ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Results: Gross examination showed a fragment of the lung 4x3x0.8 cm. The resection mergin and pleura have no pathologi- cal changes. The lung tissue is brown. On a single area of the lung, a subpleural whitish focus with a yellowish centre with the formation of a small cavity is visible. The size of the focus is 0.6x0.5x0.3 cm. Microscopic examination revealed foci of pneumosclerosis with numerous confluent epithelioid cell granulomas with multinucle- ated giant cells, without caseous necrosis. There is a microcavity in the centre of granulomatous inflammation. There is also a weak lymphocytic infiltration along the edge of microcavity. The rest of the lung tissue with moderate peribronchial and perivascular fibrosis. Conclusion: Thus, we correctly diagnosed ILIP, despite the com- plexities of clinical diagnosis. ILIP is a rare interstitial lung disease affecting more and more people every year. Although the causes of ILIP are still a mystery, it is still possible to diagnose the dis- ease with the help of competent specialists. This case expands our understanding of this disease and gives hope for further adequate diagnosis and treatment. E-PS-21-006 Monophasic synovial sarcoma involving the lung E. Baliou*, E. Psychogiou, P. Megas, D. Riga, K. Papadopoulou, K. Theochari, I. Vamvakaris *General Hospital of Thoracic Diseases of Athens "Sotiria", Greece Background & objectives: Synovial Sarcoma (SS) is an entity of deep soft tissue usually. This tumour generally occurs in the extremities and near the knee joint and mostly in young patients, but in elderly individual, too. Rarely, can involve the trunk, mediastinum and vari- ous viscera. Methods: A 62-year old male presented to our hospital with pro- gressive dyspnea and persistent cough. CT scan revealed a lobulated mass nodule with distinct borders in the upper lobe of the right lung, measuring 7X6,4X3 cm in dimensions. The mass was extending to the thoracic wall and invading two ribs, the 3rd and the 4th ribs. The patient underwent surgery. Results: Microscopic examination of the mass, revealed a mesen- chymal tumour, consisted of uniform blue spindle cells or sheets of spindle cells often arranged in kind of fascicles. Sometimes the fascicles were more swirly or they intersected at sharp angles and had a herring-bone appearance, Dilated branching vessels or heman- giopericytic pattern of vessels were seen. Poorly differentiated areas with rounded or spindled cells showing severe nuclear atypia, high mitotic activity, extensive areas of necrosis and some haemorrhages were also present. Immunohistochemistry was performed: EMA focal (+), Pankeratin (-),TLE-1 (+), CD34 (-), STAT6 (-), S-100 patchy (+). The differential diagnosis was between Synovial Sar- coma and Solitary Fibrous Tumour or Malignant Peripreral Nerve Sheath Tumour. Conclusion: Synovial Sarcoma, Solitary Fibrous Tumour and Malignant Peripreral Nerve Sheath Tumour can all stain with TLE-1.Synovial Sarcoma is a translocation-associated sarcoma, characterized by a translocation t(X;18)(p11;q11) between cho- mosome 18 that leads to a formation of a SS18-SSX fusion gene. The genes involved are the SS18 gene (Synovial Sarcoma 18) that fuses with a partner gene called SSX. There are three different SSX genes: SSX1 and SSX2 being the most common genes and rarely SSX4. Molecular testing confirmed the above diagnosis. E-PS-21-007 Pulmonary benign metastasizing leiomyomatosis presented by severe dyspnea; report of a case M. Elgammal*, A. Saad Rizk *Shefaa Al-Orman Hospital, Egypt Background & objectives: Pulmonary benign metastasizing leiomyomatosis (PBML) is a rare entity with unclear pathogenesis, characterized by pulmonary metastases of benign leiomyoma with history of surgical intervention for uterine leiomyoma. We report a case of PBML referred to our centre presenting with dyspnea. Methods: A 32-year-old woman, presented with severe dyspnea. A chest computed tomography revealed bilateral innumerable cannon ball lung nodules, the largest was 11.8 cm, raising the suspicion of metastatic disease. There was a past surgical history of myomec- tomy for a uterine leiomyoma at the age of 28. Ultrasound-guided biopsy was taken from the largest nodule. Results: Radiologically the nodules were variable-sized and some- times amalgamated, varying in distribution between being pleural- based, parenchymal, and hilar-based. The largest was seen encasing the right lower lobar branch of the pulmonary artery. Histopatho- logically, the pulmonary nodule consisted of intersecting fascicles, made by bland smooth muscle cells demonstrating sparse mitosis and absence of necrosis. Immunohistochemical staining for smooth muscle actin (SMA), Caldesmon and Desmin were strongly positive. CD117 and HMB45 were negative. Positive immunoreactivity for oes- trogen receptor (ER) and progesterone receptor (PR) were identified. Another ultrasound-guided biopsy from a nodule in the contralateral lung revealed the same findings. The final diagnosis was PBML. Conclusion: Pulmonary Benign Metastasizing Leiomyomatosis is a very rare condition, clonally derived from uterine leiomyomas. Despite the metastatic designation, PBMLs usually follow an indolent course with progression reported in few cases. PBML should be however considered in symptomatic women of reproductive age with a history of uterine leiomyoma who present with multiple pulmonary nodules and respiratory symptoms. The patient received chemotherapy and luteinizing hormone- releasing hormone analog with notale clinical improvement. E-PS-21-008 The expression of DNA methyltransferases in non-small cell lung cancer S. Reppas, K. Paparizou, V. Mousafeiris, P. Aroukatos, D. Nakas, N. Chrysanthakoloulos, V. Zolota, V. Tzelepi* *University of Patras Pathology Department, Greece Background & objectives: DNA methylation, mediated by DNA methyltransferases (DNMTs), regulates gene transcription and genome stability. DNMT inhibitors have shown efficacy in solid tumours. The aim of this study was to analyse the expression of DNMTs in non-small cell lung cancer (NSCLC). Methods: Tissue blocks from the lobectomy specimens of 115 patients with NSCLC (50 with squamous cell carcinoma-SqCC and 65 with adenocarcinoma-AdCa) were retrieved from the Uni- versity Hospital of Patras. The expression of DNMT1, DNMT3A, DNMT3B and DNMT3L was studied using immunohistochem- istry. Nuclear (nu) and cytoplasmic (cyt) staining in neoplastic and non-neoplastic (bronchial) cells was evaluated. Results were correlated with pathologic parameters. Results: DNMT1_nu+cyt, DNMT3A_nu and DNMT3L_nu expression was higher in neoplastic cells, whereas DNMT3A_cyt expression was higher in non-neoplastic cells. DNMT3A_cyt and DNMT3L_nu expression was higher in AdCa compared to SqCC, whereas nuclear DNMT3A and DNMT3B expression was higher in SqCC. DNMT1_cyt expression was increased in poorly compared S330