ECP 2023 Abstracts

S85 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 gland lesions can contain mature fat tissue. In this report, we present an uncommon thyroid phenomenon, termed lipomatous metaplasia in 5 different patients. Methods: Pathological examination was performed by routine hema- toxylin-eosin and histochemical staining. For the detection of amyloid, congo red stain, and crystal violet histochemical markers were used. Results: Five patients between the ages of 36 and 70 (mean age 54 years) were documented, including two male and three female patients. All patients presented with dyspnea. T3, T4, and thyroid-stimulating hormone levels were within the normal range in all cases. Three of the patients had a history of renal transplantation, and two of them had already been diagnosed with Familial Mediterranean fever (FMF). Macroscopically, all thyroid specimens showed a marked increase in weight and size, ranging from 84 to 203 grams. Microscopically, four cases showed amyloid deposition with crystal violet staining. Four cases were ultimately diagnosed as amyloid goiter. Conclusion: The majority of the available literature on lipomatous metaplasia of the thyroid gland is limited because of its rare occur- rence in surgical pathology. Patients with Cowden syndrome and those who have been exposed to radiation have both been documented to have lipomatous metaplasia in the thyroid gland. Secondary amyloidosis should also be considered in the differential diagnosis of lipomatous metaplasia of the thyroid gland in patients who have a history of chronic inflammatory disorders or long-term infections. PS-10 | Poster Session Gynaecological Pathology PS-10-001 Histomorphological evaluation of desmoplastic tumour stroma in malignant ovarian surface epithelial tumours S. Ahuja*, S. Zaheer, S. Ranga *Department of Pathology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India Background & objectives: A reactive stroma rich in cancer associ- ated fibroblasts is associated poorer prognosis in breast, colorectal and oral cancers. The present study was conducted to highlight the prognostic signifi- cance of tumour budding and fibrotic stroma in malignant ovarian sur- face epithelial tumours. Methods: This was a cross-sectional study in which all histologically diagnosed cases of malignant ovarian surface epithelial tumours were included. The fibrotic stroma was classified into three distinct catego- ries- mature, intermediate and immature. The number of tumour buds were counted at the invasive front of the tumour and graded based on the number of buds- 0-5, 5-9 and >=10 buds. Results: Among the 50 cases, 32% (16 cases) had mature stroma while 30% (15 cases) and 38% (19 cases) had intermediate and immature stroma respectively. Though, a significant association could not be established between tumour budding and stroma grade, fair agreement was established between them. However, a significant association could be established between histological grade with both tumour budding (p value=0.03) and fibrotic stroma grade (p value=0.02). Conclusion: The study highlighted the role of stromal response in malignant surface epithelial tumours of the ovary since a higher grade tumour was associated with an immature stroma while a lower grade tumour was associated with a mature stroma. PS-10-002 Optimization of diagnostic yield from macroscopically inadequate endometrial histological specimens: cytology cell block preparation permits histological diagnosis in 70% of cases S. Al Mandhari*, N. Conlon *Cork university hospital, Ireland Background & objectives: The study objective was to assess the impact of the introduction of cytology cell-block preparation into the management protocol of low/no volume endometrial specimens at our laboratory on the proportion of these cases which are labelled as "inad- equate for diagnosis". Methods: A new protocol was introduced in our laboratory, whereby on receipt of an endometrial specimen containing no or minimal visible tissue/mucoid material only, the specimen was submitted for cytology cell block preparation and a H&E-stained slide was produced. A retro- spective audit of this practice was conducted for the period 2018-2021 (4 years) via analysis of the final pathology report. Results: The study cohort involved 70 patients over 4 years. 87.5% of patients were post-menopausal, with 67% presenting with post-meno- pausal bleeding. In 73% of cases no tissue was identified grossly; 11% contained mucin only and 16% had tiny tissue fragments too small for routine processing. On microscopic examination, 70% of cases had sufficient endometrial tissue present to allow a descriptive diagnosis and avoid an "inade- quate for diagnosis" report. The most common histological diagno- ses was endometrial atrophy (39% of cases) or inactive endometrium (33%). No cases of atypical hyperplasia or malignancy were made. With follow-up of between 1 to 4 years, none of these patients had developed evidence of endometrial neoplasia. Conclusion: Low/no volume endometrial specimens frequently con- tain sufficient microscopic diagnostic material to produce a clinically- useful histological report, if the specimen is submitted for cytology cell block preparation. This retrospective audit provides evidence that this processing method does not provide false reassurance on endo- metrial status, as no patient subsequently presented with evidence of endometrial neoplasia during follow-up. This method represents an effective way to reduce the number of "inadequate for diagno- sis" histological reports, particularly in the postmenopausal patient population. PS-10-003 SATB2 cytoplasmic expression is characteristic of a subset of ovar- ian stromal cells and sex cord-stromal tumours M. Al-Hussaini*, G. McCluggage *KHCC, Jordan Background & objectives: SATB2 is a transcription factor that shows consistent nuclear staining in colorectal adenocarcinoma and osteosar- coma. Following the observation of cytoplasmic staining in luteinized ovarian stromal cells, we studied the expression of SATB2 in ovarian stromal cells and sex cord-stromal tumours. Methods: 82 cases were stained for SATB2. These included hilar Ley- dig cells, corpora lutea, follicular cysts, stromal hyperthecosis, and a variety of sex cord-stromal tumours. Results: Ovarian hilar Leydig cells (n=12), luteinized stromal cells (n=9), corpora lutea (n=4), luteinized follicular cysts (n=3), stro- mal hyperthecosis (n=6), Leydig cell tumours (n=1) and steroid cell tumours (n=3) mostly showed diffuse granular cytoplasmic staining. SATB2 also highlighted Leydig cells in Sertoli-Leydig cell tumours (n=15) and gynandroblastomas (n=3). SATB2 was essentially negative in adult granulosa cell tumours (n=14), apart from positivity in scat- tered luteinized cells, juvenile granulosa cell tumours (n=3), sex cord tumour with annular tubules (n=4), cellular fibromas (n=2), sclerosing stromal tumours (n=1), thecomas (n=1) and uterine tumours resem- bling ovarian sex cord tumour (n=1). Conclusion: SATB2 granular cytoplasmic staining has not been pre- viously described but is characteristic of a variety of ovarian stromal cells and sex cord-stromal tumours, in particular those exhibiting ster- oidogenic differentiation. SATB2 staining may be of value in iden- tifying luteinised or Leydig cells when these are morphologically inconspicuous.