No abstract

Background Highly differentiated follicular carcinoma (HDFCO) is a rare form of struma-derived thyroid-type carcinoma in ovary, defined as ovarian struma spreading beyond ovary but consisting of benign thyroid tissues. No more than 30 cases of HDFCO have been reported since it was first recognized in 2008. The clinicopathologic and molecular features of HDFCO remain unclear up till now. Case presentation A 38-year-old, para 1 gravida 5 woman has a long history of recurrent right ovarian cysts. Histological evaluation showed the tumor progressed from ovarian mature cystic teratoma (OMCT) to highly differentiated follicular carcinoma (HDFCO) during three relapses. Whole-exome sequencing revealed the germline FGFR4 Gly388Arg polymorphism. Repeated operations were performed to remove lesions for the first two relapses. On the third recurrence, the patient received radical surgery with subsequent thyroidectomy and radioactive iodine ablation. No evidence of disease was observed by February 2022 (8 months). Conclusions The germline FGFR4 Gly388Arg polymorphism may accelerate the malignant transformation of HDFCO, probably by working as a second hit in the developing spectrum.

Background: Malignant transformation such as ovarian squamous cell carcinoma (SCC) in ovarian mature cystic teratoma (OMCT) is a rare tumor. The gene mutation of ovarian SCC remains unclear. We herein report a recurrent case of ovarian squamous cell carcinoma with MET gene copy number variation. Case presentation: A 60-year-old woman presented with recurrence of ovarian SCC 8 months after primary surgery. Adhesiolysis, right abdominal wall mass excision, prosthetics, enterectomy, enterostomy and partial cystectomy were performed by laparoscope. Pathologic examination demonstrated metastatic squamous cell carcinoma in ileocecus, rectum and abdominal wall muscle. MET gene copy number was elevated with copy number of six in this case. Postoperatively, the patient was treated with four cycles of combination chemotherapy with docetaxel and carboplatin. The patient was free of disease at 20 months’ follow-up. Conclusions: Optimal cytoreductive surgery combined with platinum-based chemotherapy is recommended currently for not only primary tumor but also recurrence. For patients with malignant transformation in OMCT, prompt diagnosis and individualized treatment are crucial for better prognosis. Increased copy number of MET may be correlated with her poor PFS and can be a potential therapeutic target for this case.