Cytological findings of ROS1‐rearranged lung adenocarcinoma

Abstract

ROS1-rearranged lung adenocarcinoma has been recently identified. We report a case of ROS1-rearranged lung adenocarcinoma with special emphasis on cytological findings. Here, we report a case of young woman with ROS1-rearranged lung adenocarcinoma diagnosed by cytology and discuss the clinical, cytological, and molecular findings. Cytologically, the tumor consisted of small tight clusters of cells with high nuclear/cytoplasmic ratio. Nuclei were enlarged and small nucleoli were occasionally observed. Signet-ring cells were focally identified. Neoplastic cells were positive for ROS1 immunocytochemistry. Subsequently, the translocation of ROS1 gene was confirmed in a histological specimen. In conclusion, the specific histology of adenocarcinoma on cytological materials should promote testing for ROS1 immunohistochemistry. Immunocytochemical detection of ROS1 protein helps identify patients suitable for molecular targeted therapy.

Overview and update on molecular testing in non‐small cell lung carcinoma utilizing endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) samples

“…The last study identified two cases with ROS1 translocation, which was subsequently confirmed in FFPE samples. We have found two additional studies 46,47 . A previous case report described the cytological features of a ROS1 ‐rearranged NSCLC, which showed ROS1 overexpression, subsequently confirmed in the histological specimen 46 .…”

“…46,47 A previous case report described the cytological features of a ROS1-rearranged NSCLC, which showed ROS1 overexpression, subsequently confirmed in the histological specimen. 46 Vlajnic et al identified 13 ROS1-positive cases by cytology, which were confirmed by FISH or next generation sequencing. 47 The authors concluded that FERN ÁNDEZ ACEÑERO ET AL.…”

<p>High feasibility of cytological specimens for detection of <em>ROS1</em> fusion by reverse transcriptase PCR in Chinese patients with advanced non-small-cell lung cancer</p>

“…However, positive ROS1 IHC results should be reconfirmed by a molecular or cytogenetic method 13. Both FISH and IHC are not limited to histological tissue, but also work with cytological specimens 14–17. However, both methods require adequate quality and quantity of tumor cells; therefore, histological tissue is more suitable for screening than cytological specimens.…”