Diffuse pulmonary meningotheliomatosis: a case report and literature review

Abstract

Objective: To analyze the clinical features, diagnosis and differential diagnosis of diffuse pulmonary meningotheliomatosis (DPM), a rare subtype of minute pulmonary meningothelial-like nodules (MPMN), so as to improve the understanding of this disorder. Methods: The clinical data of a patient diagnosed as DPM admitted in department of Respiratory Medicine, Peking University Third Hospital in August 2016 were reported and the related literatures were reviewed. With "pulmonary meningothelial-like nodules" , "minute pulmonary meningothelial-like nodules" or "diffuse pulmonary meningotheliomatosis" as the search terms, and the search time before November 1st 2017 for Wanfangdata, China National Knowledge Infrastructure (CNKI), and PubMed.Twenty-five articles were retrieved, among which 6 English (all case reports) articles were found with the search term "diffuse pulmonary meningotheliomatosis" involving 10 cases, and the other 19 articles (1 Chinese, 18 English) about MPMN mainly discussed non-DPM cases,including 13 case reports and 6 pathological/genetic studies. Results: A 68-year old female was admitted to the hospital because of intermittent cough and expectoration for more than 3 years and aggravation for 3 weeks. Her pulmonary CT showed diffuse minute nodules distributed randomly throughout both lungs, and did not improve after treatment with oral Moxifloxacin for 2 weeks. A video-assisted thoracoscopic biopsy was performed. The specimens showed MPMN and no other lesions, which confirmed the final diagnosis of DPM. She was followed without any medication therapy and her pulmonary CT showed stabilization of the lesions one year later. DPM was considered as a rare type of MPMN. A total of 11 cases were analyzed, including 10 cases reported in the literature. The patients included 1man and 10 women, aged 51 to 75 years, with an average age of (64±8) years. Among the 11 patients, 8 denied a history of smoking or of occupational exposure, 7 presented with dyspnea, shortness of breath, or fatigue, and 8 had mild abnormalities of pulmonary function test. The pulmonary CT of all the patients showed randomly distributed, diffuse bilateral small solid or ground-glass nodules, with the diameters less than 5 millimeters, some of which were cavitated. Only 1 patient had pulmonary thromboembolism, while the other 10 did not have any other lung diseases. All the patients were histologically diagnosed, 8 by open lung biopsies, 2 by transbronchial lung biopsy, and 1 by CT-guided fine needle aspiration. Three patients were followed for 12-92 months and the lung lesions were all stable. Conclusions: As a rare subtype of MPMN, DPM lacks specificity of clinical manifestations, and presents with diffuse bilateral small solid or ground-glass nodules, distributed randomly throughout both lungs. An early correct diagnosis depends on biopsy.