A 47-years-old female with a past history of sarcoidosis and endometriosis was referred to the gynecological consultation of Erasme University Hospital for an acute left lower abdominal painful mass at the gynecologic examination. Abdominal computed tomography (CT) examination showed a 17 cm left adnexal cystic lesion containing thin septa highly suspicious of malignancy. This tumor was surgically resected and frozen section examination suggested the diagnosis of a (mucinous tumor possibly invasive). Therefore, due to the age of the patient (without desire of fertility), a total hysterectomy with contralateral salpingo-oophorectomy and omentectomy was performed. Macroscopic examination revealed a complex multilocular 17 cm left ovarian tumor, with yellowish mucinous component and solid areas with some of them containing osseous tissue. There was no disruption on the external surface of the tumor (Figure 1).
Microscopically, the tumor was heterogeneous with both benign, borderline, and invasive mucinous components (expansile and destructive patterns of invasion). Cytologically, the glands are lined by columnar cells with numerous goblet cells. Moderate to severe atypia and brisk mitotic activity were noted (Figures 2). By immunohistochemistry, as we have previously described, the tumoral cells were positive for CK7, CK20, CDX2, PAX8, P53 (diffuse (diffuse/mutated staining), SATB2 and negative for WT1, ER, PR, p16 (Figure 3). HER 2 staining was moderately positive (++) but FISH examination was negative. Immediately adjacent to the malignant glandular component, residual teratomatous bone tissue was observed (Figures 2). Endometriotric lesions were also observed at the periphery of the tumor but no Whaltard cell nest.
No implant was noted in the epiplon and no tumoral cell was present in the peritoneal washing. The contralateral ovary, the rest of the gynecological examination, and the appendix were unremarkable. The tumor was staged pT1a according to the UICC 2017. No complementary treatment was applied and to date with a follow-up of 3 months the patient was disease free.
After the dissection of the tumoral component, gene mutation testing has been performed by next generation sequencing (NGS), as we have previously validated, with a panel of 16 genes described in Table 1. Next generation sequencing (NGS) is a DNA sequencing technology technique that enables massive gene sequencing in parallel.
Two mutations were found: R248Q (exon 7) mutation of the P53 gene and E545K (exon 9) mutation of the PIK3CA gene.