Rapid onsite evaluation uses a very small proportion of total material aspirated at endobronchial or endoscopic ultrasound in the investigation of suspected thoracic malignancy

Abstract

Introduction The objectives were: to measure the proportion of aspirated material used to make direct slides for rapid onsite evaluation (ROSE) at endobronchial (EBUS) and endoscopic ultrasound (EUS) in suspected thoracic malignancy; and to correlate pass weights with ROSE category and needle size. Method All EBUS and EUS cases for possible thoracic malignancy October 2018‐May 2019 were included. All material from each pass was expelled into a Petri dish. One drop of material was placed on each of two slides; one used for ROSE, the other fixed and remaining material processed to cell block. Dish and slides were weighed before and after this procedure on a sensitive balance and weight of aspirate and slide material calculated. When ROSE identified malignancy, slide production ceased but target sampling for ancillary studies continued. Results ROSE accuracy was 96.8%. Mean percentage by target of aspirated material used to make direct slides for ROSE was 1.9% in malignant cases and 3.6% in non‐malignant cases (P = .027 for difference). Mean percentage by pass was 5.9%. Mean weight of a single aspirate was 128.8 mg. Mean weight of aspirates insufficient on ROSE (175.7 mg) was significantly higher than the mean weight of benign or malignant aspirates (117.1 and 114.0 mg, respectively). Mean weight of aspirates using 22G needles (132.6 mg) was significantly higher than that for 25G needles (87.1 mg). Conclusion Material made into direct slides at EBUS and EUS and used in part for ROSE uses a tiny proportion of aspirated material with over 98% processed to cell block and available for ancillary testing in malignant cases.

Technical aspects of the use of cytopathological specimens for diagnosis and predictive testing in malignant epithelial neoplasms of the lung

“…A concern has been expressed that material is “wasted” on direct slides that could otherwise be placed in a CB and used for molecular analysis. However, in one study, the proportion of material used on slides was very low in malignant sites (a mean of 1.9% by weight), and all solid material was processed to CB, regardless 37 …”

“…However, in one study, the proportion of material used on slides was very low in malignant sites (a mean of 1.9% by weight), and all solid material was processed to CB, regardless. 37 There are two indirect advantages. First, pathology staff (medical and non-medical) are exposed to the experiences that patients undergo in order to produce these precious samples and this may underline their value and need for careful and efficient handling as well as emphasising the crucial clinical relevance of pathological examination.…”

“…Centres already offering ROSE will have optimised their own protocols, 28,34‐37 but for those who are contemplating a service, a few pointers may be useful.…”

“…Once ROSE establishes malignancy, slide production can cease and the site can be further sampled for diagnostic and predictive material 37 (Figure 2).…”

“…The corollary to this is that if a sample with high tumour content is produced from a particular trajectory, this can be repeated to maximise the chances of success in predictive testing. 25,28 Centres already offering ROSE will have optimised their own protocols, 28,[34][35][36][37] but for those who are contemplating a service, a few pointers may be useful.…”