ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Background & objectives: Undifferentiated carcinoma with osteo- clast-like giant cells of the urinary tract are rare, with less than 15 cases described involving the renal pelvis. Another case is presented, with the aim of delving the clinicopathologic, immunohistochemical and biological behaviour of this entity. Methods: A case of a 63-year-old male, with no medical history of interest, who attends the urology office due to haematuria and right flank pain. An ultrasound and a URO-TAC with contrast is requested, where a repletion defect of 3.3 x 2.5 cm in the right upper calicial group was detected. The patient underwent a right nephroureterectomy. Results: Histological study revealed an eosinophilic biphasic tumour composed of a monotonous population of mononuclear cells with round-oval nuclei and slight nuclear pleomorphism, with prominent nucleoli, as well as numerous intercalated oste- oclast-like giant cells. There were areas of necrosis with several mitoses per high magnification field. This lesion was associated with urothelial carcinoma (UC) in situ. The immunohistochemical study was positive for GATA3 and vimentin in the mononuclear component and positive for CD68 in the multinucleated giant cells. On the other hand, it was negative for ß-HCG and pankeratin in both components. The definitive diagnosis was Undifferentiated carcinoma with osteoclast-like giant cells (UCOGC). Conclusion: UCOGC is diagnosed mainly in elderly patients with male predominance [3:1]. The intimate association of these tumours with UC and their immunohistochemical profile supports an epithelial origin for the mononuclear cells and non-neoplastic reactive histiocytic lineage for the osteoclast-like giant cells. The differential diagnosis is made with sarcomatoid carcinoma of the renal pelvis, UC with anaplastic giant cells and UC with divergent trophoblastic differentiation. It is important to keep this entity in mind because of its dismal prognosis. E-PS-24-023 Study of TERT mutations in uropathological biopsies. Use of a molecular technique in a daily practice O.B. Popescu*, E. García Fernández, P. González-Peramato *Hospital Universitario de Guadalajara, Spain Background & objectives: TERT promoter mutations are the most common somatic alteration identified in urinary bladder cancer. We present a review of 34 urinary tract biopsies and resection specimens with benign and malignant results, between 2018 and 2022, diagnosed at a Tertiary Hospital. Methods: We reviewed 34 specimens of 27 patients, including 26 malignant lesions, 7 benign lesions such as hyperplasia, verrucous squamous hyperplasia, papilloma and 1 papillary neoplasm of low malignant potential. We also included one specimen of transure- thral prostatic resection with neuroendocrine carcinoma and one lymph node metastasis of urothelial origin. TERT mutation analy- sis was performed. Results: The twenty-seven patients were represented by 5 female and 22 male. The average age was 63 years (range 13-89). Primary site was bladder for 23 specimens (67.64%) and upper urinary tract for 9 specimens (26.47%). One case corresponded to a lymph node metastasis by carcinoma of urothelial origin and one case was a neuroendocrine carcinoma of the prostate. TERT mutation was positive in 16 malignant lesions (61.53% of all malignant lesions) and in verrucous squamous hyperplasia and was negative 6 benign lesions (85.71% of all benign lesions), 8 malignant lesions (38.47% of all malignant lesions), 1 papillary neoplasm of low malignant potential. Conclusion: TERT promoter mutations are the most com- mon genetic alteration in urothelial carcinoma. We found TERT mutations occurring in papillary urothelial carcinoma, variant-predominant histology such as nested, neuroendocrine and clear cell carcinoma and sarcomatoid carcinoma of the bladder. The majority of benign lesions were negative. TERT analysis is very useful in small biopsies. It can also be useful in sarcomatoid car- cinomas of the bladder and in metastases of unknown origin where the positivity for TERT mutation can support urothelial origin. E-PS-24-024 Incidental discovery of prostatic adenocarcinoma following ureterectomy I. Saguem*, N. Ellouze, M. Triki, W. Smaoui, S. Ben Tekaya, O. Boudawara, M. Hadj Slimen, T. Boudawara, M. Mellouli *Department of Pathology, Habib Bourguiba University Hospital, Sfax, Tunisia Background & objectives: Prostate cancer is the second most com- mon cancer in men. It generally metastasizes to the lymph nodes, bone, and liver. Ureteral metastasis from prostate cancer is extremely rare. We present a case of prostatic adenocarcinoma revealed by ureteral metastasis. Methods: We report a case of a 58-year-old man with meta- static prostatic carcinoma incidentally diagnosed following ureterectomy. Results: Our patient, who has a history of nephrolithiasis, pre- sented with acute renal failure. Ultrasonography and computed tomography showed right hydroureteronephrosis secondary to obstruction of the pelvic ureter; atrophy of the left kidney and hypertrophy of the prostate. Ureteral urothelial carcinoma was suspected. Because the right kidney was a solitary function- ing kidney, our patient underwent segmental ureterectomy with lymph-node excision. Pathologic examination revealed ureteral and lymph-node metastases of prostate adenocarcinoma. Immu- nohistochemistry confirmed the diagnosis (positivity for PSA, P504s and negativity for GATA3 and p63). Subsequently, serum PSA test was made and its level was 41.14 ng/mL. Prostate MRI found a locally advanced prostatic tumour classified T4N+. The patient started hormone therapy. Conclusion: Ureteral metastasis from prostatic adenocarcinoma is rare. It can present with obstructive symptoms or as an asymp- tomatic mass on imaging. Due to the difficulty in making a pre- operative diagnosis, it is typically diagnosed after nephroureter- ectomy. Prostate cancer should be considered in the differential diagnosis of elderly men presenting with ureteral tumour. PSA test should be done on all patients over 50 to exclude the diagno- sis of metastatic ureteral tumour from prostate cancer. E-PS-24-025 Recurrent deep angiomyxoma of the bladder neck presenting as voiding dysfunction: a case report W. Lee*, Y. Lee, S. Choi *College of Medicine Dankook University, Republic of Korea Background & objectives: Deep (aggressive) angiomyxoma is a benign, locally infiltrative, myxoid soft tissue tumour that most com- monly arises in the deep soft tissues of the pelviperineal region of women. Deep angiomyxoma of the bladder has been extremely rarely reported. Methods: A 57-year-old male patient presented with recently aggravated voiding difficulty. Twelve years ago, the patient had undergone transurethral resection (TUR) of the prostate and blad- der tumour due to voiding symptoms. Computed tomography revealed a 3 cm sized heterogeneously enhancing lesion in the S355