Case Presentation: A 64-year-old woman with a past medical history of hypertension, hyperlipidemia, depression, obesity, and endometrial carcinoma (EC) presented with two new lung nodules measuring 8 mm x 9 mm in the right lower lobe and 4 mm x 4 mm in the left upper lobe on surveillance positron emission tomography – computerized tomography, this was concerning of malignancy.Ten years back, she was diagnosed with high-grade endometrial carcinoma with squamous differentiation; immunohistochemistry (IHC) was positive for estrogen receptor, progesterone receptor, PAX 8, P16, aberrant expression of p53, diffuse expression of p16 gene, with no loss of nuclear expression of mismatch repair (MMR) proteins, and low probability of microsatellite instability (MSI). She underwent hysterectomy, bilateral salpingo-oophorectomy, and paraaortic lymph node dissection. Post-operatively, pathology revealed serous uterine carcinoma, peritoneal cytology was negative, cervical or vaginal carcinoma invasion was ruled out, and there was no lymph node metastasis and no abnormality of double attachment. She completed six cycles of Carboplatin/Taxol and vaginal brachytherapy after the surgery. She was followed up periodically for a decade without any elevation of tumor markers and negative surveillance imaging. The patient underwent fine needle aspiration of the largest lung nodule during her current presentation, revealing a possible endometrial carcinoma recurrence with similar IHC staining. Due to a poor prognosis, she enrolled in a clinical trial where she was treated with Carboplatin, Paclitaxel, and Pembrolizumab/placebo. After three cycles of treatment, a repeat CT scan showed a decrease in size of the right lower lobe nodule by 4 mm and the left upper lobe nodule by 3 mm.
Discussion: EC is the second most prevalent gynecologic cancer in women worldwide. EC is classified into two groups: Type I endometrioid EC, accounting for 85-90% of cases, and type II non-endometrioid EC. The most common presentation for endometrial carcinoma is post-menopausal bleeding, and most guidelines recommend either transvaginal ultrasonography or endometrial biopsy as the initial study. (1,2) The mainstay of treatment for endometrial carcinoma is total hysterectomy with bilateral salpingo-oophorectomy with adjuvant radiotherapy. The incidence of Stage IV B disease is approximately 5-10%, with a 5-year overall survival of less than 10%. Most recurrences occur within three years after the completion of primary treatment and are considered to have poor prognoses. Typical metastatic sites include local pelvic recurrence, pelvic and para-aortic nodes, peritoneum, and lungs. They require timely diagnosis and management. The first-line regimen for advanced or recurrent EC is a combination of carboplatin and paclitaxel, with an overall response rate of 50 to 60%. Treatment options after failure of first-line treatment are limited. Humanized monoclonal anti-PD-1 antibody Pembrolizumab demonstrated anti-tumor activity in patients with MSI/MMR endometrial cancer. (2,3)
Conclusions: We discussed a case of EC in remission presenting as lung metastasis a decade after remission. Pulmonary lesions are an uncommon presentation of metastatic EC. They must be considered a differential in patients with a history of uterine carcinoma, and it is essential to initiate treatment in a timely manner.