Vol.:(0123456789) 1 3 Rheumatology International https://doi.org/10.1007/s00296-020-04548-x OBSERVATIONAL RESEARCH Shear wave elastography as a new method to identify parotid lymphoma in primary Sjögren Syndrome patients: an observational study Maria Bădărînză 1  · Oana Serban 1  · Lavinia Maghear 1  · Corina Bocsa 1  · Mihaela Micu 2  · Laura Damian 3  · Ioana Felea 3  · Daniela Fodor 1 Received: 7 January 2020 / Accepted: 6 March 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Parotid non-Hodgkin lymphoma (NHL) in primary Sjögren syndrome (pSS) has no specifc biomarker for diagnosis. Salivary glands ultrasound (US) is largely used, but its contribution in detecting parotid NHL has not been established. The aim of our study was to determine the added value of bidimensional shear wave elastography (2D-SWE) in pSS diagnosis and to determine its accuracy in identifying parotid NHL. Grey-scale US (GSUS) and 2D-SWE of salivary glands were performed in 35 patients with pSS and 35 healthy controls. The GSUS scores were calculated and the mean of three SWE consecutive measurements was used to appreciate the gland stifness. SWE increase the diagnostic rate at a cut-of of 6.45 kPa (from 88.6 to 94.2%, p < 0.001) only if applied in patients with insufcient GSUS criteria for pSS diagnosis. The parotid glands with NHL (8 patients, all mucosa-associated lymphoid tissue type) had hyperechoic bands in more than half of the glandular parenchyma (in 68.75% of the glands), large hypoechoic area > 20 mm (all glands), traced gland area over 5 cm 2 (all glands), parotid US score greater than 13 (in 68.75% of the glands), and high stifness (elasticity modulus 13.9 ± 4.08 vs 6.32 ± 2.24) (all p < 0.001). These fndings give high sensitivity (92.3%), specifcity (100%), and positive (100%) and negative predictive values (98.3%) for NHL identifcation. The rest of GSUS fndings did not correlate with the classic risk factors for lymphoma development (all p > 0.05). 2D-SWE had added value for pSS diagnosis in cases where GSUS aspect is normal or nonspecifc. The higher stifness of parotid NHL can be used for early diagnosis, biopsy guidance, and, possible, for treatment monitoring. Keywords Ultrasonography · Shear wave elastography · Primary Sjögren’s syndrome · Parotid lymphoma Introduction Primary Sjögren syndrome (pSS) has an increased risk for developing non-Hodgkin’s lymphoma (NHL) [1] which is a cause of mortality in pSS patients. Clinical and biological Rheumatology INTERNATIONAL Maria Bădărînză and Oana Serban shared the frst authorship Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00296-020-04548-x) contains supplementary material, which is available to authorized users. * Daniela Fodor dfodor@umfcluj.ro Oana Serban serban.oana@umfcluj.ro Lavinia Maghear lavinia_dancos@yahoo.com Corina Bocsa hosu.delia@umfcluj.ro Mihaela Micu mcmicu@yahoo.com Laura Damian lauradamiancj@yahoo.com Ioana Felea foanaf@yahoo.com 1 Second Internal Medicine Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 2-4 Clinicilor street, 400006 Cluj Napoca, Romania 2 Rheumatology Division, Rehabilitation Clinical Hospital, Cluj-Napoca, Romania 3 Rheumatology Division, Emergency Clinical County Hospital, Cluj-Napoca, Romania