 1 adverse histologic factors versus those with 2 to 3 offers the advantage of separating patients into two groups that have a markedly different risk for adverse outcome in the short term (0.02 events versus 0.54 events per person-year; P < .001, respectively). Extragastrointestinal (soft tissue) stromal tumors are histologically and immunophenotypically similar to their gastrointestinal counterpart but have an aggressive course more akin to small intestinal than gastric stromal tumors.