Contrast carotid ultrasound for the detection of unstable plaques with neoangiogenesis: a pilot study.

OBJECTIVES: To evaluate whether contrast ultrasonography can be used to distinguish asymptomatic from symptomatic carotid plaques and provide insight into underlying pathophysiological differences. DESIGN: Contrast carotid ultrasound was performed in both symptomatic and asymptomatic patients referred for carotid endarterectomy. MATERIALS AND METHODS: Of 77 consecutive patients referred for carotid artery evaluation, 64 underwent carotid endarterectomy for asymptomatic cerebrovascular disease and 9 underwent urgent surgery for acute neurological deficits with hemiparesis. The endarterectomy specimens were assessed immunohistologically. RESULTS: In all 9 patients undergoing urgent surgery, contrast ultrasonography showed the accumulation of diffuse microbubble contrast at the base of the carotid plaque. This pattern was observed only in 1/64 of the patients undergoing surgery for asymptomatic carotid disease. Immunohistologically staining of the endarterectomy specimens showed that the area of microbubble contrast at the base of the symptomatic plaques was associated with an increased number of small diameter (20-30 microm) microvessels staining for vascular endothelial growth factor (VEGF). CONCLUSIONS: Contrast carotid ultrasonography may allow the identification of microvessels with neoangiogenesis at the base of carotid plaques, and differentiate symptomatic from asymptomatic plaques.

Value of cytology as an adjunctive intraoperative diagnostic method. An audit of 2,250 consecutive cases.

OBJECTIVE: To evaluate the role of intraoperative cytology (IC) in the improvement of diagnostic accuracy obtained by frozen section (FS) alone. STUDY DESIGN: Comparison of 2,250 intraoperative cytologies performed along with frozen sections, with the final diagnoses achieved on paraffin sections. RESULTS: In 18 cases the diagnoses were deferred until the paraffin sections at the time of intraoperative consultation. The diagnostic accuracy in distinguishing benign from malignant lesions by combined intraoperative cytology and frozen section was 99.2%. The accuracy rate is significantly higher than that reported in large series based on frozen section preparations alone. Sensitivity and specificity were, respectively, 98.2% and 100%. The diagnostic accuracy of each technique alone was 94.9% for FS (sensitivity 89.9%, specificity 97.9%) and 96% for IC (sensitivity 94.9%, and specificity 96.8%). Although specific diagnoses were more frequently formulated on the bases of frozen section examination, FSs were not diagnostic in 113 case in which cytology allowed a specific diagnosis. CONCLUSION: Our results emphasize the increasingly important diagnostic role of intraoperative cytology as an adjunct to frozen section. The approach does have limitations.

Intraoperative diagnosis of nervous system lesions.

OBJECTIVE: To determine the accuracy of comparative cytologic and frozen section intraoperative diagnosis in neuropathology and the relevance of diagnostic accuracy during both craniotomic and stereotactic biopsies and to provide further data on rare and/or diagnostically controversial lesions. STUDY DESIGN: Both cytologic and frozen section preparations were employed in the intraoperative diagnosis of 85 consecutive central and peripheral nervous system lesions obtained from classical surgery (70 samples, 4 of which were intramedullary) and stereotactic biopsies (15 samples). RESULTS: Combining cytologic and frozen section details allowed a fair diagnosis in 81 cases (95.29%), confirmed on paraffin sections. In the remaining cases intraoperative misdiagnosis was due to technical-staining defects (1 case); absence of tumor differentiation, resolved only by ultrastructural examination (2 cases); and marked tumor heterogeneity, resolved by wide tissue sampling and immunohistochemistry (1 case). CONCLUSION: Besides providing a general description of cytologic and frozen section criteria useful in intraoperative diagnostic neuropathology and adding further details about some problematic and/or rare entities, our work confirmed: (1) the usefulness of comparative cytologic and frozen section examination in the intraoperative diagnosis of central nervous system lesions, (2) the relevance of the accuracy of intraoperative diagnosis during both craniotomy and stereotaxis, including intramedullary samples; and (3) the importance of fair "conduct" in intraoperative neuropathology, always comparatively considering morphologic and clinicoradiologic data.