Unique Ovarian Metastasis of Small-Cell Lung Cancer and Complete Response After Chemo-Immunotherapy: An Unusual Spread as a Predictor Factor.

A 41-year-old woman, never-smoker, accessed the emergency room for an episode of hemoptysis in September 2019. CT scan showed a defect of opacification in the left pulmonary artery and a solid mass of 12 cm in the left annex. PET confirmed high metabolic activity in the ovarian mass and, surprisingly, in the left hilar lung. The patient underwent a left annessiectomy and the histological examination showed a metastasis of small-cell lung cancer (SCLC) that mimicked a primary ovarian cancer. Fibrobronchoscopy and echo-guided biopsy confirmed the diagnosis of pulmonary SCLC. From January 2020, we started systemic therapy with carboplatin, etoposide, and atezolizumab. After six cycles of induction therapy with a complete response, thoracic and prophylactic cranial radiotherapy was done and maintenance therapy with atezolizumab was administered. After 53 months, the patient is still under treatment with a complete radiological response. This case report describes a rare instance of ovarian metastasis from SCLC that responded exceptionally well to immunotherapy. By reviewing literature from 1950 to the present, we identified other cases of ovarian metastases from SCLC, highlighting shared clinical and pathological traits and distinguishing them from primary ovarian tumors. We also examined the potential mechanisms behind the prolonged immunotherapy response observed in this case. As research on SCLC and immunotherapy evolves, this case may offer valuable insights into prognostic and predictive factors for this typically fatal cancer.