TY - JOUR T1 - Difficulties in diagnostics of lung tumours in biopsies: an interpathologist concordance study evaluating the international diagnostic guidelines JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 302 LP - 309 DO - 10.1136/jclinpath-2020-207257 VL - 75 IS - 5 AU - Kajsa Ericson Lindquist AU - Cristina Ciornei AU - Sofia Westbom-Fremer AU - Inga Gudinaviciene AU - Anna Ehinger AU - Nektaria Mylona AU - Rodrigo Urdar AU - Maria Lianou AU - Franziska Svensson AU - Tomas Seidal AU - Felix Haglund AU - Katalin Dobra AU - Mátyás Béndek AU - Erika Bardóczi AU - Aneta Szablewska AU - Marek Witkowski AU - Maria Ramnefjell AU - Luis E De Las Casas AU - Miklos Gulyas AU - Agnes Hegedus AU - Patrick Micke AU - Hans Brunnström Y1 - 2022/05/01 UR - http://jcp.bmj.com/content/75/5/302.abstract N2 - Aims Accurate and reliable diagnosis is essential for lung cancer treatment. The study aim was to investigate interpathologist diagnostic concordance for pulmonary tumours according to WHO diagnostic criteria.Methods Fifty-two unselected lung and bronchial biopsies were diagnosed by a thoracic pathologist based on a broad spectrum of immunohistochemical (IHC) stainings, molecular data and clinical/radiological information. Slides stained with H&E, thyroid transcription factor-1 (TTF-1) clone SPT24 and p40 were scanned and provided digitally to 20 pathologists unaware of reference diagnoses. The pathologists independently diagnosed the cases and stated if further diagnostic markers were deemed necessary.Results In 31 (60%) of the cases, ≥80% of the pathologists agreed with each other and with the reference diagnosis. Lower agreement was seen in non-small cell neuroendocrine tumours and in squamous cell carcinoma with diffuse TTF-1 positivity. Agreement with the reference diagnosis ranged from 26 to 45 (50%–87%) for the individual pathologists. The pathologists requested additional IHC staining in 15–44 (29%–85%) of the 52 cases. In nearly half (17 of 36) of the malignant cases, one or more pathologist advocated for a different final diagnosis than the reference without need of additional IHC markers, potentially leading to different clinical treatment.Conclusions Interpathologist diagnostic agreement is moderate for small unselected bronchial and lung biopsies based on a minimal panel of markers. Neuroendocrine morphology is sometimes missed and TTF-1 clone SPT24 should be interpreted with caution. Our results suggest an intensified education need for thoracic pathologists and a more generous use of diagnostic IHC markers.Data are available on reasonable request. ER -