Synchronous ovarian and uterine mesonephric-like carcinoma that potentially arose from endometrioid adenofibroma: A case report

Ovarian Mesonephric-like Adenocarcinoma: Its Prevalence in a Japanese High-Volume Cancer Center and a Literature Review on Therapeutic Targets

BACKGROUND

Ovarian mesonephric-like adenocarcinoma (MLA) is a newly described histological type known for its aggressive behavior. This study aims to determine the frequency of ovarian MLA, review the existing literature, and elucidate its clinicopathological characteristics, including the potential therapeutic targets.

METHODS

We retrospectively reviewed the pathological diagnoses of 501 primary ovarian cancer surgical cases at our institution from 2010 to 2023. MLAs exhibiting typical morphological and immunohistochemical features were included. The frequency and clinicopathological characteristics of these cases were summarized. Additionally, we conducted a literature search using PubMed to collect and summarize previously reported cases of ovarian MLAs.

RESULTS

Among the 501 primary ovarian cancer cases, we identified 3 cases (0.6%) of MLA. The patients were 52-76 years old, and the initial FIGO stages were IC1 (two cases) and IIIB (one case). All the cases exhibited HRP, pMMR, PD-L1 negativity (CPS < 1), and low HER2 expression. Two cases experienced metastatic recurrence. A literature review identified 97 cases of MLA. The MLAs frequently exhibited KRAS mutations (90%, 38/42), with a recurrence rate of 39% (26/67).

CONCLUSION

MLAs accounted for 0.6% of malignant ovarian tumors at our institution, all of which were advanced or recurrent cases. These cases showed HRP, pMMR, and PD-L1 negativity, indicating a lack of current therapeutic targets. The literature also reported a high incidence of advanced and recurrent cases, highlighting the need for accurate diagnosis and the development of new treatments. The frequent KRAS mutations suggest a potential therapeutic target for recurrent or metastatic MLA.

Ovarian Mesonephric-Like Adenocarcinoma With Recurrent Liver Metastases: A Case Report with Analysis of Therapeutic Molecular Targets

Ovarian mesonephric-like adenocarcinoma (MLA) is a rare cancer subtype. We describe a patient with ovarian MLA wherein liver metastases developed 1 month after surgery. A phenotypic analysis of the tumor was performed to identify molecular therapeutic targets. A 53-year-old woman, without any symptoms, underwent uterine cancer screening. Transvaginal ultrasonography revealed an ovarian mass, and subsequent pelvic magnetic resonance imaging showed a 13 × 10 cm multicystic ovarian lesion with a solid part. No extra ovarian lesions were observed and a staging laparotomy was performed. Pathological examination revealed an MLA of the left ovary (stage IC1). The tumor comprised tumor cells in a tubular pattern with intraluminal eosinophilic material, as well as mixed glandular and papillary, cord-like, and solid patterns. Endometriosis was also observed. Immunohistochemically, the tumor cells were positive for PAX8, GATA3 (focal), TTF1 (focal), and CD10 (luminal) and negative for the estrogen receptor, progesterone receptor, and WT1. One month after surgery, computed tomography revealed multiple liver metastases. Additional immunohistochemistry for therapeutic targets revealed that the tumor cells were weakly positive for human epidermal growth factor receptor 2 (focal; score 1+), pan-tropomyosin receptor kinase-negative, programmed death-ligand 1-negative, and PMS2 and MSH6 intact. The companion homologous recombination deficiency test (MyChoice®) showed homologous recombination repair proficiency. These findings suggest that poly(ADP-ribose) polymerase inhibitors and immune checkpoint inhibitors may not be effective treatment options. A literature review revealed that data on therapeutic targets in MLA are scarce. In summary, we report a patient with ovarian MLA showing an aggressive clinical course and the phenotypic analysis of the tumor may contribute to the identification of therapeutic targets for MLA.

Mesonephric-like adenocarcinoma arising from endometrioid adenofibroma in a patient with in-utero exposure to diethylstilbestrol: A case report

Mesonephric-like adenocarcinomas are newly classified rare neoplasms of the upper genital tract. They share identical features with mesonephric adenocarcinomas, with the exception of location. There is ongoing discussion on whether mesonephric-like adenocarcinomas arise from mesonephric remnants or are of Müllerian origin. A 65-year-old woman (G2P1) presented with pelvic pain. Transvaginal ultrasound revealed multiple fibroids, and a robotic total laparoscopic hysterectomy with bilateral salpingo-oophorectomy was planned. Intraoperatively, a complex mass with cystic and solid components was found on the left ovary, which also adhered to the rectosigmoid colon. Pathologic reports documented mesonephric-like adenocarcinoma that appeared to be arising in association with an endometrioid adenofibroma. This case is notable due to the patient's unique background of in-utero exposure to diethylstilbestrol (DES) and multiple gynecological malignancies within her mother, as well as the associated endometrioid adenofibroma. This case contributes evidence to two seemingly opposing theories of mesonephric-like adenocarcinoma histogenesis: the mesonephric remnant theory (supported by the patient's DES exposure), and the Müllerian theory (supported by the associated endometrioid adenofibroma).