Ovarian metastases from ALK-positive lung adenocarcinoma: a case report and review of the literature

BACKGROUND: Ovarian metastasis is an extremely rare condition in patients with lung adenocarcinoma. Lung adenocarcinoma patients with ovarian metastases were difficult to distinguish from primary ovarian cancer. Anaplastic lymphoma kinase (ALK) gene rearrangement is only found in 3–7% of patients with lung cancer. It is worth noting that the incidence of lung cancer with ovarian metastasis is extremely low, however, ALK rearrangement is often reported in these cases. Here we reported a young woman, aged 23 years, with ALK-positive lung adenocarcinoma and ovarian metastasis. CASE DESCRIPTION: The patient underwent laparoscopic bilateral ovarian tumor resection after discovering an abdominal mass accidentally. A series of lung adenocarcinoma-specific immunohistochemical features were detected postoperatively by immunohistochemistry (IHC) analysis. Then extensive-stage metastatic masses of different sizes were identified by 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) positron emission tomography combined with low-dose computed tomography (PET/CT), among which the largest nodule was 1.7 cm × 1.4 cm located in the middle lobe of the right lung. Genetic testing of the paraffin tissue DNA revealed the fusion mutation of EML4_ALK (E14:A20) gene. The patient was pathologically diagnosed with lung adenocarcinoma with bilateral ovarian metastasis, administered with oral alectinib [600 mg twice daily (bid)] and followed-up quarterly. Currently, the patient responded to alectinib stably, with a progression-free survival (PFS) of more than 12 months, and experienced no significant adverse events. In addition, we reviewed the publications associated with the characteristics of ALK-positive lung cancer with ovarian metastases and the identification of primary and secondary ovarian tumors. CONCLUSIONS: This case provides a meaningful reference for the possibility of adnexal metastases from lung cancer, particularly for ALK-rearranged young female patients. In addition, this case highlights the advantages of IHC together with genetic testing for identifying origin sites of ovarian metastases and provides a promising treatment option.