ECP 2023 Abstracts

S379 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 vascular markers (CD31,CD34,FLİ-1) were positive. Pancytokeratin and HHV-8 was also negative. These finding were consistent with vascular origin not mesothelial or epithelial. With low ki67 and nega- tive HHV-8 supported benign proliferation. Papillary projections are not expected in haemangiomas so we rendered the diagnosis of Mas- son’s tumour. Conclusion: With combination of ancillary study and morphologi- cal findings we rendered the diagnosis of Masson’s tumour. Masson’s tumour is mostly localised in head and neck region and we couldn’t find any case of Masson’s tumour in spermatocele wall reported up-to-date. E-PS-24-049 A rare site of metastasis of lung adenocarcinoma: kidney A.S. Mavuş*, A. Tarlacı *Haseki Education and Research Hospital, Turkey Background & objectives: Lung adenocarcinomas (ACA) are known to metastasize frequently. Most common site of metastasis are bone, brain, adrenal and liver. Kidney is a rare site of metastasis for lung ACA. Herein, we represent our case of renal metastasis from lung origin. Methods: Our patient was 53-year-old man who was diagnosed stage 3 lung ACA and received chemotherapy. 1,5 year after the diagnosis patient developed renal metastasis. Gross material was left nephroure- terectomy with 15,5x 8,5x 6,5 cm dimensions. When opened, there was centrally necrotic, solid dirty white-tan mass with 3,5 x 3 x 2 cm dimensions in the lower pole of kidney. Results: On Hematoxyline- Eosine stained slides, we saw highly hap- hazardly arranged, solid tumoral areas and large necrotic areas on low power. Tumour cells were highly pleomorphic with hyperchromatic nuclei. There were lots of mitotic figures and frequent lymphovas- cular invasion. Histopathologically, our case ha necrotic areas which may be as a result of neoadjuvant chemotherapy. On ancillary study, TTF-1 (nuclear), napsin-A (cytoplasmic), cytokeratin-7 were posi- tive and markers for renal primary (PAX-2, PAX-8 , RCComa, CD10, vimentin) and urothelial and squamous cell carcinoma (p63, uroplakin) were negative. Histopathological and ancillary findings combined with patients’ history we made the diagnosis of "metastatic adenocarcinoma consistent with patient’s known lung primary." Conclusion: Although renal metastases from non-small cell lung cancer (NSCLC) are frequent at postmortem examination, clinically recognized isolated metastasis to the kidney from NSCLC is very rare. Due to rarity, renal metastasis of lung ACAs cause major problem in diagnosis especially in absence of clinical history. Primary RCCs, other primary kidney tumours (like collecting duct carcinomas), and metastatic carcinomas (like urothelial carcinomas and ACAs from other primary) are other differential diagnosis. E-PS-24-050 TFE3 translocation renal cell carcinoma: A case report M.R. Meléndez Gispert*, C. Ariño-Palao, N. Cadavid-Fernández, A. Tenelanda-Santillán, E. Moreno Moreno, S. Molés Caparrós, A. Sáiz González *Ramón y Cajal University Hospital, Spain Background & objectives: TFE3 translocation renal cell carcinoma(TFE3-tRCC) is a rare and aggressive tumour, which is more frequent in young adults. It is characterized by translocations involving TFE3. Diagnosis is achieved with histopathological and immunohistochemical findings or TFE break-apart fluorescent in situ hybridization(FISH). Methods: We present a case of a 37-year-old male without previous medical history who consulted for pain in left lumbar area, haematu- ria and weight loss in the last 2 months. A CT scan showed a renal mass in the left kidney with invasion of both the renal vein and the inferior vena cava. Left radical nephrectomy and cava thrombectomy were performed. Results: The microscopic study showed a high grade tumour with predominance of clear cells with abundant cytoplasm, pleomorphic and sarcomatoid areas, extensive necrosis and a minor component of papillary type carcinoma. The tumour infiltrated renal parenchyma, renal sinus fat, perirenal fat and renal vein as well as an adenop- athic conglomerate of the hilium with extranodal extension (stage pT3bN1 AJCC 8th ed, 2017). Immunohistochemistry (IHC) showed intense nuclear positivity for TFE-3. The diagnosis was therefore TFE3-tRCC. The patient started adjuvant therapy, but he died four months later. Conclusion: In TFE3-tRCC the clinical behaviour is aggressive and the response to targeted therapy and immune checkpoint inhibitors is low. Because of the morphological overlap with more common renal cell carcinomas, we are probably misdiagnosing this entity. We should always keep in mind the particular morphology of this entity and always perform TFE3 in our IHC panel in order to diagnose this carcinoma earlier for a better prognosis. E-PS-24-051 Strong PD-L1 expression in high grade inflammatory prostate A. Mollova- Kyosebekirova*, M. Koleva, D. Dikov *Department of General and Clinical Pathology, University Hospital “Sveti Georgi”, Plovdiv, Bulgaria Background & objectives: Chronic inflammation (CI) is associated with the most frequent socially important prostate diseases: prostati- tis, benign prostatic hyperplasia (BPH), and prostate adenocarcinoma (PCa). We examined the programmed death-ligand 1 (PD-L1) expres- sion in benign prostatic tissue in inflammatory microenvironment of these diseases. Methods: We studied the PD-L1 expression in 144 prostatic surgical and autopsy specimens with various types of CI:nonspecific histologic prostatitis (HP), granulomatous prostatitis (GP), and reactive lymphoid infiltrates in the vicinity of BPH and PCa. HP was scored in low and high grade (LG,HG) accordingto the severity of inflammation. The control group included autopsy prostates of medico-legal cases of young men. Results: It was established a strong PD-L1 immunoreactivity in the epithelium of ductal lympho- epithelial lesions (LEL) in prostates with HG HP and fully positivity in the foci of localised granulomatous inflammation in GP. The lack of positivity of the marker was showed in the control group of prostates. Conclusion: The study presents the first attempt to examine the PD-L1 expression in inflammatory human prostate. The results of this study proving strong expression of PD-L1 in the epithelium of ductal LEL in prostate HG HP and in the granulomas in GP. The unregulated expres- sion of PD-L1 during HG prostatic inflammation prevent tissue injury and consequently lead to peripheral prostatic immune tolerance and inflammatory microenvironment in prostatitis, BPH and PCa. E-PS-24-052 Is the cribiform pattern in the prostate cell biopsy already indica- tive of a poor prognosis? G. Moreno Abenza*, F. Gómez Pálomo, J.L. Ruiz Cerdá, D. Ramos Soler *Hospital universitario y politécnico La Fe, Spain Background & objectives: It is known that the cribriform pattern in a radical prostatectomy specimen confers a poor prognosis, but in cylinder biopsy this prognosis is controversial. We are going to evaluate cribriform pattern in the cylinder biopsy of intermediate-risk patients. Methods: Prospective cohort study carried out in 271 patients. Quan- tification of global, small and large cribriform pattern was performed