The management of lupus nephritis as proposed by EULAR/ERA 2019 versus KDIGO 2021

In 2019 and 2021, the European League for Rheumatism (EULAR) jointly with the European Renal Association (ERA) and the Kidney Disease Improving Global Outcomes (KDIGO), respectively, released updated guidelines on the management of lupus nephritis. The Immunology Working Group of the ERA reviewed and compared both updates. Recommendations were either consistent or differences were of negligible clinical relevance for: Indication for kidney biopsy, kidney biopsy interpretation, treatment targets, hydroxychloroquine dosing, first line initial immunosuppressive therapy for active class III, IV (±V) LN, pregnancy in LN, LN in paediatric patients, and LN patients with kidney failure. Relevant differences in the recommended management relate to the recognition of lupus podocytopathies, uncertainties in steroid dosing, drug preferences in specific populations and maintenance therapy, treatment of pure class V LN, therapy of recurrent LN, evolving alternative drug options, and diagnostic work-up of thrombotic microangiopathy. Altogether, both documents provide an excellent guidance to the growing complexity of LN management. This article endeavours to prevent confusion by identifying differences and clarifying discrepancies.

Nodular Hidradenocarcinoma, Trichelemmal Carcinoma and Squamous Cell Carcinoma with Clear Cell Changes: Pitfalls of Biopsy Diagnosis of Skin and Adnexal Tumours

Skin and Adnexal tumours are a group of benign and malignant tumours whose basic diagnosis relies on histopathology. A single tumour may show more than 1 appendageal differentiation. Morphologic distinction between benign and its malignant counterpart is of utmost importance as it affects the treatment and prognosis of patient. We have described 3 cases who presented in our university hospital, in which final resection pathological diagnosis differed from initial core biopsy interpretation. The authors have made an attempt to provide a brief overview of diagnostic overlap existing between nodular hidradenocarcinoma and tumours of clear cell histology. Salient morphologic features differentiating cylindroma or trichilemmal carcinoma from squamous cell carcinoma have also been discussed. Final diagnosis is paramount for adjuvant management and prognostication of the patient in a clinical setting.

Prospective Consensus Reporting by Gynecologic Pathology and Dermatopathology Improves Diagnosis of Vulvar Biopsies

Context.— Vulvar biopsy interpretation and reporting, particularly of vulvar dermatoses, can be challenging in daily practice for both surgical pathologists (SPs) and dermatopathologists (DPs). Objective.— To investigate whether prospective consensus reporting of vulvar biopsies by SPs and DPs would provide value and improve overall diagnostic concordance. Design.— Consecutive vulvar biopsies during a 6-month period were reviewed prospectively by both gynecologic SPs and DPs. Preliminary, independently generated diagnoses were recorded and then shared in consensus review (SPs+DPs). A third pathologist adjudicated cases without consensus. Multiple data elements were collected for each case: division (SP/DP), age, site, clinical history, diagnostic category, preliminary and final (consensus) diagnosis, need for adjudication, ancillary tests, and diagnostic discrepancy. Results.— Eighty-four biopsies (48 SP, 36 DP) from 70 patients were reviewed. Forty-two of 84 cases (50%) were neoplastic, 38 of 84 (45%) were reactive/inflammatory, with the remaining (5%) showing both or other features. Independent diagnoses were discrepant in 22 of 84 cases (26%), but consensus review resulted in an agreed-upon diagnosis in all cases, with adjudication required in 6 cases. Independent diagnostic agreement increased over time with a reduction in major and minor discrepancies between the first and second half of the study period. Conclusions.— Prospective review of vulvar biopsies by both SPs and DPs can improve overall reporting. Consensus review allows pathologists to gain diagnostic confidence in interpretation of inflammatory (for SPs) and neoplastic (for DPs) vulvar biopsies; therefore, intradepartmental consultation is of value, particularly in select cases.

Approach to native medical renal biopsy interpretation of glomerular disease

Diverse pathogenetic mechanisms and clinical manifestation of renal diseases may produce the same renal morphologic pattern or variety of renal morphologic pattern can lead to the same clinical syndrome. The primary role of the renal biopsy is to provide a diagnosis and information about disease activity and chronicity. The systematic approach to native medical renal biopsy includes evaluation of the four compartments of the kidney sequentially (glomeruli, tubules, interstitium, and blood vessels). The diagnosis in renal pathology is an integrated process in which we must analyze all clinical data, light microscopy, immunohistology, and electron microscopy studies for diagnosis. The aim of the article is to describe the handling of the renal tissue in the anatomical pathology laboratory. It also provides the guideline to renal biopsy evaluation and approach to arrive at the diagnosis of glomerular diseases with similar clinical presentations.

Idiopathic inflammatory myopathy

ObjectiveTo determine interrater variability in diagnosing individual muscle biopsy abnormalities and diagnosis.MethodsWe developed a scoring tool to analyze consensus in muscle biopsy reading of an ad hoc workgroup of international experts. Twenty-four samples from patients with suspected idiopathic inflammatory myopathy (IIM) were randomly selected, providing sections that were stained with standard histologic and immunohistochemical methods. Sections were made available on an online platform, and experts were queried about myopathologic features within 4 pathologic domains: muscle fibers, inflammation, connective tissue, and vasculature. A short clinical presentation of cases was included, and experts were asked to give a tentative diagnosis of polymyositis, dermatomyositis, inclusion-body myositis, antisynthetase syndrome–related myositis, immune-mediated necrotizing myopathy, nonspecific myositis, or other disease. Fleiss κ values, scoring interrater variability, showed the highest agreement within the muscle fiber and connective tissue domains.ResultsDespite overall low κ values, moderate agreement was achieved for tentative diagnosis, supporting the idea of using holistic muscle biopsy interpretation rather than adding up individual features.ConclusionThe assessment of individual pathologic features needs to be standardized and harmonized and should be measured for sensitivity and specificity for subgroup classification. Standardizing the process of diagnostic muscle biopsy reading would allow identification of more homogeneous patient cohorts for upcoming treatment trials.