ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 lymphomas, 5 follicular tumours, 1 sarcoma, 1 NUT carcinoma (with NSD3-NUTM1 fusion), 1 deep fibrohistiocytoma, 2 inflam- matory lesions. Hematoma at the biopsy site was observed in two patients and the cancer cells seeding along the needle tract in one patient. Conclusion: CNB of the thyroid lesions according to strictly defined indications in a hospital setting allows a confident diag- nosis with a low risk of complications in cases of failure of a FNAB. This method can be particularly useful for the diagnosis of anaplastic/poorly differentiated and metastatic carcinomas. E-PS-08-015 Predominantly necrotic but follicle-preserving pattern of a rectal cancer metastasis causing misinterpretation of cytological image from fine-needle aspiration biopsy of a thyroid tumour M. Biskup-Fruzynska*, E. Chmielik *Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice Branch, Poland Background & objectives: Metastases to thyroid are uncommon, accounting for 1,4-3% of thyroid neoplasms. In a 68-year-old woman with rectal cancer in stage T3bN2Mx a PET/CT scan revealed a thyroid tumour in the right lobe, suggestive of a synchronous neoplasm with nodal metastases. Methods: The ultrasound suggested a malignant tumour (22x18x30 mm; EU-TIRADS 5). FNAB showed numerous sheets of atypical epithelial cells without obvious differentiation in an abundant necrotic debris. PAX-8 positivity in a few cells was interpreted as confirming thyroid origin of the lesion. Anaplastic thyroid carcinoma, TBS VI was reported. A similar cytological picture was seen in FNABs from neck lymph nodes. Results: Total thyroidectomy with lateral neck dissection was performed. On HE slides the tumour presented evidently glandular, with large, centrally necrotic cribriform and smaller tubular structures, as well as less differentiated single cells in a desmoplastic stroma, with normal thyroid follicles preserved in between. Necrosis constituted about 70% of the tumour. The tumour cells were positive for: CDX-2, SATB2 and CK20, and negative for TG, TTF-1 and PAX-8, with Ki67 index about 60%. There was angioinvasion and extrathyroidal extension with R1 margins, and additional small metastatic foci found in the left lobe and isthmus. There were also numerous and large metastases in the central neck compartment and right neck lymph nodes. Conclusion: Differential diagnosis of high grade tumours can be challenging in cytology specimens. Positivity for PAX-8 in some cells should not result in prompt diagnosis of a lesion of thyroid origin, as follicular cells might be admixed to the cells of the metastasis depending on the pattern of the metastatic tumour growth. In the presented case of a rectal cancer metastasis, two contrasting elements led to an erroneous interpretation of the cytol- ogy image: abundant necrosis and preservation of some follicular structures. E-PS-08-016 Epithelioid angiosarcoma of the adrenal gland: a rare case report B. Konuk*, C.S. Topal *Umraniye EducationTraining Hospital, Turkey Background & objectives: Angiosarcomas are aggressive malignant tumours originating from the blood and lymphatic vessel endothelium. It accounts for approximately 1% of all sarcomas. Although they are mostly seen in the skin and soft tissue, they rarely present with organ involvement. Methods: We report on a 72-year-old man with an epitheloid angiosarcoma of the left adrenal gland. The patient had under- gone cardiac bypass surgery for coronary artery disease and had chronic obstructive pulmonary disease. In routine screenings,a cystic bleeding mass with a diameter of 11cm was detected in the left adrenal gland in computed tomography.Clinically,the non-functional mass was evaluated as adrenal insidentheloma and operated. Results: Histologically, the tumour is a vascular tumour con- sisting of epithelioid cells with vesicular nuclei and prominent nucleoli that occupies irregular vascular spaces and also forms solid areas, showing pleomorphism, necrosis, and viable mitotic activity. Immunohistochemical stain that revealed positive reactiv- ity for cytokeratin, CD31, ERG, FLI-1. The case was diagnosed with primary adrenal epithelioid angiosarcoma, as there was only a lesion in the adrenal gland in the clinically and radiologically examinations. The differential diagnosis includes malignant vascu- lar tumour, melanoma, poorly differentiated carcinoma, clear cell sarcoma, epithelioid sarcoma, and anaplastic large cell lymphoma. Conclusion: Epithelioid angiosarcoma is a highly aggressive endothelial cell malignancy. Although it often occurs in deep soft tissue, it has been reported that it can occur in various tissues such as adrenal, thyroid, skin and bone. Early diagnosis of these tumours due to their aggressive behaviour is important for treatment and prognosis. Therefore, we aimed to present our case, which requires careful evaluation of histomorphological immunohistochemical examinations in the diagnosis due to its unusual location. E-PS-08-017 Micromorphometric parameters of the adrenal cortex of rats under conditions of constant lighting and chronic alcohol intoxication Y. Kirillov, L. Makartseva, M. Kozlova, S. Timofeev*, M. Mura- tova, E. Rusina, D. Areshidze *Moscow MCC Kommunarka, Russia Background & objectives: Excessive light exposure and chronic alcohol intoxication are characterized by the development of morphological changes in the adrenal glands. We examined the influence of constant lighting, chronic alcohol intoxication and their joint action on micromorphometric parameters of rat adrenal cortex. Methods: The study was conducted on 160 male Wistar rats, which were divided into 4 groups and were kept for 3 weeks: control and I group – under fixed light regime, II and III group – under constant light regime, but I and III group received a 15-% water solution of ethanol. The width of the adrenal cortex zones was conducted. Results: It was found that in animals of II group there was a decrease in the width of the cortex compared with the control, mainly due to the fascicular and reticular zones. In animals of I and III groups, an increase in the width of all zones of the cortex was observed, and in III group the increase in the glomerular and reticular zones was more pronounced than in animals of group I. Conclusion: The conducted study indicates that constant illumina- tion leads to a decrease in the thickness of the adrenal cortex, and the effect of ethanol, both separate and combined with constant illumination, leads to an increase in the width of the adrenal cortex. E-PS-08-018 Anaplastic thyroid carcinoma: a 12-year observational retro- spective study S252