Pulmonary papillary serous adenocarcinoma with intraperitoneal and ovarian tumors: Identification of primary site. A case report

Papillary serous adenocarcinoma has been recognized as a highly malignant ovarian cancer and is also not uncommonly seen in primary lung cancer. Difficulty may exist in determining the origin of the primary tumor in women with synchronous pulmonary and ovarian tumors. We present a patient who was initially diagnosed and treated as stage IV papillary serous ovarian cancer with diffuse pulmonary metastases. Only transient symptomatic improvement was achieved after standard chemotherapy for ovarian cancer, and then she died of respiratory distress during treatment. Poor tumor response to chemotherapy prompted us to reevaluate the previous bronchoscopic biopsy, and immunohistochemical studies, which were cytokeratin (CK) 7 positive, CK20 negative, and thyroid transcription factor-1 (TTF-1)-positive, provided irrefutable evidences for the diagnosis of primary lung cancer. We suggest that in dealing with coexistence of ovarian and pulmonary tumors, immunohistochemical study by using CK7, CK20, and TTF-1 may be helpful in the differentiation of the primary origin.