ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Results: 70% (n=7) of ALK+ ALCL are men, and only 20% (n=2) are children (<18y). 80% (n=8) were diagnosed at an advanced stage (Ann-Arbor staging III-IV), involving nodal and extranodal sites in 60% (n=6), and limited to nodal compart- ments in 3 cases (30%). 40% (n=4) had bone marrow involve- ment, and 30% (n=3) presented hemophagocytic syndrome. Upon follow-up, survival rate is 70% (n=7). 100% of cases are CD30+. Morphological patterns and immunohistochemistry markers were reviewed. Moreover, molecular tests (FISH) for ALK were con- ducted in two cases. Inter-observer agreement regarding ALK staining pattern was low with a kappa coefficient of 0,197 (CI 95% -0,135-0,520, p value: 0,127). Conclusion: For the majority of the variables analysed, o u r f i n d i n g s a g r e e w i t h c u r r e n t k n owl e d ge . ALK immunohistochemistry is useful for diagnosis, but there is high inter-observer variability in the assessment of ALK staining patterns; thus, molecular testing may be advisable in order to characterize the genetic alterations. These findings should be consolidated on future studies with a larger sample size and a higher number of observers. E-PS-10-010 Splenic Epstein-Barr virus (EBV) associated inflammatory pseudotumour (IPT) E. Vázquez*, L. Molina, A. Sabio González, R.J. Luque Barona *Complejo Hospitalario de Jaén, Spain Background & objectives: IPT is a rare lesion that is composed of variable proportion of spindle cells, which can express myofibroblastic or follicular dendritic cell (FDC) markers, interpersed with polymor- phous inflammatory cellularity. Splenic IPT associated with EBV infec- tion can be a diagnostic challenge. Methods: We report the case of a 63-year-old male, with abdomi- nal pain and clinical suspicion of chronic cholecystitis. His initial work up revealed two well-demarcated hypodense solid lesion in his spleen, with abnormally uptake on CT scan, raising suspicion for malignancy. The patient underwent a diagnostic splenectomy. Results: The histopathological evaluation revealed 4 nodular lesions, with a bland spindle cell population (SMA/LMP-1/ EBER+; ALK/CD21/CD23-) associated with a mixed cellular infiltrate composed of lymphocytes, plasma cells, histiocytes and scattered eosinophils. We also identified multiple non necrotiz- ing granulomas, with multi-nucleated giant cells and foreign body reaction. The histological findings were compatible with a diagnosis of splenic inflammatory pseudotumor associated with EBV infection.EBV associated IPTs are slow growing masses that are usually seen in liver, spleen and, less frecuently, in lymph nodes. Conclusion: Splenic IPT-like FDC tumours and EBV+IPTs with- out expression of FDC markers are 2related entities that have in common that the spindle cell is the one infected by EBV.Both are considered low-grade malignant lesions, possibly of mesen- chymal origin capable of differentiating along different pathways (some will show myofibroblastic phenotype with positive for SMA, while others will acquire FDC characteristics and CD21+). In contrast to splenic conventional EBV-negative IPT (which is considered a benign entity) total splenectomy is the main treat- ment for this pathology. E-PS-10-011 A case of multicentric Castleman’s disease mimicking non- Hodgkin lymphoma: when splenectomy is diagnostic and therapeutic D. Marchiori*, L. Campiotti, F. Sessa, S. Uccella *Dept. of Medicine and Surgery, University of Insubria, Varese, Italy Background & objectives: Castleman’s disease encompasses a group of disorders with well-defined histological features. Non-specific symp- toms can mimic a wide variety of conditions. We describe a multicen- tric Castleman’s disease diagnosed on splenectomy with a complete response after 6 years of follow up. Methods: A 65-years old man experienced B-symptoms. Laboratory examination revealed anaemia, monoclonal gammopathy, splenomegaly and small deep lymphadenopathies. The patient underwent splenectomy with diagnostic purposes. After the pathological examination, a diagnosis of HHV8-related multicentric Castleman’s disease was made, R-COP (Pituximab, Cyclophosphamide sulphate, Vincristine and Prednisolone) chemotherapy was administered, and complete remission was obtained. The patient is disease-free after 6 years. Results: Splenic localization of Castleman’s disease is rare. To date, three unicentric Castleman’s disease involving the spleen (Lee, 2015; Taura, 2000; Kujat, 1990) and three cases involving accessory spleen (Sakaguchi, 2005; Sbrana, 2017; Al Rasheed, 2018) have been described. Splenectomies performed for splenomegaly associated with B-symptoms are anedoctical (Levo, 1987; Carr, 2002; Han, 2008; Mantas, 2016) and only four cases of Castleman’s disease were foun in these studies. The association of splenectomy and high-dose chemotherapy, which was never described before, attenuates symptoms and pre- vent relapses; our patient did not develop either HHV8-related neoplasm or relapsing of Castleman’s disease after R-COP treat- ment and blood analysis resulted normalized after splenectomy. Conclusion: We describe a case of Castleman’s disease successfully treated with splenectomy and R-COP. Although splenomegaly alone is not a typical manifestation, in symptomatic patients with splenomegaly, splenectomy represents a diagnostic and therapeutic procedure alternative to lymphadenectomy. E-PS-10-012 Auer rod-like inclusions in B lymphoblastic leukaemia: a diag- nostic quandary for the morphologist I.P. Thayakaran*, J. Sawhney *Gujarat Cancer and Research Institute, India Background & objectives: Auer rods are diagnostic of myeloid dif- ferentiation with a compatible blast morphology. Albeit rare, auer rod- like inclusions(ARLI) can be seen in other hematopoietic neoplasms. Here we report a rare case of ARLI in B lymphoblastic leukaemia with review of literature. Methods: A comprehensive workup of the current case was undertaken along with literature search using the keywords ’auer rod-like inclusions’ and ’lymphoblastic leukaemia’. Only few case reports have been published till date. All cases showed a B-lymphoblast immunophenotype. The clinicomorphological and immunophenotypic data were analysed and compared with our case. Results: 70-year-old male presented with pancytopenia. Periph- eral blood showed pancytopenia with absent blasts. Bone marrow aspirate revealed numerous blasts with azurophilic needle shaped inclusions and few obscuring the nucleus. The nuclear morphology showed coarse granular chromatin with occasional nucleoli connot- ing a lymphoblastic origin. The inclusions were negative for Sudan Black B and periodic acid-schiff. Flow cytometry showed 82% gated blasts expressing CD79a, CD19, CD20, CD10, TdT, CD34, HLA-DR and negative for MPO, CD15, CD13, CD117, CD33, S274