Cytologic Diagnosis of Central Neurocytoma in Intraoperative Squash Preparations

Cytologic Features during Intraoperative Assessment of Central Neurocytoma: A Report of Three Cases and Review of the Literature

“…Since their early description in 1982, CNs have been difficult to distinguish from oligodendrogliomas, ependymomas, subependymal giant cell astrocytomas and non-Hodgkin's lymphomas [1,3,6,7,8,9,10,11,12], mainly due to the fact that all of these tumors have a uniform cell population. This distinction is very important during intraoperative assessment because CNs require only tumor removal, while oligodendrogliomas require a wider surgical resection, ependymomas a less extensive excision and non-Hodgkin's lymphoma only diagnostic sampling [2,11].…”

“…This distinction is very important during intraoperative assessment because CNs require only tumor removal, while oligodendrogliomas require a wider surgical resection, ependymomas a less extensive excision and non-Hodgkin's lymphoma only diagnostic sampling [2,11]. Very few cytology descriptions have been published in the literature concerning the cytodiagnosis of CNs during intraoperative assessment [6,7,8,9,10,11,12], and therefore, a thorough investigation of the cytologic features that have been described in previous reports was exhaustively examined. Only three cytologic features were common in all 18 cases previously reported for squash and imprint preparation during intraoperative assessment.…”

“…Only three cytologic features were common in all 18 cases previously reported for squash and imprint preparation during intraoperative assessment. These cytologic features are: (1) monotonous or isomorphic round cells, (2) small nuclei with stippled or granular chromatin, and (3) acellular fibrillary areas (neuropil) [6,7,8,9,10,11,12]. Some authors have claimed that the smears characteristically reveal other less common cytologic features which should be sought for during intraoperative assessment (table 1).…”

“…They claimed that this finding should also be considered as a cytomorphologic characteristic of CNs, although they are the only ones to describe this finding. Most authors claim that CNs have a characteristic cytomorphology and can be diagnosed reliably during intraoperative assessment using a combination of cytologic preparations, frozen sections and radiologic imaging [1,6,7,8,9,10,11,12]. This approach is valid for most tumors of the CNS.…”

“…In light of this knowledge, an accurate and precise intraoperative diagnosis is essential, thus making the cytologic features of CNs the hallmark of the diagnostic process during intraoperative assessment for cytopathologists, surgical pathologists and neurosurgeons alike. Seven previous reports describing a total of 18 cases have addressed the cytodiagnosis of central CNs in the English medical literature [6,7,8,9,10,11,12]. In this paper, we describe 3 new cases of CNs diagnosed during intraoperative assessment as well as a compilation of cytologic features described in previous reports that are important for a correct diagnosis.…”