No abstract

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.

No abstract

No abstract