INTRODUCTION:Fibrothorax occurs as a long-term complication of untreated pleural infections. Well-known causes of fibrothorax include recurrent parapneumonic effusions, empyema, and frank hemorrhage in the pleural space. Here we present a case of massive fibrothorax secondary to silent aspiration pneumonias in a patient with Down's syndrome. CASE PRESENTATION:A 24-year-old male with Down's syndrome and autism presents with a complaint of right-sided back pain and fever for two days. The patient is non-verbal at baseline but is able to communicate with his mother, who is the primary caregiver. He has a fixed routine throughout the day, owing to his autism, and his mother takes excessive precautions in tracking his symptoms and keeping his healthcare appointments.In the ER, the patient was hypoxic and tachypneic; initially requiring noninvasive ventilation, and subsequently mechanical ventilation with admission to the ICU. Work-up including chest radiograph revealed complete opacification of the right hemithorax, while the CT chest revealed a large right-sided pleural effusion, consolidation, and a thick pleural peel. Broad-spectrum antibiotics were initiated, and the patient subsequently underwent a rightsided VATS and lung decortication. Intraoperative findings revealed massive fibrothorax without frank pus. Blood and respiratory cultures were negative, surgical culture from pleural peel, however, grew Streptococcus intermedius (S. intermedius). Pathology demonstrated granulation tissue with abundant adherent fibrin and fibrinopurulent exudate, compatible with empyema. On day 7, he was transferred out of the ICU after showing marked clinical improvement.DISCUSSION: Diffuse pleural thickening or fibrothorax occurs due to severe pleural space inflammation. The development of empyema is an uncommon complication, with a reported incidence of 2-3% of all pneumonias. We hypothesize the etiology in our patient to be attributed to recurrent silent aspirations in a patient with Downs syndrome. Anatomical and functional abnormalities including macroglossia, poor neuromotor control, and gastroesophageal reflux make these patients aspirationprone, which quite often are silent. This is further supported by the presence of S. intermedius in the pleural culture. This bacterium is commonly found in the oral flora but has been associated with brain, liver and thoracic empyema. Recent literature review revealed a limited number of reported cases of pneumonia caused by S. intermedius. Decortication is an effective strategy for treating symptomatic patients, regardless of cause, when significant underlying parenchymal disease has been excluded, as was done in our patient. CONCLUSIONS:It is important for clinicians to be aware of uncommon causes of fibrothorax, such as seen in this case of recurrent silent aspirations, without recurrent pleural effusions, leading to strep intermedius-associated pleural fibrosis.

Fibrosing pleuritis is a condition not widely reported or well understood, and is thought to develop in response to recurrent pleural inflammation associated with exudative effusions. In Waldenström's macroglobulinemia (WM), patients with extramedullary pulmonary involvement are sparingly mentioned as a cause of fibrosing pleuritis in literature. We discuss a rare presentation of fibrosing pleuritis in a patient with Waldenström's macroglobulinemia-associated pleural effusions.CASE PRESENTATION: An 88 year old male presented with shortness of breath with a CTA chest showing a moderate rightsided pleural effusion, para-aortic lymphadenopathy and T-5 vertebral body lucencies. A diagnostic thoracentesis revealed an exudative fluid with elevated protein of 5.1 g/dL and negative cytology. Serum protein electrophoresis showed an M spike of 1.2 g/ dL, immunofixation showed monoclonal IgM lambda, quantitative IgM was elevated at 2079 mg/dL and bone marrow biopsy revealed metastatic prostate adenocarcinoma and lymphoplasmacytic lymphoma (LPL). A month later, he presented with similar complaints and findings of recurrent effusions necessitating a right-sided VATS, decortication and pleurodesis. The pleural biopsy was reported as fibrosing pleuritis, with genetic pleural fluid analysis showing positivity for MYD88 gene mutation, suggestive of Waldenström's macroglobulinemia.DISCUSSION: Waldenström's macroglobulinemia is a rare cancer characterized by an infiltration of the bone marrow by IgMsecreting lymphoplasmacytic cells, and it is the most common type of LPL. Apart from bone marrow involvement, there are a few reports of pulmonary involvement with presentations ranging from lung nodules, diffuse infiltrates to pleural effusions. Attempting to establish a malignant etiology for pleural effusion and fibrosing pleuritis in WM can be challenging, and standard techniques may be insensitive. Diagnosis is made by identifying IgM monoclonal protein and greater than 10 % of clonal lymphoplasmacytic cells in the bone marrow, with MYD88 L265P mutation found to be positive in 93-97% of patients. PCR detection of this mutation had a 100% sensitivity and 92.1% specificity for WM based on one study. Treatment decisions of WM are based on symptoms, with prospective studies demonstrating durable response to Ibrutinib monotherapy; the greatest effect seen in patients with MYD88 mutation. Our patient showed MYD88 mutation positivity and was treated successfully with Ibrutinib.CONCLUSIONS: Malignant pleural effusions and resultant fibrosing pleuritis are a rare extramedullary pulmonary manifestation of Waldenström's macroglobulinemia.Greater than 90 % of these patients have MYD88 gene mutations, with growing evidence that testing for pleural fluid can point towards the diagnosis of a malignant pleural effusion in the absence of positive cytology findings of WM, and aid prompt treatment.

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