Added value of pathology consultations in cutaneous lymphomas: a 2-year review from the Dutch national referral and expertise centre

Abstract

Background The accurate diagnosis of cutaneous lymphomas (CLs) and lymphoproliferative disorders (LPDs) presents significant challenges due to their rarity, the diversity of clinicopathological entities, and the necessity of integrating clinical, immunophenotypic and molecular analyses with histopathology. Misdiagnosis and diagnostic delays are common, potentially leading to inappropriate treatments. The contribution of an expert centre specifically for the pathology of CL has not been previously investigated.Objectives To evaluate the value of pathology consultations at the Dutch national referral centre for CLs focusing on diagnostic agreement and identifying common diagnostic pitfalls.Methods We retrospectively reviewed all pathology consultations concerning CLs received at the Leiden University Medical Centre during 2020 and 2021. Cases were categorized into informative and ambiguous conclusions. Diagnostic agreement between submitting and expert pathologists was assessed and categorized as essential agreement, more specific conclusion, minor disagreement or major disagreement.Results A total of 239 consultations from 230 patients were analysed. The submitted conclusion was categorized as informative in 64% of the consultations and as ambiguous in 36%. Most (59%) consultations in our study exhibited essential agreement with the submitting pathologist. The expert centre reduced ambiguous conclusions from 36% to 13%, primarily by resolving differential diagnostic considerations between lymphoma and pseudolymphomatous infiltrates. However, major diagnostic disagreements, with a potentially significant impact on treatment or prognosis, were found in 12% of consultations mostly involving reclassification from benign dermatoses to lymphomas. Mycosis fungoides, primary cutaneous follicle centre lymphoma, CD30+ LPDs and pseudolymphomas were delineated as specific areas of diagnostic difficulty.Conclusions The findings indicate that a national referral and expertise centre for CL pathology contributes to ensuring accurate diagnoses and appropriate patient management. Our data encourage low-threshold consultation in an expert centre for all patients with clinical and/or histological suspicion of CL.Cutaneous lymphomas (CLs) are a group of rare cancers that affect the skin. Diagnosing CLs correctly can be difficult because these conditions are uncommon and involve complex tests. Mistakes in diagnosis can lead to wrong treatments, so it is important to understand how expert centres can help with diagnosis.This research was carried out at Leiden University Medical Centre, a Dutch expert centre for CLs. We reviewed all their pathology consultations from 2020 to 2021. We wanted to see how often our expert diagnoses matched those of other pathologists and determine where any mistakes may have occurred. We looked at 239 consultations from 230 patients. We found that in 59% of cases, our expert diagnosis was the same as the original. We also reduced the proportion of unclear conclusions from 36% to 13% by distinguishing better between different types of lymphomas or recognizing non-life-threatening conditions such as eczema and insect bites. However, we encountered major disagreements in 12% of cases, which could seriously affect treatment decisions. Some conditions were sent more often to the expert centre and were particularly hard to diagnose.In conclusion, our study findings highlight how expert centres for CLs can play a crucial role in accurately diagnosing CL and improving patient care. We recommend that clinicians seek advice from expert centres for patients suspected of having CLs to ensure they get the best diagnosis and treatment promptly.This study evaluates the added value of pathology consultations at the Dutch national referral centre for cutaneous lymphomas, highlighting a reduction in diagnostic ambiguity and identification of major diagnostic disagreements. The findings support the value of specialized centres in ensuring accurate diagnoses and optimal patient management.