INTRODUCTION:Bullous lung disease is most commonly found in patients with emphysema. This case report presents a patient with severe bullous lung disease secondary to an usual cause.
CASE PRESENTATION:A 49 year-old dentist presented to his primary care physician complaining of gradually worsening dyspnea. A CT scan was ordered which showed multiple pulmonary nodules with significant bullous lung disease. Alpha 1-antitrypsin level was normal. An open lung biopsy was performed that revealed amyloidosis on congo red staining and significant lymphocyte infiltration which stained strongly positive for CD20. The pathology results were felt to be consistent with a marginal zone lymphoma with secondary pulmonary amyloid deposition.
DISCUSSIONS:Mucosa-associated lymphoid tissue (MALT) associated lymphoma, also known as marginal zone lymphoma, is the most frequent form of primary pulmonary lymphoma. MALT-associated lymphomas are rare, comprising less than one percent of all primary lung malignancies. The average age of onset is 50 to 60 years (12-79 years), with subjects less than 30 years of age rarely affected. Males and females are equally affected. Most patients are asymptomatic at the time of diagnosis, although cough, dyspnea, hemoptysis and chest pain can occur. The typical radiographic appearance of a MALT-associated lymphoma are alveolar opacities less than 5 cm in diameter. The margins may be well defined or blurred, and in approximately 50% of cases, air bronchograms are noted within the opacities. Lesions are bilateral in 60-70% of cases and multiple in 70-77% of cases.MALT-associated lymphomas are indolent malignancies with an excellent prognosis. The 5-year survival rate is >80% and the median survival time is greater than 10 years. There is no consensus on treatment of PPL, due to a lack of studies comparing available modalities. Some authors have advocated simple observation, given the indolent nature of the disease. In general, surgical resection is reserved for localized tumors, and chemotherapy is given for bilateral or diffuse involvement. Multiple agents have shown efficacy, but combination regimens have not been proven superior to single drugs. Radiotherapy is rarely used.The association of MALT-lymphoma with localized pulmonary amyloidosis has been well documented. Amyloid production secondary to a primary pulmonary lymphoma has a similar histologic appearance to nodular amyloidoma, which can lead to morphologic confusion. Nodular parenchymal amyloidosis is characterized by multiple nodules on CT, with single nodules occurring less commonly. These lesions generally have sharp, lobulated margins and are in a subpleural or peripheral distribution. About half have calcifications, with sizes ranging from micronodular to very large, up to 15 cm in diameter. They grow slowly over the course of years without regression.Cystic disease can occur in patients with nodular amyloidosis. The proposed mechanism is a valve-mechanism resulting from the obstructive infiltration of small airways. This may be a direct result of amyloid deposition causing small airway compromise. On our review of the literature, this is the first reported case of bullous lung disease secondary to amyloidosis from MALT-lymphoma.
CONCLUSION:Bullous lung disease may occur secondary to amyloidosis. The presence of primary pulmonary amyloidosis should prompt a search for a primary pulmonary lymphoma, as the processes may be related. Diagnosis of primary pulmonary lymphoma relies on tissue diagnosis and immunohistochemical staining. Generally this will require open lung biopsy. The prognosis of primary pulmonary lymphoma is favorable with a 5 year survival rate >80%. Surgery is generally the preferred treatment for localized lesions, while chemotherapy is favored for more diffuse disease.
DISCLOSURE:Christopher King, No Financial Disclosure Information; No Product/Research Disclosure Information