ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 instability and the ensuing gene expression and phenotypic altera- tions in DKD. Funding: Work supported by UEFISCDI (PN-III-P4-ID- PCE-2020-1898, PN-III-P1-1.1-TE-2021-0180, PN-III-P2-2.1- PED-2019-2497, PN-III-P2-2.1-PED-2019-2512). PS-04-009 A multihierarchical terminology for non-neoplastic kidney biopsies: kidney biopsy codes for pathologists A. Dendooven*, H. Weishaupt, K. Amann, H. Hopfer, R. Cornet, L. Gesualdo, S. Leh *UZ Gent, Belgium Background & objectives: A kidney biopsy is often the only option to correctly diagnose a kidney disease and to gain informa- tion about prognosis and possible treatment. However, an interna- tional standardized system for coding morphological findings and diagnoses has been missing. Methods: An expert workshop defined the principles for the Kid- ney Biopsy Codes for Pathologists (KBC) system. Based on experi- ence, literature review, and 60 nephropathology reports, a terminol- ogy with synonyms and parent-child relationships was established. Then, a project-internal review process and a second workshop were carried out. Several visualisations of the system have been developed using R/Shiny. Results: The aim of the Kidney Biopsy Codes for Pathologists project (KBC, https://kibico.org/) is to establish a comprehensive coding system for non-neoplastic kidney biopsies. KBC currently consists of 576 active concepts, of which 168 belong to a compact and 408 to a detailed set of terms. The KBC structure is multi- hierarchical with a pattern of injury (276 concepts) and a disease concept axis (266 concepts) as well as attributes (43 concepts) including qualifiers for certainty (3 concepts). Concepts are further grouped according to kidney compartments. For each concept, a preferred term and synonyms have been defined. Conclusion: A comprehensive coding system for non-neoplastic kidney diseases is established. In order to provide governance and to promote use within existing frameworks, the KBC team aims to collaborate with SNOMED international to make a subset in SNOMED CT. Finally, an international review process will be conducted. PS-04-010 Association of amyloid deposits with C4d immunohistochemi- cal staining in kidney allografts on the onset of AA amyloidosis recurrence S. Şen, C.A. Gomez Gonzalez*, A. Çeltik, G. Aşcı, B. Sarsık Kumbaracı, H. Töz *Department of Pathology, Medical Faculty, Ege University, Izmir, Turkey Background & objectives: Serum amyloid A protein-related AA amyloidosis can lead to ESRD,therefore renal transplantation. Surveillance of allografts with C4d immunohistochemical stain- ing assesses humoral rejection.Immune complex-mediated diseases and amyloidosis describe positive staining.We analysed the C4d immunohistochemical staining pattern in allograft biopsies with recurrent amyloidosis. Methods: This retrospective analysis included allograft biopsies performed in our centre that were previously positive for amy- loid with congo red and C4d evaluation. Amyloidosis scoring and description of C4d immunohistochemical pattern staining (glomerular, vascular, interstitial and/or capillary peritubular) were evaluated, and C4d staining was correlated with congo red staining. Results: 41 biopsies belonging to 22 patients were analysed. Among the indication of biopsy were graft dysfunction (n=9; 40,9%), non-nephrotic proteinuria (n=5; 22,7%) and nephrotic pro- teinuria (n=8; 36,3%). During the investigation 12 graft cases had preserved function, 6 cases had graft dysfunction and 4 patients died. Amyloid deposits were frequently founded in arteriolar vessel walls (N=12; 54,5%) and combined glomerular/vascular staining (n=6;45,4%). There was one biopsy with C4d insufficient staining, in 5 cases the amyloid deposits were small and the evaluation of C4d and congo red at the same time was necessary. In the other cases, C4d staining highlighted amyloid deposits within blood ves- sels and glomeruli. Conclusion: Amyloid deposits in recurrent AA amyloidosis in kidney allografts show a distribution over blood vessel walls. This nonspecific finding at the walls of the arterioles is seen as well in arteriolar hyalinization, in contrast, glomeruli staining with arte- riolar staining seems to be more specific for amyloidosis. C4d can be used as a marker for amyloid using mass spectrophotometry identifying C4d protein as part of the AA amyloid component. PS-05 | Poster Session Ophthalmic Pathology PS-05-001 Conjunctival Melanoma in Ireland – a sixty year review L. Coady*, C. Hegarty, K. Kulakova, S. Kennedy *St. Vincent’s University Hospital, Ireland Background & objectives: Conjunctival melanoma is a rare ocu- lar neoplasm with an unpredictable pathological course. Reported incidences vary from 0.1–0.9/1,000,000. Lack of population studies coupled with the rarity of the tumour has resulted in poor under- standing of risk-factors and limited therapeutic options. Methods: A retrospective review of all cases of conjunctival mela- noma accessioned in the largest eye unit in Ireland over a 60 year period (1961 – 2021) was performed. The age, sex, eye laterality, size of tumour, development of metastasis and/or recurrence was determined. Genome sequencing was performed on a select number of samples from the cohort and any mutations found recorded. Results: 72 cases of conjunctival melanoma were diagnosed since 1961. There was a female preponderance (n = 42, 58.3%). Median age of diagnosis was 77 (Range:32-91). Tumour size varied from 5–56mm in maximum dimension. Thirty-five (48.6%) have died. Time of death ranged from 1 month to 12 years post diagnosis. 28 (40%) developed metastases (brain, lung, liver, kidney, bowel, thyroid, prostate, parotid, lymph nodes), 20 (28.6%) developed recurrences. The left eye was more commonly affected (n=36, 50%). 14 of 70 specimens dating back to 1996 were sent for analysis with either Sequenom or Oncomine platforms. Mutations were detected in 12 patients. These included PIK3R1, M326I, PIK3CA, MET, N3755, BRAF and NRAS. Conclusion: Conjunctival melanoma is a rare neoplasm with only 72 cases diagnosed in Ireland in the last 60 years. Recurrence and metastases are common. Options for treatment of conjunctival melanoma include excision, cryotherapy, corneal epitheliectomy, radiotherapy and topical mito- mycin C. Adjuvant therapy is limited, with conjunctival melanomas showing intermediate sensitivity to immunotherapy. Extended follow up of patients will allow identification of risk fac- tors for the disease, while further genetic sequencing will enable identification of potential therapeutic targets. S87