High-Grade Sarcoma Arising in the Background of Growing Teratoma Syndrome; A Rare Case

Introduction/Objective Growing teratoma syndrome is a rare condition seen in patients with a history of immature teratomas or mixed germ cell tumor status post-treatment. It usually occurs within the first two years of diagnosis but rarely can be seen years later. Methods/Case Report We report a case of a 48-year-old female with a previous history of ovarian malignancy in adolescence status post-TAH/BSO and chemotherapy, now presenting with a 23 cm multi cystic septate mass with some solid components in the subdiaphragmatic area, extending into the liver on imaging. Nodular implants along the surface of the right hepatic lobe and multiple peritoneal implants were seen. Histology of peritoneal implants showed fibro adipose tissue admixed with rare scattered glandular elements, epithelial fragments, and mature neuroglial tissue, consistent with mature teratoma. Liver biopsy revealed short fascicles of spindled, epithelioid and rhabdoid tumor cells admixed with foci of the myxoid stroma. Scattered moderate cytologic atypia, atypical mitosis, and necrosis were appreciated. Tumor cells showed strong and diffuse reactivity to vimentin while being negative for epithelial, neural/mesenchymal, mesothelial, sex cord-stromal, and germ cell differentiation markers. Differential diagnostic considerations included spindle cell transformation of a germ cell tumor or high-grade sarcoma, not otherwise specified arising in the background of growing teratoma syndrome. FISH testing for isochromosome 12p was negative excluding sarcomatoid germ cell tumor. Results (if a Case Study enter NA) NA Conclusion This case study highlights the importance of considering the rare complication of high-grade sarcoma arising in the background of growing teratoma syndrome.

Cytology of peritoneal implants of borderline serous tumor of ovaries in ascitic fluid

Objectives: Peritoneal fluid cytology is done routinely in cases with serous carcinoma of ovary. However, morphologic features of borderline serous tumors (BSTs) of ovary in ascitic fluid have been rarely described. The aim of our study was to evaluate the morphologic features of BST with and without ascitic fluid involvement (BST+ and BST-, respectively) and compare with those of serous carcinomas, both in conventional and liquid-based cytology (LBC) smears. Material and Methods: Out of 30 BST cases reported in 3 years, seven cases had BST+. We compared the cytomorphology of seven cases of BST+, seven cases of BST-, and seven cases of serous adenocarcinoma with positive ascitic fluid cytology. Both conventional and LBC smears were studied in all cases and compared. Histopathology of omentum in these cases was also studied. Results: Most cases with BST+ had regular papillary fragment borders with nuclei showing mild-to-moderate pleomorphism, fine nuclear chromatin with small nucleoli as compared with serous carcinomas all of which had irregular borders with moderate-to-severe nuclear pleomorphism, coarse chromatin, and macronucleoli. Conclusion: A combination of cytoarchitectural and nuclear features can help in suspecting BST in ascitic fluid. Ascitic fluid cytology together with tissue histology can increase the rate of the detection of peritoneal implants.

Clinical significance of peritoneal molecular markers in patients with locally advanced gastric cancer (LAGC) without macroscopic peritoneal implants treated with perioperative chemotherapy (ChT).

e15583 Background: Presence of malignant cells in the peritoneal lavage (Cyt+) of patients with LAGC in absence of macroscopic peritoneal implants reflects bad prognosis and is a surrogate of metastatic disease. The presence of molecular markers (Mol+), such as CEA and CK20 mRNA, had also been suggested to carry the same bad prognosis as Cyt+ after upfront curative gastrectomy. There is no recommendation about the management of Mol+ patients (pts) within the current perioperative ChT. Methods: We retrospectively analyzed all pts treated in our high volume multidisciplinary team between 2011 – 2015, with LAGC amenable to surgical resection, without macroscopic peritoneal implants in laparoscopy staging and treated with perioperative ChT. Pre-treatment peritoneal Cyt and Mol analysis (CEA and CK20 mRNA detected by RT-PCR), as well other clinical factors were analyzed. Results: From a total a 310 pts, 60 were included. Median follow up was 72.9 months (m). Mean age was 60y, 37% had PS0, 37% had diffuse histology, 85% wereT4(a-b), 93% N+ stage and 50% were located in gastric body. Accordig Cyt and Mol markers: 3% were Cyt+ and 18% were Mol+, 63% were Cyt-/Mol-, 15% Cyt-/Mol+, 3% Cyt+/Mol+, 0% Cyt+/Mol-, and 18% were Cyt or Mol unknown (uk). 83% underwent gastric surgery, of them, 93% achieved R0. Median PFS (mPFS) was 61.9m. mPFS for Mol+ was 11.0m (95%CI 2.6-19.4) vs the rest (Mol-/uk and Cyt +/-/uk) 69.9m (95%CI 45.0-94.8), p < 0.001. HR = 3.8. mOS was 68.3m. mOS for Mol+ vs the rest was 20.7m (95%CI 4.5-36.8) and not reached, respectively, p = 0.002. HR = 3.4. Mol+ pts who underwent surgery had longer mOS than Mol+ pts which did not (not-reached vs 7.8m (95CI% 3.4-12.9), p = 0.03). In the multivariate adjusted analysis PS (0 vs 1-2) and Mol (- vs +) were significant both for mPFS and mOS. Mol+: HR = 4.0 (95%CI 2.0-11.0),p < 0.001 for mPFS and HR = 5.4 (95%CI 1.9-14.9),p = 0.001 for mOS. Conclusions: Molecular peritoneal analysis may identify a subset of LAGC patients with bad prognosis despite negative cytology and absence of peritoneal macroscopic implants (Cyt-Mol+). Gastric surgery and perioperative chemotherapy may improve prognosis in some Mol+ patients