ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 E-PS-02-026 Cystic neutrophilic granulomatous mastitis - case report I. Poinareanu*, D. Sporis, M. Cristian, A.A. Serb, T.A. Domsa *Department of Pathology, Faculty of Medicine, “Ovidius” University of Constanţa, Romania; Department of Pathology, Sacele Municipal Hospital, Brasov, Romania Background & objectives: Cystic neutrophilic granulomatous mastitis is a rare type of infectious, granulomatous mastitis, usually occurring in parous or currently pregnant women. Methods: We present the case of a 30-year-old breastfeeding secundigesta secundipara, reaching the surgery department, one month after emphirical antibiotic treatment, for a poorly delineated, palpable breast mass, measuring 7/7/5 cm (ultrasound confirmed). Results: In the pathology department, we received a 5.5/4.5/3 cm secto- rectomy specimen. The piece was entirely occupied by a whitish-pearly lesion, with an irregular, polylobate contour that extended focally to the level of the resection margin. Microscopically, the area consisted of multiple inflammatory foci, with a tendency to fuse, composed of neutrophils, lymphocytes, collections of histiocytes and giant multi- nucleated cells, with the destruction of lobes and ducts of the breast parenchyma and the formation of microabscesses. Pseudocystic spaces were detected, containing isolated pale-basophilic, linear structures (his- tological aspect suggestive of bacilli). The pseudocystic spaces were delineated by a crown of neutrophils and numerous epithelioid cells arranged radially in the periphery. Conclusion: The pathological changes were highly suggestive of cystic neutrophilic granulomatous mastitis. A Gram stain was per- formed to support our diagnosis. Typically presenting as a palpa- ble mass, CNGM may mimic breast carcinoma. Early diagnosis is essential for the proper management of these patients. In medical literature these cases are uncommon, almost all being reported after childbirth. E-PS-02-027 Decreases discrepancies between frozen and final diagnosis in the evaluation of breast sentinel lymph node G. Sahraoui*, Y. Houcine, K. Hamza, S. Kammoun, S. Ayadi, R. Chargui, M. Driss, R. Doghri *Pathology Department, Salah Azaiez Institute, Research Labora- tory LR21SP01, Tunis, Tunisia Background & objectives: Frozen section of breast sentinel lymph nodes is an extremely useful tool to reduce morbidity associated with unnecessary axillary dissection. We aimed to evaluate discordances rates between frozen section diagnosis and final diagnosis of BSLN at our institution. Methods: We evaluated at least 2 serial sections at 2mm of BSLN with Frozen. Final evaluation after formalin fixation was done by a second pathologist with breast expertise, and was considered as the gold standard. Comparison of discordance rate and aetiology of discordant cases was performed to cases that were retrospectively identified from the two-years prior. Results: Seventy specimens retrospectively collected from 2019- 2021. Discordances were observed in 8 cases (11,4%). Four causes of discordance were identified: gross sampling (2cases), block sampling (1 case), micro-metastasis/isolated tumour cells (3 cases) and misdiagnosis (2 cases) (metastases from lobular carcinoma). Conclusion: The rate of observed discrepancies was relatively high. We think that the implementation of a standardized BSLN grossing protocol can decrease the rate of discordance between frozen section and final diagnosis. E-PS-02-028 Synchronous bilateral primary breast angiosarcoma after reduction mammoplasty: an extremely rare case and litera- ture review C. Sönmez*, B.E. Gözükara, Y.K. Akgök, E. Ekren, F. Aker *Haydarpasa Numune Education and Research Hospital, Turkey Background & objectives: Primary angiosarcoma of the breast is extremely rare. Since its radiological features are nonspecific, diagnosis can be challenging. Its aetiology is unclear due to its rarity. Methods: A 31-year-old female who is breastfeeding presented with rapidly growing masses in both breasts. She had bilateral reduction mammoplasty 3 years ago. She had no history of radio- therapy. Her first ultrasonographic examination was evaluated as postlactational mastitis. Tru-cut biopsy performed due to the pro- gression of the masses was reported as angiosarcoma. Bilateral simple mastectomy was performed. Results: A 10 cm mass in the right breast and four masses in the left breast, the largest of which is 4 cm, were observed on gross examination. The tumoural lesions had irregular borders and contained small haemorrhagic cystic spaces. All lesions had similar morphology. On microscopic examination, the tumours consisted of pleomorphic cells with spindle/oval nuclei and vascular structures anastomosing with papillary formations in their lumens. The tumour cells expressed CD34, CD31, ERG, and FLI-1. Ki-67 proliferation index was 15-20%. C-myc and D2-40 staining were not observed. It was reported as grade III angiosarcoma due to necrosis, frequent mitosis (>50/10 HPF), blood lakes, endothelial tufting, and solid areas. Conclusion: Primary angiosarcoma of the breast accounts for less than 0.04% of all malignant breast tumours. It is known to be unrelated to radiation, but its aetiology remains unclear. In this article, we present a unique case of bilateral primary angiosarcoma, initially confused with postlactational mastitis, with a history of reduction mammoplasty 3 years ago. E-PS-02-029 Primary osteosarcoma of the breast – diagnosis of exclusion with metaplastic carcinoma and malignant phyllodes tumour A. Szumera-Ciećkiewicz*, J. Owczarek, O. Kuczkiewicz-Siemion, K. Kurek, A. Borkowska, M. Spałek, Z. Nowecki, P. Rutkowski *Narodowy Instytut Onkologii im. M. Sklodowskiej-Curie, Poland Background & objectives: Primary osteosarcoma of the breast (BOS) accounts for <0.125% of all breast malignancies and 12.5% of mam- mary sarcomas. BOS has an inferior prognosis with 5-year overall sur- vival below 40%. The common presentation is a progressively enlarg- ing mass with coarse calcifications. Methods: We present a 53-year-old female with a tumour 7cm diameter localized in the left breast. The patient had no medical history of breast or preceding fibroadenoma or phyllodes tumour. In January 2022 patient underwent a core biopsy, and in March 2022, a mastectomy. An extended histopathological examination was performed. Results: Microscopically, the neoplasm was highly cellular, composed of spindle cells with moderate to high atypia and high mitotic activity, necrosis and multiple haemorrhages, and numerous multinucleated giant cells. The large osteoid formation, lace-like ossification fields, and chondroid islets were seen in the stroma. Immunohistochemically, the tumour cells were: SATB2(+) strongly positive, p53(+/-), CKAE1/AE3(-), CAM5.2(-), CK5/6(-), p63(- ), CD10(-), ER(-). PRG(-), HER2(-), SMA(-), Desmin(-), Calde- smon(-), CD34(-), S100(-), MDM2(-), H3F3A(-), H3F3B(-), CD163(-). The tumour was examined in several sections and did not show cytokeratin expression or malignant tumour phyllodes (MTP) S198