Rao Shilpa, Vazhayil Vikas, Nandeesh B N, Beniwal Manish, Rao K V L Narasinga, Yasha T C, Somanna Sampath, Santosh Vani, Mahadevan Anita
Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
Neurol India. 2020 Nov-Dec;68(6):1385-1388. doi: 10.4103/0028-3886.304072.
Cavitron Ultrasonic Surgical Aspirator (CUSA) is a technique used for the surgical treatment of tumors that aids the surgeon in highly selective tumor sampling with minimal injury to surrounding tissues. The utility of the tissue obtained from CUSA for histopathological diagnosis of central nervous system tumors is not as well-known as its surgical benefits. Even though a few studies have evaluated the diagnostic accuracy of CUSA specimen, these have dealt with very few cases.
In this study, we nil analysed 73 cases of CNS tumors (glial and non-glial) where CUSA specimen was available for histopathological examination and compared with findings on conventional samples as gold standard.
Most frequent types of artefacts induced by CUSA included tissue breakdown resembling necrosis, empty spaces in tissues, and crush artefacts particularly in cellular tumors, that interfered with interpretation. CUSA samples were found optimal for diagnosis of non-glial tumors (45/73), (mainly mesenchymal), wherein the diagnostic utility was comparable to the conventional samples. Difficulties were encountered in glial neoplasms, medulloblastomas and meningiomas. In glial neoplasms (28/73), accurate grading was not possible (9/28, 32%) utilising CUSA samples alone as necrosis and mitosis were not represented. Similarly in meningiomas, mitosis and brain invasion, essential for grading, was not recognizable in CUSA samples. In medulloblastomas, extensive crush artefacts interfered with diagnosis and histological subtyping making it mandatory to examine conventional tissue samples and CUSA. Immunohistochemistry results were optimal with CUSA tissue, wherever performed.
The greatest benefits of CUSA, is its ability to sample multiple areas enhancing the yield in heterogenous tumors like gliosarcomas and its utility in tumors at surgically inaccessible sites. As a policy, we recommend that it is beneficial that all surgically excised tissues including those from the CUSA bottle and suction be sent for histopathological analysis for optimising diagnostic accuracy.
超声外科吸引器（CUSA）是一种用于肿瘤外科治疗的技术，可帮助外科医生进行高度选择性的肿瘤采样，同时对周围组织的损伤最小。从CUSA获得的组织用于中枢神经系统肿瘤组织病理学诊断的效用，并不像其手术益处那样广为人知。尽管有一些研究评估了CUSA标本的诊断准确性，但这些研究处理的病例很少。
在本研究中，我们分析了73例中枢神经系统肿瘤（神经胶质和非神经胶质），这些病例有CUSA标本可用于组织病理学检查，并与作为金标准的传统样本的结果进行了比较。
CUSA引起的最常见伪像类型包括类似坏死的组织分解、组织中的空隙以及挤压伪像，尤其是在细胞性肿瘤中，这些会干扰诊断。发现CUSA样本最适合诊断非神经胶质肿瘤（占73例中的45例），（主要是间叶性肿瘤），其诊断效用与传统样本相当。在神经胶质肿瘤、髓母细胞瘤和脑膜瘤中遇到了困难。在神经胶质肿瘤（占73例中的28例）中，仅使用CUSA样本无法进行准确分级（28例中的9例，32%），因为坏死和有丝分裂未表现出来。同样，在脑膜瘤中，CUSA样本中无法识别对分级至关重要的有丝分裂和脑浸润。在髓母细胞瘤中，广泛的挤压伪像干扰了诊断和组织学亚型分类，因此必须检查传统组织样本和CUSA样本。无论何处进行免疫组织化学检测，CUSA组织的结果都是最佳的。
CUSA的最大益处在于它能够对多个区域进行采样，提高了在异质性肿瘤（如胶质肉瘤）中的取材率，以及在手术难以到达部位的肿瘤中的效用。作为一项政策，我们建议将所有手术切除的组织，包括来自CUSA瓶和吸引物的组织，送去进行组织病理学分析，以优化诊断准确性，这是有益的。
