ECP 2023 Abstracts

S271 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 clinical presentation, histological features, classified as unicentric or mul- ticentric according to the involved lymph nodes. We aimed to evaluate the epidemiological and histopathological features of CD’s. Methods: We included patients with a diagnosis of CD between 2001 and 2023. Patients’ demographic information, clinical histories, labo- ratory and imaging studies’ findings were collected retrospectively. The 146 cases were re-classified from 3 tertiary consulting centres in Türkiye according to the 5th WHO classification criteria. Results: A total of 146 patients (80 male and 66 female) from 3 centres with a diagnosis of UCD (n= 101) or MCD (n= 45) were included in the study. The mean age was 43.5 (1 to 83 years). The most common site of involvement was the cervical region (%22.6). Histopathologi- cally, 84 cases (%83.1) revealed hyaline vascular subtype, 15 cases (%14.8) were plasmacytic subtype. 2 cases were mixed subtype among UCD cases. Human immunodeficiency virus (HIV) positivity was detected in 5 patients. Polyclonal plasma cell infiltration was present in 38% of cases on which have taken bone marrow biopsy. 5 cases had POEMS syndrome and 1 case had TAFRO syndrome. Conclusion: Castleman disease is a heterogeneous lymphoprolifera- tive disease and requires a multidisciplinary approach. Classification should be made with detailed clinical, laboratory radiological and his- topathological examination. Besides HIV status, Human herpes virus 8 (HHV8) positivity, presence of systemic symptoms, blood levels, renal function tests, organomegaly status, presence of oedema or effu- sions, fever and other laboratory studies are needed for the correct diagnosis of CD. E-PS-11-006 The need to set up a biobank dedicated to lymphoid malignancies: experience of a single centre (Laboratory of Clinical and Experi- mental Pathology, University Côte d’Azur, Nice, France) C. Bontoux*, A. Marcovich, S. Goffinet, F. Pesce, V. Tanga, D. Bohly, M. Salah, J. Benzaquen, C. Marquette, S. Lassalle, E. Long-Mira, V. Hofman, L. Xerri, M. Ilié, P. Hofman *Laboratory of Clinical and Experimental Pathology, Hospital-Inte- grated Biobank (BB- 0033-00025), Pasteur Hospital, IRCAN Team 4, Inserm U1081, CNRS 7284, FHU OncoAge, Université Côte d’Azur, Nice, France Background & objectives: Many therapies are under investigation to improve the management of lymphoma. To identify new biomarkers, high quality and clinically annotated biological material is required. We have formed a lymphoma biobank and outlined our strategy for sustaining this collection. Methods: We listed available biological material (tissues specimens and matched-additional biological resources) and associated clinical data of patients with lymphoma diagnosed between 2005 and 2022, according to the 2022 WHO classification, in the Laboratory of Clini- cal and Experimental Pathology, University Côte d’Azur, Nice, France. Selected cases were then retrospectively included as a new collection within the Côte d’Azur Biobank (BB-0033-00025). Results: 2150 samples from 363 cases (351 patients) were selected, collected, annotated, registered and then stored in the biobank. Median cold ischemia was 20 minutes [IQR:15-25] and median tumour content was 70% [range:1 to 100]. Male/female ratio was 1.3. Median age at diagnosis was 58 years [IQR:43-71]. 30% of patients were dead at time of retrospectively inclusion. Main types of lymphoma were classical Hodgkin lymphoma (26%), diffuse large B-cell lymphoma (17%) and extra-nodal marginal zone lymphoma of MALT tissue (11%). Main sites of lymphoma were mediastinum (36%), lymph node (23%) and Waldeyer’s ring (14%). Age at diagnosis >60, male, stages III-IV and T-cell lymphoma subtype were associated with shorter survival. Conclusion: The Côte d’Azur Biobank holds certifications in both ISO 9001 and ISO 20387, enabling comprehensive lymphoma sample char- acterization for research purposes. Its objective is to supply high quality and varied materials to any research facility that proposes translational research projects related to lymphoma. The resulting data would facili- tate the identification of new biomarkers, ultimately improving survival in lymphoid malignancies. E-PS-11-007 Medullary eosinophilia, a clue to reconsider the diagnosis of lymphoma M.M. Buda*, V. Moreno Nieto, È. Iglesias Martinez, A. Sifre Ruiz, A. Onaindia Perez *Clinical Department Unit of Pathological Anatomy, OSI Araba, Araba University Hospital. Bioaraba Health Research Institute, Vitoria- Gasteiz, Alava, Spain Background & objectives: Myeloid sarcoma (MS) is a rare entity consisting of a tumour mass composed of mature or immature myeloid blasts that occurs at any extramedullary site. We report the case of a 65-year-old man with MS involving the shoulder. Methods: We reviewed the patient’s medical history which showed a 3-month history of pain in the left arm. Imaging tests revealed a large soft tissue mass in the left shoulder with the complete occupation of the axilla, encompassing the vascular-nervous structures and infiltrating the perihumeral musculature. A biopsy of the tumour was performed with the consequent histological analysis. Results: The biopsy of the lesion showed infiltration by a medium- large lymphoid population with an irregular nucleus and occasional nucleoli. The cells showed CD4, CD25, CD43, Tia-1 and Granzyme expression. A diagnosis of Peripheral T cell lymphoma NOS was made. Afterward, we received a bone marrow (MO) biopsy. It was hypercellu- lar with eosinophils and signs of multiline dysplasia, making the diag- nosis of unclassifiable myelodysplastic/myeloproliferative neoplasm. Given the findings of the BM biopsy and the polyclonality of the TCR Gamma rearrangement, we reviewed the first biopsy by performing additional techniques. The lesion was positive for myeloperoxidase, lysozyme and CD68. All in all, a final diagnosis of MS was made. Conclusion: MS could be the first manifestation of acute myeloid leu- kaemia, myeloproliferative neoplasm, or myelodysplastic syndrome or it could manifest at relapse. That’s why reaching the final diagnosis of MS can be challenging, especially in the absence of BM involvement. Moreover, histologically it can be misdiagnosed as malignant lym- phoma, as occurred in our case. To avoid this error, the most sensitive markers for MS are CD43 and lysozyme. In addition, myeloperoxidase is expressed in up to 96% of cases. E-PS-11-009 Clinical overlapping of idiopathic multicentric Castleman disease- NOS and indolent symptoms despite a large intrapulmonary mass and complete pleural effusion J.O. Cázares Lara*, O.E. Falcón Antonio, M.K. Suaste Luna, L.M. Soberanes Contreras, M.J. Ballesteros Alfaro, E.A. Alamo Capula, E. Carrillo Maravilla, D. Montante Montes de Oca *Salvador Zubiran, Mexico Background & objectives: 42-year-old woman with dyspnea and infrascapular pain. Thoracic CT- scan unveiled a heterogeneous and calcified middle-mediastinum lesion, with 2,700 cc of exudate. In labo- ratories only polyclonal hypergammaglobulinemia. Enhancement on the lesion plus cervical and mediastinal lymph node on PET-CT scan. Methods: The resection of mediastinal mass (8.7x5.5x6cm) confirmed a Castleman disease principally hyaline vascular but with plasmacytic traits, 4 of 21 positive ganglions, negative for LANA1 reactive. Dur- ing the entire follow-up, she didn’t have fever, oedema, polyneuropa- thy, organomegaly, endocrinopathy, or skin changes. The only trait of inflammation was thrombocytosis (Ptl 677) 6 months after the begin- ning of symptoms.