A pulmonary tumor embolism which mimicked pulmonary tumor thrombotic microangiopathy caused by uterine cervical cancer

A 58-year-old woman presented with cough and dyspnea on exertion. A chest CT scan showed infiltrative cuneiform shadows in the peripheral lung fields. Pulmonary perfusion scintigraphy showed multiple nonsegmental defects. Histological analysis of the transbronchial lung biopsy specimens obtained from the right lower lobe showed tumor cell embolism and fibrocellular intimal proliferation, but no thrombus formation or recanalization in the small arteries. On the basis of these findings, we diagnosed pulmonary tumor embolism, not pulmonary tumor thrombotic microangiopathy (PTTM), because the pathological findings did not reveal either thrombus formation or recanalization, and the patient did not show hemodynamic effects such as hemolytic anemia, severe pulmonary hypertension, or disseminated intravascular coagulation. Systemic examinations revealed uterine cervical cancer. Her symptoms improved after the administration of chemotherapy and radiation therapy. Furthermore, the multiple nonsegmental defects observed on pulmonary perfusion scintigraphy disappeared. She was discharged, and her uterine cervical cancer has not recurred to date. Generally, a diagnosis of pulmonary tumor embolism and PTTM is difficult to establish in living patients. It is important that therapy is started before the disease progresses to PTTM, if pulmonary tumor embolism is diagnosed.