Tworek J A, Goldblum J R, Weiss S W, Greenson J K, Appelman H D
Department of Pathology, University of Michigan Hospitals, Ann Arbor, USA.
Am J Surg Pathol. 1999 Aug;23(8):946-54. doi: 10.1097/00000478-199908000-00013.
Stromal tumors of the anorectum are a rare group of mesenchymal tumors that often have a protracted clinical course. We sought to determine which clinical, morphologic, and immunophenotypic features correlated with an adverse outcome in 22 patients with anorectal stromal tumors. An adverse outcome, defined as either tumor recurrence or metastasis, occurred in nine patients. Seven patients had metastases, two of whom also had local recurrences. Four of these patients also died from their disease. One patient had one local recurrence, and one patient had two local recurrences; neither of these patients had metastases. Recurrences were found as long as 103 months and metastases as late as 117 months after initial presentation. However, for patients without an adverse outcome, maximum follow-up was only 84 months. Thus both recurrence and metastasis may not appear until several years after treatment, indicating that a long-term follow-up period, probably longer than available for many tumors without an adverse outcome in this study, is needed before a patient can be considered to be cured. Tumor size greater than five centimeters correlated with an adverse outcome. However, given the protracted course of these tumors and the relatively limited follow-up available, other features such as location within the muscularis propria, mitotic activity, necrosis, and pleomorphism that did not significantly correlate with an adverse outcome may become significant with longer follow-up periods. We also found that on the basis of morphologic appearance and whether tumors were confined to the submucosa or located within the muscularis propria, anorectal stromal tumors could be divided into three groups, and that the behavior of anorectal stromal tumors may also depend upon their phenotype. The largest group of 17 tumors was located within the muscularis propria, mitotically active, and composed of densely cellular spindle-shaped cells. A second group of two tumors was also located within the muscularis propria and was composed of spindle-shaped cells, but lacked dense cellularity and mitotic activity. The third group was composed of three submucosal, polypoid tumors.
直肠肛管间质瘤是一组罕见的间叶性肿瘤，其临床病程往往迁延。我们试图确定22例直肠肛管间质瘤患者中哪些临床、形态学和免疫表型特征与不良预后相关。9例患者出现不良预后，定义为肿瘤复发或转移。7例患者发生转移，其中2例同时有局部复发。这些患者中有4例也死于该疾病。1例患者有1次局部复发，1例患者有2次局部复发；这2例患者均无转移。复发最早在初次就诊后103个月出现，转移最晚在117个月出现。然而，对于无不良预后的患者，最长随访时间仅84个月。因此，复发和转移可能在治疗后数年才出现，这表明在患者被认为治愈之前，需要长期随访，可能比本研究中许多无不良预后肿瘤的随访时间更长。肿瘤大小大于5厘米与不良预后相关。然而，鉴于这些肿瘤病程迁延且随访相对有限，其他特征，如固有肌层内的位置、有丝分裂活性、坏死和多形性，虽然与不良预后无显著相关性，但随着随访时间延长可能会变得显著。我们还发现，根据形态学表现以及肿瘤是局限于黏膜下层还是位于固有肌层内，直肠肛管间质瘤可分为三组，并且直肠肛管间质瘤的行为可能还取决于其表型。最大的一组17个肿瘤位于固有肌层内，有丝分裂活跃，由密集的梭形细胞组成。第二组有2个肿瘤，也位于固有肌层内，由梭形细胞组成，但细胞密集度和有丝分裂活性较低。第三组由3个黏膜下息肉样肿瘤组成。
