An Uncommon Etiology for Pleural Effusion with Rib Lesion in a 78-year-old Woman: A Case Report

Abstract Background: Pleural effusion with rib lesion is generally considered as metastasis of thoracic carcinoma or rib tuberculosis and tuberculous pleuritis. Myelomatous pleural effusion with rib lesion is rare and poses a great diagnostic challenge. We described an easily-misdiagnosed extrapulmonary disease with concomitant pulmonary and rib manifestations, bilateral pleural effusion with lytic rib lesion in multiple myeloma, in order to raise awareness of this disease and avoid misdiagnose. Case presentation: A 78-year-old woman was referred to the thoracic department with chest distress, breathlessness, poor appetite and weight loss for 3 months. Chest computed tomography demonstrated bilateral pleural effusion and lytic lesion on the left 5th rib. Whole-body bone scan showed the intense uptake lesions on the sixth, seventh vertebrae and a central defect with the peripheral uptake of the "donut"-like change sign on the left 5th rib. Percutaneous CT-guided core biopsy for the rib lesion was performed and the diagnosis was multiple myeloma. Combined chemotherapy and supportive treatment were prescribed. She did not respond to the therapy and died 3 months later due to pleural cavity infection and cardiopulmonary failure.Conclusion: Some uncommon extrapulmonary diseases with concomitant pulmonary and rib manifestations should be reminded in order to avoid misdiagnose. Extramedullary multiple myeloma can affect any tissue and is an aggressive entity with poor prognosis. Percutaneous CT-guided core biopsy for the rib lesion is of higher positive rate than pleural fluid cytology and more minimally invasive than pleural biopsy via thoracoscope or rib excision biopsy.