Strong J A, Hatten H P, Brown M T, Debatin J F, Friedman H S, Oakes W J, Tien R
Department of Radiology, Duke University Medical Center, Durham, NC 27710.
AJR Am J Roentgenol. 1993 Aug;161(2):369-72. doi: 10.2214/ajr.161.2.8333380.
Astrocytomas are classified as either fibrillary or pilocytic on the basis of their histologic appearance. The imaging features of the fibrillary astrocytoma correlate closely with the tumor's clinical aggressiveness and are, therefore, useful in predicting prognosis. Correlation between the imaging features and the clinical aggressiveness of the pilocytic astrocytoma, however, is not well established. Accordingly, we compared the initial MR and CT appearances of the lesion with tumor aggressiveness as seen clinically to determine if a correlation exists.
We retrospectively evaluated the initial MR images or CT scans of 32 consecutive patients who had a histologic diagnosis of pilocytic astrocytoma. The lesions were evaluated with regard to location, size, calcification, morphology, and degree of contrast enhancement. These initial imaging features were correlated with the aggressiveness of the tumor as seen clinically. Tumors were classified as aggressive or nonaggressive on the basis of their clinical manifestations. Patients with clinically aggressive lesions had progressive symptoms and radiologic evidence of tumor progression or recurrence within an unusually short period. Patients with clinically nonaggressive lesions had a more indolent course, either improving or remaining stable, on both clinical and radiologic evaluations. In 12 patients, the tumor was classified as aggressive clinically, either progressing or recurring within a median time of 7.5 months (range, 2.5-118 months) from the initial diagnosis. The remaining 20 patients had a clinically nonaggressive course.
In our series of patients, lesion size and location were not significantly different between the nonaggressive and aggressive tumors, as noted clinically. Furthermore, the aggressive and nonaggressive tumors were similar with regard to the presence or absence of calcium. Most tumors in both groups showed either moderate or marked enhancement and were multilobular.
The initial CT and MR features of pilocytic astrocytoma are unreliable for predicting which lesions will behave in a more aggressive manner clinically and have a poor prognosis.
星形细胞瘤根据其组织学表现分为纤维型或毛细胞型。纤维型星形细胞瘤的影像学特征与肿瘤的临床侵袭性密切相关，因此有助于预测预后。然而，毛细胞型星形细胞瘤的影像学特征与临床侵袭性之间的相关性尚未明确确立。因此，我们将病变的初始磁共振成像（MR）和计算机断层扫描（CT）表现与临床所见的肿瘤侵袭性进行比较，以确定是否存在相关性。
我们回顾性评估了32例经组织学诊断为毛细胞型星形细胞瘤患者的初始MR图像或CT扫描。对病变的位置、大小、钙化、形态和对比增强程度进行评估。这些初始影像学特征与临床所见的肿瘤侵袭性相关。根据临床表现将肿瘤分为侵袭性或非侵袭性。临床侵袭性病变的患者有进行性症状，且在异常短的时间内有肿瘤进展或复发的影像学证据。临床非侵袭性病变的患者病程较为惰性，在临床和影像学评估中病情改善或保持稳定。12例患者的肿瘤临床分类为侵袭性，自初始诊断起中位时间7.5个月（范围2.5 - 118个月）内进展或复发。其余20例患者病程临床非侵袭性。
在我们的患者系列中，临床所见的非侵袭性和侵袭性肿瘤之间，病变大小和位置无显著差异。此外，侵袭性和非侵袭性肿瘤在有无钙化方面相似。两组中的大多数肿瘤均表现为中度或明显强化，且为多叶状。
毛细胞型星形细胞瘤的初始CT和MR特征对于预测哪些病变在临床上行为更具侵袭性且预后不良并不可靠。
